- GC unused code.

- vespalib::Lock -> std::mutex

72 files changed, 132 insertions, 2940 deletions

diff --git a/config/src/vespa/config/retriever/configretriever.cpp b/config/src/vespa/config/retriever/configretriever.cpp
index f144cf9aa99..f34ee6f70af 100644
--- a/config/src/vespa/config/retriever/configretriever.cpp
+++ b/config/src/vespa/config/retriever/configretriever.cpp
@@ -52,7 +52,7 @@ ConfigRetriever::getConfigs(const ConfigKeySet & keySet, milliseconds timeoutInM
     if (keySet != _lastKeySet) {
         _lastKeySet = keySet;
         {
-            vespalib::LockGuard guard(_lock);
+            std::lock_guard guard(_lock);
             if (_closed)
                 return ConfigSnapshot();
             _configSubscriber = std::make_unique<GenericConfigSubscriber>(_context);
@@ -83,7 +83,7 @@ ConfigRetriever::getConfigs(const ConfigKeySet & keySet, milliseconds timeoutInM
 void
 ConfigRetriever::close()
 {
-    vespalib::LockGuard guard(_lock);
+    std::lock_guard guard(_lock);
     _closed = true;
     _bootstrapSubscriber.close();
     if (_configSubscriber)
diff --git a/config/src/vespa/config/retriever/configretriever.h b/config/src/vespa/config/retriever/configretriever.h
index 14e3171fc62..9ef67edd7b8 100644
--- a/config/src/vespa/config/retriever/configretriever.h
+++ b/config/src/vespa/config/retriever/configretriever.h
@@ -1,7 +1,6 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 #pragma once
 
-#include "configkeyset.h"
 #include "configsnapshot.h"
 #include "genericconfigsubscriber.h"
 #include "fixedconfigsubscriber.h"
@@ -94,7 +93,7 @@ public:
 private:
     FixedConfigSubscriber                    _bootstrapSubscriber;
     std::unique_ptr<GenericConfigSubscriber> _configSubscriber;
-    vespalib::Lock                           _lock;
+    std::mutex                               _lock;
     std::vector<ConfigSubscription::SP>      _subscriptionList;
     ConfigKeySet                _lastKeySet;
     IConfigContext::SP          _context;
diff --git a/document/src/vespa/document/bucket/CMakeLists.txt b/document/src/vespa/document/bucket/CMakeLists.txt
index 7704fe94bd0..fbbfe8b8466 100644
--- a/document/src/vespa/document/bucket/CMakeLists.txt
+++ b/document/src/vespa/document/bucket/CMakeLists.txt
@@ -2,7 +2,6 @@
 vespa_add_library(document_bucket OBJECT
     SOURCES
     bucket.cpp
-    bucketdistribution.cpp
     bucketid.cpp
     bucketidfactory.cpp
     bucketidlist.cpp
diff --git a/document/src/vespa/document/bucket/bucketdistribution.cpp b/document/src/vespa/document/bucket/bucketdistribution.cpp
deleted file mode 100644
index 34ce9a9eccf..00000000000
--- a/document/src/vespa/document/bucket/bucketdistribution.cpp
+++ /dev/null
@@ -1,115 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-
-#include "bucketdistribution.h"
-#include <vespa/log/log.h>
-
-LOG_SETUP(".bucketdistribution");
-
-namespace document {
-
-BucketDistribution::BucketDistribution(uint32_t numColumns, uint32_t numBucketBits) :
-    _numColumns(0),
-    _numBucketBits(numBucketBits),
-    _bucketToColumn(),
-    _lock()
-{
-    _bucketToColumn.resize(getNumBuckets());
-    reset();
-    setNumColumns(numColumns);
-}
-
-void
-BucketDistribution::getBucketCount(uint32_t numColumns, uint32_t numBucketBits, std::vector<uint32_t> &ret)
-{
-    ret.resize(numColumns);
-    uint32_t cnt = getNumBuckets(numBucketBits) / numColumns;
-    uint32_t rst = getNumBuckets(numBucketBits) % numColumns;
-    for (uint32_t i = 0; i < numColumns; ++i) {
-        ret[i] = cnt + (i < rst ? 1 : 0);
-    }
-}
-
-void
-BucketDistribution::getBucketMigrateCount(uint32_t numColumns, uint32_t numBucketBits, std::vector<uint32_t> &ret)
-{
-    getBucketCount(numColumns++, numBucketBits, ret);
-    uint32_t cnt = getNumBuckets(numBucketBits) / numColumns;
-    uint32_t rst = getNumBuckets(numBucketBits) % numColumns;
-    for (uint32_t i = 0; i < numColumns - 1; ++i) {
-        ret[i] -= cnt + (i < rst ? 1 : 0);
-    }
-}
-
-void
-BucketDistribution::reset()
-{
-    for (std::vector<uint32_t>::iterator it = _bucketToColumn.begin();
-         it != _bucketToColumn.end(); ++it) {
-        *it = 0;
-    }
-    _numColumns = 1;
-}
-
-void
-BucketDistribution::addColumn()
-{
-    uint32_t newColumns = _numColumns + 1;
-    std::vector<uint32_t> migrate;
-    getBucketMigrateCount(_numColumns, _numBucketBits, migrate);
-    uint32_t numBuckets = getNumBuckets(_numBucketBits);
-    for (uint32_t i = 0; i < numBuckets; ++i) {
-        uint32_t old = _bucketToColumn[i];
-        if (migrate[old] > 0) {
-            _bucketToColumn[i] = _numColumns; // move this bucket to the new column
-            migrate[old]--;
-        }
-    }
-    _numColumns = newColumns;
-}
-
-void
-BucketDistribution::setNumColumns(uint32_t numColumns)
-{
-    vespalib::LockGuard guard(_lock);
-    if (numColumns < _numColumns) {
-        reset();
-    }
-    if (numColumns == _numColumns) {
-        return;
-    }
-    for (int i = numColumns - _numColumns; --i >= 0; ) {
-        addColumn();
-    }
-}
-
-void
-BucketDistribution::setNumBucketBits(uint32_t numBucketBits)
-{
-    uint32_t numColumns;
-    {
-        vespalib::LockGuard guard(_lock);
-        if (numBucketBits == _numBucketBits) {
-            return;
-        }
-        _numBucketBits = numBucketBits;
-        _bucketToColumn.resize(getNumBuckets(numBucketBits));
-        numColumns = _numColumns;
-        reset();
-    }
-    setNumColumns(numColumns);
-}
-
-uint32_t
-BucketDistribution::getColumn(const document::BucketId &bucketId) const
-{
-    uint32_t ret = (uint32_t)(bucketId.getId() & (getNumBuckets(_numBucketBits) - 1));
-    if (ret >= _bucketToColumn.size()) {
-        LOG(error,
-            "The bucket distribution map is not in sync with the number of bucket bits. "
-            "This should never happen! Distribution is broken!!");
-        return 0;
-    }
-    return _bucketToColumn[ret];
-}
-
-}
diff --git a/document/src/vespa/document/bucket/bucketdistribution.h b/document/src/vespa/document/bucket/bucketdistribution.h
deleted file mode 100644
index c451ed9b9a7..00000000000
--- a/document/src/vespa/document/bucket/bucketdistribution.h
+++ /dev/null
@@ -1,136 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-/**
- * \class document::BucketDistribution
- * \ingroup bucket
- *
- * Stable algorithmic hash distribution; this class assigns hash buckets to
- * targets. The number of hash buckets should be large compared to the number
- * of targets. The mapping from hash value to hash bucket is performed outside
- * this class.
- *
- * This is used to determine which search column a bucket should go to.
- */
-#pragma once
-
-#include "bucketid.h"
-#include <vector>
-#include <vespa/vespalib/util/sync.h>
-
-namespace document {
-
-class BucketDistribution {
-public:
-    /**
-     * Constructs a new bucket distribution object with a given number of
-     * columns and buckets.
-     *
-     * @param numColumns    The number of columns to distribute to.
-     * @param numBucketBits The number of bits to use for bucket id.
-     */
-    BucketDistribution(uint32_t numColumns, uint32_t numBucketBits);
-
-    /**
-     * Returns the number of buckets that the given number of bucket bits will
-     * allow.
-     *
-     * @param numBucketBits The number of bits to use for bucket id.
-     * @return              The number of buckets allowed.
-     */
-    static uint32_t getNumBuckets(uint32_t numBucketBits) { return 1 << numBucketBits; }
-
-    /**
-     * This method returns a list that contains the distributions of the given
-     * number of buckets over the given number of columns.
-     *
-     * @param numColumns    The number of columns to distribute to.
-     * @param numBucketBits The number of bits to use for bucket id.
-     * @param ret           List to fill with the bucket distribution.
-     */
-    static void getBucketCount(uint32_t numColumns, uint32_t numBucketBits,
-                               std::vector<uint32_t> &ret);
-
-    /**
-     * This method returns a list similar to getBucketCount(int,int), except
-     * that the returned list contains the number of buckets that will have to
-     * be migrated from each column if an additional column was added.
-     *
-     * @param numColumns    The original number of columns.
-     * @param numBucketBits The number of bits to use for bucket id.
-     * @param ret           List to fill with the number of buckets to migrate,
-     *                      one value per column.
-     */
-    static void getBucketMigrateCount(uint32_t numColumns,
-                        uint32_t numBucketBits, std::vector<uint32_t> &ret);
-
-    /**
-     * Sets the number of columns to distribute to to 1, and resets the content
-     * of the internal bucket-to-column map so that it all buckets point to
-     * that single column.
-     */
-    void reset();
-
-    /**
-     * Sets the number of columns to use for this document distribution object.
-     * This will reset and setup this object from scratch. The original number
-     * of buckets is maintained.
-     *
-     * @param numColumns The new number of columns to distribute to.
-     */
-    void setNumColumns(uint32_t numColumns);
-
-    /**
-     * Returns the number of columns to distribute to.
-     *
-     * @return The number of columns.
-     */
-    uint32_t getNumColumns() const { return _numColumns; }
-
-    /**
-     * Sets the number of buckets to use for this document distribution object.
-     * This will reset and setup this object from scratch. The original number
-     * of columns is maintained.
-     *
-     * @param numBucketBits The new number of bits to use for bucket id.
-     */
-    void setNumBucketBits(uint32_t numBucketBits);
-
-    /**
-     * Returns the number of bits used for bucket identifiers.
-     *
-     * @return The number of bits.
-     */
-    uint32_t getNumBucketBits() const { return _numBucketBits; }
-
-    /**
-     * Returns the number of buckets available using the configured number of
-     * bucket bits.
-     *
-     * @return The number of buckets.
-     */
-    uint32_t getNumBuckets() const { return getNumBuckets(_numBucketBits); }
-
-    /**
-     * This method maps the given bucket id to its corresponding column.
-     *
-     * @param bucketId The bucket whose column to lookup.
-     * @return         The column to distribute the bucket to.
-     */
-    uint32_t getColumn(const document::BucketId &bucketId) const;
-
-private:
-    /**
-     * Adds a single column to this bucket distribution object. This will
-     * modify the internal bucket-to-column map so that it takes into account
-     * the new column.
-     */
-    void addColumn();
-
-private:
-    uint32_t              _numColumns;     // The number of columns to distribute to.
-    uint32_t              _numBucketBits;  // The number of bits to use for bucket identification.
-    std::vector<uint32_t> _bucketToColumn; // A map from bucket id to column index.
-    vespalib::Lock        _lock;
-};
-
-} // document
-
diff --git a/document/src/vespa/document/datatype/positiondatatype.cpp b/document/src/vespa/document/datatype/positiondatatype.cpp
index a8e9c81c895..8b323d20fb5 100644
--- a/document/src/vespa/document/datatype/positiondatatype.cpp
+++ b/document/src/vespa/document/datatype/positiondatatype.cpp
@@ -1,17 +1,18 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 
 #include "positiondatatype.h"
+#include <mutex>
 
 namespace document {
 
 namespace {
 
 const vespalib::string ZCURVE("_zcurve");
+std::mutex     _G_lock;
 
 }
 
 StructDataType::UP PositionDataType::_instance;
-vespalib::Lock     PositionDataType::_lock;
 
 const vespalib::string PositionDataType::STRUCT_NAME("position");
 const vespalib::string PositionDataType::FIELD_X("x");
@@ -30,7 +31,7 @@ const StructDataType &
 PositionDataType::getInstance()
 {
     if ( ! _instance) {
-        vespalib::LockGuard guard(_lock);
+        std::lock_guard guard(_G_lock);
         if ( ! _instance) {
             _instance = createInstance();
         }
diff --git a/document/src/vespa/document/datatype/positiondatatype.h b/document/src/vespa/document/datatype/positiondatatype.h
index fa8e44ad847..c7cf1926159 100644
--- a/document/src/vespa/document/datatype/positiondatatype.h
+++ b/document/src/vespa/document/datatype/positiondatatype.h
@@ -2,14 +2,12 @@
 #pragma once
 
 #include <vespa/document/datatype/structdatatype.h>
-#include <vespa/vespalib/util/sync.h>
 
 namespace document {
 
 class PositionDataType {
 private:
     static StructDataType::UP _instance;
-    static vespalib::Lock     _lock;
 
     PositionDataType();
     static StructDataType::UP createInstance();
diff --git a/document/src/vespa/document/datatype/urldatatype.cpp b/document/src/vespa/document/datatype/urldatatype.cpp
index 00ea31408af..bc8c2bee2c7 100644
--- a/document/src/vespa/document/datatype/urldatatype.cpp
+++ b/document/src/vespa/document/datatype/urldatatype.cpp
@@ -1,11 +1,17 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 
 #include "urldatatype.h"
+#include <mutex>
 
 namespace document {
 
+namespace {
+
+std::mutex   _G_lock;
+
+}
+
 StructDataType::UP UrlDataType::_instance;
-vespalib::Lock     UrlDataType::_lock;
 
 const vespalib::string UrlDataType::STRUCT_NAME("url");
 const vespalib::string UrlDataType::FIELD_ALL("all");
@@ -34,7 +40,7 @@ const StructDataType &
 UrlDataType::getInstance()
 {
     if ( ! _instance ) {
-        vespalib::LockGuard guard(_lock);
+        std::lock_guard guard(_G_lock);
         if ( ! _instance ) {
             _instance = createInstance();
         }
diff --git a/document/src/vespa/document/datatype/urldatatype.h b/document/src/vespa/document/datatype/urldatatype.h
index 902abd940e3..df28b9e56b9 100644
--- a/document/src/vespa/document/datatype/urldatatype.h
+++ b/document/src/vespa/document/datatype/urldatatype.h
@@ -2,14 +2,12 @@
 #pragma once
 
 #include <vespa/document/datatype/structdatatype.h>
-#include <vespa/vespalib/util/sync.h>
 
 namespace document {
 
 class UrlDataType {
 private:
     static StructDataType::UP _instance;
-    static vespalib::Lock     _lock;
 
     UrlDataType() { /* hide */ }
     static StructDataType::UP createInstance();
diff --git a/document/src/vespa/document/select/valuenodes.cpp b/document/src/vespa/document/select/valuenodes.cpp
index 73fc1c6486b..36cb92dfe33 100644
--- a/document/src/vespa/document/select/valuenodes.cpp
+++ b/document/src/vespa/document/select/valuenodes.cpp
@@ -2,7 +2,6 @@
 #include "valuenodes.h"
 #include "visitor.h"
 #include "parser.h"
-#include <vespa/document/bucket/bucketdistribution.h>
 #include <vespa/document/base/exceptions.h>
 #include <vespa/document/update/documentupdate.h>
 #include <vespa/document/fieldvalue/fieldvalues.h>
diff --git a/searchcore/src/tests/proton/documentdb/document_subdbs/document_subdbs_test.cpp b/searchcore/src/tests/proton/documentdb/document_subdbs/document_subdbs_test.cpp
index aebe5a61198..43f16e87986 100644
--- a/searchcore/src/tests/proton/documentdb/document_subdbs/document_subdbs_test.cpp
+++ b/searchcore/src/tests/proton/documentdb/document_subdbs/document_subdbs_test.cpp
@@ -24,7 +24,6 @@
 #include <vespa/searchcore/proton/matching/querylimiter.h>
 #include <vespa/searchcore/proton/test/test.h>
 #include <vespa/searchcore/proton/test/thread_utils.h>
-#include <vespa/searchcorespi/plugin/iindexmanagerfactory.h>
 #include <vespa/searchlib/common/idestructorcallback.h>
 #include <vespa/searchlib/index/docbuilder.h>
 #include <vespa/searchlib/test/directory_handler.h>
diff --git a/searchcorespi/CMakeLists.txt b/searchcorespi/CMakeLists.txt
index 32469886bf8..2faa2be3b82 100644
--- a/searchcorespi/CMakeLists.txt
+++ b/searchcorespi/CMakeLists.txt
@@ -18,8 +18,4 @@ vespa_define_module(
     src/vespa/searchcorespi
     src/vespa/searchcorespi/flush
     src/vespa/searchcorespi/index
-    src/vespa/searchcorespi/plugin
-
-    TESTS
-    src/tests/plugin
 )
diff --git a/searchcorespi/src/tests/plugin/.gitignore b/searchcorespi/src/tests/plugin/.gitignore
deleted file mode 100644
index e49000038ad..00000000000
--- a/searchcorespi/src/tests/plugin/.gitignore
+++ /dev/null
@@ -1,5 +0,0 @@
-Makefile
-.depend
-*_test
-searchcorespi_factoryregistry_test_app
-searchcorespi_plugin_test_app
diff --git a/searchcorespi/src/tests/plugin/CMakeLists.txt b/searchcorespi/src/tests/plugin/CMakeLists.txt
deleted file mode 100644
index da785b09b6a..00000000000
--- a/searchcorespi/src/tests/plugin/CMakeLists.txt
+++ /dev/null
@@ -1,32 +0,0 @@
-# Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-vespa_add_library(searchcorespi_tplugin
-        SOURCES
-        plugin.cpp
-        DEPENDS
-        searchcorespi
-)
-vespa_add_library(searchcorespi_illegal-plugin
-        SOURCES
-        empty.cpp
-        DEPENDS
-        searchcorespi
-)
-vespa_add_executable(searchcorespi_plugin_test_app TEST
-    SOURCES
-    plugin_test.cpp
-    DEPENDS
-    searchcorespi
-)
-vespa_add_test(
-    NAME searchcorespi_plugin_test_app
-    COMMAND searchcorespi_plugin_test_app
-    ENVIRONMENT "LD_LIBRARY_PATH=."
-    DEPENDS searchcorespi_tplugin searchcorespi_illegal-plugin
-)
-vespa_add_executable(searchcorespi_factoryregistry_test_app TEST
-    SOURCES
-    factoryregistry_test.cpp
-    DEPENDS
-    searchcorespi
-)
-vespa_add_test(NAME searchcorespi_factoryregistry_test_app COMMAND searchcorespi_factoryregistry_test_app)
diff --git a/searchcorespi/src/tests/plugin/empty.cpp b/searchcorespi/src/tests/plugin/empty.cpp
deleted file mode 100644
index c7c47fc98c5..00000000000
--- a/searchcorespi/src/tests/plugin/empty.cpp
+++ /dev/null
@@ -1 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
diff --git a/searchcorespi/src/tests/plugin/factoryregistry_test.cpp b/searchcorespi/src/tests/plugin/factoryregistry_test.cpp
deleted file mode 100644
index 10a1c95f191..00000000000
--- a/searchcorespi/src/tests/plugin/factoryregistry_test.cpp
+++ /dev/null
@@ -1,59 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-
-#include <vespa/searchcorespi/plugin/factoryregistry.h>
-#include <vespa/searchcorespi/plugin/iindexmanagerfactory.h>
-#include <vespa/vespalib/stllike/string.h>
-#include <vespa/vespalib/testkit/testapp.h>
-#include <vespa/vespalib/util/exceptions.h>
-
-using vespalib::string;
-using namespace searchcorespi;
-
-namespace {
-
-struct MyFactory : IIndexManagerFactory {
-
-    virtual IIndexManager::UP createIndexManager(const IndexManagerConfig &,
-                                                 const index::IndexMaintainerConfig &,
-                                                 const index::IndexMaintainerContext &) override {
-        return IIndexManager::UP();
-    }
-    virtual config::ConfigKeySet getConfigKeys(
-            const string &,
-            const search::index::Schema &,
-            const config::ConfigInstance &) override {
-        return config::ConfigKeySet();
-    }
-};
-
-const string name = "factory";
-
-TEST("require that factories can be added and removed") {
-    FactoryRegistry registry;
-    EXPECT_FALSE(registry.isRegistered(name));
-    registry.add(name, IIndexManagerFactory::SP(new MyFactory));
-    EXPECT_TRUE(registry.get(name).get());
-    EXPECT_TRUE(registry.isRegistered(name));
-    registry.remove(name);
-    EXPECT_EXCEPTION(registry.get(name), vespalib::IllegalArgumentException,
-                     "No factory is registered with the name");
-}
-
-TEST("require that two factories with the same name cannot be added") {
-    FactoryRegistry registry;
-    registry.add(name, IIndexManagerFactory::SP(new MyFactory));
-    EXPECT_EXCEPTION(
-            registry.add(name, IIndexManagerFactory::SP(new MyFactory)),
-            vespalib::IllegalArgumentException,
-            "A factory is already registered with the same name");
-}
-
-TEST("require that a non-existent factory cannot be removed") {
-    FactoryRegistry registry;
-    EXPECT_EXCEPTION(registry.remove(name), vespalib::IllegalArgumentException,
-                     "No factory is registered with the name");
-}
-
-}  // namespace
-
-TEST_MAIN() { TEST_RUN_ALL(); }
diff --git a/searchcorespi/src/tests/plugin/plugin.cpp b/searchcorespi/src/tests/plugin/plugin.cpp
deleted file mode 100644
index d32b02f45fd..00000000000
--- a/searchcorespi/src/tests/plugin/plugin.cpp
+++ /dev/null
@@ -1,78 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-#include <vespa/searchcorespi/plugin/iindexmanagerfactory.h>
-
-using namespace search;
-using namespace search::index;
-using namespace vespalib;
-using namespace config;
-
-namespace searchcorespi {
-class IndexManager : public searchcorespi::IIndexManager
-{
-public:
-
-    typedef search::SerialNum SerialNum;
-    typedef search::index::Schema Schema;
-    typedef document::Document Document;
-    using OnWriteDoneType =
-        const std::shared_ptr<search::IDestructorCallback> &;
-    virtual void putDocument(uint32_t, const Document &, SerialNum) override { }
-    virtual void removeDocument(uint32_t, SerialNum) override { }
-    virtual void commit(SerialNum, OnWriteDoneType) override { }
-    virtual void heartBeat(SerialNum ) override {}
-    void compactLidSpace(uint32_t, SerialNum) override {}
-    virtual SerialNum getCurrentSerialNum() const override { return 0; }
-    virtual SerialNum getFlushedSerialNum() const override { return 0; }
-    virtual IndexSearchable::SP getSearchable() const override {
-        IndexSearchable::SP s;
-        return s;
-    }
-    virtual SearchableStats getSearchableStats() const override {
-        SearchableStats s;
-        return s;
-    }
-    virtual searchcorespi::IFlushTarget::List getFlushTargets() override {
-        searchcorespi::IFlushTarget::List l;
-        return l;
-    }
-    virtual void setSchema(const Schema &, SerialNum) override { }
-    virtual void setMaxFlushed(uint32_t) override { }
-};
-
-class IndexManagerFactory : public searchcorespi::IIndexManagerFactory
-{
-public:
-    virtual IIndexManager::UP createIndexManager(const IndexManagerConfig &managerCfg,
-                                                 const index::IndexMaintainerConfig &maintainerConfig,
-                                                 const index::IndexMaintainerContext &maintainerContext) override;
-
-    virtual ConfigKeySet getConfigKeys(const string &configId,
-                                       const Schema &schema,
-                                       const ConfigInstance &rootConfig) override;
-};
-
-IIndexManager::UP
-IndexManagerFactory::createIndexManager(const IndexManagerConfig &,
-                                        const index::IndexMaintainerConfig &,
-                                        const index::IndexMaintainerContext &)
-{
-    return IIndexManager::UP(new IndexManager());
-}
-
-ConfigKeySet
-IndexManagerFactory::getConfigKeys(const string &,
-                                   const Schema &,
-                                   const ConfigInstance &)
-{
-    ConfigKeySet keys;
-    return keys;
-}
-
-}
-
-searchcorespi::IIndexManagerFactory *
-createIndexManagerFactory()
-{
-    return new searchcorespi::IndexManagerFactory();
-}
-
diff --git a/searchcorespi/src/tests/plugin/plugin_test.cpp b/searchcorespi/src/tests/plugin/plugin_test.cpp
deleted file mode 100644
index 733c2834c24..00000000000
--- a/searchcorespi/src/tests/plugin/plugin_test.cpp
+++ /dev/null
@@ -1,37 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-
-#include <vespa/vespalib/testkit/testapp.h>
-#include <vespa/searchcorespi/plugin/factoryloader.h>
-#include <vespa/vespalib/util/exceptions.h>
-
-using namespace searchcorespi;
-
-namespace {
-TEST("require that plugins can be loaded.") {
-    FactoryLoader fl;
-    IIndexManagerFactory::UP f = fl.create("searchcorespi_tplugin");
-    ASSERT_TRUE(f.get());
-}
-
-TEST("require that non-existent plugin causes failure") {
-    FactoryLoader fl;
-#ifdef __APPLE__
-    EXPECT_EXCEPTION(fl.create("no-such-plugin"),
-                     vespalib::IllegalArgumentException,
-                     "image not found");
-#else
-    EXPECT_EXCEPTION(fl.create("no-such-plugin"),
-                     vespalib::IllegalArgumentException,
-                     "cannot open shared object file");
-#endif
-}
-
-TEST("require that missing factory function causes failure") {
-    FactoryLoader fl;
-    EXPECT_EXCEPTION(fl.create("searchcorespi_illegal-plugin"),
-                     vespalib::IllegalArgumentException,
-                     "Failed locating symbol 'createIndexManagerFactory'");
-}
-}  // namespace
-
-TEST_MAIN() { TEST_RUN_ALL(); }
diff --git a/searchcorespi/src/vespa/searchcorespi/CMakeLists.txt b/searchcorespi/src/vespa/searchcorespi/CMakeLists.txt
index 3cbe1265136..bee83a7f936 100644
--- a/searchcorespi/src/vespa/searchcorespi/CMakeLists.txt
+++ b/searchcorespi/src/vespa/searchcorespi/CMakeLists.txt
@@ -3,7 +3,6 @@ vespa_add_library(searchcorespi
     SOURCES
     $<TARGET_OBJECTS:searchcorespi_flush>
     $<TARGET_OBJECTS:searchcorespi_index>
-    $<TARGET_OBJECTS:searchcorespi_plugin>
     INSTALL lib64
     DEPENDS
 )
diff --git a/searchcorespi/src/vespa/searchcorespi/plugin/.gitignore b/searchcorespi/src/vespa/searchcorespi/plugin/.gitignore
deleted file mode 100644
index 7e7c0fe7fae..00000000000
--- a/searchcorespi/src/vespa/searchcorespi/plugin/.gitignore
+++ /dev/null
@@ -1,2 +0,0 @@
-/.depend
-/Makefile
diff --git a/searchcorespi/src/vespa/searchcorespi/plugin/CMakeLists.txt b/searchcorespi/src/vespa/searchcorespi/plugin/CMakeLists.txt
deleted file mode 100644
index b564a593e4e..00000000000
--- a/searchcorespi/src/vespa/searchcorespi/plugin/CMakeLists.txt
+++ /dev/null
@@ -1,7 +0,0 @@
-# Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-vespa_add_library(searchcorespi_plugin OBJECT
-    SOURCES
-    factoryregistry.cpp
-    factoryloader.cpp
-    DEPENDS
-)
diff --git a/searchcorespi/src/vespa/searchcorespi/plugin/factoryloader.cpp b/searchcorespi/src/vespa/searchcorespi/plugin/factoryloader.cpp
deleted file mode 100644
index ba2b0b962f6..00000000000
--- a/searchcorespi/src/vespa/searchcorespi/plugin/factoryloader.cpp
+++ /dev/null
@@ -1,32 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-#include "factoryloader.h"
-#include <vespa/vespalib/util/exceptions.h>
-
-using vespalib::stringref;
-using vespalib::make_string;
-using vespalib::IllegalArgumentException;
-
-namespace searchcorespi {
-
-FactoryLoader::FactoryLoader() :
-    _libraries()
-{
-}
-
-FactoryLoader::~FactoryLoader() = default;
-
-IIndexManagerFactory::UP
-FactoryLoader::create(stringref factory)
-{
-    typedef IIndexManagerFactory* (*FuncT)();
-    _libraries.loadLibrary(factory);
-    const FastOS_DynamicLibrary & lib = *_libraries.get(factory);
-    FuncT registrationMethod = reinterpret_cast<FuncT>(lib.GetSymbol("createIndexManagerFactory"));
-    if (registrationMethod == nullptr) {
-        throw IllegalArgumentException(make_string("Failed locating symbol 'createIndexManagerFactory' in library '%s' for factory '%s'.",
-                                                   lib.GetLibName(), vespalib::string(factory).c_str()));
-    }
-    return IIndexManagerFactory::UP(registrationMethod());
-}
-
-}
diff --git a/searchcorespi/src/vespa/searchcorespi/plugin/factoryloader.h b/searchcorespi/src/vespa/searchcorespi/plugin/factoryloader.h
deleted file mode 100644
index 3eda6557fa0..00000000000
--- a/searchcorespi/src/vespa/searchcorespi/plugin/factoryloader.h
+++ /dev/null
@@ -1,26 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-#pragma once
-
-#include <vespa/searchcorespi/plugin/iindexmanagerfactory.h>
-#include <vespa/vespalib/util/librarypool.h>
-
-namespace searchcorespi {
-
-class FactoryLoader
-{
-public:
-    FactoryLoader();
-    ~FactoryLoader();
-    /**
-     * Will load the library containing the factory. It will then locate the 'createIndexManagerFactory'
-     * symbol and run it to create the factory.
-     * @param the name of the library. Like 'vesparise'.
-     * @return the factory that is created.
-     */
-    IIndexManagerFactory::UP create(vespalib::stringref factory);
-private:
-    vespalib::LibraryPool _libraries;
-};
-
-} // namespace searchcorespi
-
diff --git a/searchcorespi/src/vespa/searchcorespi/plugin/factoryregistry.cpp b/searchcorespi/src/vespa/searchcorespi/plugin/factoryregistry.cpp
deleted file mode 100644
index bd1b914cf39..00000000000
--- a/searchcorespi/src/vespa/searchcorespi/plugin/factoryregistry.cpp
+++ /dev/null
@@ -1,54 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-#include <vespa/searchcorespi/plugin/factoryregistry.h>
-#include <vespa/vespalib/util/exceptions.h>
-
-using vespalib::LockGuard;
-using vespalib::IllegalArgumentException;
-using vespalib::stringref;
-using vespalib::string;
-
-namespace searchcorespi {
-
-FactoryRegistry::FactoryRegistry() = default;
-
-FactoryRegistry::~FactoryRegistry() = default;
-
-void FactoryRegistry::add(stringref uniqueName, const IIndexManagerFactory::SP & factory)
-{
-    LockGuard guard(_lock);
-    if (_registry.find(uniqueName) == _registry.end()) {
-        _registry[uniqueName] = factory;
-    } else {
-        throw IllegalArgumentException("A factory is already registered with the same name as '" + uniqueName + "'.", VESPA_STRLOC);
-    }
-}
-
-void FactoryRegistry::remove(stringref uniqueName)
-{
-    LockGuard guard(_lock);
-    if (_registry.find(uniqueName) == _registry.end()) {
-        throw IllegalArgumentException("No factory is registered with the name of '" + uniqueName + "'.", VESPA_STRLOC);
-    }
-    _registry.erase(uniqueName);
-}
-
-const IIndexManagerFactory::SP &
-FactoryRegistry::get(stringref uniqueName) const
-{
-    LockGuard guard(_lock);
-    Registry::const_iterator found = _registry.find(uniqueName);
-    if (found == _registry.end()) {
-        throw IllegalArgumentException("No factory is registered with the name of '" + uniqueName + "'.", VESPA_STRLOC);
-    }
-    return found->second;
-}
-
-bool
-FactoryRegistry::isRegistered(vespalib::stringref uniqueName) const
-{
-    LockGuard guard(_lock);
-    Registry::const_iterator found = _registry.find(uniqueName);
-    return found != _registry.end();
-}
-
-}
diff --git a/searchcorespi/src/vespa/searchcorespi/plugin/factoryregistry.h b/searchcorespi/src/vespa/searchcorespi/plugin/factoryregistry.h
deleted file mode 100644
index feb27d62950..00000000000
--- a/searchcorespi/src/vespa/searchcorespi/plugin/factoryregistry.h
+++ /dev/null
@@ -1,50 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-#pragma once
-
-#include <vespa/searchcorespi/plugin/iindexmanagerfactory.h>
-
-namespace searchcorespi {
-
-/**
- */
-class FactoryRegistry
-{
-public:
-    FactoryRegistry();
-    ~FactoryRegistry();
-    /**
-     * This will register the plugged in factory under its official
-     * name. The plugin should call this method when it is loaded.  E.g.
-     * by using either '__attribute__((constructor))' or using a
-     * global static object that will use its constructor to register
-     * the factory.
-     * @param uniqueName This is a name that is unique over all IndexManager factories.
-     * @param factory The factory instance for producing IndexManagers.
-     * @throws vespalib::IllegalArgument if factory is already registered.
-     */
-    void add(vespalib::stringref uniqueName, const IIndexManagerFactory::SP & factory);
-    /**
-     * Will unregister a factory. Should be called when a sharedlibrary is being unloaded.
-     * @param uniqueName Unique name of factory to remove from registry.
-     * @throws vespalib::IllegalArgument if factory is already registered.
-     */
-    void remove(vespalib::stringref uniqueName);
-    /**
-     * This method will fetch a factory given its unique name.
-     * @param name The name of the factory to return.
-     * @return The factory.
-     */
-    const IIndexManagerFactory::SP & get(vespalib::stringref uniqueName) const;
-    /**
-     * Returns true if a factory with the given name has been registered.
-     */
-    bool isRegistered(vespalib::stringref uniqueName) const;
-
-private:
-    typedef std::map<vespalib::string, IIndexManagerFactory::SP> Registry;
-    Registry       _registry;
-    vespalib::Lock _lock;
-};
-
-} // namespace searchcorespi
-
diff --git a/searchcorespi/src/vespa/searchcorespi/plugin/iindexmanagerfactory.h b/searchcorespi/src/vespa/searchcorespi/plugin/iindexmanagerfactory.h
deleted file mode 100644
index c2eddc15cde..00000000000
--- a/searchcorespi/src/vespa/searchcorespi/plugin/iindexmanagerfactory.h
+++ /dev/null
@@ -1,76 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-#pragma once
-
-#include <vespa/searchcorespi/index/iindexmanager.h>
-#include <vespa/searchcorespi/index/indexmaintainerconfig.h>
-#include <vespa/searchcorespi/index/indexmaintainercontext.h>
-#include <vespa/searchcorespi/index/indexmanagerconfig.h>
-#include <vespa/config/configgen/configinstance.h>
-#include <vespa/config/retriever/configsnapshot.h>
-#include <vespa/config/retriever/configkeyset.h>
-
-namespace searchcorespi {
-
-/**
- * Interface for an index manager factory. Every provider of an index manager is supposed to provide a
- * factory for producing them. It is given the basedir, the schema and a collection of configs.
- * The factory implementation must pick the config it needs and return an IIndexManager instance.
- * The factory is registered by using the registerFactory() method.
- */
-class IIndexManagerFactory
-{
-public:
-    typedef std::shared_ptr<IIndexManagerFactory> SP;
-    typedef std::unique_ptr<IIndexManagerFactory> UP;
-
-    virtual ~IIndexManagerFactory() {}
-
-    /**
-     * This method will be called by a document db when it needs to create an index manager that
-     * uses an index maintainer (with source selector) in its implementation.
-     * The factory implementation must use RTTI to figure out what configs are what.
-     * It should receive all configs it needs, but wise to do sanity checking.
-     *
-     * @param managerConfig The config that will be used to construct an index manager.
-     *                      Note that if the factory used a different config id when populating the
-     *                      ConfigKeySet compared to the one in this config instance, it must
-     *                      also override the config id when fetching from the config snapshot.
-     *                      The root config received in the @ref getConfigKeys() call will also be
-     *                      part of the config snapshot in this config instance.
-     * @param maintainerConfig The config needed to construct an index maintainer.
-     * @param maintainerContext The context object used by an index maintainer during its lifetime.
-     * @return The index manager created or NULL if not, fx if configs are not as expected.
-     */
-    virtual IIndexManager::UP createIndexManager(const IndexManagerConfig &managerConfig,
-                                                 const index::IndexMaintainerConfig &maintainerConfig,
-                                                 const index::IndexMaintainerContext &maintainerContext) = 0;
-
-    /**
-     * The factory must return the set of config keys that it will require the config from.
-     * This will facilitate that the searchcore can fetch all configs needed in a pluggable way.
-     *
-     * @param configId The config id to use when generating the config keys.
-     * @param schema This is the initial index schema to be used.
-     * @param rootConfig This is an config instance that is the root config for the factory.
-     *                   Based on this config it must be able to tell if it needs any other config,
-     *                   and in that case provide the config keys.
-     * @return The set containing keys for all configs required.
-     */
-    virtual config::ConfigKeySet getConfigKeys(const vespalib::string &configId,
-                                               const search::index::Schema &schema,
-                                               const config::ConfigInstance &rootConfig) = 0;
-};
-
-} // namespace searchcorespi
-
-extern "C" {
-/**
- * This is a method that each shared library must have in order provide a factory.
- * This will be called by the one loading the library.
- * @return The created factory that the caller will take ownership of.
- */
-searchcorespi::IIndexManagerFactory * createIndexManagerFactory();
-
-}
-
-
diff --git a/searchlib/src/vespa/searchlib/docstore/compacter.h b/searchlib/src/vespa/searchlib/docstore/compacter.h
index cf059b6cb04..52691d2c415 100644
--- a/searchlib/src/vespa/searchlib/docstore/compacter.h
+++ b/searchlib/src/vespa/searchlib/docstore/compacter.h
@@ -51,7 +51,7 @@ private:
     uint64_t                   _writeCount;
     vespalib::duration         _maxBucketGuardDuration;
     vespalib::steady_time      _lastSample;
-    vespalib::Lock             _lock;
+    std::mutex                 _lock;
     vespalib::MemoryDataStore  _backingMemory;
     std::vector<StoreByBucket> _tmpStore;
     GenerationHandler::Guard   _lidGuard;
diff --git a/searchlib/src/vespa/searchlib/docstore/randreaders.cpp b/searchlib/src/vespa/searchlib/docstore/randreaders.cpp
index 2eb419cf8eb..cb670f513f7 100644
--- a/searchlib/src/vespa/searchlib/docstore/randreaders.cpp
+++ b/searchlib/src/vespa/searchlib/docstore/randreaders.cpp
@@ -107,7 +107,7 @@ MMapRandReadDynamic::MMapRandReadDynamic(const vespalib::string &fileName, int m
 void
 MMapRandReadDynamic::remap(size_t sz)
 {
-    vespalib::LockGuard guard(_lock);
+    std::lock_guard guard(_lock);
     if ((sz > 0) && _holder.hasValue() && contains(*_holder.get(), sz)) {
         return;
     }
diff --git a/searchlib/src/vespa/searchlib/docstore/randreaders.h b/searchlib/src/vespa/searchlib/docstore/randreaders.h
index 4503c3600d4..00dc371bddf 100644
--- a/searchlib/src/vespa/searchlib/docstore/randreaders.h
+++ b/searchlib/src/vespa/searchlib/docstore/randreaders.h
@@ -47,7 +47,7 @@ private:
     vespalib::PtrHolder<FastOS_FileInterface> _holder;
     int                                       _mmapFlags;
     int                                       _fadviseOptions;
-    vespalib::Lock                            _lock;
+    std::mutex                                _lock;
 };
 
 class NormalRandRead : public FileRandRead
diff --git a/searchlib/src/vespa/searchlib/memoryindex/memory_index.cpp b/searchlib/src/vespa/searchlib/memoryindex/memory_index.cpp
index 34c5d65ab23..789b7fcf452 100644
--- a/searchlib/src/vespa/searchlib/memoryindex/memory_index.cpp
+++ b/searchlib/src/vespa/searchlib/memoryindex/memory_index.cpp
@@ -18,7 +18,6 @@ LOG_SETUP(".searchlib.memoryindex.memory_index");
 
 using document::ArrayFieldValue;
 using document::WeightedSetFieldValue;
-using vespalib::LockGuard;
 
 namespace search {
 
@@ -215,7 +214,7 @@ MemoryIndex::getNumWords() const {
 void
 MemoryIndex::pruneRemovedFields(const Schema &schema)
 {
-    LockGuard lock(_lock);
+    std::lock_guard lock(_lock);
     if (_prunedSchema.get() == nullptr) {
         auto newSchema = Schema::intersect(_schema, schema);
         if (_schema == *newSchema) {
@@ -241,7 +240,7 @@ MemoryIndex::pruneRemovedFields(const Schema &schema)
 Schema::SP
 MemoryIndex::getPrunedSchema() const
 {
-    LockGuard lock(_lock);
+    std::lock_guard lock(_lock);
     return _prunedSchema;
 }
 
diff --git a/searchlib/src/vespa/searchlib/memoryindex/memory_index.h b/searchlib/src/vespa/searchlib/memoryindex/memory_index.h
index a9f153f7dd8..56eb4ad7a66 100644
--- a/searchlib/src/vespa/searchlib/memoryindex/memory_index.h
+++ b/searchlib/src/vespa/searchlib/memoryindex/memory_index.h
@@ -48,14 +48,14 @@ private:
     std::unique_ptr<DocumentInverter>  _inverter0;
     std::unique_ptr<DocumentInverter>  _inverter1;
     DocumentInverter                  *_inverter;
-    bool              _frozen;
-    uint32_t          _maxDocId;
-    uint32_t          _numDocs;
-    vespalib::Lock    _lock;
-    std::vector<bool> _hiddenFields;
-    index::Schema::SP _prunedSchema;
+    bool                _frozen;
+    uint32_t            _maxDocId;
+    uint32_t            _numDocs;
+    mutable std::mutex  _lock;
+    std::vector<bool>   _hiddenFields;
+    index::Schema::SP   _prunedSchema;
     vespalib::hash_set<uint32_t> _indexedDocs; // documents in memory index
-    const uint64_t    _staticMemoryFootprint;
+    const uint64_t      _staticMemoryFootprint;
 
     MemoryIndex(const MemoryIndex &) = delete;
     MemoryIndex(MemoryIndex &&) = delete;
diff --git a/slobrok/src/vespa/slobrok/sblist.cpp b/slobrok/src/vespa/slobrok/sblist.cpp
index 9fc58aa2974..e7528fb6db2 100644
--- a/slobrok/src/vespa/slobrok/sblist.cpp
+++ b/slobrok/src/vespa/slobrok/sblist.cpp
@@ -5,7 +5,7 @@
 #include <vespa/log/log.h>
 LOG_SETUP(".slobrok.list");
 
-using vespalib::LockGuard;
+using LockGuard = std::lock_guard<std::mutex>;
 
 namespace slobrok::api {
 
@@ -83,7 +83,7 @@ SlobrokList::setup(const std::vector<std::string> &specList)
         _slobrokSpecs.push_back(specList[i]);
     }
 
-    vespalib::RandomGen randomizer(time(NULL));
+    vespalib::RandomGen randomizer(time(nullptr));
     // randomize order
     for (size_t i = 0; i + 1 < cfgSz; ++i) {
         size_t lim = cfgSz - i;
diff --git a/slobrok/src/vespa/slobrok/sblist.h b/slobrok/src/vespa/slobrok/sblist.h
index e5f31c23e5b..08328b99d1a 100644
--- a/slobrok/src/vespa/slobrok/sblist.h
+++ b/slobrok/src/vespa/slobrok/sblist.h
@@ -2,7 +2,6 @@
 #pragma once
 
 #include "cfg.h"
-#include <vespa/vespalib/util/sync.h>
 
 namespace slobrok::api {
 
@@ -42,7 +41,7 @@ public:
     /** check if the list contains a given spec */
     bool contains(const std::string &spec);
 private:
-    vespalib::Lock _lock;
+    std::mutex _lock;
     std::vector<std::string> _slobrokSpecs;
     size_t _nextSpec;
     size_t _currSpec;
diff --git a/staging_vespalib/src/vespa/vespalib/stllike/cache.h b/staging_vespalib/src/vespa/vespalib/stllike/cache.h
index 99b601f7c3c..2c7722724cf 100644
--- a/staging_vespalib/src/vespa/vespalib/stllike/cache.h
+++ b/staging_vespalib/src/vespa/vespalib/stllike/cache.h
@@ -123,7 +123,6 @@ protected:
     vespalib::LockGuard getGuard();
     void invalidate(const vespalib::LockGuard & guard, const K & key);
     bool hasKey(const vespalib::LockGuard & guard, const K & key) const;
-    bool hasLock() const;
 private:
     /**
      * Called when an object is inserted, to see if the LRU should be removed.
diff --git a/staging_vespalib/src/vespa/vespalib/stllike/cache.hpp b/staging_vespalib/src/vespa/vespalib/stllike/cache.hpp
index 906621d623c..ebad3ef6a09 100644
--- a/staging_vespalib/src/vespa/vespalib/stllike/cache.hpp
+++ b/staging_vespalib/src/vespa/vespalib/stllike/cache.hpp
@@ -42,13 +42,7 @@ cache<P>::hasKey(const K & key) const {
 }
 
 template< typename P >
-bool
-cache<P>::hasLock() const {
-    return TryLock(_hashLock).hasLock();
-}
-
-template< typename P >
-cache<P>::~cache() { }
+cache<P>::~cache() = default;
 
 template< typename P >
 cache<P>::cache(BackingStore & b, size_t maxBytes) :
diff --git a/staging_vespalib/src/vespa/vespalib/util/varholder.h b/staging_vespalib/src/vespa/vespalib/util/varholder.h
index fdcc15d1fb4..980d773adc4 100644
--- a/staging_vespalib/src/vespa/vespalib/util/varholder.h
+++ b/staging_vespalib/src/vespa/vespalib/util/varholder.h
@@ -2,7 +2,7 @@
 
 #pragma once
 
-#include <vespa/vespalib/util/sync.h>
+#include <mutex>
 
 namespace vespalib {
 
@@ -10,7 +10,7 @@ template <typename T>
 class VarHolder
 {
     T     _v;
-    Lock  _lock;
+    std::mutex  _lock;
 public:
     VarHolder() : _v(), _lock() {}
     explicit VarHolder(const T &v) : _v(v), _lock() {}
@@ -21,7 +21,7 @@ public:
     void set(const T &v) {
         T old;
         {
-            vespalib::LockGuard guard(_lock);
+            std::lock_guard guard(_lock);
             old = _v;
             _v = v;
         }
@@ -30,7 +30,7 @@ public:
     void clear() { set(T()); }
 
     T get() const {
-        vespalib::LockGuard guard(_lock);
+        std::lock_guard guard(_lock);
         return _v;
     }
 };
diff --git a/storage/src/vespa/storage/persistence/filestorage/filestorhandlerimpl.cpp b/storage/src/vespa/storage/persistence/filestorage/filestorhandlerimpl.cpp
index 6878c0d0e82..6efb282ecbf 100644
--- a/storage/src/vespa/storage/persistence/filestorage/filestorhandlerimpl.cpp
+++ b/storage/src/vespa/storage/persistence/filestorage/filestorhandlerimpl.cpp
@@ -75,7 +75,7 @@ FileStorHandlerImpl::~FileStorHandlerImpl() = default;
 void
 FileStorHandlerImpl::addMergeStatus(const document::Bucket& bucket, MergeStatus::SP status)
 {
-    vespalib::LockGuard mlock(_mergeStatesLock);
+    std::lock_guard mlock(_mergeStatesLock);
     if (_mergeStates.find(bucket) != _mergeStates.end()) {
         LOG(warning, "A merge status already existed for %s. Overwriting it.", bucket.toString().c_str());
     }
@@ -85,7 +85,7 @@ FileStorHandlerImpl::addMergeStatus(const document::Bucket& bucket, MergeStatus:
 MergeStatus&
 FileStorHandlerImpl::editMergeStatus(const document::Bucket& bucket)
 {
-    vespalib::LockGuard mlock(_mergeStatesLock);
+    std::lock_guard mlock(_mergeStatesLock);
     MergeStatus::SP status = _mergeStates[bucket];
     if (status.get() == 0) {
         throw vespalib::IllegalStateException("No merge state exist for " + bucket.toString(), VESPA_STRLOC);
@@ -96,21 +96,21 @@ FileStorHandlerImpl::editMergeStatus(const document::Bucket& bucket)
 bool
 FileStorHandlerImpl::isMerging(const document::Bucket& bucket) const
 {
-    vespalib::LockGuard mlock(_mergeStatesLock);
+    std::lock_guard mlock(_mergeStatesLock);
     return (_mergeStates.find(bucket) != _mergeStates.end());
 }
 
 uint32_t
 FileStorHandlerImpl::getNumActiveMerges() const
 {
-    vespalib::LockGuard mlock(_mergeStatesLock);
+    std::lock_guard mlock(_mergeStatesLock);
     return _mergeStates.size();
 }
 
 void
 FileStorHandlerImpl::clearMergeStatus(const document::Bucket& bucket, const api::ReturnCode* code)
 {
-    vespalib::LockGuard mlock(_mergeStatesLock);
+    std::lock_guard mlock(_mergeStatesLock);
     auto it = _mergeStates.find(bucket);
     if (it == _mergeStates.end()) {
         if (code != 0) {
@@ -301,7 +301,7 @@ void
 FileStorHandlerImpl::updateMetrics(const MetricLockGuard &)
 {
     for (Disk & disk : _diskInfo) {
-        vespalib::MonitorGuard lockGuard(_mergeStatesLock);
+        std::lock_guard lockGuard(_mergeStatesLock);
         disk.metrics->pendingMerges.addValue(_mergeStates.size());
         disk.metrics->queueSize.addValue(disk.getQueueSize());
 
@@ -1310,7 +1310,7 @@ FileStorHandlerImpl::getStatus(std::ostream& out, const framework::HttpUrlPath&
         out << "</ul>\n";
     }
 
-    vespalib::LockGuard mergeGuard(_mergeStatesLock);
+    std::lock_guard mergeGuard(_mergeStatesLock);
     out << "<tr><td>Active merge operations</td><td>" << _mergeStates.size() << "</td></tr>\n";
     if (verbose) {
         out << "<h4>Active merges</h4>\n";
diff --git a/storage/src/vespa/storage/persistence/filestorage/filestorhandlerimpl.h b/storage/src/vespa/storage/persistence/filestorage/filestorhandlerimpl.h
index 34cb7ba9266..02dcfea0654 100644
--- a/storage/src/vespa/storage/persistence/filestorage/filestorhandlerimpl.h
+++ b/storage/src/vespa/storage/persistence/filestorage/filestorhandlerimpl.h
@@ -288,7 +288,7 @@ private:
     std::vector<Disk>     _diskInfo;
     MessageSender&        _messageSender;
     const document::BucketIdFactory& _bucketIdFactory;
-    vespalib::Lock        _mergeStatesLock;
+    mutable std::mutex    _mergeStatesLock;
     std::map<document::Bucket, MergeStatus::SP> _mergeStates;
     uint32_t              _getNextMessageTimeout;
     const uint32_t        _max_active_merges_per_stripe; // Read concurrently by stripes.
diff --git a/vdslib/CMakeLists.txt b/vdslib/CMakeLists.txt
index b997bf5f983..3c1ee756e56 100644
--- a/vdslib/CMakeLists.txt
+++ b/vdslib/CMakeLists.txt
@@ -21,7 +21,6 @@ vespa_define_module(
 
     TESTS
     src/tests
-    src/tests/bucketdistribution
     src/tests/container
     src/tests/distribution
     src/tests/state
diff --git a/vdslib/src/tests/CMakeLists.txt b/vdslib/src/tests/CMakeLists.txt
index bc230a7157b..6cf1ba5e33f 100644
--- a/vdslib/src/tests/CMakeLists.txt
+++ b/vdslib/src/tests/CMakeLists.txt
@@ -6,7 +6,6 @@ vespa_add_executable(vdslib_gtest_runner_app TEST
     SOURCES
     gtest_runner.cpp
     DEPENDS
-    vdslib_bucketdistributiontest
     vdslib_containertest
     vdslib_testdistribution
     vdslib_teststate
diff --git a/vdslib/src/tests/bucketdistribution/.gitignore b/vdslib/src/tests/bucketdistribution/.gitignore
deleted file mode 100644
index 583460ae288..00000000000
--- a/vdslib/src/tests/bucketdistribution/.gitignore
+++ /dev/null
@@ -1,3 +0,0 @@
-*.So
-.depend
-Makefile
diff --git a/vdslib/src/tests/bucketdistribution/CMakeLists.txt b/vdslib/src/tests/bucketdistribution/CMakeLists.txt
deleted file mode 100644
index 79ca63b72f2..00000000000
--- a/vdslib/src/tests/bucketdistribution/CMakeLists.txt
+++ /dev/null
@@ -1,8 +0,0 @@
-# Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-vespa_add_library(vdslib_bucketdistributiontest
-    SOURCES
-    bucketdistributiontest.cpp
-    DEPENDS
-    vdslib
-    GTest::GTest
-)
diff --git a/vdslib/src/tests/bucketdistribution/bucketdistributiontest.cpp b/vdslib/src/tests/bucketdistribution/bucketdistributiontest.cpp
deleted file mode 100644
index 7f2b012680c..00000000000
--- a/vdslib/src/tests/bucketdistribution/bucketdistributiontest.cpp
+++ /dev/null
@@ -1,92 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-
-#include <vespa/vdslib/bucketdistribution.h>
-#include <gtest/gtest.h>
-
-using namespace vdslib;
-
-void
-assertDistribution(uint32_t numColumns, uint32_t numBucketBits, const uint32_t expected[])
-{
-    BucketDistribution bd(numColumns, numBucketBits);
-    EXPECT_EQ(numColumns, bd.getNumColumns());
-    EXPECT_EQ((uint32_t)(1 << numBucketBits), bd.getNumBuckets());
-    for (uint32_t i = 0; i < bd.getNumBuckets(); ++i) {
-        EXPECT_EQ(expected[i], bd.getColumn(document::BucketId(16, i)));
-    }
-}
-
-TEST(BucketDistributionTest, testDistribution)
-{
-    const uint32_t expected4[] = {
-        10, 11, 9, 6, 4, 8, 14, 1, 13, 2, 12, 3, 5, 7, 15, 0 };
-    assertDistribution(16, 4, expected4);
-
-    const uint32_t expected5[] = {
-        11, 12, 11, 13, 8, 13, 8, 9, 4, 5, 6, 12, 10, 15, 1, 1, 7, 9, 14, 2, 2, 14, 3, 3, 4, 5, 6, 7, 10, 15, 0, 0 };
-    assertDistribution(16, 5, expected5);
-
-    const uint32_t expected6[] = {
-        13, 13, 13, 13, 9, 11, 8, 9, 11, 14, 9, 11, 14, 14, 8, 10, 11, 14, 4, 5, 5, 6, 6, 7, 8, 10, 12, 15, 1, 1, 1, 1,
-        6, 7, 8, 10, 12, 15, 2, 2, 2, 2, 12, 15, 3, 3, 3, 3, 4, 4, 4, 5, 5, 6, 7, 7, 9, 10, 12, 15, 0, 0, 0, 0 };
-    assertDistribution(16, 6, expected6);
-
-    const uint32_t expected7[] = {
-        14, 14, 14, 13, 11, 14, 14, 10, 13, 14, 10, 12, 8, 8, 9, 10, 9, 10, 11, 12, 13, 15, 11, 12, 13, 13, 15, 8, 8, 9, 10, 11,
-        11, 12, 13, 15, 4, 4, 5, 5, 5, 5, 15, 6, 6, 7, 7, 7, 8, 9, 9, 10, 11, 12, 14, 15, 1, 1, 1, 1, 1, 1, 1, 1,
-        6, 6, 6, 7, 7, 8, 8, 9, 10, 11, 12, 13, 15, 2, 2, 2, 2, 2, 2, 2, 2, 12, 13, 15, 3, 3, 3, 3, 3, 3, 3, 3,
-        4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 7, 7, 7, 8, 9, 9, 10, 11, 12, 14, 15, 0, 0, 0, 0, 0, 0, 0, 0 };
-    assertDistribution(16, 7, expected7);
-
-    const uint32_t expected8[] = {
-        15, 14, 15, 15, 12, 14, 15, 12, 12, 11, 12, 13, 14, 13, 13, 13, 14, 15, 15, 9, 14, 9, 15, 10, 11, 11, 12, 8, 8, 8, 8, 9,
-        9, 10, 10, 10, 11, 11, 12, 13, 13, 14, 10, 11, 11, 12, 13, 13, 14, 13, 13, 14, 15, 7, 8, 8, 8, 9, 9, 9, 10, 10, 10, 11,
-        10, 10, 11, 11, 12, 13, 13, 14, 15, 4, 4, 4, 4, 15, 5, 5, 5, 5, 5, 5, 5, 15, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7,
-        8, 8, 8, 9, 9, 9, 10, 10, 11, 11, 12, 12, 13, 14, 14, 15, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-        6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10, 10, 11, 11, 12, 12, 13, 14, 14, 15, 2, 2, 2, 2, 2, 2,
-        2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 12, 12, 13, 14, 14, 15, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
-        4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7,
-        8, 8, 8, 9, 9, 9, 10, 10, 11, 11, 12, 12, 13, 14, 15, 15, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
-    assertDistribution(16, 8, expected8);
-
-    const uint32_t expected9[] = {
-        15, 15, 15, 15, 14, 14, 15, 13, 13, 13, 13, 13, 14, 14, 15, 12, 14, 15, 15, 11, 11, 12, 13, 13, 13, 14, 14, 15, 15, 10, 12, 12,
-        12, 13, 13, 13, 14, 14, 15, 15, 9, 9, 9, 10, 10, 11, 11, 11, 12, 12, 12, 12, 13, 13, 14, 15, 15, 8, 8, 8, 8, 9, 9, 9,
-        9, 9, 9, 10, 9, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 13, 13, 14, 14, 14, 10, 10, 10, 11, 11, 11, 12, 12, 12, 12,
-        13, 13, 14, 14, 14, 15, 15, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11, 11,
-        10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 14, 15, 15, 4, 4, 4, 4, 4, 4, 4, 15, 15, 5, 5, 5, 5, 5,
-        5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 14, 14, 14, 15, 15, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7,
-        8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 15, 15, 15,
-        1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-        6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9,
-        9, 9, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 14, 15, 15, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
-        2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 12, 12, 12, 13, 13, 13, 14, 14, 14, 15, 15,
-        3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
-        4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5,
-        5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
-        8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 13, 13, 13, 14, 14, 15, 15, 15,
-        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
-    assertDistribution(16, 9, expected9);
-}
-
-TEST(BucketDistributionTest, testNumBucketBits)
-{
-    BucketDistribution bd(1, 4);
-    for (uint32_t i = 0; i <= 0xf; ++i) {
-        EXPECT_EQ(0u, bd.getColumn(document::BucketId(32, (rand() << 4) & i)));
-    }
-
-    bd.reset();
-    bd.setNumColumns(1);
-    bd.setNumBucketBits(8);
-    for (uint32_t i = 0; i <= 0xff; ++i) {
-        EXPECT_EQ(0u, bd.getColumn(document::BucketId(32, (rand() << 8) & i)));
-    }
-
-    bd.reset();
-    bd.setNumColumns(1);
-    bd.setNumBucketBits(16);
-    for (uint32_t i = 0; i <= 0xffff; ++i) {
-        EXPECT_EQ(0u, bd.getColumn(document::BucketId(32, (rand() << 16) & i)));
-    }
-}
diff --git a/vdslib/src/vespa/vdslib/CMakeLists.txt b/vdslib/src/vespa/vdslib/CMakeLists.txt
index ace44439a23..cf5053a5ceb 100644
--- a/vdslib/src/vespa/vdslib/CMakeLists.txt
+++ b/vdslib/src/vespa/vdslib/CMakeLists.txt
@@ -1,7 +1,6 @@
 # Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 vespa_add_library(vdslib
     SOURCES
-    bucketdistribution.cpp
     $<TARGET_OBJECTS:vdslib_container>
     $<TARGET_OBJECTS:vdslib_state>
     $<TARGET_OBJECTS:vdslib_distribution>
diff --git a/vdslib/src/vespa/vdslib/bucketdistribution.cpp b/vdslib/src/vespa/vdslib/bucketdistribution.cpp
deleted file mode 100644
index 15947d82fed..00000000000
--- a/vdslib/src/vespa/vdslib/bucketdistribution.cpp
+++ /dev/null
@@ -1,115 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-#include "bucketdistribution.h"
-
-#include <vespa/log/log.h>
-LOG_SETUP(".bucketdistribution");
-
-namespace vdslib {
-
-BucketDistribution::BucketDistribution(uint32_t numColumns, uint32_t numBucketBits) :
-    _numColumns(0),
-    _numBucketBits(numBucketBits),
-    _bucketToColumn(),
-    _lock()
-{
-    _bucketToColumn.resize(getNumBuckets());
-    reset();
-    setNumColumns(numColumns);
-}
-
-BucketDistribution::~BucketDistribution() = default;
-
-void
-BucketDistribution::getBucketCount(uint32_t numColumns, uint32_t numBucketBits, std::vector<uint32_t> &ret)
-{
-    ret.resize(numColumns);
-    uint32_t cnt = getNumBuckets(numBucketBits) / numColumns;
-    uint32_t rst = getNumBuckets(numBucketBits) % numColumns;
-    for (uint32_t i = 0; i < numColumns; ++i) {
-        ret[i] = cnt + (i < rst ? 1 : 0);
-    }
-}
-
-void
-BucketDistribution::getBucketMigrateCount(uint32_t numColumns, uint32_t numBucketBits, std::vector<uint32_t> &ret)
-{
-    getBucketCount(numColumns++, numBucketBits, ret);
-    uint32_t cnt = getNumBuckets(numBucketBits) / numColumns;
-    uint32_t rst = getNumBuckets(numBucketBits) % numColumns;
-    for (uint32_t i = 0; i < numColumns - 1; ++i) {
-        ret[i] -= cnt + (i < rst ? 1 : 0);
-    }
-}
-
-void
-BucketDistribution::reset()
-{
-    for (uint32_t & value : _bucketToColumn) {
-        value = 0;
-    }
-    _numColumns = 1;
-}
-
-void
-BucketDistribution::addColumn()
-{
-    uint32_t newColumns = _numColumns + 1;
-    std::vector<uint32_t> migrate;
-    getBucketMigrateCount(_numColumns, _numBucketBits, migrate);
-    uint32_t numBuckets = getNumBuckets(_numBucketBits);
-    for (uint32_t i = 0; i < numBuckets; ++i) {
-        uint32_t old = _bucketToColumn[i];
-        if (migrate[old] > 0) {
-            _bucketToColumn[i] = _numColumns; // move this bucket to the new column
-            migrate[old]--;
-        }
-    }
-    _numColumns = newColumns;
-}
-
-void
-BucketDistribution::setNumColumns(uint32_t numColumns)
-{
-    vespalib::LockGuard guard(_lock);
-    if (numColumns < _numColumns) {
-        reset();
-    }
-    if (numColumns == _numColumns) {
-        return;
-    }
-    for (int i = numColumns - _numColumns; --i >= 0; ) {
-        addColumn();
-    }
-}
-
-void
-BucketDistribution::setNumBucketBits(uint32_t numBucketBits)
-{
-    uint32_t numColumns;
-    {
-        vespalib::LockGuard guard(_lock);
-        if (numBucketBits == _numBucketBits) {
-            return;
-        }
-        _numBucketBits = numBucketBits;
-        _bucketToColumn.resize(getNumBuckets(numBucketBits));
-        numColumns = _numColumns;
-        reset();
-    }
-    setNumColumns(numColumns);
-}
-
-uint32_t
-BucketDistribution::getColumn(const document::BucketId &bucketId) const
-{
-    uint32_t ret = (uint32_t)(bucketId.getId() & (getNumBuckets(_numBucketBits) - 1));
-    if (ret >= _bucketToColumn.size()) {
-        LOG(error,
-            "The bucket distribution map is not in sync with the number of bucket bits. "
-            "This should never happen! Distribution is broken!!");
-        return 0;
-    }
-    return _bucketToColumn[ret];
-}
-
-}
diff --git a/vdslib/src/vespa/vdslib/bucketdistribution.h b/vdslib/src/vespa/vdslib/bucketdistribution.h
deleted file mode 100644
index 5d06be53b49..00000000000
--- a/vdslib/src/vespa/vdslib/bucketdistribution.h
+++ /dev/null
@@ -1,119 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-#pragma once
-
-#include <vespa/document/bucket/bucketid.h>
-#include <vespa/vespalib/util/sync.h>
-#include <vector>
-
-namespace vdslib {
-
-/**
- * Stable algorithmic hash distribution; this class assigns hash buckets to targets. The number of hash buckets should
- * be large compared to the number of targets. The mapping from hash value to hash bucket is performed outside this
- * class.
- */
-class BucketDistribution {
-public:
-    /**
-     * Constructs a new bucket distribution object with a given number of columns and buckets.
-     *
-     * @param numColumns    The number of columns to distribute to.
-     * @param numBucketBits The number of bits to use for bucket id.
-     */
-    BucketDistribution(uint32_t numColumns, uint32_t numBucketBits);
-    ~BucketDistribution();
-
-    /**
-     * Returns the number of buckets that the given number of bucket bits will allow.
-     *
-     * @param numBucketBits The number of bits to use for bucket id.
-     * @return              The number of buckets allowed.
-     */
-    static uint32_t getNumBuckets(uint32_t numBucketBits) { return 1 << numBucketBits; }
-
-    /**
-     * This method returns a list that contains the distributions of the given number of buckets over the given number
-     * of columns.
-     *
-     * @param numColumns    The number of columns to distribute to.
-     * @param numBucketBits The number of bits to use for bucket id.
-     * @param ret           List to fill with the bucket distribution.
-     */
-    static void getBucketCount(uint32_t numColumns, uint32_t numBucketBits, std::vector<uint32_t> &ret);
-
-    /**
-     * This method returns a list similar to {@link this#getBucketCount(int,int)}, except that the returned list
-     * contains the number of buckets that will have to be migrated from each column if an additional column was added.
-     *
-     * @param numColumns    The original number of columns.
-     * @param numBucketBits The number of bits to use for bucket id.
-     * @param ret           List to fill with the number of buckets to migrate, one value per column.
-     */
-    static void getBucketMigrateCount(uint32_t numColumns, uint32_t numBucketBits, std::vector<uint32_t> &ret);
-
-    /**
-     * Sets the number of columns to distribute to to 1, and resets the content of the internal bucket-to-column map so
-     * that it all buckets point to that single column.
-     */
-    void reset();
-
-    /**
-     * Sets the number of columns to use for this document distribution object. This will reset and setup this object
-     * from scratch. The original number of buckets is maintained.
-     *
-     * @param numColumns The new number of columns to distribute to.
-     */
-    void setNumColumns(uint32_t numColumns);
-
-    /**
-     * Returns the number of columns to distribute to.
-     *
-     * @return The number of columns.
-     */
-    uint32_t getNumColumns() const { return _numColumns; }
-
-    /**
-     * Sets the number of buckets to use for this document distribution object. This will reset and setup this object
-     * from scratch. The original number of columns is maintained.
-     *
-     * @param numBucketBits The new number of bits to use for bucket id.
-     */
-    void setNumBucketBits(uint32_t numBucketBits);
-
-    /**
-     * Returns the number of bits used for bucket identifiers.
-     *
-     * @return The number of bits.
-     */
-    uint32_t getNumBucketBits() const { return _numBucketBits; }
-
-    /**
-     * Returns the number of buckets available using the configured number of bucket bits.
-     *
-     * @return The number of buckets.
-     */
-    uint32_t getNumBuckets() const { return getNumBuckets(_numBucketBits); }
-
-    /**
-     * This method maps the given bucket id to its corresponding column.
-     *
-     * @param bucketId The bucket whose column to lookup.
-     * @return         The column to distribute the bucket to.
-     */
-    uint32_t getColumn(const document::BucketId &bucketId) const;
-
-private:
-    /**
-     * Adds a single column to this bucket distribution object. This will modify the internal bucket-to-column map so
-     * that it takes into account the new column.
-     */
-    void addColumn();
-
-private:
-    uint32_t              _numColumns;     // The number of columns to distribute to.
-    uint32_t              _numBucketBits;  // The number of bits to use for bucket identification.
-    std::vector<uint32_t> _bucketToColumn; // A map from bucket id to column index.
-    vespalib::Lock        _lock;
-};
-
-}
diff --git a/vespalib/CMakeLists.txt b/vespalib/CMakeLists.txt
index ec003329999..278d32c118d 100644
--- a/vespalib/CMakeLists.txt
+++ b/vespalib/CMakeLists.txt
@@ -46,7 +46,6 @@ vespa_define_module(
     src/tests/datastore/unique_store
     src/tests/datastore/unique_store_dictionary
     src/tests/datastore/unique_store_string_allocator
-    src/tests/delegatelist
     src/tests/detect_type_benchmark
     src/tests/dotproduct
     src/tests/drop-file-from-cache
@@ -94,7 +93,6 @@ vespa_define_module(
     src/tests/regex
     src/tests/rendezvous
     src/tests/runnable_pair
-    src/tests/rwlock
     src/tests/sha1
     src/tests/sharedptr
     src/tests/signalhandler
diff --git a/vespalib/src/tests/delegatelist/.cvsignore b/vespalib/src/tests/delegatelist/.cvsignore
deleted file mode 100644
index 0e8f4d0be0b..00000000000
--- a/vespalib/src/tests/delegatelist/.cvsignore
+++ /dev/null
@@ -1,3 +0,0 @@
-.depend
-Makefile
-delegatelist_test
diff --git a/vespalib/src/tests/delegatelist/.gitignore b/vespalib/src/tests/delegatelist/.gitignore
deleted file mode 100644
index 42ac4beb0c3..00000000000
--- a/vespalib/src/tests/delegatelist/.gitignore
+++ /dev/null
@@ -1,4 +0,0 @@
-.depend
-Makefile
-delegatelist_test
-vespalib_delegatelist_test_app
diff --git a/vespalib/src/tests/delegatelist/CMakeLists.txt b/vespalib/src/tests/delegatelist/CMakeLists.txt
deleted file mode 100644
index 71551474445..00000000000
--- a/vespalib/src/tests/delegatelist/CMakeLists.txt
+++ /dev/null
@@ -1,8 +0,0 @@
-# Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-vespa_add_executable(vespalib_delegatelist_test_app TEST
-    SOURCES
-    delegatelist.cpp
-    DEPENDS
-    vespalib
-)
-vespa_add_test(NAME vespalib_delegatelist_test_app COMMAND vespalib_delegatelist_test_app)
diff --git a/vespalib/src/tests/delegatelist/delegatelist.cpp b/vespalib/src/tests/delegatelist/delegatelist.cpp
deleted file mode 100644
index 4dc7e5c97d7..00000000000
--- a/vespalib/src/tests/delegatelist/delegatelist.cpp
+++ /dev/null
@@ -1,824 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-
-#include <vespa/vespalib/testkit/testapp.h>
-#include <vespa/vespalib/util/delegatelist.hpp>
-#include <vespa/vespalib/util/guard.h>
-#include <vespa/fastos/thread.h>
-#include <queue>
-
-#include <vespa/log/log.h>
-LOG_SETUP("delegatelist_test");
-
-using namespace vespalib;
-
-//-----------------------------------------------------------------------------
-
-class Test : public TestApp
-{
-public:
-    void testEmpty();
-    void testAdd();
-    void testRemove();
-    void testOneShot();
-    void testMultiSnapshot();
-    void testActors();
-    void testWaitSnapshots();
-    void stressTest();
-    int Main() override;
-};
-
-//-----------------------------------------------------------------------------
-
-namespace {
-
-class Handler
-{
-private:
-    int _num;
-public:
-    Handler() : _num(0) {}
-    void add() { _num++; }
-    int getNum() { return _num; }
-};
-
-typedef DelegateList<Handler> DL;
-
-void multicast(DL &dl) {
-    for (DL::Snapshot snap(dl) ; snap.valid(); snap.next()) {
-        snap.get()->add();
-    }
-}
-
-void multicast_clear(DL &dl) {
-    DL::Snapshot snap(dl);
-    dl.clear();
-    for (; snap.valid(); snap.next()) {
-        snap.get()->add();
-    }
-}
-
-//-----------------------------------------------------------------------------
-
-enum {
-    CMD_MULTICAST,
-    CMD_MULTICAST_CLEAR,
-    CMD_ADD,
-    CMD_REMOVE,
-    CMD_CLEAR,
-    CMD_WAIT_SNAP,
-    CMD_DO,
-    CMD_DONE,
-    CMD_EXIT
-};
-
-struct Command
-{
-    DL          *dl;
-    int          cmd;
-    int          cnt;
-    Handler *handler;
-    Command(DL *dl_, int cmd_, int cnt_, Handler *handler_) noexcept
-        : dl(dl_), cmd(cmd_), cnt(cnt_), handler(handler_) {}
-    Command(const Command &rhs) noexcept
-        : dl(rhs.dl), cmd(rhs.cmd), cnt(rhs.cnt), handler(rhs.handler) {}
-    Command &operator=(const Command &rhs) noexcept {
-        memcpy(this, &rhs, sizeof(Command));
-        return *this;
-    }
-    bool operator==(const Command &rhs) noexcept {
-        return memcmp(this, &rhs, sizeof(Command)) == 0;
-    }
-};
-
-Command
-cmd_multicast(DL *dl) {
-    return Command(dl, CMD_MULTICAST, 0, 0);
-}
-
-Command
-cmd_multicast_clear(DL *dl) {
-    return Command(dl, CMD_MULTICAST_CLEAR, 0, 0);
-}
-
-Command
-cmd_add(DL *dl, Handler *handler) {
-    return Command(dl, CMD_ADD, 0, handler);
-}
-
-Command
-cmd_remove(DL *dl, Handler *handler) {
-    return Command(dl, CMD_REMOVE, 0, handler);
-}
-
-Command
-cmd_clear(DL *dl) {
-    return Command(dl, CMD_CLEAR, 0, 0);
-}
-
-Command
-cmd_wait_snap(DL *dl) {
-    return Command(dl, CMD_WAIT_SNAP, 0, 0);
-}
-
-Command
-cmd_do(int cnt) {
-    return Command(0, CMD_DO, cnt, 0);
-}
-
-Command
-cmd_done() {
-    return Command(0, CMD_DONE, 0, 0);
-}
-
-Command
-cmd_exit() {
-    return Command(0, CMD_EXIT, 0, 0);
-}
-
-typedef std::vector<Command>    CmdList;
-typedef std::pair<Command, int> HistEntry;
-typedef std::vector<HistEntry>  HistList;
-
-//-----------------------------------------------------------------------------
-
-struct History {
-    Lock         lock;
-    HistList     list;
-    History() : lock(), list() {}
-    void add(const HistEntry &entry) {
-        LockGuard guard(lock);
-        list.push_back(entry);
-    }
-};
-
-//-----------------------------------------------------------------------------
-
-template <typename T>
-class Queue {
-private:
-    std::queue<T> _q;
-    Monitor       _cond;
-    int           _waitCnt;
-    Queue(const Queue &);
-    Queue &operator=(const Queue &);
-public:
-    Queue() : _q(), _cond(), _waitCnt(0) {}
-    void enqueue(const T &entry) {
-        MonitorGuard guard(_cond);
-        _q.push(entry);
-        if (_waitCnt > 0) {
-            guard.signal();
-        }
-    }
-    T dequeue() {
-        MonitorGuard guard(_cond);
-        CounterGuard cntGuard(_waitCnt);
-        while (_q.empty()) {
-            guard.wait();
-        }
-        T tmp = _q.front();
-        _q.pop();
-        return tmp;
-    }
-    size_t size() const { return _q.size(); }
-};
-
-typedef Queue<CmdList> CmdListQueue;
-
-//-----------------------------------------------------------------------------
-
-class Actor : public FastOS_Runnable
-{
-public:
-    enum {
-        STATE_INIT,
-        STATE_IDLE,
-        STATE_BUSY,
-        STATE_DONE
-    };
-private:
-    int           _id;
-    History      *_hist;
-    CmdListQueue  _queue;
-    Monitor       _cond;
-    int           _state;
-    int           _waitCnt;
-    int           _opCnt;
-    bool          _exit;
-    Actor(const Actor &);
-    Actor &operator=(const Actor &);
-    void setState(int state, MonitorGuard &guard);
-    void doneOp(const Command &cmd);
-    int perform(int cnt, int start, const CmdList &cmdList);
-public:
-    Actor(int id, History *hist);
-    ~Actor();
-    int getOpCnt() const { return _opCnt; }
-    int getState() const { return _state; }
-    void doIt(const CmdList &cmdList);
-    void doIt(const Command &cmd);
-    void waitState(int state);
-    void Run(FastOS_ThreadInterface *, void *) override;
-};
-
-Actor::Actor(int id, History *hist)
-    : _id(id), _hist(hist), _queue(), _cond(), _state(STATE_INIT),
-      _waitCnt(0), _opCnt(0), _exit(false)
-{}
-Actor::~Actor() {}
-
-void
-Actor::setState(int state, MonitorGuard &guard) {
-    _state = state;
-    if (_waitCnt > 0) {
-        guard.broadcast();
-    }
-}
-
-
-void
-Actor::doneOp(const Command &cmd)
-{
-    ++_opCnt;
-    if (_hist != 0) {
-        _hist->add(HistEntry(cmd, _id));
-    }
-}
-
-
-int
-Actor::perform(int cnt, int start, const CmdList &cmdList)
-{
-    int doneIdx = cmdList.size();
-    for (int i = 0; i < cnt; ++i) {
-        for (uint32_t idx = start; idx < cmdList.size(); ++idx) {
-            Command cmd = cmdList[idx];
-            switch (cmd.cmd) {
-            case CMD_MULTICAST:
-                multicast(*cmd.dl);
-                doneOp(cmd);
-                break;
-            case CMD_MULTICAST_CLEAR:
-                multicast_clear(*cmd.dl);
-                doneOp(cmd);
-                break;
-            case CMD_ADD:
-                cmd.dl->add(cmd.handler);
-                doneOp(cmd);
-                break;
-            case CMD_REMOVE:
-                cmd.dl->remove(cmd.handler);
-                doneOp(cmd);
-                break;
-            case CMD_CLEAR:
-                cmd.dl->clear();
-                doneOp(cmd);
-                break;
-            case CMD_WAIT_SNAP:
-                cmd.dl->waitSnapshots();
-                doneOp(cmd);
-                break;
-            case CMD_DO:
-                idx = perform(cmd.cnt, idx + 1, cmdList);
-                break;
-            case CMD_DONE:
-                doneIdx = idx;
-                idx = cmdList.size();
-                break;
-            case CMD_EXIT:
-                _exit = true;
-                return cmdList.size();
-                break;
-            default:
-                LOG_ABORT("should not be reached"); // that does not seem to work
-            }
-        }
-    }
-    return doneIdx;
-}
-
-
-void
-Actor::doIt(const CmdList &cmdList)
-{
-    MonitorGuard guard(_cond);
-    setState(STATE_BUSY, guard);
-    _queue.enqueue(cmdList);
-}
-
-
-void
-Actor::doIt(const Command &cmd)
-{
-    CmdList cmdList;
-    cmdList.push_back(cmd);
-    doIt(cmdList);
-}
-
-
-void
-Actor::waitState(int state) {
-    MonitorGuard guard(_cond);
-    CounterGuard cntGuard(_waitCnt);
-    while (_state != state) {
-        guard.wait();
-    }
-}
-
-
-void
-Actor::Run(FastOS_ThreadInterface *, void *)
-{
-    while (!_exit) {
-        {
-            MonitorGuard guard(_cond);
-            if (_queue.size() == 0) {
-                setState(STATE_IDLE, guard);
-            }
-        }
-        CmdList cmdList = _queue.dequeue();
-        perform(1, 0, cmdList);
-    }
-    {
-        MonitorGuard guard(_cond);
-        setState(STATE_DONE, guard);
-    }
-}
-
-} // namespace <unnamed>
-
-//-----------------------------------------------------------------------------
-
-void
-Test::testEmpty()
-{
-    DL multicaster;
-    multicast(multicaster);
-    multicast_clear(multicaster);
-    DL::Snapshot empty_snap(multicaster);
-    EXPECT_TRUE(!empty_snap.valid());
-}
-
-
-void
-Test::testAdd()
-{
-    DL multicaster;
-    Handler h1;
-    Handler h2;
-    Handler h3;
-    Handler h4;
-    Handler h5;
-
-    // ensure correct initial state
-    EXPECT_TRUE(h1.getNum() == 0);
-    EXPECT_TRUE(h2.getNum() == 0);
-    EXPECT_TRUE(h3.getNum() == 0);
-    EXPECT_TRUE(h4.getNum() == 0);
-    EXPECT_TRUE(h5.getNum() == 0);
-
-    // test basic adding
-    multicaster.add(&h1);
-    multicast(multicaster);
-    multicaster.add(&h2);
-    multicast(multicaster);
-    multicaster.add(&h3);
-    multicast(multicaster);
-    multicaster.add(&h4);
-    multicast(multicaster);
-    multicaster.add(&h5);
-    multicast(multicaster);
-    EXPECT_TRUE(h1.getNum() == 5);
-    EXPECT_TRUE(h2.getNum() == 4);
-    EXPECT_TRUE(h3.getNum() == 3);
-    EXPECT_TRUE(h4.getNum() == 2);
-    EXPECT_TRUE(h5.getNum() == 1);
-
-    // duplicate adds
-    multicaster.add(&h1);
-    multicaster.add(&h1);
-    multicaster.add(&h1);
-    multicast(multicaster);
-    EXPECT_TRUE(h1.getNum() == 6);
-    EXPECT_TRUE(h2.getNum() == 5);
-    EXPECT_TRUE(h3.getNum() == 4);
-    EXPECT_TRUE(h4.getNum() == 3);
-    EXPECT_TRUE(h5.getNum() == 2);
-}
-
-
-void
-Test::testRemove()
-{
-    DL multicaster;
-    Handler h1;
-    Handler h2;
-    Handler h3;
-    Handler h4;
-    Handler h5;
-
-    multicaster.add(&h1).add(&h2).add(&h3).add(&h4).add(&h5);
-    multicast(multicaster);
-    EXPECT_TRUE(h1.getNum() == 1);
-    EXPECT_TRUE(h2.getNum() == 1);
-    EXPECT_TRUE(h3.getNum() == 1);
-    EXPECT_TRUE(h4.getNum() == 1);
-    EXPECT_TRUE(h5.getNum() == 1);
-
-    // remove middle
-    multicaster.remove(&h3);
-    multicast(multicaster);
-    EXPECT_TRUE(h1.getNum() == 2);
-    EXPECT_TRUE(h2.getNum() == 2);
-    EXPECT_TRUE(h3.getNum() == 1);
-    EXPECT_TRUE(h4.getNum() == 2);
-    EXPECT_TRUE(h5.getNum() == 2);
-
-    // remove head
-    multicaster.remove(&h1);
-    multicast(multicaster);
-    EXPECT_TRUE(h1.getNum() == 2);
-    EXPECT_TRUE(h2.getNum() == 3);
-    EXPECT_TRUE(h3.getNum() == 1);
-    EXPECT_TRUE(h4.getNum() == 3);
-    EXPECT_TRUE(h5.getNum() == 3);
-
-    // remove tail
-    multicaster.remove(&h5);
-    multicast(multicaster);
-    EXPECT_TRUE(h1.getNum() == 2);
-    EXPECT_TRUE(h2.getNum() == 4);
-    EXPECT_TRUE(h3.getNum() == 1);
-    EXPECT_TRUE(h4.getNum() == 4);
-    EXPECT_TRUE(h5.getNum() == 3);
-
-    // duplicate removes
-    multicaster.remove(&h1).remove(&h3).remove(&h5);
-    multicast(multicaster);
-    EXPECT_TRUE(h1.getNum() == 2);
-    EXPECT_TRUE(h2.getNum() == 5);
-    EXPECT_TRUE(h3.getNum() == 1);
-    EXPECT_TRUE(h4.getNum() == 5);
-    EXPECT_TRUE(h5.getNum() == 3);
-
-    // remove all
-    multicaster.clear();
-    multicast(multicaster);
-    EXPECT_TRUE(h1.getNum() == 2);
-    EXPECT_TRUE(h2.getNum() == 5);
-    EXPECT_TRUE(h3.getNum() == 1);
-    EXPECT_TRUE(h4.getNum() == 5);
-    EXPECT_TRUE(h5.getNum() == 3);
-}
-
-
-void
-Test::testOneShot()
-{
-    DL multicaster;
-    Handler h1;
-    Handler h2;
-    Handler h3;
-    Handler h4;
-    Handler h5;
-
-    // oneshot multicast removes handlers
-    multicaster.add(&h1).add(&h2).add(&h3).add(&h4).add(&h5);
-    multicast_clear(multicaster);
-    multicast(multicaster);
-    EXPECT_TRUE(h1.getNum() == 1);
-    EXPECT_TRUE(h2.getNum() == 1);
-    EXPECT_TRUE(h3.getNum() == 1);
-    EXPECT_TRUE(h4.getNum() == 1);
-    EXPECT_TRUE(h5.getNum() == 1);
-}
-
-
-void
-Test::testMultiSnapshot()
-{
-    DL multicaster;
-    Handler h1;
-    Handler h2;
-    Handler h3;
-    Handler h4;
-    Handler h5;
-
-    DL::Snapshot empty_snap(multicaster);
-    multicaster.add(&h1).add(&h2).add(&h3).add(&h4).add(&h5);
-    DL::Snapshot snap1(multicaster);
-    multicaster.remove(&h3);
-    DL::Snapshot snap2(multicaster);
-    multicaster.remove(&h1);
-    DL::Snapshot snap3(multicaster);
-    multicaster.remove(&h5);
-    DL::Snapshot snap4(multicaster);
-
-    EXPECT_TRUE(!empty_snap.valid());
-    for (; snap1.valid(); snap1.next()) {
-        snap1.get()->add();
-    }
-    EXPECT_TRUE(h1.getNum() == 1);
-    EXPECT_TRUE(h2.getNum() == 1);
-    EXPECT_TRUE(h3.getNum() == 1);
-    EXPECT_TRUE(h4.getNum() == 1);
-    EXPECT_TRUE(h5.getNum() == 1);
-    for (; snap2.valid(); snap2.next()) {
-        snap2.get()->add();
-    }
-    EXPECT_TRUE(h1.getNum() == 2);
-    EXPECT_TRUE(h2.getNum() == 2);
-    EXPECT_TRUE(h3.getNum() == 1);
-    EXPECT_TRUE(h4.getNum() == 2);
-    EXPECT_TRUE(h5.getNum() == 2);
-    for (; snap3.valid(); snap3.next()) {
-        snap3.get()->add();
-    }
-    EXPECT_TRUE(h1.getNum() == 2);
-    EXPECT_TRUE(h2.getNum() == 3);
-    EXPECT_TRUE(h3.getNum() == 1);
-    EXPECT_TRUE(h4.getNum() == 3);
-    EXPECT_TRUE(h5.getNum() == 3);
-    for (; snap4.valid(); snap4.next()) {
-        snap4.get()->add();
-    }
-    EXPECT_TRUE(h1.getNum() == 2);
-    EXPECT_TRUE(h2.getNum() == 4);
-    EXPECT_TRUE(h3.getNum() == 1);
-    EXPECT_TRUE(h4.getNum() == 4);
-    EXPECT_TRUE(h5.getNum() == 3);
-}
-
-
-void
-Test::testActors()
-{
-    FastOS_ThreadPool pool(65000);
-    History           hist;
-    Actor             a1(1, &hist);
-    Actor             a2(2, &hist);
-    DL                dl;
-    Handler           h1;
-    Handler           h2;
-
-    ASSERT_TRUE(pool.NewThread(&a1, 0) != 0);
-    ASSERT_TRUE(pool.NewThread(&a2, 0) != 0);
-
-    {
-        CmdList prog;
-        prog.push_back(cmd_add(&dl, &h1));
-        prog.push_back(cmd_multicast(&dl));
-        prog.push_back(cmd_add(&dl, &h2));
-        prog.push_back(cmd_multicast(&dl));
-        a1.doIt(prog);
-        a1.waitState(Actor::STATE_IDLE);
-    }
-
-    EXPECT_TRUE(h1.getNum() == 2);
-    EXPECT_TRUE(h2.getNum() == 1);
-
-    {
-        CmdList prog;
-        prog.push_back(cmd_remove(&dl, &h1));
-        prog.push_back(cmd_multicast(&dl));
-        prog.push_back(cmd_clear(&dl));
-        prog.push_back(cmd_multicast(&dl));
-        a2.doIt(prog);
-        a2.waitState(Actor::STATE_IDLE);
-    }
-
-    EXPECT_TRUE(h1.getNum() == 2);
-    EXPECT_TRUE(h2.getNum() == 2);
-
-    {
-        CmdList prog;
-        prog.push_back(cmd_add(&dl, &h1));
-        prog.push_back(cmd_add(&dl, &h2));
-        prog.push_back(cmd_multicast_clear(&dl));
-        prog.push_back(cmd_multicast(&dl));
-        a1.doIt(prog);
-        a1.waitState(Actor::STATE_IDLE);
-    }
-
-    EXPECT_TRUE(h1.getNum() == 3);
-    EXPECT_TRUE(h2.getNum() == 3);
-
-    {
-        CmdList prog;
-        prog.push_back(cmd_add(&dl, &h1));
-        prog.push_back(cmd_add(&dl, &h2));
-        prog.push_back(cmd_do(10));
-        prog.push_back(cmd_do(10));
-        prog.push_back(cmd_multicast(&dl));
-        prog.push_back(cmd_done());
-        prog.push_back(cmd_done());
-        prog.push_back(cmd_exit());
-        a2.doIt(prog);
-        a2.waitState(Actor::STATE_DONE);
-    }
-
-    EXPECT_TRUE(h1.getNum() == 103);
-    EXPECT_TRUE(h2.getNum() == 103);
-
-    EXPECT_TRUE(hist.list.size() == 114);
-
-    EXPECT_TRUE(hist.list[0].first == cmd_add(&dl, &h1));
-    EXPECT_TRUE(hist.list[1].first == cmd_multicast(&dl));
-    EXPECT_TRUE(hist.list[2].first == cmd_add(&dl, &h2));
-    EXPECT_TRUE(hist.list[3].first == cmd_multicast(&dl));
-    for (int i = 0; i < 4; i++) {
-        EXPECT_TRUE(hist.list[i].second == 1);
-    }
-
-    EXPECT_TRUE(hist.list[4].first == cmd_remove(&dl, &h1));
-    EXPECT_TRUE(hist.list[5].first == cmd_multicast(&dl));
-    EXPECT_TRUE(hist.list[6].first == cmd_clear(&dl));
-    EXPECT_TRUE(hist.list[7].first == cmd_multicast(&dl));
-    for (int i = 4; i < 8; i++) {
-        EXPECT_TRUE(hist.list[i].second == 2);
-    }
-
-    EXPECT_TRUE(hist.list[8].first == cmd_add(&dl, &h1));
-    EXPECT_TRUE(hist.list[9].first == cmd_add(&dl, &h2));
-    EXPECT_TRUE(hist.list[10].first == cmd_multicast_clear(&dl));
-    EXPECT_TRUE(hist.list[11].first == cmd_multicast(&dl));
-    for (int i = 8; i < 12; i++) {
-        EXPECT_TRUE(hist.list[i].second == 1);
-    }
-
-    EXPECT_TRUE(hist.list[12].first == cmd_add(&dl, &h1));
-    EXPECT_TRUE(hist.list[13].first == cmd_add(&dl, &h2));
-    EXPECT_TRUE(hist.list[12].second == 2);
-    EXPECT_TRUE(hist.list[13].second == 2);
-
-    for (int i = 14; i < 114; i++) {
-        EXPECT_TRUE(hist.list[i].first == cmd_multicast(&dl));
-        EXPECT_TRUE(hist.list[i].second == 2);
-    }
-
-    a1.doIt(cmd_exit());
-    a1.waitState(Actor::STATE_DONE);
-
-    EXPECT_TRUE(a1.getOpCnt() == 8);
-    EXPECT_TRUE(a2.getOpCnt() == 106);
-}
-
-
-void
-Test::stressTest()
-{
-    FastOS_ThreadPool pool(65000);
-    Actor             a1(1, 0);
-    Actor             a2(2, 0);
-    Actor             a3(3, 0);
-    Actor             a4(4, 0);
-    Actor             a5(5, 0);
-    Actor             a6(6, 0);
-    DL                dl;
-    Handler           h1;
-    Handler           h2;
-    Handler           h3;
-    Handler           h4;
-    Handler           h5;
-    int               scale = 10000;
-
-    ASSERT_TRUE(pool.NewThread(&a1, 0) != 0);
-    ASSERT_TRUE(pool.NewThread(&a2, 0) != 0);
-    ASSERT_TRUE(pool.NewThread(&a3, 0) != 0);
-    ASSERT_TRUE(pool.NewThread(&a4, 0) != 0);
-    ASSERT_TRUE(pool.NewThread(&a5, 0) != 0);
-    ASSERT_TRUE(pool.NewThread(&a6, 0) != 0);
-
-    CmdList prog_multicast;
-    prog_multicast.push_back(cmd_do(10 * scale));
-    prog_multicast.push_back(cmd_multicast(&dl));
-    prog_multicast.push_back(cmd_done());
-    prog_multicast.push_back(cmd_exit());
-
-    CmdList prog_wait_snap;
-    prog_wait_snap.push_back(cmd_do(10 * scale));
-    prog_wait_snap.push_back(cmd_wait_snap(&dl));
-    prog_wait_snap.push_back(cmd_done());
-    prog_wait_snap.push_back(cmd_exit());
-
-    CmdList prog_add_remove_1;
-    prog_add_remove_1.push_back(cmd_do(scale));
-    prog_add_remove_1.push_back(cmd_add(&dl, &h1));
-    prog_add_remove_1.push_back(cmd_add(&dl, &h3));
-    prog_add_remove_1.push_back(cmd_remove(&dl, &h2));
-    prog_add_remove_1.push_back(cmd_remove(&dl, &h4));
-    prog_add_remove_1.push_back(cmd_add(&dl, &h4));
-    prog_add_remove_1.push_back(cmd_add(&dl, &h2));
-    prog_add_remove_1.push_back(cmd_remove(&dl, &h5));
-    prog_add_remove_1.push_back(cmd_remove(&dl, &h3));
-    prog_add_remove_1.push_back(cmd_add(&dl, &h5));
-    prog_add_remove_1.push_back(cmd_remove(&dl, &h1));
-    prog_add_remove_1.push_back(cmd_done());
-    prog_add_remove_1.push_back(cmd_exit());
-
-    CmdList prog_add_remove_2;
-    prog_add_remove_2.push_back(cmd_do(scale));
-    prog_add_remove_2.push_back(cmd_add(&dl, &h5));
-    prog_add_remove_2.push_back(cmd_add(&dl, &h4));
-    prog_add_remove_2.push_back(cmd_remove(&dl, &h1));
-    prog_add_remove_2.push_back(cmd_remove(&dl, &h3));
-    prog_add_remove_2.push_back(cmd_add(&dl, &h1));
-    prog_add_remove_2.push_back(cmd_remove(&dl, &h2));
-    prog_add_remove_2.push_back(cmd_add(&dl, &h2));
-    prog_add_remove_2.push_back(cmd_add(&dl, &h3));
-    prog_add_remove_2.push_back(cmd_remove(&dl, &h5));
-    prog_add_remove_2.push_back(cmd_remove(&dl, &h4));
-    prog_add_remove_2.push_back(cmd_done());
-    prog_add_remove_2.push_back(cmd_exit());
-
-    CmdList prog_add_remove_3;
-    prog_add_remove_3.push_back(cmd_do(scale));
-    prog_add_remove_3.push_back(cmd_add(&dl, &h3));
-    prog_add_remove_3.push_back(cmd_remove(&dl, &h4));
-    prog_add_remove_3.push_back(cmd_remove(&dl, &h3));
-    prog_add_remove_3.push_back(cmd_add(&dl, &h5));
-    prog_add_remove_3.push_back(cmd_add(&dl, &h2));
-    prog_add_remove_3.push_back(cmd_remove(&dl, &h2));
-    prog_add_remove_3.push_back(cmd_add(&dl, &h1));
-    prog_add_remove_3.push_back(cmd_add(&dl, &h4));
-    prog_add_remove_3.push_back(cmd_remove(&dl, &h1));
-    prog_add_remove_3.push_back(cmd_remove(&dl, &h5));
-    prog_add_remove_3.push_back(cmd_done());
-    prog_add_remove_3.push_back(cmd_exit());
-
-    a1.doIt(prog_multicast);
-    a2.doIt(prog_multicast);
-    a3.doIt(prog_wait_snap);
-    a4.doIt(prog_add_remove_1);
-    a5.doIt(prog_add_remove_2);
-    a6.doIt(prog_add_remove_3);
-
-    a1.waitState(Actor::STATE_DONE);
-    a2.waitState(Actor::STATE_DONE);
-    a3.waitState(Actor::STATE_DONE);
-    a4.waitState(Actor::STATE_DONE);
-    a5.waitState(Actor::STATE_DONE);
-    a6.waitState(Actor::STATE_DONE);
-
-    EXPECT_TRUE(a1.getOpCnt() == 10 * scale);
-    EXPECT_TRUE(a2.getOpCnt() == 10 * scale);
-    EXPECT_TRUE(a3.getOpCnt() == 10 * scale);
-    EXPECT_TRUE(a4.getOpCnt() == 10 * scale);
-    EXPECT_TRUE(a5.getOpCnt() == 10 * scale);
-    EXPECT_TRUE(a6.getOpCnt() == 10 * scale);
-}
-
-
-void
-Test::testWaitSnapshots()
-{
-    FastOS_ThreadPool pool(65000);
-    Actor             a1(1, 0);
-    DL                dl;
-    std::unique_ptr<DL::Snapshot> s1;
-    std::unique_ptr<DL::Snapshot> s2;
-    ASSERT_TRUE(pool.NewThread(&a1, 0) != 0);
-    s1.reset(new DL::Snapshot(dl));                 // create snap 1
-    a1.doIt(cmd_wait_snap(&dl));                    // wait for snaps
-    std::this_thread::sleep_for(1s);
-    EXPECT_TRUE(a1.getState() == Actor::STATE_BUSY); // still waiting...
-    s2.reset(new DL::Snapshot(dl));                 // create snap 2
-    s1.reset();                                     // destroy snap 1
-    std::this_thread::sleep_for(1s);
-    EXPECT_TRUE(a1.getState() == Actor::STATE_IDLE); // wait done!
-    a1.doIt(cmd_exit());
-    a1.waitState(Actor::STATE_DONE);
-    s2.reset();                                     // destroy snap 2
-    EXPECT_TRUE(a1.getOpCnt() == 1);
-}
-
-//-----------------------------------------------------------------------------
-
-struct Foo { void completeBarrier() {} };
-
-int
-Test::Main()
-{
-    TEST_INIT("delegatelist_test");
-    LOG(info, "Lock         size: %4zu bytes", sizeof(Lock));
-    LOG(info, "ArrayQueue   size: %4zu bytes", sizeof(ArrayQueue<Foo>));
-    LOG(info, "std::vector  size: %4zu bytes", sizeof(std::vector<Foo>));
-    LOG(info, "EventBarrier size: %4zu bytes", sizeof(EventBarrier<Foo>));
-    LOG(info, "DelegateList size: %4zu bytes", sizeof(DelegateList<Foo>));
-
-    testEmpty();
-    testAdd();
-    testRemove();
-    testOneShot();
-    testMultiSnapshot();
-
-    TEST_FLUSH();
-    testActors();
-    testWaitSnapshots();
-
-    TEST_FLUSH();
-    stressTest();
-    TEST_DONE();
-}
-
-TEST_APPHOOK(Test);
diff --git a/vespalib/src/tests/rwlock/.gitignore b/vespalib/src/tests/rwlock/.gitignore
deleted file mode 100644
index 3ba74c11b14..00000000000
--- a/vespalib/src/tests/rwlock/.gitignore
+++ /dev/null
@@ -1,4 +0,0 @@
-.depend
-Makefile
-rwlock_test
-vespalib_rwlock_test_app
diff --git a/vespalib/src/tests/rwlock/CMakeLists.txt b/vespalib/src/tests/rwlock/CMakeLists.txt
deleted file mode 100644
index 2eda95a200c..00000000000
--- a/vespalib/src/tests/rwlock/CMakeLists.txt
+++ /dev/null
@@ -1,8 +0,0 @@
-# Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-vespa_add_executable(vespalib_rwlock_test_app TEST
-    SOURCES
-    rwlock_test.cpp
-    DEPENDS
-    vespalib
-)
-vespa_add_test(NAME vespalib_rwlock_test_app COMMAND vespalib_rwlock_test_app)
diff --git a/vespalib/src/tests/rwlock/rwlock_test.cpp b/vespalib/src/tests/rwlock/rwlock_test.cpp
deleted file mode 100644
index 66e73c3a5d9..00000000000
--- a/vespalib/src/tests/rwlock/rwlock_test.cpp
+++ /dev/null
@@ -1,78 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-
-#include <vespa/vespalib/testkit/testapp.h>
-#include <vespa/vespalib/util/rwlock.h>
-
-using namespace vespalib;
-
-class RWLockTest : public TestApp
-{
-public:
-    int Main() override;
-    static RWLockReader rbvReader(RWLock & lock) { RWLockReader r(lock); return r; }
-    static RWLockWriter rbvWriter(RWLock & lock) { RWLockWriter r(lock); return r; }
-};
-
-
-int
-RWLockTest::Main()
-{
-    TEST_INIT("rwlock_test");
-
-    RWLock lock;
-    EXPECT_TRUE(lock._givenLocks == 0);
-    {
-        EXPECT_TRUE(lock._givenLocks == 0);
-        RWLockReader r1(lock);
-        EXPECT_TRUE(lock._givenLocks == 1);
-        RWLockReader r2(lock);
-        EXPECT_TRUE(lock._givenLocks == 2);
-        RWLockReader r3(lock);
-        EXPECT_TRUE(lock._givenLocks == 3);
-    }
-    EXPECT_TRUE(lock._givenLocks == 0);
-    {
-        EXPECT_TRUE(lock._givenLocks == 0);
-        RWLockWriter w(lock);
-        EXPECT_TRUE(lock._givenLocks == -1);
-    }
-    EXPECT_TRUE(lock._givenLocks == 0);
-    {
-        RWLockReader rbv(rbvReader(lock));
-        EXPECT_TRUE(lock._givenLocks == 1);
-        RWLockReader copy(rbv);
-        EXPECT_TRUE(lock._givenLocks == 1);
-        RWLockReader copy2(copy);
-        EXPECT_TRUE(lock._givenLocks == 1);
-    }
-    EXPECT_TRUE(lock._givenLocks == 0);
-    {
-        RWLock lock2;
-        RWLockReader copy(rbvReader(lock));
-        EXPECT_TRUE(lock._givenLocks == 1);
-        RWLockReader copy2(rbvReader(lock2));
-        EXPECT_TRUE(lock._givenLocks == 1);
-        EXPECT_TRUE(lock2._givenLocks == 1);
-        RWLockReader rbv(rbvReader(lock));
-        EXPECT_TRUE(lock._givenLocks == 2);
-        copy=rbv;
-        EXPECT_TRUE(lock._givenLocks == 1);
-        copy2=copy;
-        EXPECT_TRUE(lock2._givenLocks == 0);
-        EXPECT_TRUE(lock._givenLocks == 1);
-    }
-    EXPECT_TRUE(lock._givenLocks == 0);
-    {
-        RWLockWriter rbv(rbvWriter(lock));
-        EXPECT_TRUE(lock._givenLocks == -1);
-        RWLockWriter copy(rbv);
-        EXPECT_TRUE(lock._givenLocks == -1);
-        RWLockWriter copy2(copy);
-        EXPECT_TRUE(lock._givenLocks == -1);
-    }
-    EXPECT_TRUE(lock._givenLocks == 0);
-
-    TEST_DONE();
-}
-
-TEST_APPHOOK(RWLockTest)
diff --git a/vespalib/src/tests/sync/sync_test.cpp b/vespalib/src/tests/sync/sync_test.cpp
index c8888bc8e54..0925ce060a0 100644
--- a/vespalib/src/tests/sync/sync_test.cpp
+++ b/vespalib/src/tests/sync/sync_test.cpp
@@ -3,6 +3,44 @@
 #include <vespa/vespalib/testkit/testapp.h>
 #include <vespa/vespalib/util/sync.h>
 
+namespace vespalib {
+class TryLock
+{
+private:
+    friend class LockGuard;
+    friend class MonitorGuard;
+
+    std::unique_lock<std::mutex> _guard;
+    std::condition_variable     *_cond;
+
+public:
+    TryLock(const Lock &lock)
+        : _guard(*lock._mutex, std::try_to_lock), _cond(nullptr)
+    {}
+    TryLock(const Monitor &mon)
+        : _guard(*mon._mutex, std::try_to_lock),
+          _cond(_guard ? mon._cond.get() : nullptr)
+    {}
+    ~TryLock() = default;
+
+    TryLock(const TryLock &) = delete;
+    TryLock &operator=(const TryLock &) = delete;
+
+    /**
+     * @brief Check whether this object holds a lock
+     *
+     * @return true if this object holds a lock
+     **/
+    bool hasLock() const { return static_cast<bool>(_guard); }
+    void unlock() {
+        if (_guard) {
+            _guard.unlock();
+            _cond = nullptr;
+        }
+    }
+};
+
+}
 using namespace vespalib;
 
 #define CHECK_LOCKED(m) { TryLock tl(m); EXPECT_TRUE(!tl.hasLock()); }
@@ -18,7 +56,7 @@ private:
     LockGuard    lockMonitor()   { return LockGuard(_monitor); }
     MonitorGuard obtainMonitor() { return MonitorGuard(_monitor); }
 public:
-    ~Test();
+    ~Test() override;
     void testCountDownLatch();
     int Main() override;
 };
@@ -139,97 +177,6 @@ Test::Main()
         MonitorGuard guard(monitor);
         CHECK_LOCKED(monitor);
     }
-    // TryLock hands the lock over to a LockGuard/MonitorGuard
-    {
-        Lock    lock;
-        CHECK_UNLOCKED(lock);
-        TryLock a(lock);
-        CHECK_LOCKED(lock);
-        if (a.hasLock()) {
-            LockGuard guard(std::move(a));
-            CHECK_LOCKED(lock);
-        }
-        CHECK_UNLOCKED(lock);
-    }
-    {
-        Monitor mon;
-        CHECK_UNLOCKED(mon);
-        TryLock a(mon);
-        CHECK_LOCKED(mon);
-        if (a.hasLock()) {
-            LockGuard guard(std::move(a));
-            CHECK_LOCKED(mon);
-        }
-        CHECK_UNLOCKED(mon);
-    }
-    {
-        Monitor mon;
-        CHECK_UNLOCKED(mon);
-        TryLock a(mon);
-        CHECK_LOCKED(mon);
-        if (a.hasLock()) {
-            MonitorGuard guard(std::move(a));
-            CHECK_LOCKED(mon);
-        }
-        CHECK_UNLOCKED(mon);
-    }
-    {
-        Lock lock;
-
-        CHECK_UNLOCKED(lock);
-        TryLock a(lock);
-        CHECK_LOCKED(lock);
-        TryLock b(lock);
-        CHECK_LOCKED(lock);
-
-        EXPECT_TRUE(a.hasLock());
-        EXPECT_TRUE(!b.hasLock());
-        {
-            CHECK_LOCKED(lock);
-            EXPECT_TRUE(a.hasLock());
-            LockGuard guard(std::move(a));
-            EXPECT_TRUE(!a.hasLock());
-            CHECK_LOCKED(lock);
-        }
-        CHECK_UNLOCKED(lock);
-    }
-    // TryLock will unlock when exiting scope if lock was not passed on
-    {
-        Lock    lock;
-        Monitor mon;
-        CHECK_UNLOCKED(lock);
-        CHECK_UNLOCKED(mon);
-        {
-            TryLock a(lock);
-            EXPECT_TRUE(a.hasLock());
-            TryLock b(mon);
-            EXPECT_TRUE(b.hasLock());
-            CHECK_LOCKED(lock);
-            CHECK_LOCKED(mon);
-        }
-        CHECK_UNLOCKED(lock);
-        CHECK_UNLOCKED(mon);
-    }
-    // TryLock explicitt unlock of lock
-    {
-        Lock    lock;
-        TryLock tl(lock);
-        EXPECT_TRUE(tl.hasLock());
-        tl.unlock();
-        EXPECT_FALSE(tl.hasLock());
-        tl.unlock();
-        EXPECT_FALSE(tl.hasLock());
-    }
-    // TryLock explicitt unlock of monitor
-    {
-        Monitor    lock;
-        TryLock tl(lock);
-        EXPECT_TRUE(tl.hasLock());
-        tl.unlock();
-        EXPECT_FALSE(tl.hasLock());
-        tl.unlock();
-        EXPECT_FALSE(tl.hasLock());
-    }
     // LockGuard/MonitorGuard have destructive move
     {
         Lock lock;
diff --git a/vespalib/src/vespa/vespalib/data/memorydatastore.cpp b/vespalib/src/vespa/vespalib/data/memorydatastore.cpp
index df1b68cff12..1f8c72a5a64 100644
--- a/vespalib/src/vespa/vespalib/data/memorydatastore.cpp
+++ b/vespalib/src/vespa/vespalib/data/memorydatastore.cpp
@@ -5,8 +5,9 @@
 namespace vespalib {
 
 using alloc::Alloc;
+using LockGuard = std::lock_guard<std::mutex>;
 
-MemoryDataStore::MemoryDataStore(Alloc && initialAlloc, Lock * lock) :
+MemoryDataStore::MemoryDataStore(Alloc && initialAlloc, std::mutex * lock) :
     _buffers(),
     _writePos(0),
     _lock(lock)
diff --git a/vespalib/src/vespa/vespalib/data/memorydatastore.h b/vespalib/src/vespa/vespalib/data/memorydatastore.h
index 2d02bfb107c..fa6113279da 100644
--- a/vespalib/src/vespa/vespalib/data/memorydatastore.h
+++ b/vespalib/src/vespa/vespalib/data/memorydatastore.h
@@ -3,8 +3,8 @@
 
 #include <vespa/vespalib/util/alloc.h>
 #include <vespa/vespalib/util/array.h>
-#include <vespa/vespalib/util/sync.h>
 #include <vector>
+#include <mutex>
 
 namespace vespalib {
 
@@ -24,7 +24,7 @@ public:
     private:
         void   * _data;
     };
-    MemoryDataStore(alloc::Alloc && initialAlloc=alloc::Alloc::alloc(256), Lock * lock=nullptr);
+    MemoryDataStore(alloc::Alloc && initialAlloc=alloc::Alloc::alloc(256), std::mutex * lock=nullptr);
     MemoryDataStore(const MemoryDataStore &) = delete;
     MemoryDataStore & operator = (const MemoryDataStore &) = delete;
     ~MemoryDataStore();
@@ -41,7 +41,7 @@ public:
 private:
     std::vector<alloc::Alloc> _buffers;
     size_t _writePos;
-    Lock * _lock;
+    std::mutex * _lock;
 };
 
 class VariableSizeVector
diff --git a/vespalib/src/vespa/vespalib/testkit/test_master.cpp b/vespalib/src/vespa/vespalib/testkit/test_master.cpp
index 4b673d0ee0d..60e51ac3a91 100644
--- a/vespalib/src/vespa/vespalib/testkit/test_master.cpp
+++ b/vespalib/src/vespa/vespalib/testkit/test_master.cpp
@@ -37,7 +37,7 @@ __thread TestMaster::ThreadState *TestMaster::_threadState = 0;
 TestMaster::TraceItem::~TraceItem() = default;
 
 TestMaster::ThreadState &
-TestMaster::threadState(const vespalib::LockGuard &)
+TestMaster::threadState(const lock_guard &)
 {
     if (_threadState == 0) {
         std::ostringstream threadName;
@@ -55,7 +55,7 @@ TestMaster::threadState()
         return *_threadState;
     }
     {
-        vespalib::LockGuard guard(_lock);
+        lock_guard guard(_lock);
         return threadState(guard);
     }
 }
@@ -63,7 +63,7 @@ TestMaster::threadState()
 //-----------------------------------------------------------------------------
 
 void
-TestMaster::checkFailed(const vespalib::LockGuard &guard,
+TestMaster::checkFailed(const lock_guard &guard,
                         const char *file, uint32_t line, const char *str)
 {
     ThreadState &thread = threadState(guard);
@@ -81,7 +81,7 @@ TestMaster::checkFailed(const vespalib::LockGuard &guard,
 }
 
 void
-TestMaster::printDiff(const vespalib::LockGuard &guard,
+TestMaster::printDiff(const lock_guard &guard,
                       const std::string &text, const std::string &file, uint32_t line,
                       const std::string &lhs, const std::string &rhs)
 {
@@ -106,7 +106,7 @@ TestMaster::printDiff(const vespalib::LockGuard &guard,
 }
 
 void
-TestMaster::handleFailure(const vespalib::LockGuard &guard, bool fatal)
+TestMaster::handleFailure(const lock_guard &guard, bool fatal)
 {
     ThreadState &thread = threadState(guard);
     if (fatal) {
@@ -120,7 +120,7 @@ TestMaster::handleFailure(const vespalib::LockGuard &guard, bool fatal)
 }
 
 void
-TestMaster::closeDebugFiles(const vespalib::LockGuard &)
+TestMaster::closeDebugFiles(const lock_guard &)
 {
     if (_state.lhsFile != NULL) {
         fclose(_state.lhsFile);
@@ -133,7 +133,7 @@ TestMaster::closeDebugFiles(const vespalib::LockGuard &)
 }
 
 void
-TestMaster::importThreads(const vespalib::LockGuard &)
+TestMaster::importThreads(const lock_guard &)
 {
     size_t importCnt = 0;
     for (size_t i = 0; i < _threadStorage.size(); ++i) {
@@ -149,7 +149,7 @@ TestMaster::importThreads(const vespalib::LockGuard &)
 }
 
 bool
-TestMaster::reportConclusion(const vespalib::LockGuard &)
+TestMaster::reportConclusion(const lock_guard &)
 {
     bool ok = (_state.failCnt == 0);
     fprintf(stderr, "%s: info:  summary --- %zu check(s) passed --- %zu check(s) failed\n",
@@ -175,7 +175,7 @@ TestMaster::TestMaster()
 void
 TestMaster::init(const char *name)
 {
-    vespalib::LockGuard guard(_lock);
+    lock_guard guard(_lock);
     _name = skip_path(name);
     fprintf(stderr, "%s: info:  running test suite '%s'\n", _name.c_str(), _name.c_str());
 }
@@ -183,7 +183,7 @@ TestMaster::init(const char *name)
 std::string
 TestMaster::getName()
 {
-    vespalib::LockGuard guard(_lock);
+    lock_guard guard(_lock);
     return _name;
 }
 
@@ -226,7 +226,7 @@ TestMaster::setThreadIgnore(bool ignore)
         size_t revertCnt = (thread.failCnt - thread.preIgnoreFailCnt);
         thread.failCnt = thread.preIgnoreFailCnt;
         if (revertCnt > 0) {
-            vespalib::LockGuard guard(_lock);
+            lock_guard guard(_lock);
             assert(_state.failCnt >= revertCnt);
             _state.failCnt -= revertCnt;
         }
@@ -272,7 +272,7 @@ TestMaster::getThreadFailCnt()
 TestMaster::Progress
 TestMaster::getProgress()
 {
-    vespalib::LockGuard guard(_lock);
+    lock_guard guard(_lock);
     return Progress(_state.passCnt, _state.failCnt);
 }
 
@@ -280,7 +280,7 @@ void
 TestMaster::openDebugFiles(const std::string &lhsFile,
                            const std::string &rhsFile)
 {
-    vespalib::LockGuard guard(_lock);
+    lock_guard guard(_lock);
     closeDebugFiles(guard);
     _state.lhsFile = fopen(lhsFile.c_str(), "w");
     _state.rhsFile = fopen(rhsFile.c_str(), "w");
@@ -318,7 +318,7 @@ TestMaster::check(bool rc, const char *file, uint32_t line,
         return true;
     }
     {
-        vespalib::LockGuard guard(_lock);
+        lock_guard guard(_lock);
         checkFailed(guard, file, line, str);
         handleFailure(guard, fatal);
     }
@@ -330,7 +330,7 @@ TestMaster::flush(const char *file, uint32_t line)
 {
     ThreadState &thread = threadState();
     if (thread.passCnt > 0) {
-        vespalib::LockGuard guard(_lock);
+        lock_guard guard(_lock);
         _state.passCnt += thread.passCnt;
         fprintf(stderr, "%s: info:  flushed %zu passed check(s) from thread '%s' (%s:%d)\n",
                 _name.c_str(), thread.passCnt, thread.name.c_str(), skip_path(file), line);
@@ -349,7 +349,7 @@ TestMaster::trace(const char *file, uint32_t line)
 bool
 TestMaster::discardFailedChecks(size_t failCnt)
 {
-    vespalib::LockGuard guard(_lock);
+    lock_guard guard(_lock);
     ThreadState &thread = threadState(guard);
     if (failCnt == _state.failCnt) {
         fprintf(stderr, "%s: info:  discarding %zu failed check(s)\n", _name.c_str(), _state.failCnt);
@@ -367,7 +367,7 @@ TestMaster::discardFailedChecks(size_t failCnt)
 bool
 TestMaster::fini()
 {
-    vespalib::LockGuard guard(_lock);
+    lock_guard guard(_lock);
     closeDebugFiles(guard);
     importThreads(guard);
     return reportConclusion(guard);
diff --git a/vespalib/src/vespa/vespalib/testkit/test_master.h b/vespalib/src/vespa/vespalib/testkit/test_master.h
index a9dc5ebb3a2..c20982b994d 100644
--- a/vespalib/src/vespa/vespalib/testkit/test_master.h
+++ b/vespalib/src/vespa/vespalib/testkit/test_master.h
@@ -2,10 +2,10 @@
 
 #pragma once
 
-#include <vespa/vespalib/util/sync.h>
 #include <string>
 #include <vector>
 #include <memory>
+#include <mutex>
 
 namespace vespalib {
 
@@ -69,24 +69,25 @@ private:
     };
 
 private:
-    vespalib::Lock                                 _lock;
+    std::mutex                                     _lock;
     std::string                                    _name;
     std::string                                    _path_prefix;
     SharedState                                    _state;
     std::vector<std::unique_ptr<ThreadState> > _threadStorage;
+    using lock_guard = std::lock_guard<std::mutex>;
 
 private:
-    ThreadState &threadState(const vespalib::LockGuard &);
+    ThreadState &threadState(const lock_guard &);
     ThreadState &threadState();
-    void checkFailed(const vespalib::LockGuard &,
+    void checkFailed(const lock_guard &,
                      const char *file, uint32_t line, const char *str);
-    void printDiff(const vespalib::LockGuard &,
+    void printDiff(const lock_guard &,
                    const std::string &text, const std::string &file, uint32_t line,
                    const std::string &lhs, const std::string &rhs);
-    void handleFailure(const vespalib::LockGuard &, bool do_abort);
-    void closeDebugFiles(const vespalib::LockGuard &);
-    void importThreads(const vespalib::LockGuard &);
-    bool reportConclusion(const vespalib::LockGuard &);
+    void handleFailure(const lock_guard &, bool do_abort);
+    void closeDebugFiles(const lock_guard &);
+    void importThreads(const lock_guard &);
+    bool reportConclusion(const lock_guard &);
 
 private:
     TestMaster();
diff --git a/vespalib/src/vespa/vespalib/testkit/test_master.hpp b/vespalib/src/vespa/vespalib/testkit/test_master.hpp
index f165458c9aa..245c128b788 100644
--- a/vespalib/src/vespa/vespalib/testkit/test_master.hpp
+++ b/vespalib/src/vespa/vespalib/testkit/test_master.hpp
@@ -33,7 +33,7 @@ TestMaster::compare(const char *file, uint32_t line,
     lhs << a;
     rhs << b;
     {
-        vespalib::LockGuard guard(_lock);
+        lock_guard guard(_lock);
         checkFailed(guard, file, line, str.c_str());
         printDiff(guard, str, file, line, lhs.str(), rhs.str());
         handleFailure(guard, fatal);
diff --git a/vespalib/src/vespa/vespalib/util/CMakeLists.txt b/vespalib/src/vespa/vespalib/util/CMakeLists.txt
index fd645f9008c..ea2189fc3a8 100644
--- a/vespalib/src/vespa/vespalib/util/CMakeLists.txt
+++ b/vespalib/src/vespa/vespalib/util/CMakeLists.txt
@@ -40,7 +40,6 @@ vespa_add_library(vespalib_vespalib_util OBJECT
     reusable_set_pool.cpp
     runnable.cpp
     runnable_pair.cpp
-    rwlock.cpp
     sequence.cpp
     sha1.cpp
     sig_catch.cpp
diff --git a/vespalib/src/vespa/vespalib/util/alloc.cpp b/vespalib/src/vespa/vespalib/util/alloc.cpp
index 5ae499f5482..745fb50db03 100644
--- a/vespalib/src/vespa/vespalib/util/alloc.cpp
+++ b/vespalib/src/vespa/vespalib/util/alloc.cpp
@@ -4,11 +4,11 @@
 #include <vespa/vespalib/util/stringfmt.h>
 #include <vespa/vespalib/util/exceptions.h>
 #include <vespa/vespalib/util/backtrace.h>
-#include <vespa/vespalib/util/sync.h>
 #include <map>
 #include <atomic>
 #include <unordered_map>
 #include <cassert>
+#include <mutex>
 #include <vespa/fastos/file.h>
 #include <unistd.h>
 
@@ -25,7 +25,7 @@ int  _G_HugeFlags = 0;
 const size_t _G_pageSize = getpagesize();
 size_t _G_MMapLogLimit = std::numeric_limits<size_t>::max();
 size_t _G_MMapNoCoreLimit = std::numeric_limits<size_t>::max();
-Lock _G_lock;
+std::mutex _G_lock;
 std::atomic<size_t> _G_mmapCount(0);
 
 size_t
@@ -362,7 +362,7 @@ MMapAllocator::salloc(size_t sz, void * wantedAddress)
         }
 #endif
         if (sz >= _G_MMapLogLimit) {
-            LockGuard guard(_G_lock);
+            std::lock_guard guard(_G_lock);
             _G_HugeMappings[buf] = MMapInfo(mmapId, sz, stackTrace);
             LOG(info, "%ld mappings of accumulated size %ld", _G_HugeMappings.size(), sum(_G_HugeMappings));
         }
@@ -412,7 +412,7 @@ void MMapAllocator::sfree(PtrAndSize alloc)
         retval = munmap(alloc.first, alloc.second);
         assert(retval == 0);
         if (alloc.second >= _G_MMapLogLimit) {
-            LockGuard guard(_G_lock);
+            std::lock_guard guard(_G_lock);
             MMapInfo info = _G_HugeMappings[alloc.first];
             assert(alloc.second == info._sz);
             _G_HugeMappings.erase(alloc.first);
diff --git a/vespalib/src/vespa/vespalib/util/delegatelist.hpp b/vespalib/src/vespa/vespalib/util/delegatelist.hpp
deleted file mode 100644
index 716474f66f7..00000000000
--- a/vespalib/src/vespa/vespalib/util/delegatelist.hpp
+++ /dev/null
@@ -1,309 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-
-#pragma once
-
-#include "eventbarrier.hpp"
-#include "sync.h"
-
-namespace vespalib {
-
-/**
- * Data structure for robust event multi-casting in a multi-threaded
- * environment. The state tracked by this class can be modeled as a
- * set of bald object pointers; the delegates. All interaction with
- * the delegates is done through a snapshot of the delegate list. The
- * list may be modified at any time. Modifications will not be visible
- * to already existing snapshots. A separate method may be used to
- * wait for the destruction of all currently active snapshots. This
- * synchronization will ensure visibility of any previous
- * modifications to the delegate list. State snapshotting is
- * implemented with reference counted immutable lists. Snapshot
- * waiting is implemented using event barriers.
- **/
-template <typename T>
-class DelegateList
-{
-private:
-    /**
-     * Simple class used to synchronize with the completion of an
-     * event barrier by coupling barrier completion to a gate.
-     **/
-    struct Sync
-    {
-        Gate gate;
-        Sync() : gate() {}
-        void completeBarrier() { gate.countDown(); }
-    };
-
-    /**
-     * Inner structure used when keeping track of a set of delegates.
-     **/
-    struct Node {
-        uint32_t refcnt;   // the number of incoming pointers to this node.
-        T       *delegate; // the delegate tracked by this node.
-        Node    *next;     // the next node in this list.
-    };
-
-    Lock               _lock;        // lock protecting access to this object
-    Node              *_head;        // head of current list of delegates
-    EventBarrier<Sync> _barrier;     // object used to resolve event barriers
-    Node              *_freeNodes;   // a list of recyclable internal nodes
-    int                _activeNodes; // number of internal nodes currently in use
-    ArrayQueue<T*>     _stack;       // explicit stack for cheap 'recursion'
-
-    /**
-     * Allocate a new node and initialize it with the given data
-     * members. Nodes are recycled internally by this object to reduce
-     * overhead.
-     *
-     * @return the new node
-     * @param delegate the delegate for the new node
-     * @param next the next pointer for the new node
-     **/
-    Node *allocNode(T *delegate, Node *next) {
-        Node *node = _freeNodes;
-        if (node != 0) {
-            _freeNodes = node->next;
-        } else {
-            node = new Node();
-        }
-        node->refcnt = 1;
-        node->delegate = delegate;
-        node->next = next;
-        ++_activeNodes;
-        return node;
-    }
-
-    /**
-     * Copy a list of nodes. This will increase the reference count of
-     * the list.
-     *
-     * @return the copy of the list
-     * @param list the list to copy
-     **/
-    Node *copyList(Node *list) {
-        if (list != 0) {
-            ++list->refcnt;
-        }
-        return list;
-    }
-
-    /**
-     * Free a list of nodes. This will decrease the reference count of
-     * the list. Any nodes no longer in use will be put back on the
-     * internal free list.
-     *
-     * @return 0
-     * @param list the list to free
-     **/
-    Node *freeList(Node *list) {
-        while (list != 0 && --list->refcnt == 0) {
-            Node *node = list;
-            list = node->next;
-            node->next = _freeNodes;
-            _freeNodes = node;
-            --_activeNodes;
-        }
-        return 0;
-    }
-
-    DelegateList(const DelegateList &);
-    DelegateList &operator=(const DelegateList &);
-
-public:
-    /**
-     * A snapshot of a delegate list. The only way to access the
-     * delegates kept by a delegate list is to create a snapshot of
-     * it. The snapshot lets the user traverse the list of delegates,
-     * accessing each of them in turn. The existence of a snapshot is
-     * used by the delegate list to identify that someone is observing
-     * the delegate list in a specific state. Snapshots should be
-     * created on the stack in a scope as close as possible to the
-     * code actually accessing the delegates. The delegate list itself
-     * may not be destructed until all snapshots of that list have
-     * been destructed.
-     **/
-    class Snapshot
-    {
-    private:
-        DelegateList &_list;  // the parent object
-        Node         *_head;  // head of the snapshotted list
-        Node         *_node;  // current position within snapshot
-        uint32_t      _token; // token used for barrier resolving
-
-        Snapshot(const Snapshot &);
-        Snapshot &operator=(const Snapshot &);
-    public:
-        /**
-         * Create a snapshot of the given delegate list. The snapshots
-         * current position will be set to the first delegate part of
-         * the snapshot.
-         *
-         * @param list the delegate list we are snapshotting
-         **/
-        explicit Snapshot(DelegateList &list) : _list(list) {
-            LockGuard guard(list._lock);
-            _head = list.copyList(list._head);
-            _node = _head;
-            _token = list._barrier.startEvent();
-        }
-
-        /**
-         * Destructing a snapshot will tell the delegate list that we
-         * are no longer accessing the list in the state observed by
-         * the snapshot.
-         **/
-        ~Snapshot() {
-            LockGuard guard(_list._lock);
-            _list.freeList(_head);
-            _list._barrier.completeEvent(_token);
-        }
-
-        /**
-         * Check whether the current delegate is valid. A snapshot
-         * becomes invalid after the user has stepped through all
-         * delegates part of the snapshot using the 'next' method.
-         *
-         * @return true if the current delegate is valid
-         **/
-        bool valid() const {
-            return (_node != 0);
-        }
-
-        /**
-         * Step to the next delegate. This method may only be called
-         * if the 'valid' method returns true.
-         **/
-        void next() {
-            _node = _node->next;
-        }
-
-        /**
-         * Get the current delegate. This method may only be called if
-         * the 'valid' method returns true.
-         *
-         * @return current delegate
-         **/
-        T *get() const {
-            return _node->delegate;
-        }
-    };
-
-    /**
-     * Create an initially empty delegate list.
-     **/
-    DelegateList()
-        : _lock(),
-          _head(0),
-          _barrier(),
-          _freeNodes(0),
-          _activeNodes(0),
-          _stack()
-    {
-    }
-
-    /**
-     * The destructor will clean up internal memory usage. The
-     * delegate list itself does not need to be empty when it is
-     * deleted. However, there may be no active snapshots of it and
-     * no-one may be waiting for snapshot destruction.
-     **/
-    ~DelegateList() {
-        freeList(_head);
-        assert(_barrier.countBarriers() == 0);
-        assert(_barrier.countEvents() == 0);
-        assert(_activeNodes == 0);
-        while (_freeNodes != 0) {
-            Node *node = _freeNodes;
-            _freeNodes = node->next;
-            delete node;
-        }
-    }
-
-    /**
-     * Add a delegate to this list. Adding a delegate that is already
-     * in the list will have no effect.
-     *
-     * @return this object, for chaining
-     * @param delegate the delegate to add
-     **/
-    DelegateList &add(T *delegate) {
-        LockGuard guard(_lock);
-        Node *node = _head;
-        while (node != 0 && node->delegate != delegate) {
-            node = node->next;
-        }
-        if (node == 0) {
-            _head = allocNode(delegate, _head);
-        }
-        return *this;
-    }
-
-    /**
-     * Remove a delegate from this list.
-     *
-     * @return this object, for chaining
-     * @param delegate the delegate to remove
-     **/
-    DelegateList &remove(T *delegate) {
-        LockGuard guard(_lock);
-        _stack.clear();
-        Node *node = _head;
-        while (node != 0 && node->delegate != delegate) {
-            _stack.push(node->delegate);
-            node = node->next;
-        }
-        if (node != 0) { // delegate found in list
-            node = copyList(node->next);
-            while (!_stack.empty()) {
-                try {
-                    node = allocNode(_stack.back(), node);
-                } catch (...) {
-                    freeList(node);
-                    throw;
-                }
-                _stack.popBack();
-            }
-            freeList(_head);
-            _head = node;
-        }
-        return *this;
-    }
-
-    /**
-     * Remove all delegates currently in this list.
-     *
-     * @return this object, for chaining
-     **/
-    DelegateList &clear() {
-        LockGuard guard(_lock);
-        _head = freeList(_head);
-        return *this;
-    }
-
-    /**
-     * Wait for the destruction of all currently active snapshots of
-     * this list. This method will block until all relevant snapshots
-     * are destructed. The creation of new snapshots will not
-     * interfere with the completion of this method. This method is
-     * used to enforce visibility between threads; after this method
-     * returns, any modifications performed on the list before this
-     * method was invoked will be visible to all threads.
-     *
-     * @return this object, for chaining
-     **/
-    DelegateList &waitSnapshots() {
-        Sync sync;
-        {
-            LockGuard guard(_lock);
-            if (!_barrier.startBarrier(sync)) {
-                return *this;
-            }
-        }
-        sync.gate.await();
-        return *this;
-    }
-};
-
-} // namespace vespalib
-
diff --git a/vespalib/src/vespa/vespalib/util/ptrholder.h b/vespalib/src/vespa/vespalib/util/ptrholder.h
index 1c06e5c53e6..be528ba25db 100644
--- a/vespalib/src/vespa/vespalib/util/ptrholder.h
+++ b/vespalib/src/vespa/vespalib/util/ptrholder.h
@@ -4,7 +4,7 @@
 
 #include <algorithm>
 #include <memory>
-#include <vespa/vespalib/util/sync.h>
+#include <mutex>
 
 namespace vespalib {
 
@@ -29,11 +29,11 @@ class PtrHolder
 private:
     std::shared_ptr<T>  _current;
     std::shared_ptr<T>  _next;
-    mutable Lock  _lock;
-
-    PtrHolder(const PtrHolder &);
-    PtrHolder &operator=(const PtrHolder &);
+    mutable std::mutex  _lock;
+    using LockGuard = std::lock_guard<std::mutex>;
 public:
+    PtrHolder(const PtrHolder &) = delete;
+    PtrHolder &operator=(const PtrHolder &) = delete;
     /**
      * @brief Create an empty PtrHolder with both current and new
      * pointers set to 0
@@ -53,14 +53,14 @@ public:
      *
      * @return true if the current value is set (not 0)
      **/
-    bool hasValue() const { return (_current.get() != nullptr); }
+    bool hasValue() const { return bool(_current); }
 
     /**
      * @brief Check if the new value is set (not 0)
      *
      * @return true if the new value is set (not 0)
      **/
-    bool hasNewValue() const { return (_next.get() != nullptr); }
+    bool hasNewValue() const { return bool(_next); }
 
     /**
      * @brief Set a new value
diff --git a/vespalib/src/vespa/vespalib/util/rwlock.cpp b/vespalib/src/vespa/vespalib/util/rwlock.cpp
deleted file mode 100644
index fc3799bc1d0..00000000000
--- a/vespalib/src/vespa/vespalib/util/rwlock.cpp
+++ /dev/null
@@ -1,59 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-
-#include "rwlock.h"
-#include <cassert>
-
-namespace vespalib {
-
-void RWLock::lockRead() {
-    MonitorGuard guard(_monitor);
-    CounterGuard waitCnt(_waitingReaders);
-    while (_givenLocks == -1 || _waitingWriters > 0) {
-        guard.wait();
-    }
-    ++_givenLocks;
-}
-
-void RWLock::unlockRead() {
-    MonitorGuard guard(_monitor);
-    assert(_givenLocks > 0);
-    if (--_givenLocks == 0 && _waitingWriters > 0) {
-        guard.broadcast();
-    }
-}
-
-void RWLock::lockWrite() {
-    MonitorGuard guard(_monitor);
-    CounterGuard waitCnt(_waitingWriters);
-    while (_givenLocks != 0) {
-        guard.wait();
-    }
-    _givenLocks = -1;
-}
-
-void RWLock::unlockWrite() {
-    MonitorGuard guard(_monitor);
-    assert(_givenLocks == -1);
-    _givenLocks = 0;
-    if (_waitingReaders > 0 || _waitingWriters > 0) {
-        guard.broadcast();
-    }
-}
-
-RWLock *
-RWLockReader::stealLock() {
-    RWLock * ret(_lock);
-    assert(ret != nullptr);
-    _lock = nullptr;
-    return ret;
-}
-
-RWLock *
-RWLockWriter::stealLock() {
-    RWLock * ret(_lock);
-    assert(ret != nullptr);
-    _lock = nullptr;
-    return ret;
-}
-
-} // namespace vespalib
diff --git a/vespalib/src/vespa/vespalib/util/rwlock.h b/vespalib/src/vespa/vespalib/util/rwlock.h
deleted file mode 100644
index 8818291ae6c..00000000000
--- a/vespalib/src/vespa/vespalib/util/rwlock.h
+++ /dev/null
@@ -1,240 +0,0 @@
-// Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-
-#pragma once
-
-#include <vespa/vespalib/util/sync.h>
-#include <vespa/vespalib/util/guard.h>
-
-class RWLockTest;
-
-namespace vespalib {
-
-/**
- * @brief An RWLock is a reader/writer lock. It can either be held by
- * any number of readers or a single writer at any time.
- *
- * The RWLockReader and RWLockWriter classes are used to acquire and
- * release reader and writer locks respectively.
- *
- * Writer locks have priority above reader locks to prevent
- * starvation.
- **/
-class RWLock
-{
-private:
-    friend class ::RWLockTest;
-    friend class RWLockReader;
-    friend class RWLockWriter;
-
-    int     _givenLocks;
-    int     _waitingReaders;
-    int     _waitingWriters;
-    Monitor _monitor;
-
-    void lockRead();
-    void unlockRead();
-    void lockWrite();
-    void unlockWrite();
-public:
-    /**
-     * @brief Create a new RWLock
-     **/
-    RWLock()
-        : _givenLocks(0),
-          _waitingReaders(0),
-          _waitingWriters(0),
-          _monitor() {}
-    /**
-     * @brief Create a new RWLock, ignoring the right hand side.
-     *
-     * It makes no sense to copy the state of an RWLock, but we want
-     * to allow copying objects that contain RWLock objects.
-     *
-     * @param rhs ignore this
-     **/
-    RWLock(const RWLock &rhs)
-        : _givenLocks(0),
-          _waitingReaders(0),
-          _waitingWriters(0),
-          _monitor() { (void) rhs;}
-    /**
-     * @brief Assignment operator ignoring the right hand side.
-     *
-     * It makes no sense to assign the state of one RWLock to another,
-     * but we want to allow assigning objects that contain RWLock
-     * objects.
-     *
-     * @param rhs ignore this
-     **/
-    RWLock &operator=(const RWLock &rhs) {
-        (void) rhs;
-        return *this;
-    }
-
-    /**
-     * To get an instance of RWLockReader or RWLockWriter that isn't
-     * associated with a specific RWLock at initialization, you may
-     * construct them from this tag type.
-     **/
-    struct InitiallyUnlockedGuard {};
-};
-
-#ifndef IAM_DOXYGEN
-class RWLockReaderHandover
-{
-private:
-    friend class RWLockReader;
-    RWLock *_lock;
-    RWLockReaderHandover(const RWLockReaderHandover &);
-    RWLockReaderHandover &operator=(const RWLockReaderHandover &);
-    RWLockReaderHandover(RWLock *m) : _lock(m) {}
-public:
-};
-
-class RWLockWriterHandover
-{
-private:
-    friend class RWLockWriter;
-    RWLock *_lock;
-    RWLockWriterHandover(const RWLockWriterHandover &);
-    RWLockWriterHandover &operator=(const RWLockWriterHandover &);
-    RWLockWriterHandover(RWLock *m) : _lock(m) {}
-public:
-};
-#endif
-
-
-/**
- * @brief An RWLockReader holds a reader lock on an RWLock.
- *
- * The lock is acquired in the constructor and released in the
- * destructor.
- *
- * RWLockReader has destructive copy (like unique_ptr). Assigning from
- * or copying a RWLockReader has the semantic of transferring the lock
- * from one object to the other.  Note that assigning from or copying
- * a RWLockReader that does not have a lock will result in an assert.
- **/
-class RWLockReader
-{
-private:
-    RWLock * _lock;
-    RWLock * stealLock();
-    void cleanup() { if (_lock != nullptr) { _lock->unlockRead(); } }
-public:
-
-    /**
-     * @brief Obtain reader lock.
-     *
-     * This will block until a reader lock can be acquired.
-     *
-     * @param lock the underlying RWLock object
-     **/
-    RWLockReader(RWLock &lock) : _lock(&lock) { _lock->lockRead(); }
-
-    /**
-     * @brief Construct initially unlocked guard.
-     * @param tag (unused) marker argument
-     **/
-    RWLockReader(const RWLock::InitiallyUnlockedGuard &tag) : _lock(nullptr) { (void)tag; }
-
-    /**
-     * @brief Steal the lock from the given RWLockReader
-     *
-     * @param rhs steal the lock from this one
-     **/
-    RWLockReader(RWLockReader &rhs) : _lock(rhs.stealLock()) {}
-
-    /**
-     * @brief Steal the lock from the given RWLockReader
-     *
-     * @param rhs steal the lock from this one
-     **/
-    RWLockReader &operator=(RWLockReader & rhs) {
-        if (this != & rhs) {
-            cleanup();
-            _lock = rhs.stealLock();
-        }
-        return *this;
-    }
-
-    /**
-     * @brief Release the lock obtained in the constructor
-     **/
-    ~RWLockReader() { cleanup(); }
-
-#ifndef IAM_DOXYGEN
-    RWLockReader(const RWLockReaderHandover &rhs) : _lock(rhs._lock) {}
-    operator RWLockReaderHandover() { return RWLockReaderHandover(stealLock()); }
-#endif
-};
-
-
-/**
- * @brief An RWLockWriter holds a writer lock on an RWLock.
- *
- * The lock is acquired in the constructor and released in the
- * destructor.
- *
- * RWLockWriter has destructive copy (like unique_ptr). Assigning from
- * or copying a RWLockWriter has the semantic of transferring the lock
- * from one object to the other, and assignment is similar.  Note that
- * assigning from or copying a RWLockWriter that does not have a lock
- * will result in an assert.
- **/
-class RWLockWriter
-{
-private:
-    RWLock * _lock;
-    RWLock * stealLock();
-    void cleanup() { if (_lock != nullptr) { _lock->unlockWrite(); } }
-public:
-
-    /**
-     * @brief Obtain writer lock.
-     *
-     * This will block until a writer lock can be acquired.
-     *
-     * @param lock the underlying RWLock object
-     **/
-    RWLockWriter(RWLock &lock) : _lock(&lock) { _lock->lockWrite(); }
-
-    /**
-     * @brief Construct initially unlocked guard.
-     * @param tag (unused) marker argument
-     **/
-    RWLockWriter(const RWLock::InitiallyUnlockedGuard &tag) : _lock(nullptr) { (void)tag; }
-
-    /**
-     * @brief Steal the lock from the given RWLockWriter
-     *
-     * @param rhs steal the lock from this one
-     **/
-    RWLockWriter(RWLockWriter &rhs) : _lock(rhs.stealLock()) {}
-
-    /**
-     * @brief Steal the lock from the given RWLockWriter
-     *
-     * @param rhs steal the lock from this one
-     **/
-    RWLockWriter &operator=(RWLockWriter & rhs) {
-        if (this != & rhs) {
-            cleanup();
-            _lock = rhs.stealLock();
-        }
-        return *this;
-    }
-
-    /**
-     * @brief Release the lock obtained in the constructor
-     **/
-    ~RWLockWriter() { cleanup(); }
-
-#ifndef IAM_DOXYGEN
-    RWLockWriter(const RWLockWriterHandover &rhs) : _lock(rhs._lock) {}
-    operator RWLockWriterHandover() { return RWLockWriterHandover(stealLock()); }
-#endif
-};
-
-} // namespace vespalib
-
diff --git a/vespalib/src/vespa/vespalib/util/simple_thread_bundle.cpp b/vespalib/src/vespa/vespalib/util/simple_thread_bundle.cpp
index 886003a2ab6..e0d78c5d1b7 100644
--- a/vespalib/src/vespa/vespalib/util/simple_thread_bundle.cpp
+++ b/vespalib/src/vespa/vespalib/util/simple_thread_bundle.cpp
@@ -69,7 +69,7 @@ SimpleThreadBundle::UP
 SimpleThreadBundle::Pool::obtain()
 {
     {
-        LockGuard guard(_lock);
+        std::lock_guard guard(_lock);
         if (!_bundles.empty()) {
             SimpleThreadBundle::UP ret(_bundles.back());
             _bundles.pop_back();
@@ -82,7 +82,7 @@ SimpleThreadBundle::Pool::obtain()
 void
 SimpleThreadBundle::Pool::release(SimpleThreadBundle::UP bundle)
 {
-    LockGuard guard(_lock);
+    std::lock_guard guard(_lock);
     _bundles.push_back(bundle.get());
     bundle.release();
 }
diff --git a/vespalib/src/vespa/vespalib/util/simple_thread_bundle.h b/vespalib/src/vespa/vespalib/util/simple_thread_bundle.h
index dbf9f7025b6..135fc2d7562 100644
--- a/vespalib/src/vespa/vespalib/util/simple_thread_bundle.h
+++ b/vespalib/src/vespa/vespalib/util/simple_thread_bundle.h
@@ -2,7 +2,6 @@
 
 #pragma once
 
-#include "sync.h"
 #include "count_down_latch.h"
 #include "thread.h"
 #include "runnable.h"
@@ -94,8 +93,8 @@ public:
     class Pool
     {
     private:
-        Lock _lock;
-        size_t _bundleSize;
+        std::mutex _lock;
+        size_t     _bundleSize;
         std::vector<SimpleThreadBundle*> _bundles;
 
     public:
diff --git a/vespalib/src/vespa/vespalib/util/sync.cpp b/vespalib/src/vespa/vespalib/util/sync.cpp
index 3819b2b3369..ac55f12c341 100644
--- a/vespalib/src/vespa/vespalib/util/sync.cpp
+++ b/vespalib/src/vespa/vespalib/util/sync.cpp
@@ -19,47 +19,10 @@ Monitor::Monitor() noexcept
 Monitor::Monitor(Monitor &&rhs) noexcept = default;
 Monitor::~Monitor() = default;
 
-
-TryLock::TryLock(const Lock &lock)
-    : _guard(*lock._mutex, std::try_to_lock),
-      _cond(nullptr)
-{}
-
-TryLock::TryLock(const Monitor &mon)
-    : _guard(*mon._mutex, std::try_to_lock),
-      _cond(_guard ? mon._cond.get() : nullptr)
-{}
-
-TryLock::TryLock(TryLock &&rhs) noexcept
-    : _guard(std::move(rhs._guard)),
-      _cond(rhs._cond)
-{
-    rhs._cond = nullptr;
-}
-
-TryLock::~TryLock() = default;
-
-bool
-TryLock::hasLock() const {
-    return static_cast<bool>(_guard);
-}
-
-void
-TryLock::unlock() {
-    if (_guard) {
-        _guard.unlock();
-        _cond = nullptr;
-    }
-}
-
 LockGuard::LockGuard() : _guard() {}
 
 LockGuard::LockGuard(LockGuard &&rhs) noexcept : _guard(std::move(rhs._guard)) { }
 LockGuard::LockGuard(const Lock &lock) : _guard(*lock._mutex) { }
-LockGuard::LockGuard(TryLock &&tlock) : _guard(std::move(tlock._guard))
-{
-    tlock._cond = nullptr;
-}
 
 LockGuard &
 LockGuard::operator=(LockGuard &&rhs) noexcept{
@@ -93,16 +56,6 @@ MonitorGuard::MonitorGuard(const Monitor &monitor)
     : _guard(*monitor._mutex),
       _cond(monitor._cond.get())
 { }
-MonitorGuard::MonitorGuard(TryLock &&tlock)
-    : _guard(),
-      _cond(nullptr)
-{
-    if (tlock._guard && tlock._cond != nullptr) {
-        _guard = std::move(tlock._guard);
-        _cond = tlock._cond;
-        tlock._cond = nullptr;
-    }
-}
 
 MonitorGuard &
 MonitorGuard::operator=(MonitorGuard &&rhs) noexcept {
diff --git a/vespalib/src/vespa/vespalib/util/sync.h b/vespalib/src/vespa/vespalib/util/sync.h
index b1227ce658e..3207206a753 100644
--- a/vespalib/src/vespa/vespalib/util/sync.h
+++ b/vespalib/src/vespa/vespalib/util/sync.h
@@ -70,89 +70,6 @@ public:
 
 
 /**
- * @brief A TryLock object is used to try to obtain the lock on a Lock
- * or a Monitor without blocking.
- *
- * A TryLock will typically fail to obatin the lock if someone else
- * already has it. In that case, the TryLock object has no further
- * use.
- *
- * If the TryLock managed to acquire the lock, it can be passed over
- * to a LockGuard or MonitorGuard object. If the lock is not passed
- * on, the TryLock object will release it when it goes out of scope.
- *
- * Note that passing the lock obtained from a Lock to a MonitorGuard
- * is illegal. Also note that if the TryLock fails to aquire the lock,
- * it cannot be passed on. Trying to do so will result in an assert.
- *
- * copy/assignment of a TryLock is illegal.
- *
- * <pre>
- * Example:
- *
- * Lock lock;
- * TryLock tl(lock);
- * if (tl.hasLock()) {
- *   LockGuard guard(tl)
- *   ... do stuff
- * } // the lock is released as 'guard' goes out of scope
- * </pre>
- **/
-class TryLock
-{
-private:
-    friend class LockGuard;
-    friend class MonitorGuard;
-
-    std::unique_lock<std::mutex> _guard;
-    std::condition_variable     *_cond;
-
-public:
-    /**
-     * @brief Try to obtain the lock represented by the given Lock object
-     *
-     * @param lock the lock to obtain
-     **/
-    TryLock(const Lock &lock);
-
-    /**
-     * @brief Try to lock the given Monitor
-     *
-     * @param mon the monitor to lock
-     **/
-    TryLock(const Monitor &mon);
-
-    TryLock(TryLock &&rhs) noexcept;
-
-    /**
-     * @brief Release the lock held by this object, if any
-     **/
-    ~TryLock();
-
-    TryLock(const TryLock &) = delete;
-    TryLock &operator=(const TryLock &) = delete;
-
-    TryLock &operator=(TryLock &&rhs) noexcept;
-
-    /**
-     * @brief Check whether this object holds a lock
-     *
-     * @return true if this object holds a lock
-     **/
-    bool hasLock() const;
-    /**
-     * @brief Release the lock held by this object.
-     *
-     * No methods may be invoked after invoking unlock (except the
-     * destructor). Note that this method should only be used if you
-     * need to release the lock before the object is destructed, as
-     * the destructor will release the lock.
-     **/
-    void unlock();
-};
-
-
-/**
  * @brief A LockGuard holds the lock on either a Lock or a Monitor.
  *
  * LockGuards are typically created on the stack to hold a lock within
@@ -191,17 +108,6 @@ public:
      **/
     LockGuard(const Lock &lock);
 
-    /**
-     * @brief Create a LockGuard from a TryLock.
-     *
-     * The TryLock may have been created from either a Lock or a
-     * Monitor, but it must have managed to acquire the lock. The lock
-     * will be handed over from the TryLock to the new object.
-     *
-     * @param tlock take the lock from this one
-     **/
-    LockGuard(TryLock &&tlock);
-
     LockGuard &operator=(LockGuard &&rhs) noexcept;
 
     /**
@@ -267,16 +173,6 @@ public:
      * @param monitor take the lock on it
      **/
     MonitorGuard(const Monitor &monitor);
-    /**
-     * @brief Create a MonitorGuard from a TryLock.
-     *
-     * The TryLock must have been created from a Monitor, and it must
-     * have managed to acquire the lock. The lock will be handed over
-     * from the TryLock to the new object.
-     *
-     * @param tlock take the lock from this one
-     **/
-    MonitorGuard(TryLock &&tlock);
 
     MonitorGuard &operator=(MonitorGuard &&rhs) noexcept;
 
diff --git a/vsm/src/vespa/vsm/vsm/vsm-adapter.cpp b/vsm/src/vespa/vsm/vsm/vsm-adapter.cpp
index 8307954faae..db238279fa3 100644
--- a/vsm/src/vespa/vsm/vsm/vsm-adapter.cpp
+++ b/vsm/src/vespa/vsm/vsm/vsm-adapter.cpp
@@ -116,7 +116,7 @@ DocsumTools::obtainFieldNames(const FastS_VsmsummaryHandle &cfg)
 void
 VSMAdapter::configure(const VSMConfigSnapshot & snapshot)
 {
-    vespalib::LockGuard guard(_lock);
+    std::lock_guard guard(_lock);
     LOG(debug, "(re-)configure VSM (docsum tools)");
 
     std::shared_ptr<SummaryConfig>      summary(snapshot.getConfig<SummaryConfig>().release());
@@ -141,7 +141,7 @@ VSMAdapter::configure(const VSMConfigSnapshot & snapshot)
     }
 
     // init keyword extractor
-    std::unique_ptr<KeywordExtractor> kwExtractor(new KeywordExtractor(NULL));
+    auto kwExtractor = std::make_unique<KeywordExtractor>(nullptr);
     kwExtractor->AddLegalIndexSpec(_highlightindexes.c_str());
     vespalib::string spec = kwExtractor->GetLegalIndexSpec();
     LOG(debug, "index highlight spec: '%s'", spec.c_str());
diff --git a/vsm/src/vespa/vsm/vsm/vsm-adapter.h b/vsm/src/vespa/vsm/vsm/vsm-adapter.h
index 31e472713de..f6895dd71a6 100644
--- a/vsm/src/vespa/vsm/vsm/vsm-adapter.h
+++ b/vsm/src/vespa/vsm/vsm/vsm-adapter.h
@@ -127,7 +127,7 @@ private:
     vespalib::PtrHolder<DocsumTools>          _docsumTools;
     std::unique_ptr<JuniperProperties>        _juniperProps;
 
-    vespalib::Lock                                  _lock;
+    std::mutex                                _lock;
 
     VSMAdapter(const VSMAdapter &);
     VSMAdapter &operator=(const VSMAdapter &);