Merge pull request #22318 from vespa-engine/toregge/use-atomic-variables-for-raw-document-meta-data

Use atomic variables in proton::RawDocumentMetaData.

1 files changed, 33 insertions, 24 deletions

diff --git a/searchcore/src/vespa/searchcore/proton/documentmetastore/raw_document_meta_data.h b/searchcore/src/vespa/searchcore/proton/documentmetastore/raw_document_meta_data.h
index e5f7dcc7192..b5e512fcd9e 100644
--- a/searchcore/src/vespa/searchcore/proton/documentmetastore/raw_document_meta_data.h
+++ b/searchcore/src/vespa/searchcore/proton/documentmetastore/raw_document_meta_data.h
@@ -5,6 +5,8 @@
 #include <vespa/document/base/globalid.h>
 #include <vespa/document/bucket/bucketid.h>
 #include <persistence/spi/types.h>
+#include <algorithm>
+#include <atomic>
 #include <cassert>
 
 namespace proton {
@@ -18,35 +20,41 @@ struct RawDocumentMetaData
     using BucketId = document::BucketId;
     using Timestamp = storage::spi::Timestamp;
     GlobalId  _gid;
-    uint8_t   _bucketUsedBits;
-    uint8_t   _docSizeLow;
-    uint16_t  _docSizeHigh;
-    Timestamp _timestamp;
+    std::atomic<uint32_t> _bucket_used_bits_and_doc_size;
+    std::atomic<uint64_t> _timestamp;
+
+    static uint32_t capped_doc_size(uint32_t doc_size) { return std::min(0xffffffu, doc_size); }
 
     RawDocumentMetaData() noexcept
         : _gid(),
-          _bucketUsedBits(BucketId::minNumBits),
-          _docSizeLow(0),
-          _docSizeHigh(0),
-          _timestamp()
+          _bucket_used_bits_and_doc_size(BucketId::minNumBits),
+          _timestamp(0)
     { }
 
     RawDocumentMetaData(const GlobalId &gid, const BucketId &bucketId, const Timestamp &timestamp, uint32_t docSize) noexcept
         : _gid(gid),
-          _bucketUsedBits(bucketId.getUsedBits()),
-          _docSizeLow(docSize),
-          _docSizeHigh(docSize >> 8),
+          _bucket_used_bits_and_doc_size(bucketId.getUsedBits() | (capped_doc_size(docSize) << 8)),
           _timestamp(timestamp)
     {
         assert(bucketId.valid());
         BucketId verId(gid.convertToBucketId());
-        verId.setUsedBits(_bucketUsedBits);
+        verId.setUsedBits(bucketId.getUsedBits());
         assert(bucketId.getRawId() == verId.getRawId() ||
                bucketId.getRawId() == verId.getId());
-        if (docSize >= (1u << 24)) {
-            _docSizeLow = 0xff;
-            _docSizeHigh = 0xffff;
-        }
+    }
+
+    RawDocumentMetaData(const RawDocumentMetaData& rhs)
+        : _gid(rhs._gid),
+          _bucket_used_bits_and_doc_size(rhs._bucket_used_bits_and_doc_size.load(std::memory_order_relaxed)),
+          _timestamp(rhs._timestamp.load(std::memory_order_relaxed))
+    {
+    }
+
+    RawDocumentMetaData& operator=(const RawDocumentMetaData& rhs) {
+        _gid = rhs._gid;
+        _bucket_used_bits_and_doc_size.store(rhs._bucket_used_bits_and_doc_size.load(std::memory_order_relaxed), std::memory_order_relaxed);
+        _timestamp.store(rhs._timestamp.load(std::memory_order_relaxed), std::memory_order_relaxed);
+        return *this;
     }
 
     bool operator<(const GlobalId &rhs) const noexcept { return _gid < rhs; }
@@ -57,17 +65,17 @@ struct RawDocumentMetaData
     const GlobalId &getGid() const { return _gid; }
     GlobalId &getGid() { return _gid; }
     void setGid(const GlobalId &rhs) { _gid = rhs; }
-    uint8_t getBucketUsedBits() const { return _bucketUsedBits; }
+    uint8_t getBucketUsedBits() const { return _bucket_used_bits_and_doc_size.load(std::memory_order_relaxed) & 0xffu; }
 
     BucketId getBucketId() const {
         BucketId ret(_gid.convertToBucketId());
-        ret.setUsedBits(_bucketUsedBits);
+        ret.setUsedBits(getBucketUsedBits());
         return ret;
     }
 
     void setBucketUsedBits(uint8_t bucketUsedBits) {
         assert(BucketId::validUsedBits(bucketUsedBits));
-        _bucketUsedBits = bucketUsedBits;
+        _bucket_used_bits_and_doc_size.store((_bucket_used_bits_and_doc_size.load(std::memory_order_relaxed) & ~0xffu) | bucketUsedBits, std::memory_order_relaxed);
     }
 
     void setBucketId(const BucketId &bucketId) {
@@ -77,15 +85,16 @@ struct RawDocumentMetaData
         verId.setUsedBits(bucketUsedBits);
         assert(bucketId.getRawId() == verId.getRawId() ||
                bucketId.getRawId() == verId.getId());
-        _bucketUsedBits = bucketUsedBits;
+        setBucketUsedBits(bucketUsedBits);
     }
 
-    Timestamp getTimestamp() const { return _timestamp; }
+    Timestamp getTimestamp() const { return Timestamp(_timestamp.load(std::memory_order_relaxed)); }
+
+    void setTimestamp(const Timestamp &timestamp) { _timestamp.store(timestamp.getValue(), std::memory_order_relaxed); }
 
-    void setTimestamp(const Timestamp &timestamp) { _timestamp = timestamp; }
+    uint32_t getDocSize() const { return _bucket_used_bits_and_doc_size.load(std::memory_order_relaxed) >> 8; }
+    void setDocSize(uint32_t docSize) { _bucket_used_bits_and_doc_size.store((_bucket_used_bits_and_doc_size.load(std::memory_order_relaxed) & 0xffu) | (capped_doc_size(docSize) << 8), std::memory_order_relaxed); }
 
-    uint32_t getDocSize() const { return _docSizeLow + (static_cast<uint32_t>(_docSizeHigh) << 8); }
-    void setDocSize(uint32_t docSize) { _docSizeLow = docSize; _docSizeHigh = docSize >> 8; }
 };
 
 } // namespace proton