Extend use of search::Chunk::_lock to close more races.

4 files changed, 30 insertions, 11 deletions

diff --git a/searchlib/src/vespa/searchlib/docstore/chunk.cpp b/searchlib/src/vespa/searchlib/docstore/chunk.cpp
index d7d390d5db8..2c0e47301d9 100644
--- a/searchlib/src/vespa/searchlib/docstore/chunk.cpp
+++ b/searchlib/src/vespa/searchlib/docstore/chunk.cpp
@@ -30,6 +30,18 @@ Chunk::read(uint32_t lid, vespalib::DataBuffer & buffer) const
     return buf.size();
 }
 
+std::pair<size_t, vespalib::alloc::Alloc>
+Chunk::read(uint32_t lid) const
+{
+    std::lock_guard guard(_lock);
+    vespalib::ConstBufferRef buf = getLid(lid);
+    auto copy = vespalib::alloc::Alloc::alloc(buf.size());
+    if (buf.size() != 0) {
+        memcpy(copy.get(), buf.data(), buf.size());
+    }
+    return std::make_pair(buf.size(), std::move(copy));
+}
+
 bool
 Chunk::hasRoom(size_t len) const
 {
@@ -108,6 +120,7 @@ Chunk::getLid(uint32_t lid) const
 
 size_t
 Chunk::size() const {
+    std::lock_guard guard(_lock);
     return getData().size();
 }
 
diff --git a/searchlib/src/vespa/searchlib/docstore/chunk.h b/searchlib/src/vespa/searchlib/docstore/chunk.h
index bd82315a7d8..40600663106 100644
--- a/searchlib/src/vespa/searchlib/docstore/chunk.h
+++ b/searchlib/src/vespa/searchlib/docstore/chunk.h
@@ -13,6 +13,7 @@ namespace vespalib {
     class nbostream;
     class DataBuffer;
 }
+namespace vespalib::alloc { class Alloc; }
 
 namespace search {
 
@@ -90,6 +91,7 @@ public:
     ~Chunk();
     LidMeta append(uint32_t lid, const void * buffer, size_t len);
     ssize_t read(uint32_t lid, vespalib::DataBuffer & buffer) const;
+    std::pair<size_t, vespalib::alloc::Alloc> read(uint32_t lid) const;
     size_t count() const { return _lids.size(); }
     bool empty() const { return count() == 0; }
     size_t size() const;
diff --git a/searchlib/src/vespa/searchlib/docstore/writeablefilechunk.cpp b/searchlib/src/vespa/searchlib/docstore/writeablefilechunk.cpp
index 2f6d570dbb7..20b7fd02dbe 100644
--- a/searchlib/src/vespa/searchlib/docstore/writeablefilechunk.cpp
+++ b/searchlib/src/vespa/searchlib/docstore/writeablefilechunk.cpp
@@ -219,6 +219,18 @@ struct LidAndBuffer {
 
 }
 
+const Chunk&
+WriteableFileChunk::get_chunk(uint32_t chunk) const
+{
+    auto found = _chunkMap.find(chunk);
+    if (found != _chunkMap.end()) {
+        return *found->second;
+    } else {
+        assert(chunk == _active->getId());
+        return *_active;
+    }
+}
+
 void
 WriteableFileChunk::read(LidInfoWithLidV::const_iterator begin, size_t count, IBufferVisitor & visitor) const
 {
@@ -232,17 +244,8 @@ WriteableFileChunk::read(LidInfoWithLidV::const_iterator begin, size_t count, IB
                 const LidInfoWithLid & li = *(begin + i);
                 uint32_t chunk = li.getChunkId();
                 if ((chunk >= _chunkInfo.size()) || !_chunkInfo[chunk].valid()) {
-                    auto found = _chunkMap.find(chunk);
-                    vespalib::ConstBufferRef buffer;
-                    if (found != _chunkMap.end()) {
-                        buffer = found->second->getLid(li.getLid());
-                    } else {
-                        assert(chunk == _active->getId());
-                        buffer = _active->getLid(li.getLid());
-                    }
-                    auto copy = vespalib::alloc::Alloc::alloc(buffer.size());
-                    memcpy(copy.get(), buffer.data(), buffer.size());
-                    buffers.emplace_back(li.getLid(), buffer.size(), std::move(copy));
+                    auto copy = get_chunk(chunk).read(li.getLid());
+                    buffers.emplace_back(li.getLid(), copy.first, std::move(copy.second));
                 } else {
                     chunksOnFile[chunk] = _chunkInfo[chunk];
                 }
diff --git a/searchlib/src/vespa/searchlib/docstore/writeablefilechunk.h b/searchlib/src/vespa/searchlib/docstore/writeablefilechunk.h
index 0b9ab0ce5f4..5e1479ed13c 100644
--- a/searchlib/src/vespa/searchlib/docstore/writeablefilechunk.h
+++ b/searchlib/src/vespa/searchlib/docstore/writeablefilechunk.h
@@ -104,6 +104,7 @@ private:
     void updateCurrentDiskFootprint();
     size_t getDiskFootprint(const unique_lock & guard) const;
     std::unique_ptr<FastOS_FileInterface> openIdx();
+    const Chunk& get_chunk(uint32_t chunk) const;
 
     Config            _config;
     SerialNum         _serialNum;