Repository: cassandra Updated Branches: refs/heads/trunk 14bbab642 -> d8164c643
In BufferPool, make allocating thread receive a Chunk. Prevents a condition where the thread allocating the macro chunk could have all of the chunks taken from the queue before it is able to use one. patch by Jon Meredith; reviewed by Benedict for CASSANDRA-14832 Project: http://git-wip-us.apache.org/repos/asf/cassandra/repo Commit: http://git-wip-us.apache.org/repos/asf/cassandra/commit/d8164c64 Tree: http://git-wip-us.apache.org/repos/asf/cassandra/tree/d8164c64 Diff: http://git-wip-us.apache.org/repos/asf/cassandra/diff/d8164c64 Branch: refs/heads/trunk Commit: d8164c643395e3b6579a2fe6ce6ff0423df2f520 Parents: 14bbab6 Author: Jon Meredith <jmeredit...@gmail.com> Authored: Thu Oct 18 09:56:46 2018 -0600 Committer: Benedict Elliott Smith <bened...@apache.org> Committed: Fri Nov 30 12:35:50 2018 +0000 ---------------------------------------------------------------------- CHANGES.txt | 1 + .../cassandra/utils/memory/BufferPool.java | 33 +++++++++++--------- 2 files changed, 19 insertions(+), 15 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/cassandra/blob/d8164c64/CHANGES.txt ---------------------------------------------------------------------- diff --git a/CHANGES.txt b/CHANGES.txt index 6d04416..f145a06 100644 --- a/CHANGES.txt +++ b/CHANGES.txt @@ -1,4 +1,5 @@ 4.0 + * BufferPool: allocating thread for new chunks should acquire directly (CASSANDRA-14832) * Send correct messaging version in internode messaging handshake's third message (CASSANDRA-14896) * Make Read and Write Latency columns consistent for proxyhistograms and tablehistograms (CASSANDRA-11939) * Make protocol checksum type option case insensitive (CASSANDRA-14716) http://git-wip-us.apache.org/repos/asf/cassandra/blob/d8164c64/src/java/org/apache/cassandra/utils/memory/BufferPool.java ---------------------------------------------------------------------- diff --git a/src/java/org/apache/cassandra/utils/memory/BufferPool.java b/src/java/org/apache/cassandra/utils/memory/BufferPool.java index c8ad078..a67f520 100644 --- a/src/java/org/apache/cassandra/utils/memory/BufferPool.java +++ b/src/java/org/apache/cassandra/utils/memory/BufferPool.java @@ -241,23 +241,23 @@ public class BufferPool /** Return a chunk, the caller will take owership of the parent chunk. */ public Chunk get() { - while (true) - { - Chunk chunk = chunks.poll(); - if (chunk != null) - return chunk; + Chunk chunk = chunks.poll(); + if (chunk != null) + return chunk; - if (!allocateMoreChunks()) - // give it one last attempt, in case someone else allocated before us - return chunks.poll(); - } + chunk = allocateMoreChunks(); + if (chunk != null) + return chunk; + + // another thread may have just allocated last macro chunk, so make one final attempt before returning null + return chunks.poll(); } /** * This method might be called by multiple threads and that's fine if we add more * than one chunk at the same time as long as we don't exceed the MEMORY_USAGE_THRESHOLD. */ - private boolean allocateMoreChunks() + private Chunk allocateMoreChunks() { while (true) { @@ -266,7 +266,7 @@ public class BufferPool { noSpamLogger.info("Maximum memory usage reached ({}), cannot allocate chunk of {}", MEMORY_USAGE_THRESHOLD, MACRO_CHUNK_SIZE); - return false; + return null; } if (memoryUsage.compareAndSet(cur, cur + MACRO_CHUNK_SIZE)) break; @@ -284,20 +284,23 @@ public class BufferPool "Attempting to continue; buffers will be allocated in on-heap memory which can degrade performance. " + "Make sure direct memory size (-XX:MaxDirectMemorySize) is large enough to accommodate off-heap memtables and caches.", MACRO_CHUNK_SIZE, sizeInBytes(), oom.toString()); - return false; + return null; } chunk.acquire(null); macroChunks.add(chunk); - for (int i = 0 ; i < MACRO_CHUNK_SIZE ; i += CHUNK_SIZE) + + final Chunk callerChunk = new Chunk(chunk.get(CHUNK_SIZE)); + if (DEBUG) + debug.register(callerChunk); + for (int i = CHUNK_SIZE ; i < MACRO_CHUNK_SIZE; i += CHUNK_SIZE) { Chunk add = new Chunk(chunk.get(CHUNK_SIZE)); chunks.add(add); if (DEBUG) debug.register(add); } - - return true; + return callerChunk; } public void recycle(Chunk chunk) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org
