diff options
Diffstat (limited to 'qpid/cpp/src/qpid/sys/AsynchIOHandler.cpp')
-rw-r--r-- | qpid/cpp/src/qpid/sys/AsynchIOHandler.cpp | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/qpid/cpp/src/qpid/sys/AsynchIOHandler.cpp b/qpid/cpp/src/qpid/sys/AsynchIOHandler.cpp index 3bc05e4bf9..6b7e7b5145 100644 --- a/qpid/cpp/src/qpid/sys/AsynchIOHandler.cpp +++ b/qpid/cpp/src/qpid/sys/AsynchIOHandler.cpp @@ -84,10 +84,11 @@ void AsynchIOHandler::giveReadCredit(int32_t credit) { // Check whether we started in the don't about credit state if (readCredit.boolCompareAndSwap(InfiniteCredit, credit)) return; - else if (readCredit.fetchAndAdd(credit) != 0) - return; - // Lock and retest credit to make sure we don't race with decreasing credit + // TODO In theory should be able to use an atomic operation before taking the lock + // but in practice there seems to be an unexplained race in that case ScopedLock<Mutex> l(creditLock); + if (readCredit.fetchAndAdd(credit) != 0) + return; assert(readCredit.get() >= 0); if (readCredit.get() != 0) aio->startReading(); @@ -141,9 +142,10 @@ bool AsynchIOHandler::readbuff(AsynchIO& , AsynchIO::BufferBase* buff) { } // Check here for read credit if (readCredit.get() != InfiniteCredit) { + // TODO In theory should be able to use an atomic operation before taking the lock + // but in practice there seems to be an unexplained race in that case + ScopedLock<Mutex> l(creditLock); if (--readCredit == 0) { - // Lock and retest credit to make sure we don't race with increasing credit - ScopedLock<Mutex> l(creditLock); assert(readCredit.get() >= 0); if (readCredit.get() == 0) { aio->stopReading(); |