Describe the bug
Implementation of statistics in cpp client have two concurrency issues.
ProducerStatsImpl (and ConsumerStatsImpl) classes use a single shared lock to protect access to internal data. The lock is taken on each sent or received message. Under high load this shared lock causes signficant contention and performance degradation.
Profiler shows that sending and receiving threads block each-other.
Since sending and receving functions access different member subset they should be protected by different mutex or other approach should be selected.
As example after patching issue I've got about 1/3 throughtput improvement. As you can see on screenshot below threads are witing on I/O but not on mutexes.
ProducerStatsImpl implementation has races between destructor and DeadlineTimer callback. Consider following scenario:
ProducerStatsImpl destructor acquire the mutex
DeadlineTimer calls calback flushAndReset and blocked on mutex
ProducerStatsImpl calls timer.cancel and cancel any pending operation but it cannot cancel already executed callback at step 2
ProducerStatsImpl destructor release mutex
DeadlineTimer acquire the mutex
ProducerStatsImpl destructor destroy object
DeadlineTimer callback access to deallocated memory
Are you willing accept PR for issue number one or both?
Original Issue: apache/pulsar-client-cpp#116
Describe the bug Implementation of statistics in cpp client have two concurrency issues.
Since sending and receving functions access different member subset they should be protected by different mutex or other approach should be selected. As example after patching issue I've got about 1/3 throughtput improvement. As you can see on screenshot below threads are witing on I/O but not on mutexes.
ProducerStatsImpl implementation has races between destructor and DeadlineTimer callback. Consider following scenario:
Are you willing accept PR for issue number one or both?