diff options
| -rw-r--r-- | absl/synchronization/mutex.cc | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/absl/synchronization/mutex.cc b/absl/synchronization/mutex.cc index c0268b62..69103ed8 100644 --- a/absl/synchronization/mutex.cc +++ b/absl/synchronization/mutex.cc @@ -2342,22 +2342,26 @@ ABSL_ATTRIBUTE_NOINLINE void Mutex::UnlockSlow(SynchWaitParams *waitp) { } // end of for(;;)-loop if (wake_list != kPerThreadSynchNull) { - int64_t wait_cycles = 0; + int64_t total_wait_cycles = 0; + int64_t max_wait_cycles = 0; int64_t now = base_internal::CycleClock::Now(); do { - // Sample lock contention events only if the waiter was trying to acquire + // Profile lock contention events only if the waiter was trying to acquire // the lock, not waiting on a condition variable or Condition. if (!wake_list->cond_waiter) { - wait_cycles += (now - wake_list->waitp->contention_start_cycles); + int64_t cycles_waited = + (now - wake_list->waitp->contention_start_cycles); + total_wait_cycles += cycles_waited; + if (max_wait_cycles == 0) max_wait_cycles = cycles_waited; wake_list->waitp->contention_start_cycles = now; wake_list->waitp->should_submit_contention_data = true; } wake_list = Wakeup(wake_list); // wake waiters } while (wake_list != kPerThreadSynchNull); - if (wait_cycles > 0) { - mutex_tracer("slow release", this, wait_cycles); + if (total_wait_cycles > 0) { + mutex_tracer("slow release", this, total_wait_cycles); ABSL_TSAN_MUTEX_PRE_DIVERT(this, 0); - submit_profile_data(wait_cycles); + submit_profile_data(total_wait_cycles); ABSL_TSAN_MUTEX_POST_DIVERT(this, 0); } } |