diff options
Diffstat (limited to 'runtime/thread-inl.h')
| -rw-r--r-- | runtime/thread-inl.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/runtime/thread-inl.h b/runtime/thread-inl.h index d75a788e96..6c3811b8e5 100644 --- a/runtime/thread-inl.h +++ b/runtime/thread-inl.h @@ -312,6 +312,37 @@ inline void Thread::PoisonObjectPointersIfDebug() { } } +inline bool Thread::ModifySuspendCount(Thread* self, + int delta, + AtomicInteger* suspend_barrier, + bool for_debugger) { + if (delta > 0 && ((kUseReadBarrier && this != self) || suspend_barrier != nullptr)) { + // When delta > 0 (requesting a suspend), ModifySuspendCountInternal() may fail either if + // active_suspend_barriers is full or we are in the middle of a thread flip. Retry in a loop. + while (true) { + if (LIKELY(ModifySuspendCountInternal(self, delta, suspend_barrier, for_debugger))) { + return true; + } else { + // Failure means the list of active_suspend_barriers is full or we are in the middle of a + // thread flip, we should release the thread_suspend_count_lock_ (to avoid deadlock) and + // wait till the target thread has executed or Thread::PassActiveSuspendBarriers() or the + // flip function. Note that we could not simply wait for the thread to change to a suspended + // state, because it might need to run checkpoint function before the state change or + // resumes from the resume_cond_, which also needs thread_suspend_count_lock_. + // + // The list of active_suspend_barriers is very unlikely to be full since more than + // kMaxSuspendBarriers threads need to execute SuspendAllInternal() simultaneously, and + // target thread stays in kRunnable in the mean time. + Locks::thread_suspend_count_lock_->ExclusiveUnlock(self); + NanoSleep(100000); + Locks::thread_suspend_count_lock_->ExclusiveLock(self); + } + } + } else { + return ModifySuspendCountInternal(self, delta, suspend_barrier, for_debugger); + } +} + } // namespace art #endif // ART_RUNTIME_THREAD_INL_H_ |