From a43e67ea1a314e5c6faf77457ffc5ea39c24d4ca Mon Sep 17 00:00:00 2001 From: Hans Boehm Date: Sat, 9 Sep 2023 23:19:28 +0000 Subject: Revert "Revert^14 "Thread suspension cleanup and deadlock fix"" This reverts commit f9fdd3ce0180972dc8d4f0c8410ea7702828a703. Reason for revert: Very suspicious host-x86_64-debug failure on LUCI. Change-Id: Ia01dd3df8d64d6bc0d12319b06a8380f64a46785 --- runtime/native/dalvik_system_VMStack.cc | 29 +++++++++++------------------ 1 file changed, 11 insertions(+), 18 deletions(-) (limited to 'runtime/native/dalvik_system_VMStack.cc') diff --git a/runtime/native/dalvik_system_VMStack.cc b/runtime/native/dalvik_system_VMStack.cc index bf441b4b1d..71078c9ad2 100644 --- a/runtime/native/dalvik_system_VMStack.cc +++ b/runtime/native/dalvik_system_VMStack.cc @@ -48,29 +48,19 @@ static ResultT GetThreadStack(const ScopedFastNativeObjectAccess& soa, } else { // Never allow suspending the heap task thread since it may deadlock if allocations are // required for the stack trace. - Thread* heap_task_thread = nullptr; - for (int i = 0; i < 20; ++i) { - heap_task_thread = Runtime::Current()->GetHeap()->GetTaskProcessor()->GetRunningThread(); - if (heap_task_thread != nullptr) { - break; - } - // heap_task_thread could be null if the daemons aren't fully running yet. But it can appear - // in enumerations, and thus we could try to get its stack even before that. Try to wait - // for a non-null value so we can avoid suspending it. - static constexpr int kHeapTaskDaemonSleepMicros = 5000; - usleep(kHeapTaskDaemonSleepMicros); - } - if (heap_task_thread == nullptr) { - LOG(ERROR) << "No HeapTaskDaemon; refusing to get thread stack."; - return nullptr; - } - if (decoded_peer == heap_task_thread->GetPeerFromOtherThread()) { + Thread* heap_task_thread = + Runtime::Current()->GetHeap()->GetTaskProcessor()->GetRunningThread(); + // heap_task_thread could be null if the daemons aren't yet started. + if (heap_task_thread != nullptr && decoded_peer == heap_task_thread->GetPeerFromOtherThread()) { return nullptr; } // Suspend thread to build stack trace. ScopedThreadSuspension sts(soa.Self(), ThreadState::kNative); ThreadList* thread_list = Runtime::Current()->GetThreadList(); - Thread* thread = thread_list->SuspendThreadByPeer(peer, SuspendReason::kInternal); + bool timed_out; + Thread* thread = thread_list->SuspendThreadByPeer(peer, + SuspendReason::kInternal, + &timed_out); if (thread != nullptr) { // Must be runnable to create returned array. { @@ -80,6 +70,9 @@ static ResultT GetThreadStack(const ScopedFastNativeObjectAccess& soa, // Restart suspended thread. bool resumed = thread_list->Resume(thread, SuspendReason::kInternal); DCHECK(resumed); + } else if (timed_out) { + LOG(ERROR) << "Trying to get thread's stack failed as the thread failed to suspend within a " + "generous timeout."; } } return trace; -- cgit v1.2.3-59-g8ed1b