blob: 7ad731dfc46f70e8df4e04e7d6f9c9222f890877 [file] [log] [blame]
// Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/lockers.h"
#include "platform/assert.h"
#include "vm/heap/safepoint.h"
#include "vm/isolate.h"
namespace dart {
Monitor::WaitResult MonitorLocker::WaitWithSafepointCheck(Thread* thread,
int64_t millis) {
ASSERT(thread == Thread::Current());
ASSERT(thread->execution_state() == Thread::kThreadInVM);
#if defined(DEBUG)
if (no_safepoint_scope_) {
thread->DecrementNoSafepointScopeDepth();
}
#endif
thread->set_execution_state(Thread::kThreadInBlockedState);
thread->EnterSafepoint();
Monitor::WaitResult result = monitor_->Wait(millis);
// First try a fast update of the thread state to indicate it is not at a
// safepoint anymore.
if (!thread->TryExitSafepoint()) {
// Fast update failed which means we could potentially be in the middle
// of a safepoint operation and need to block for it.
monitor_->Exit();
SafepointHandler* handler = thread->isolate_group()->safepoint_handler();
handler->ExitSafepointUsingLock(thread);
monitor_->Enter();
}
thread->set_execution_state(Thread::kThreadInVM);
#if defined(DEBUG)
if (no_safepoint_scope_) {
thread->IncrementNoSafepointScopeDepth();
}
#endif
return result;
}
SafepointMutexLocker::SafepointMutexLocker(Mutex* mutex) : mutex_(mutex) {
ASSERT(mutex != NULL);
if (!mutex_->TryLock()) {
// We did not get the lock and could potentially block, so transition
// accordingly.
Thread* thread = Thread::Current();
if (thread != NULL) {
TransitionVMToBlocked transition(thread);
mutex->Lock();
} else {
mutex->Lock();
}
}
}
SafepointMonitorLocker::SafepointMonitorLocker(Monitor* monitor)
: monitor_(monitor) {
ASSERT(monitor_ != NULL);
if (!monitor_->TryEnter()) {
// We did not get the lock and could potentially block, so transition
// accordingly.
Thread* thread = Thread::Current();
if (thread != NULL) {
TransitionVMToBlocked transition(thread);
monitor_->Enter();
} else {
monitor_->Enter();
}
}
}
Monitor::WaitResult SafepointMonitorLocker::Wait(int64_t millis) {
Thread* thread = Thread::Current();
if (thread != NULL) {
Monitor::WaitResult result;
{
TransitionVMToBlocked transition(thread);
result = monitor_->Wait(millis);
}
return result;
} else {
return monitor_->Wait(millis);
}
}
} // namespace dart