diff options
| -rw-r--r-- | runtime/monitor.cc | 15 | ||||
| -rw-r--r-- | runtime/monitor.h | 8 | ||||
| -rw-r--r-- | runtime/read_barrier-inl.h | 15 | ||||
| -rw-r--r-- | runtime/read_barrier.h | 4 |
4 files changed, 33 insertions, 9 deletions
diff --git a/runtime/monitor.cc b/runtime/monitor.cc index f783edb..7d297cb 100644 --- a/runtime/monitor.cc +++ b/runtime/monitor.cc @@ -111,7 +111,7 @@ bool Monitor::Install(Thread* self) { MutexLock mu(self, monitor_lock_); // Uncontended mutex acquisition as monitor isn't yet public. CHECK(owner_ == nullptr || owner_ == self || owner_->IsSuspended()); // Propagate the lock state. - LockWord lw(obj_->GetLockWord(false)); + LockWord lw(GetObject()->GetLockWord(false)); switch (lw.GetState()) { case LockWord::kThinLocked: { CHECK_EQ(owner_->GetThreadId(), lw.ThinLockOwner()); @@ -137,7 +137,7 @@ bool Monitor::Install(Thread* self) { } LockWord fat(this); // Publish the updated lock word, which may race with other threads. - bool success = obj_->CasLockWord(lw, fat); + bool success = GetObject()->CasLockWord(lw, fat); // Lock profiling. if (success && owner_ != nullptr && lock_profiling_threshold_ != 0) { locking_method_ = owner_->GetCurrentMethod(&locking_dex_pc_); @@ -228,7 +228,7 @@ void Monitor::Lock(Thread* self) { monitor_lock_.Unlock(self); // Let go of locks in order. { ScopedThreadStateChange tsc(self, kBlocked); // Change to blocked and give up mutator_lock_. - self->SetMonitorEnterObject(obj_); + self->SetMonitorEnterObject(GetObject()); MutexLock mu2(self, monitor_lock_); // Reacquire monitor_lock_ without mutator_lock_ for Wait. if (owner_ != NULL) { // Did the owner_ give the lock up? monitor_contenders_.Wait(self); // Still contended so wait. @@ -363,7 +363,7 @@ bool Monitor::Unlock(Thread* self) { // We don't own this, so we're not allowed to unlock it. // The JNI spec says that we should throw IllegalMonitorStateException // in this case. - FailedUnlock(obj_, self, owner, this); + FailedUnlock(GetObject(), self, owner, this); return false; } return true; @@ -895,7 +895,7 @@ void Monitor::DescribeWait(std::ostream& os, const Thread* thread) { MutexLock mu(self, *thread->GetWaitMutex()); Monitor* monitor = thread->GetWaitMonitor(); if (monitor != nullptr) { - pretty_object = monitor->obj_; + pretty_object = monitor->GetObject(); } } else if (state == kBlocked) { wait_message = " - waiting to lock "; @@ -1101,12 +1101,13 @@ void MonitorList::SweepMonitorList(IsMarkedCallback* callback, void* arg) { MutexLock mu(Thread::Current(), monitor_list_lock_); for (auto it = list_.begin(); it != list_.end(); ) { Monitor* m = *it; - mirror::Object* obj = m->GetObject(); + // Disable the read barrier in GetObject() as this is called by GC. + mirror::Object* obj = m->GetObject<kWithoutReadBarrier>(); // The object of a monitor can be null if we have deflated it. mirror::Object* new_obj = obj != nullptr ? callback(obj, arg) : nullptr; if (new_obj == nullptr) { VLOG(monitor) << "freeing monitor " << m << " belonging to unmarked object " - << m->GetObject(); + << obj; delete m; it = list_.erase(it); } else { diff --git a/runtime/monitor.h b/runtime/monitor.h index bc1b2ed4..7af2d4c 100644 --- a/runtime/monitor.h +++ b/runtime/monitor.h @@ -27,6 +27,7 @@ #include "atomic.h" #include "base/mutex.h" #include "object_callbacks.h" +#include "read_barrier.h" #include "thread_state.h" namespace art { @@ -92,8 +93,9 @@ class Monitor { static bool IsValidLockWord(LockWord lock_word); + template<ReadBarrierOption kReadBarrierOption = kWithReadBarrier> mirror::Object* GetObject() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { - return obj_; + return ReadBarrier::BarrierForWeakRoot<mirror::Object, kReadBarrierOption>(obj_); } void SetObject(mirror::Object* object); @@ -190,7 +192,9 @@ class Monitor { // Owner's recursive lock depth. int lock_count_ GUARDED_BY(monitor_lock_); - // What object are we part of. + // What object are we part of. This is a weak root. Do not access + // this directly, use GetObject() to read it so it will be guarded + // by a read barrier. mirror::Object* obj_; // Threads currently waiting on this monitor. diff --git a/runtime/read_barrier-inl.h b/runtime/read_barrier-inl.h index 88e2f8f..4302c9e 100644 --- a/runtime/read_barrier-inl.h +++ b/runtime/read_barrier-inl.h @@ -43,6 +43,21 @@ inline MirrorType* ReadBarrier::Barrier( } } +template <typename MirrorType, ReadBarrierOption kReadBarrierOption> +inline MirrorType* ReadBarrier::BarrierForWeakRoot(MirrorType* ref) { + UNUSED(ref); + const bool with_read_barrier = kReadBarrierOption == kWithReadBarrier; + if (with_read_barrier && kUseBakerReadBarrier) { + // To be implemented. + return ref; + } else if (with_read_barrier && kUseBrooksReadBarrier) { + // To be implemented. + return ref; + } else { + return ref; + } +} + } // namespace art #endif // ART_RUNTIME_READ_BARRIER_INL_H_ diff --git a/runtime/read_barrier.h b/runtime/read_barrier.h index 73c3d43..e40e8ea 100644 --- a/runtime/read_barrier.h +++ b/runtime/read_barrier.h @@ -37,6 +37,10 @@ class ReadBarrier { ALWAYS_INLINE static MirrorType* Barrier( mirror::Object* obj, MemberOffset offset, mirror::HeapReference<MirrorType>* ref_addr) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); + + template <typename MirrorType, ReadBarrierOption kReadBarrierOption = kWithReadBarrier> + ALWAYS_INLINE static MirrorType* BarrierForWeakRoot(MirrorType* ref) + SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); }; } // namespace art |