You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
99 lines
3.3 KiB
99 lines
3.3 KiB
/*
|
|
* Copyright (C) 2016 The Android Open Source Project
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#ifndef ART_RUNTIME_GC_SYSTEM_WEAK_H_
|
|
#define ART_RUNTIME_GC_SYSTEM_WEAK_H_
|
|
|
|
#include "base/mutex.h"
|
|
#include "object_callbacks.h"
|
|
#include "thread-inl.h"
|
|
|
|
namespace art {
|
|
namespace gc {
|
|
|
|
class AbstractSystemWeakHolder {
|
|
public:
|
|
virtual ~AbstractSystemWeakHolder() {}
|
|
|
|
virtual void Allow() REQUIRES_SHARED(Locks::mutator_lock_) = 0;
|
|
virtual void Disallow() REQUIRES_SHARED(Locks::mutator_lock_) = 0;
|
|
// See Runtime::BroadcastForNewSystemWeaks for the broadcast_for_checkpoint definition.
|
|
virtual void Broadcast(bool broadcast_for_checkpoint) = 0;
|
|
|
|
virtual void Sweep(IsMarkedVisitor* visitor) REQUIRES_SHARED(Locks::mutator_lock_) = 0;
|
|
};
|
|
|
|
class SystemWeakHolder : public AbstractSystemWeakHolder {
|
|
public:
|
|
explicit SystemWeakHolder(LockLevel level)
|
|
: allow_disallow_lock_("SystemWeakHolder", level),
|
|
new_weak_condition_("SystemWeakHolder new condition", allow_disallow_lock_),
|
|
allow_new_system_weak_(true) {
|
|
}
|
|
virtual ~SystemWeakHolder() {}
|
|
|
|
void Allow() override
|
|
REQUIRES_SHARED(Locks::mutator_lock_)
|
|
REQUIRES(!allow_disallow_lock_) {
|
|
CHECK(!kUseReadBarrier);
|
|
MutexLock mu(Thread::Current(), allow_disallow_lock_);
|
|
allow_new_system_weak_ = true;
|
|
new_weak_condition_.Broadcast(Thread::Current());
|
|
}
|
|
|
|
void Disallow() override
|
|
REQUIRES_SHARED(Locks::mutator_lock_)
|
|
REQUIRES(!allow_disallow_lock_) {
|
|
CHECK(!kUseReadBarrier);
|
|
MutexLock mu(Thread::Current(), allow_disallow_lock_);
|
|
allow_new_system_weak_ = false;
|
|
}
|
|
|
|
void Broadcast(bool broadcast_for_checkpoint ATTRIBUTE_UNUSED) override
|
|
REQUIRES(!allow_disallow_lock_) {
|
|
MutexLock mu(Thread::Current(), allow_disallow_lock_);
|
|
new_weak_condition_.Broadcast(Thread::Current());
|
|
}
|
|
|
|
// WARNING: For lock annotations only.
|
|
Mutex* GetAllowDisallowLock() const RETURN_CAPABILITY(allow_disallow_lock_) {
|
|
return nullptr;
|
|
}
|
|
|
|
protected:
|
|
void Wait(Thread* self)
|
|
REQUIRES_SHARED(Locks::mutator_lock_)
|
|
REQUIRES(allow_disallow_lock_) {
|
|
// Wait for GC's sweeping to complete and allow new records
|
|
while (UNLIKELY((!kUseReadBarrier && !allow_new_system_weak_) ||
|
|
(kUseReadBarrier && !self->GetWeakRefAccessEnabled()))) {
|
|
// Check and run the empty checkpoint before blocking so the empty checkpoint will work in the
|
|
// presence of threads blocking for weak ref access.
|
|
self->CheckEmptyCheckpointFromWeakRefAccess(&allow_disallow_lock_);
|
|
new_weak_condition_.WaitHoldingLocks(self);
|
|
}
|
|
}
|
|
|
|
Mutex allow_disallow_lock_;
|
|
ConditionVariable new_weak_condition_ GUARDED_BY(allow_disallow_lock_);
|
|
bool allow_new_system_weak_ GUARDED_BY(allow_disallow_lock_);
|
|
};
|
|
|
|
} // namespace gc
|
|
} // namespace art
|
|
|
|
#endif // ART_RUNTIME_GC_SYSTEM_WEAK_H_
|