chromium/v8/src/heap/parked-scope.h

// Copyright 2020 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_HEAP_PARKED_SCOPE_H_
#define V8_HEAP_PARKED_SCOPE_H_

#include <optional>

#include "src/base/platform/condition-variable.h"
#include "src/base/platform/mutex.h"
#include "src/base/platform/semaphore.h"
#include "src/execution/local-isolate.h"
#include "src/heap/local-heap.h"

namespace v8 {
namespace internal {

// Scope that explicitly parks a thread, prohibiting access to the heap and the
// creation of handles. Do not use this directly! Use the family of
// ExecuteWhileParked methods, instead.
class V8_NODISCARD ParkedScope { … };

// Scope that explicitly unparks a thread, allowing access to the heap and the
// creation of handles.
class V8_NODISCARD UnparkedScope { … };

// Scope that explicitly unparks a background thread, allowing access to the
// heap and the creation of handles. It has no effect on the main thread.
class V8_NODISCARD UnparkedScopeIfOnBackground { … };

// Scope that automatically parks the thread while blocking on the given
// base::Mutex.
class V8_NODISCARD ParkedMutexGuard { … };

// Scope that automatically parks the thread while blocking on the given
// base::RecursiveMutex.
class V8_NODISCARD ParkedRecursiveMutexGuard { … };

template <base::MutexSharedType kIsShared,
          base::NullBehavior Behavior = base::NullBehavior::kRequireNotNull>
class V8_NODISCARD ParkedSharedMutexGuardIf final { … };

// A subclass of base::ConditionVariable that automatically parks the thread
// while waiting.
class V8_NODISCARD ParkingConditionVariable final
    : public base::ConditionVariable { … };

// A subclass of base::Semaphore that automatically parks the thread while
// waiting.
class V8_NODISCARD ParkingSemaphore final : public base::Semaphore { … };

class ParkingThread : public v8::base::Thread { … };

}  // namespace internal
}  // namespace v8

#endif  // V8_HEAP_PARKED_SCOPE_H_