/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- * vim: set ts=8 sts=4 et sw=4 tw=99: * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #ifndef vm_Monitor_h #define vm_Monitor_h #include "mozilla/DebugOnly.h" #include <stddef.h> #include "js/Utility.h" namespace js { // A base class used for types intended to be used in a parallel // fashion. Combines a lock and a condition variable. You can // acquire the lock or signal the condition variable using the // |AutoLockMonitor| type. class Monitor { protected: friend class AutoLockMonitor; friend class AutoUnlockMonitor; Mutex lock_; ConditionVariable condVar_; public: explicit Monitor(const MutexId& id) : lock_(id) { } }; class AutoLockMonitor : public LockGuard<Mutex> { private: using Base = LockGuard<Mutex>; Monitor& monitor; public: explicit AutoLockMonitor(Monitor& monitor) : Base(monitor.lock_) , monitor(monitor) { } bool isFor(Monitor& other) const { return monitor.lock_ == other.lock_; } void wait(ConditionVariable& condVar) { condVar.wait(*this); } void wait() { wait(monitor.condVar_); } void notify(ConditionVariable& condVar) { condVar.notify_one(); } void notify() { notify(monitor.condVar_); } void notifyAll(ConditionVariable& condVar) { condVar.notify_all(); } void notifyAll() { notifyAll(monitor.condVar_); } }; class AutoUnlockMonitor { private: Monitor& monitor; public: explicit AutoUnlockMonitor(Monitor& monitor) : monitor(monitor) { monitor.lock_.unlock(); } ~AutoUnlockMonitor() { monitor.lock_.lock(); } bool isFor(Monitor& other) const { return monitor.lock_ == other.lock_; } }; } // namespace js #endif /* vm_Monitor_h */