michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim: set ts=8 sts=2 et sw=2 tw=80: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef xpcom_build_IOInterposerPrivate_h
michael@0: #define xpcom_build_IOInterposerPrivate_h
michael@0: 
michael@0: /* This header file contains declarations for helper classes that are
michael@0:    to be used exclusively by IOInterposer and its observers. This header
michael@0:    file is not to be used by anything else and MUST NOT be exported! */
michael@0: 
michael@0: #include <prcvar.h>
michael@0: #include <prlock.h>
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace IOInterposer {
michael@0: 
michael@0: /**
michael@0:  * The following classes are simple wrappers for PRLock and PRCondVar.
michael@0:  * IOInterposer and friends use these instead of Mozilla::Mutex et al because
michael@0:  * of the fact that IOInterposer is permitted to run until the process
michael@0:  * terminates; we can't use anything that plugs into leak checkers or deadlock
michael@0:  * detectors because IOInterposer will outlive those and generate false
michael@0:  * positives.
michael@0:  */
michael@0: 
michael@0: class Monitor
michael@0: {
michael@0: public:
michael@0:   Monitor()
michael@0:     : mLock(PR_NewLock())
michael@0:     , mCondVar(PR_NewCondVar(mLock))
michael@0:   {
michael@0:   }
michael@0: 
michael@0:   ~Monitor()
michael@0:   {
michael@0:     PR_DestroyCondVar(mCondVar);
michael@0:     mCondVar = nullptr;
michael@0:     PR_DestroyLock(mLock);
michael@0:     mLock = nullptr;
michael@0:   }
michael@0: 
michael@0:   void Lock()
michael@0:   {
michael@0:     PR_Lock(mLock);
michael@0:   }
michael@0: 
michael@0:   void Unlock()
michael@0:   {
michael@0:     PR_Unlock(mLock);
michael@0:   }
michael@0: 
michael@0:   bool Wait(PRIntervalTime aTimeout = PR_INTERVAL_NO_TIMEOUT)
michael@0:   {
michael@0:     return PR_WaitCondVar(mCondVar, aTimeout) == PR_SUCCESS;
michael@0:   }
michael@0: 
michael@0:   bool Notify()
michael@0:   {
michael@0:     return PR_NotifyCondVar(mCondVar) == PR_SUCCESS;
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   PRLock*    mLock;
michael@0:   PRCondVar* mCondVar;
michael@0: };
michael@0: 
michael@0: class MonitorAutoLock
michael@0: {
michael@0: public:
michael@0:   MonitorAutoLock(Monitor &aMonitor)
michael@0:     : mMonitor(aMonitor)
michael@0:   {
michael@0:     mMonitor.Lock();
michael@0:   }
michael@0: 
michael@0:   ~MonitorAutoLock()
michael@0:   {
michael@0:     mMonitor.Unlock();
michael@0:   }
michael@0: 
michael@0:   bool Wait(PRIntervalTime aTimeout = PR_INTERVAL_NO_TIMEOUT)
michael@0:   {
michael@0:     return mMonitor.Wait(aTimeout);
michael@0:   }
michael@0: 
michael@0:   bool Notify()
michael@0:   {
michael@0:     return mMonitor.Notify();
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   Monitor&  mMonitor;
michael@0: };
michael@0: 
michael@0: class MonitorAutoUnlock
michael@0: {
michael@0: public:
michael@0:   MonitorAutoUnlock(Monitor &aMonitor)
michael@0:     : mMonitor(aMonitor)
michael@0:   {
michael@0:     mMonitor.Unlock();
michael@0:   }
michael@0: 
michael@0:   ~MonitorAutoUnlock()
michael@0:   {
michael@0:     mMonitor.Lock();
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   Monitor&  mMonitor;
michael@0: };
michael@0: 
michael@0: class Mutex
michael@0: {
michael@0: public:
michael@0:   Mutex()
michael@0:     : mPRLock(PR_NewLock())
michael@0:   {
michael@0:   }
michael@0: 
michael@0:   ~Mutex()
michael@0:   {
michael@0:     PR_DestroyLock(mPRLock);
michael@0:     mPRLock = nullptr;
michael@0:   }
michael@0: 
michael@0:   void Lock()
michael@0:   {
michael@0:     PR_Lock(mPRLock);
michael@0:   }
michael@0: 
michael@0:   void Unlock()
michael@0:   {
michael@0:     PR_Unlock(mPRLock);
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   PRLock*   mPRLock;
michael@0: };
michael@0: 
michael@0: class AutoLock
michael@0: {
michael@0: public:
michael@0:   AutoLock(Mutex& aLock)
michael@0:     : mLock(aLock)
michael@0:   {
michael@0:     mLock.Lock();
michael@0:   }
michael@0: 
michael@0:   ~AutoLock()
michael@0:   {
michael@0:     mLock.Unlock();
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   Mutex&     mLock;
michael@0: };
michael@0: 
michael@0: } // namespace IOInterposer
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif // xpcom_build_IOInterposerPrivate_h
michael@0: