Coverage Report

Created: 2018-09-25 14:53

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