3c12f4dadb
Reason for revert: Caused static initializers. BUG=chromium:556866 TBR=tommi@webrtc.org Original issue's description: > Create rtc::AtomicInt POD struct. > > Prevents accidental non-atomic reads, increments and stores since > "volatile int" doesn't enforce atomic usage. > > BUG= > R=kwiberg@webrtc.org, tommi@webrtc.org > > Committed: https://crrev.com/b27f590ece487819c3d1fda400315e582fb975b6 > Cr-Commit-Position: refs/heads/master@{#10657} TBR=kwiberg@webrtc.org,tommi@webrtc.org NOPRESUBMIT=true NOTREECHECKS=true NOTRY=true BUG= Review URL: https://codereview.webrtc.org/1453093002 Cr-Commit-Position: refs/heads/master@{#10669}
130 lines
3.6 KiB
C++
130 lines
3.6 KiB
C++
/*
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* Copyright 2004 The WebRTC Project Authors. All rights reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef WEBRTC_BASE_CRITICALSECTION_H_
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#define WEBRTC_BASE_CRITICALSECTION_H_
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#include "webrtc/base/atomicops.h"
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#include "webrtc/base/constructormagic.h"
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#include "webrtc/base/thread_annotations.h"
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#if defined(WEBRTC_WIN)
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// Include winsock2.h before including <windows.h> to maintain consistency with
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// win32.h. We can't include win32.h directly here since it pulls in
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// headers such as basictypes.h which causes problems in Chromium where webrtc
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// exists as two separate projects, webrtc and libjingle.
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#include <winsock2.h>
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#include <windows.h>
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#include <sal.h> // must come after windows headers.
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#endif // defined(WEBRTC_WIN)
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#if defined(WEBRTC_POSIX)
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#include <pthread.h>
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#endif
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#if (!defined(NDEBUG) || defined(DCHECK_ALWAYS_ON))
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#define CS_DEBUG_CHECKS 1
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#endif
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#if CS_DEBUG_CHECKS
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#define CS_DEBUG_CODE(x) x
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#else // !CS_DEBUG_CHECKS
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#define CS_DEBUG_CODE(x)
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#endif // !CS_DEBUG_CHECKS
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namespace rtc {
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class LOCKABLE CriticalSection {
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public:
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CriticalSection();
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~CriticalSection();
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void Enter() EXCLUSIVE_LOCK_FUNCTION();
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bool TryEnter() EXCLUSIVE_TRYLOCK_FUNCTION(true);
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void Leave() UNLOCK_FUNCTION();
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// Use only for RTC_DCHECKing.
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bool CurrentThreadIsOwner() const;
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// Use only for RTC_DCHECKing.
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bool IsLocked() const;
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private:
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#if defined(WEBRTC_WIN)
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CRITICAL_SECTION crit_;
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#elif defined(WEBRTC_POSIX)
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pthread_mutex_t mutex_;
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CS_DEBUG_CODE(pthread_t thread_);
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CS_DEBUG_CODE(int recursion_count_);
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#endif
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};
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// CritScope, for serializing execution through a scope.
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class SCOPED_LOCKABLE CritScope {
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public:
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explicit CritScope(CriticalSection* cs) EXCLUSIVE_LOCK_FUNCTION(cs);
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~CritScope() UNLOCK_FUNCTION();
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private:
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CriticalSection* const cs_;
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RTC_DISALLOW_COPY_AND_ASSIGN(CritScope);
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};
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// Tries to lock a critical section on construction via
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// CriticalSection::TryEnter, and unlocks on destruction if the
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// lock was taken. Never blocks.
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//
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// IMPORTANT: Unlike CritScope, the lock may not be owned by this thread in
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// subsequent code. Users *must* check locked() to determine if the
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// lock was taken. If you're not calling locked(), you're doing it wrong!
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class TryCritScope {
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public:
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explicit TryCritScope(CriticalSection* cs);
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~TryCritScope();
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#if defined(WEBRTC_WIN)
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_Check_return_ bool locked() const;
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#else
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bool locked() const __attribute__((warn_unused_result));
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#endif
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private:
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CriticalSection* const cs_;
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const bool locked_;
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CS_DEBUG_CODE(mutable bool lock_was_called_);
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RTC_DISALLOW_COPY_AND_ASSIGN(TryCritScope);
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};
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// A POD lock used to protect global variables. Do NOT use for other purposes.
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// No custom constructor or private data member should be added.
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class LOCKABLE GlobalLockPod {
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public:
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void Lock() EXCLUSIVE_LOCK_FUNCTION();
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void Unlock() UNLOCK_FUNCTION();
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volatile int lock_acquired;
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};
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class GlobalLock : public GlobalLockPod {
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public:
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GlobalLock();
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};
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// GlobalLockScope, for serializing execution through a scope.
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class SCOPED_LOCKABLE GlobalLockScope {
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public:
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explicit GlobalLockScope(GlobalLockPod* lock) EXCLUSIVE_LOCK_FUNCTION(lock);
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~GlobalLockScope() UNLOCK_FUNCTION();
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private:
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GlobalLockPod* const lock_;
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RTC_DISALLOW_COPY_AND_ASSIGN(GlobalLockScope);
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};
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} // namespace rtc
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#endif // WEBRTC_BASE_CRITICALSECTION_H_
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