3b7658a475
Instead of teaching TSAN than SkMutex is a lock to get around it not
understanding Mach semaphore_t routines, teach it that there is a
happens-before relationship between semaphore_signal() and
semaphore_wait().
This reverts commit e395bf2d18.
New changes are entirely restricted to SkSemaphore.cpp.
Change-Id: I27f647b93c48e81e8327db849881d669c4cd3d04
Reviewed-on: https://skia-review.googlesource.com/49180
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
94 lines
2.1 KiB
C++
94 lines
2.1 KiB
C++
/*
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* Copyright 2015 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#ifndef SkMutex_DEFINED
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#define SkMutex_DEFINED
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#include "../private/SkSemaphore.h"
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#include "../private/SkThreadID.h"
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#include "SkTypes.h"
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#define SK_DECLARE_STATIC_MUTEX(name) static SkBaseMutex name;
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class SkBaseMutex {
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public:
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constexpr SkBaseMutex() = default;
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void acquire() {
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fSemaphore.wait();
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SkDEBUGCODE(fOwner = SkGetThreadID();)
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}
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void release() {
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this->assertHeld();
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SkDEBUGCODE(fOwner = kIllegalThreadID;)
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fSemaphore.signal();
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}
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void assertHeld() {
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SkASSERT(fOwner == SkGetThreadID());
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}
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protected:
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SkBaseSemaphore fSemaphore{1};
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SkDEBUGCODE(SkThreadID fOwner{kIllegalThreadID};)
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};
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class SkMutex : public SkBaseMutex {
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public:
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using SkBaseMutex::SkBaseMutex;
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~SkMutex() { fSemaphore.cleanup(); }
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};
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class SkAutoMutexAcquire {
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public:
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template <typename T>
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SkAutoMutexAcquire(T* mutex) : fMutex(mutex) {
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if (mutex) {
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mutex->acquire();
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}
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fRelease = [](void* mutex) { ((T*)mutex)->release(); };
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}
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template <typename T>
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SkAutoMutexAcquire(T& mutex) : SkAutoMutexAcquire(&mutex) {}
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~SkAutoMutexAcquire() { this->release(); }
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void release() {
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if (fMutex) {
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fRelease(fMutex);
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}
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fMutex = nullptr;
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}
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private:
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void* fMutex;
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void (*fRelease)(void*);
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};
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#define SkAutoMutexAcquire(...) SK_REQUIRE_LOCAL_VAR(SkAutoMutexAcquire)
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// SkAutoExclusive is a lighter weight version of SkAutoMutexAcquire.
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// It assumes that there is a valid mutex, obviating the null check.
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class SkAutoExclusive {
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public:
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template <typename T>
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SkAutoExclusive(T& mutex) : fMutex(&mutex) {
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mutex.acquire();
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fRelease = [](void* mutex) { ((T*)mutex)->release(); };
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}
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~SkAutoExclusive() { fRelease(fMutex); }
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private:
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void* fMutex;
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void (*fRelease)(void*);
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};
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#define SkAutoExclusive(...) SK_REQUIRE_LOCAL_VAR(SkAutoExclusive)
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#endif//SkMutex_DEFINED
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