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/*
* Copyright (C) 2021 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <wtf/Compiler.h>
#include <wtf/MainThread.h>
#include <wtf/ThreadSafetyAnalysis.h>
#include <wtf/Threading.h>
namespace WTF {
// A type to use for asserting that private member functions or private member variables
// of a class are accessed from correct threads.
// Supports run-time checking with assertion enabled builds.
// Supports compile-time declaration and checking.
// Example:
// struct MyClass {
// void doTask() { assertIsCurrent(m_ownerThread); doTaskImpl(); }
// template<typename> void doTaskCompileFailure() { doTaskImpl(); }
// private:
// void doTaskImpl() WTF_REQUIRES_CAPABILITY(m_ownerThread);
// int m_value WTF_GUARDED_BY_CAPABILITY(m_ownerThread) { 0 };
// NO_UNIQUE_ADDRESS ThreadAssertion m_ownerThread;
// };
class WTF_CAPABILITY("is current") ThreadAssertion {
public:
ThreadAssertion() = default;
enum UninitializedTag { Uninitialized };
constexpr ThreadAssertion(UninitializedTag)
#if ASSERT_ENABLED
: m_uid(0) // Thread::uid() does not return this.
#endif
{
}
~ThreadAssertion() { assertIsCurrent(*this); }
void reset() { *this = ThreadAssertion { }; }
private:
#if ASSERT_ENABLED
uint32_t m_uid { Thread::current().uid() };
#endif
friend void assertIsCurrent(const ThreadAssertion&);
};
inline void assertIsCurrent(const ThreadAssertion& threadAssertion) WTF_ASSERTS_ACQUIRED_CAPABILITY(threadAssertion)
{
ASSERT_UNUSED(threadAssertion, Thread::current().uid() == threadAssertion.m_uid);
}
// Type for globally named assertions for describing access requirements.
// Can be used, for example, to require that a variable is accessed only in
// a known named thread.
// Example:
// extern NamedAssertion& mainThread;
// inline void assertIsMainThread() WTF_ASSERTS_ACQUIRED_CAPABILITY(mainThread);
// void myTask() WTF_REQUIRES_CAPABILITY(mainThread) { printf("my task is running"); }
// void runner() {
// assertIsMainThread();
// myTask();
// }
// template<typename> runnerCompileFailure() {
// myTask();
// }
class WTF_CAPABILITY("is current") NamedAssertion { };
// To be used with WTF_REQUIRES_CAPABILITY(mainThread). Symbol is undefined.
extern NamedAssertion& mainThread;
inline void assertIsMainThread() WTF_ASSERTS_ACQUIRED_CAPABILITY(mainThread) { ASSERT(isMainThread()); }
// To be used with WTF_REQUIRES_CAPABILITY(mainRunLoop). Symbol is undefined.
extern NamedAssertion& mainRunLoop;
inline void assertIsMainRunLoop() WTF_ASSERTS_ACQUIRED_CAPABILITY(mainRunLoop) { ASSERT(isMainRunLoop()); }
}
using WTF::ThreadAssertion;
using WTF::assertIsCurrent;
using WTF::NamedAssertion;
using WTF::assertIsMainThread;
using WTF::assertIsMainRunLoop;
using WTF::mainThread;
using WTF::mainRunLoop;