| /* |
| * Copyright (C) 2007, 2008, 2015 Apple Inc. All rights reserved. |
| * Copyright (C) 2009 Google Inc. All rights reserved. |
| * Copyright (C) 2009 Torch Mobile, 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. |
| * 3. Neither the name of Apple Inc. ("Apple") nor the names of |
| * its contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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. |
| */ |
| |
| /* |
| * There are numerous academic and practical works on how to implement pthread_cond_wait/pthread_cond_signal/pthread_cond_broadcast |
| * functions on Win32. Here is one example: http://www.cs.wustl.edu/~schmidt/win32-cv-1.html which is widely credited as a 'starting point' |
| * of modern attempts. There are several more or less proven implementations, one in Boost C++ library (http://www.boost.org) and another |
| * in pthreads-win32 (http://sourceware.org/pthreads-win32/). |
| * |
| * The number of articles and discussions is the evidence of significant difficulties in implementing these primitives correctly. |
| * The brief search of revisions, ChangeLog entries, discussions in comp.programming.threads and other places clearly documents |
| * numerous pitfalls and performance problems the authors had to overcome to arrive to the suitable implementations. |
| * Optimally, WebKit would use one of those supported/tested libraries directly. To roll out our own implementation is impractical, |
| * if even for the lack of sufficient testing. However, a faithful reproduction of the code from one of the popular supported |
| * libraries seems to be a good compromise. |
| * |
| * The early Boost implementation (http://www.boxbackup.org/trac/browser/box/nick/win/lib/win32/boost_1_32_0/libs/thread/src/condition.cpp?rev=30) |
| * is identical to pthreads-win32 (http://sourceware.org/cgi-bin/cvsweb.cgi/pthreads/pthread_cond_wait.c?rev=1.10&content-type=text/x-cvsweb-markup&cvsroot=pthreads-win32). |
| * Current Boost uses yet another (although seemingly equivalent) algorithm which came from their 'thread rewrite' effort. |
| * |
| * This file includes timedWait/signal/broadcast implementations translated to WebKit coding style from the latest algorithm by |
| * Alexander Terekhov and Louis Thomas, as captured here: http://sourceware.org/cgi-bin/cvsweb.cgi/pthreads/pthread_cond_wait.c?rev=1.10&content-type=text/x-cvsweb-markup&cvsroot=pthreads-win32 |
| * It replaces the implementation of their previous algorithm, also documented in the same source above. |
| * The naming and comments are left very close to original to enable easy cross-check. |
| * |
| * The corresponding Pthreads-win32 License is included below, and CONTRIBUTORS file which it refers to is added to |
| * source directory (as CONTRIBUTORS.pthreads-win32). |
| */ |
| |
| /* |
| * Pthreads-win32 - POSIX Threads Library for Win32 |
| * Copyright(C) 1998 John E. Bossom |
| * Copyright(C) 1999,2005 Pthreads-win32 contributors |
| * |
| * Contact Email: rpj@callisto.canberra.edu.au |
| * |
| * The current list of contributors is contained |
| * in the file CONTRIBUTORS included with the source |
| * code distribution. The list can also be seen at the |
| * following World Wide Web location: |
| * http://sources.redhat.com/pthreads-win32/contributors.html |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this library in the file COPYING.LIB; |
| * if not, write to the Free Software Foundation, Inc., |
| * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA |
| */ |
| |
| #include "config.h" |
| #include <wtf/Threading.h> |
| |
| #include <errno.h> |
| #include <process.h> |
| #include <windows.h> |
| #include <wtf/HashMap.h> |
| #include <wtf/Lock.h> |
| #include <wtf/MainThread.h> |
| #include <wtf/MathExtras.h> |
| #include <wtf/NeverDestroyed.h> |
| #include <wtf/ThreadingPrimitives.h> |
| |
| namespace WTF { |
| |
| static Lock globalSuspendLock; |
| |
| Thread::~Thread() |
| { |
| // It is OK because FLSAlloc's callback will be called even before there are some open handles. |
| // This easily ensures that all the thread resources are automatically closed. |
| if (m_handle != INVALID_HANDLE_VALUE) |
| CloseHandle(m_handle); |
| } |
| |
| void Thread::initializeCurrentThreadEvenIfNonWTFCreated() |
| { |
| } |
| |
| // MS_VC_EXCEPTION, THREADNAME_INFO, and setThreadNameInternal all come from <http://msdn.microsoft.com/en-us/library/xcb2z8hs.aspx>. |
| static const DWORD MS_VC_EXCEPTION = 0x406D1388; |
| |
| #pragma pack(push, 8) |
| typedef struct tagTHREADNAME_INFO { |
| DWORD dwType; // must be 0x1000 |
| LPCSTR szName; // pointer to name (in user addr space) |
| DWORD dwThreadID; // thread ID (-1=caller thread) |
| DWORD dwFlags; // reserved for future use, must be zero |
| } THREADNAME_INFO; |
| #pragma pack(pop) |
| |
| void Thread::initializeCurrentThreadInternal(const char* szThreadName) |
| { |
| #if COMPILER(MINGW) |
| // FIXME: Implement thread name setting with MingW. |
| UNUSED_PARAM(szThreadName); |
| #else |
| THREADNAME_INFO info; |
| info.dwType = 0x1000; |
| info.szName = Thread::normalizeThreadName(szThreadName); |
| info.dwThreadID = GetCurrentThreadId(); |
| info.dwFlags = 0; |
| |
| __try { |
| RaiseException(MS_VC_EXCEPTION, 0, sizeof(info) / sizeof(ULONG_PTR), reinterpret_cast<ULONG_PTR*>(&info)); |
| } __except(EXCEPTION_CONTINUE_EXECUTION) { } |
| #endif |
| initializeCurrentThreadEvenIfNonWTFCreated(); |
| } |
| |
| void Thread::initializePlatformThreading() |
| { |
| } |
| |
| static unsigned __stdcall wtfThreadEntryPoint(void* data) |
| { |
| Thread::entryPoint(reinterpret_cast<Thread::NewThreadContext*>(data)); |
| return 0; |
| } |
| |
| bool Thread::establishHandle(NewThreadContext* data, std::optional<size_t> stackSize, QOS) |
| { |
| unsigned threadIdentifier = 0; |
| unsigned initFlag = stackSize ? STACK_SIZE_PARAM_IS_A_RESERVATION : 0; |
| HANDLE threadHandle = reinterpret_cast<HANDLE>(_beginthreadex(nullptr, stackSize.value_or(0), wtfThreadEntryPoint, data, initFlag, &threadIdentifier)); |
| if (!threadHandle) { |
| LOG_ERROR("Failed to create thread at entry point %p with data %p: %ld", wtfThreadEntryPoint, data, errno); |
| return false; |
| } |
| establishPlatformSpecificHandle(threadHandle, threadIdentifier); |
| return true; |
| } |
| |
| void Thread::changePriority(int delta) |
| { |
| Locker locker { m_mutex }; |
| SetThreadPriority(m_handle, THREAD_PRIORITY_NORMAL + delta); |
| } |
| |
| int Thread::waitForCompletion() |
| { |
| HANDLE handle; |
| { |
| Locker locker { m_mutex }; |
| handle = m_handle; |
| } |
| |
| DWORD joinResult = WaitForSingleObject(handle, INFINITE); |
| if (joinResult == WAIT_FAILED) |
| LOG_ERROR("Thread %p was found to be deadlocked trying to quit", this); |
| |
| Locker locker { m_mutex }; |
| ASSERT(joinableState() == Joinable); |
| |
| // The thread has already exited, do nothing. |
| // The thread hasn't exited yet, so don't clean anything up. Just signal that we've already joined on it so that it will clean up after itself. |
| if (!hasExited()) |
| didJoin(); |
| |
| return joinResult; |
| } |
| |
| void Thread::detach() |
| { |
| // We follow the pthread semantics: even after the detach is called, |
| // we can still perform various operations onto the thread. For example, |
| // we can do pthread_kill for the detached thread. The problem in Windows |
| // is that closing HANDLE loses the way to do such operations. |
| // To do so, we do nothing here in Windows. Original detach's purpose, |
| // releasing thread resource when the thread exits, will be achieved by |
| // FlsCallback automatically. FlsCallback will call CloseHandle to clean up |
| // resource. So in this function, we just mark the thread as detached to |
| // avoid calling waitForCompletion for this thread. |
| Locker locker { m_mutex }; |
| if (!hasExited()) |
| didBecomeDetached(); |
| } |
| |
| auto Thread::suspend() -> Expected<void, PlatformSuspendError> |
| { |
| RELEASE_ASSERT_WITH_MESSAGE(this != &Thread::current(), "We do not support suspending the current thread itself."); |
| Locker locker { globalSuspendLock }; |
| DWORD result = SuspendThread(m_handle); |
| if (result != (DWORD)-1) |
| return { }; |
| return makeUnexpected(result); |
| } |
| |
| // During resume, suspend or resume should not be executed from the other threads. |
| void Thread::resume() |
| { |
| Locker locker { globalSuspendLock }; |
| ResumeThread(m_handle); |
| } |
| |
| size_t Thread::getRegisters(PlatformRegisters& registers) |
| { |
| Locker locker { globalSuspendLock }; |
| registers.ContextFlags = CONTEXT_INTEGER | CONTEXT_CONTROL; |
| GetThreadContext(m_handle, ®isters); |
| return sizeof(CONTEXT); |
| } |
| |
| Thread& Thread::initializeCurrentTLS() |
| { |
| // Not a WTF-created thread, ThreadIdentifier is not established yet. |
| WTF::initialize(); |
| Ref<Thread> thread = adoptRef(*new Thread()); |
| |
| HANDLE handle; |
| bool isSuccessful = DuplicateHandle(GetCurrentProcess(), GetCurrentThread(), GetCurrentProcess(), &handle, 0, FALSE, DUPLICATE_SAME_ACCESS); |
| RELEASE_ASSERT(isSuccessful); |
| |
| thread->establishPlatformSpecificHandle(handle, currentID()); |
| thread->initializeInThread(); |
| initializeCurrentThreadEvenIfNonWTFCreated(); |
| |
| return initializeTLS(WTFMove(thread)); |
| } |
| |
| ThreadIdentifier Thread::currentID() |
| { |
| return static_cast<ThreadIdentifier>(GetCurrentThreadId()); |
| } |
| |
| void Thread::establishPlatformSpecificHandle(HANDLE handle, ThreadIdentifier threadID) |
| { |
| Locker locker { m_mutex }; |
| m_handle = handle; |
| m_id = threadID; |
| } |
| |
| struct Thread::ThreadHolder { |
| ~ThreadHolder() |
| { |
| // The thread_local object of the main thread is destructed |
| // after Windows terminates other threads. If the terminated |
| // thread was holding a mutex, trying to lock the mutex causes |
| // deadlock. |
| if (isMainThread()) |
| return; |
| if (thread) { |
| thread->specificStorage().destroySlots(); |
| thread->didExit(); |
| } |
| } |
| |
| RefPtr<Thread> thread; |
| }; |
| |
| thread_local static Thread::ThreadHolder s_threadHolder; |
| |
| Thread* Thread::currentMayBeNull() |
| { |
| return s_threadHolder.thread.get(); |
| } |
| |
| Thread& Thread::initializeTLS(Ref<Thread>&& thread) |
| { |
| s_threadHolder.thread = WTFMove(thread); |
| return *s_threadHolder.thread; |
| } |
| |
| Atomic<int> Thread::SpecificStorage::s_numberOfKeys; |
| std::array<Atomic<Thread::SpecificStorage::DestroyFunction>, Thread::SpecificStorage::s_maxKeys> Thread::SpecificStorage::s_destroyFunctions; |
| |
| bool Thread::SpecificStorage::allocateKey(int& key, DestroyFunction destroy) |
| { |
| int k = s_numberOfKeys.exchangeAdd(1); |
| if (k >= s_maxKeys) { |
| s_numberOfKeys.exchangeSub(1); |
| return false; |
| } |
| key = k; |
| s_destroyFunctions[key].store(destroy); |
| return true; |
| } |
| |
| void* Thread::SpecificStorage::get(int key) |
| { |
| return m_slots[key]; |
| } |
| |
| void Thread::SpecificStorage::set(int key, void* value) |
| { |
| m_slots[key] = value; |
| } |
| |
| void Thread::SpecificStorage::destroySlots() |
| { |
| auto numberOfKeys = s_numberOfKeys.load(); |
| for (size_t i = 0; i < numberOfKeys; i++) { |
| auto destroy = s_destroyFunctions[i].load(); |
| if (destroy && m_slots[i]) { |
| destroy(m_slots[i]); |
| m_slots[i] = nullptr; |
| } |
| } |
| } |
| |
| Mutex::~Mutex() |
| { |
| } |
| |
| void Mutex::lock() |
| { |
| AcquireSRWLockExclusive(&m_mutex); |
| } |
| |
| bool Mutex::tryLock() |
| { |
| return TryAcquireSRWLockExclusive(&m_mutex); |
| } |
| |
| void Mutex::unlock() |
| { |
| ReleaseSRWLockExclusive(&m_mutex); |
| } |
| |
| // Returns an interval in milliseconds suitable for passing to one of the Win32 wait functions (e.g., ::WaitForSingleObject). |
| static DWORD absoluteTimeToWaitTimeoutInterval(WallTime absoluteTime) |
| { |
| WallTime currentTime = WallTime::now(); |
| |
| // Time is in the past - return immediately. |
| if (absoluteTime < currentTime) |
| return 0; |
| |
| // Time is too far in the future (and would overflow unsigned long) - wait forever. |
| if ((absoluteTime - currentTime) > Seconds::fromMilliseconds(INT_MAX)) |
| return INFINITE; |
| |
| return static_cast<DWORD>((absoluteTime - currentTime).milliseconds()); |
| } |
| |
| ThreadCondition::~ThreadCondition() |
| { |
| } |
| |
| void ThreadCondition::wait(Mutex& mutex) |
| { |
| SleepConditionVariableSRW(&m_condition, &mutex.impl(), INFINITE, 0); |
| } |
| |
| bool ThreadCondition::timedWait(Mutex& mutex, WallTime absoluteTime) |
| { |
| // https://msdn.microsoft.com/en-us/library/windows/desktop/ms686304(v=vs.85).aspx |
| DWORD interval = absoluteTimeToWaitTimeoutInterval(absoluteTime); |
| if (!interval) { |
| // Consider the wait to have timed out, even if our condition has already been signaled, to |
| // match the pthreads implementation. |
| return false; |
| } |
| |
| if (SleepConditionVariableSRW(&m_condition, &mutex.impl(), interval, 0)) |
| return true; |
| ASSERT(GetLastError() == ERROR_TIMEOUT); |
| return false; |
| } |
| |
| void ThreadCondition::signal() |
| { |
| WakeConditionVariable(&m_condition); |
| } |
| |
| void ThreadCondition::broadcast() |
| { |
| WakeAllConditionVariable(&m_condition); |
| } |
| |
| void Thread::yield() |
| { |
| SwitchToThread(); |
| } |
| |
| } // namespace WTF |