text: /*
   * Copyright (C) 2010 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. 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 INC. 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.
   */
  
  #include "config.h"
  #include "RunLoop.h"
  
  #include "BinarySemaphore.h"
  #include <wtf/CurrentTime.h>
  
  using namespace CoreIPC;
  using namespace std;
  
  static const UINT PerformWorkMessage = WM_USER + 1;
  static const LPWSTR kRunLoopMessageWindowClassName = L"RunLoopMessageWindow";
  
  LRESULT CALLBACK RunLoop::RunLoopWndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
  {
      LONG_PTR longPtr = ::GetWindowLongPtr(hWnd, 0);
      
      if (RunLoop* runLoop = reinterpret_cast<RunLoop*>(longPtr))
          return runLoop->wndProc(hWnd, message, wParam, lParam);
  
      if (message == WM_CREATE) {
          LPCREATESTRUCT createStruct = reinterpret_cast<LPCREATESTRUCT>(lParam);
  
          // Associate the RunLoop with the window.
          ::SetWindowLongPtr(hWnd, 0, (LONG_PTR)createStruct->lpCreateParams);
          return 0;
      }
  
      return ::DefWindowProc(hWnd, message, wParam, lParam);
  }
  
  LRESULT RunLoop::wndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
  {
      switch (message) {
      case PerformWorkMessage:
          performWork();
          return 0;
      case WM_TIMER:
          RunLoop::TimerBase::timerFired(this, wParam);
          return 0;
      }
  
      return ::DefWindowProc(hWnd, message, wParam, lParam);
  }
  
  void RunLoop::run()
  {
      MSG message;
      while (BOOL result = ::GetMessage(&message, 0, 0, 0)) {
          if (result == -1)
              break;
          ::TranslateMessage(&message);
          ::DispatchMessage(&message);
      }
  }
  
  bool RunLoop::dispatchSentMessagesUntil(const Vector<HWND>& windows, CoreIPC::BinarySemaphore& semaphore, double absoluteTime)
  {
      if (windows.isEmpty())
          return semaphore.wait(absoluteTime);
  
      HANDLE handle = semaphore.event();
      DWORD handleCount = 1;
  
      while (true) {
          DWORD interval = absoluteTimeToWaitTimeoutInterval(absoluteTime);
          if (!interval) {
              // Consider the wait to have timed out, even if the semaphore is currently signaled.
              // This matches the WTF::ThreadCondition implementation of BinarySemaphore::wait.
              return false;
          }
  
          DWORD result = ::MsgWaitForMultipleObjectsEx(handleCount, &handle, interval, QS_SENDMESSAGE, 0);
          if (result == WAIT_OBJECT_0) {
              // The semaphore was signaled.
              return true;
          }
          if (result == WAIT_TIMEOUT) {
              // absoluteTime was reached.
              return false;
          }
          if (result == WAIT_OBJECT_0 + handleCount) {
              // One or more sent messages are available. Process sent messages for all the windows
              // we were given, since we don't have a way of knowing which window has available sent
              // messages.
              for (size_t i = 0; i < windows.size(); ++i) {
                  MSG message;
                  ::PeekMessageW(&message, windows[i], 0, 0, PM_NOREMOVE | PM_QS_SENDMESSAGE);
              }
              continue;
          }
          ASSERT_WITH_MESSAGE(result != WAIT_FAILED, "::MsgWaitForMultipleObjectsEx failed with error %lu", ::GetLastError());
          ASSERT_WITH_MESSAGE(false, "::MsgWaitForMultipleObjectsEx returned unexpected result %lu", result);
          return false;
      }
  }
  
  void RunLoop::stop()
  {
      ::PostQuitMessage(0);
  }
  
  bool RunLoop::registerRunLoopMessageWindowClass()
  {
      // FIXME: This really only needs to be called once.
  
      WNDCLASSEX windowClass = { 0 };
      windowClass.cbSize          = sizeof(windowClass);
      windowClass.lpfnWndProc     = RunLoop::RunLoopWndProc;
      windowClass.cbWndExtra      = sizeof(RunLoop*);
      windowClass.lpszClassName   = kRunLoopMessageWindowClassName;
  
      return !!::RegisterClassEx(&windowClass);
  }
  
  RunLoop::RunLoop()
  {
      registerRunLoopMessageWindowClass();
  
      m_runLoopMessageWindow = ::CreateWindow(kRunLoopMessageWindowClassName, 0, 0,
                                              CW_USEDEFAULT, 0, CW_USEDEFAULT, 0,
                                              HWND_MESSAGE, 0, 0, this);
      ASSERT(::IsWindow(m_runLoopMessageWindow));
  }
  
  RunLoop::~RunLoop()
  {
      // FIXME: Tear down the work item queue here.
  }
  
  void RunLoop::wakeUp()
  {
      // FIXME: No need to wake up the run loop if we've already called dispatch
      // before the run loop has had the time to respond.
      ::PostMessage(m_runLoopMessageWindow, PerformWorkMessage, reinterpret_cast<WPARAM>(this), 0);
  }
  
  // RunLoop::Timer
  
  void RunLoop::TimerBase::timerFired(RunLoop* runLoop, uint64_t ID)
  {
      TimerMap::iterator it = runLoop->m_activeTimers.find(ID);
      if (it == runLoop->m_activeTimers.end()) {
          // The timer must have been stopped after the WM_TIMER message was posted to the message queue.
          return;
      }
  
      TimerBase* timer = it->second;
  
      if (!timer->m_isRepeating) {
          runLoop->m_activeTimers.remove(it);
          ::KillTimer(runLoop->m_runLoopMessageWindow, ID);
      }
  
      timer->fired();
  }
  
  static uint64_t generateTimerID()
  {
      static uint64_t uniqueTimerID = 1;
      return uniqueTimerID++;
  }
  
  RunLoop::TimerBase::TimerBase(RunLoop* runLoop)
      : m_runLoop(runLoop)
      , m_ID(generateTimerID())
      , m_isRepeating(false)
  {
  }
  
  RunLoop::TimerBase::~TimerBase()
  {
      stop();
  }
  
  void RunLoop::TimerBase::start(double nextFireInterval, bool repeat)
  {
      m_isRepeating = repeat;
      m_runLoop->m_activeTimers.set(m_ID, this);
      ::SetTimer(m_runLoop->m_runLoopMessageWindow, m_ID, nextFireInterval * 1000, 0);
  }
  
  void RunLoop::TimerBase::stop()
  {
      TimerMap::iterator it = m_runLoop->m_activeTimers.find(m_ID);
      if (it == m_runLoop->m_activeTimers.end())
          return;
  
      m_runLoop->m_activeTimers.remove(it);
      ::KillTimer(m_runLoop->m_runLoopMessageWindow, m_ID);
  }
  
  bool RunLoop::TimerBase::isActive() const
  {
      return m_runLoop->m_activeTimers.contains(m_ID);
  }
  