| /* |
| * Copyright (C) 2011, 2013 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. |
| */ |
| |
| #include "config.h" |
| #include "LayerChangesFlusher.h" |
| |
| #if USE(CA) |
| |
| #include "AbstractCACFLayerTreeHost.h" |
| #include "StructuredExceptionHandlerSuppressor.h" |
| #include <wtf/NeverDestroyed.h> |
| #include <wtf/StdLibExtras.h> |
| #include <wtf/Vector.h> |
| |
| namespace WebCore { |
| |
| LayerChangesFlusher& LayerChangesFlusher::singleton() |
| { |
| static NeverDestroyed<LayerChangesFlusher> flusher; |
| return flusher; |
| } |
| |
| LayerChangesFlusher::LayerChangesFlusher() |
| : m_hook(0) |
| , m_isCallingHosts(false) |
| { |
| } |
| |
| void LayerChangesFlusher::flushPendingLayerChangesSoon(AbstractCACFLayerTreeHost* host) |
| { |
| if (!m_hostsWithChangesToFlush.add(host).isNewEntry || m_hook) |
| return; |
| |
| setHook(); |
| } |
| |
| void LayerChangesFlusher::cancelPendingFlush(AbstractCACFLayerTreeHost* host) |
| { |
| m_hostsWithChangesToFlush.remove(host); |
| |
| if (!m_hostsWithChangesToFlush.isEmpty() || !m_hook) |
| return; |
| |
| // We handle removing the hook when we finish calling out to the hosts, so we shouldn't |
| // mess with it while we're in the process of calling them. |
| if (m_isCallingHosts) |
| return; |
| |
| removeHook(); |
| } |
| |
| LRESULT LayerChangesFlusher::hookCallback(int code, WPARAM wParam, LPARAM lParam) |
| { |
| // Suppress the exception handler Windows puts around all hook calls so we can |
| // crash for debugging purposes if an exception is hit. |
| ExceptionRegistration registrationStruct; // Note: must be stack allocated. |
| StructuredExceptionHandlerSuppressor suppressor(registrationStruct); |
| return singleton().hookFired(code, wParam, lParam); |
| } |
| |
| LRESULT LayerChangesFlusher::hookFired(int code, WPARAM wParam, LPARAM lParam) |
| { |
| ASSERT(m_hook); |
| |
| // Calling out to the hosts can cause m_hostsWithChangesToFlush to be modified, so we copy it |
| // into a Vector first. |
| auto hosts = copyToVector(m_hostsWithChangesToFlush); |
| m_hostsWithChangesToFlush.clear(); |
| |
| m_isCallingHosts = true; |
| for (size_t i = 0; i < hosts.size(); ++i) |
| hosts[i]->flushPendingLayerChangesNow(); |
| m_isCallingHosts = false; |
| |
| LRESULT result = ::CallNextHookEx(m_hook, code, wParam, lParam); |
| |
| if (m_hook && m_hostsWithChangesToFlush.isEmpty()) { |
| // We won't have any work to do next time around, so just remove our hook. |
| removeHook(); |
| } |
| |
| return result; |
| } |
| |
| void LayerChangesFlusher::setHook() |
| { |
| ASSERT(!m_hook); |
| ASSERT(!m_isCallingHosts); |
| |
| DWORD threadID = ::GetCurrentThreadId(); |
| |
| m_hook = ::SetWindowsHookExW(WH_GETMESSAGE, hookCallback, 0, threadID); |
| ASSERT_WITH_MESSAGE(m_hook, "::SetWindowsHookExW failed with error %lu", ::GetLastError()); |
| |
| // Post a message to the message queue to prevent ::GetMessage from blocking, which will ensure |
| // our hook is called soon. |
| ::PostThreadMessageW(threadID, WM_NULL, 0, 0); |
| } |
| |
| void LayerChangesFlusher::removeHook() |
| { |
| ASSERT(m_hook); |
| ASSERT(!m_isCallingHosts); |
| |
| if (!::UnhookWindowsHookEx(m_hook)) |
| ASSERT_WITH_MESSAGE(false, "::UnhookWindowsHookEx failed with error %lu", ::GetLastError()); |
| |
| m_hook = 0; |
| } |
| |
| } // namespace WebCore |
| |
| #endif |