15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2011 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/synchronization/waitable_event.h" 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <math.h> 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <windows.h> 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/logging.h" 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/threading/thread_restrictions.h" 12eb525c5499e34cc9c4b825d6d9e75bb07cc06aceBen Murdoch#include "base/time/time.h" 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace base { 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WaitableEvent::WaitableEvent(bool manual_reset, bool signaled) 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) : handle_(CreateEvent(NULL, manual_reset, signaled, NULL)) { 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // We're probably going to crash anyways if this is ever NULL, so we might as 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // well make our stack reports more informative by crashing here. 201320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci CHECK(handle_.IsValid()); 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WaitableEvent::WaitableEvent(HANDLE handle) 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) : handle_(handle) { 251320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci CHECK(handle_.IsValid()) << "Tried to create WaitableEvent from NULL handle"; 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)WaitableEvent::~WaitableEvent() { 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)HANDLE WaitableEvent::Release() { 321320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci return handle_.Take(); 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void WaitableEvent::Reset() { 361320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci ResetEvent(handle_.Get()); 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void WaitableEvent::Signal() { 401320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci SetEvent(handle_.Get()); 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)bool WaitableEvent::IsSignaled() { 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return TimedWait(TimeDelta::FromMilliseconds(0)); 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void WaitableEvent::Wait() { 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::ThreadRestrictions::AssertWaitAllowed(); 491320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci DWORD result = WaitForSingleObject(handle_.Get(), INFINITE); 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // It is most unexpected that this should ever fail. Help consumers learn 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // about it if it should ever fail. 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DCHECK_EQ(WAIT_OBJECT_0, result) << "WaitForSingleObject failed"; 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)bool WaitableEvent::TimedWait(const TimeDelta& max_time) { 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::ThreadRestrictions::AssertWaitAllowed(); 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DCHECK(max_time >= TimeDelta::FromMicroseconds(0)); 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Be careful here. TimeDelta has a precision of microseconds, but this API 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // is in milliseconds. If there are 5.5ms left, should the delay be 5 or 6? 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // It should be 6 to avoid returning too early. 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) double timeout = ceil(max_time.InMillisecondsF()); 621320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci DWORD result = WaitForSingleObject(handle_.Get(), 631320f92c476a1ad9d19dba2a48c72b75566198e9Primiano Tucci static_cast<DWORD>(timeout)); 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) switch (result) { 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) case WAIT_OBJECT_0: 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return true; 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) case WAIT_TIMEOUT: 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return false; 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // It is most unexpected that this should ever fail. Help consumers learn 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // about it if it should ever fail. 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) NOTREACHED() << "WaitForSingleObject failed"; 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return false; 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// static 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)size_t WaitableEvent::WaitMany(WaitableEvent** events, size_t count) { 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::ThreadRestrictions::AssertWaitAllowed(); 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) HANDLE handles[MAXIMUM_WAIT_OBJECTS]; 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) CHECK_LE(count, MAXIMUM_WAIT_OBJECTS) 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) << "Can only wait on " << MAXIMUM_WAIT_OBJECTS << " with WaitMany"; 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (size_t i = 0; i < count; ++i) 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) handles[i] = events[i]->handle(); 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The cast is safe because count is small - see the CHECK above. 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DWORD result = 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) WaitForMultipleObjects(static_cast<DWORD>(count), 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) handles, 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) FALSE, // don't wait for all the objects 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) INFINITE); // no timeout 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (result >= WAIT_OBJECT_0 + count) { 93cedac228d2dd51db4b79ea1e72c7f249408ee061Torne (Richard Coles) DPLOG(FATAL) << "WaitForMultipleObjects failed"; 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return 0; 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return result - WAIT_OBJECT_0; 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace base 101