1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/ipc/chromium/src/base/waitable_event_win.cc Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,97 @@
1.4 +// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
1.5 +// Use of this source code is governed by a BSD-style license that can be
1.6 +// found in the LICENSE file.
1.7 +
1.8 +#include "base/waitable_event.h"
1.9 +
1.10 +#include <math.h>
1.11 +#include <windows.h>
1.12 +
1.13 +#include "base/logging.h"
1.14 +#include "base/time.h"
1.15 +
1.16 +namespace base {
1.17 +
1.18 +WaitableEvent::WaitableEvent(bool manual_reset, bool signaled)
1.19 + : handle_(CreateEvent(NULL, manual_reset, signaled, NULL)) {
1.20 + // We're probably going to crash anyways if this is ever NULL, so we might as
1.21 + // well make our stack reports more informative by crashing here.
1.22 + CHECK(handle_);
1.23 +}
1.24 +
1.25 +WaitableEvent::WaitableEvent(HANDLE handle)
1.26 + : handle_(handle) {
1.27 + CHECK(handle) << "Tried to create WaitableEvent from NULL handle";
1.28 +}
1.29 +
1.30 +WaitableEvent::~WaitableEvent() {
1.31 + CloseHandle(handle_);
1.32 +}
1.33 +
1.34 +HANDLE WaitableEvent::Release() {
1.35 + HANDLE rv = handle_;
1.36 + handle_ = INVALID_HANDLE_VALUE;
1.37 + return rv;
1.38 +}
1.39 +
1.40 +void WaitableEvent::Reset() {
1.41 + ResetEvent(handle_);
1.42 +}
1.43 +
1.44 +void WaitableEvent::Signal() {
1.45 + SetEvent(handle_);
1.46 +}
1.47 +
1.48 +bool WaitableEvent::IsSignaled() {
1.49 + return TimedWait(TimeDelta::FromMilliseconds(0));
1.50 +}
1.51 +
1.52 +bool WaitableEvent::Wait() {
1.53 + DWORD result = WaitForSingleObject(handle_, INFINITE);
1.54 + // It is most unexpected that this should ever fail. Help consumers learn
1.55 + // about it if it should ever fail.
1.56 + DCHECK(result == WAIT_OBJECT_0) << "WaitForSingleObject failed";
1.57 + return result == WAIT_OBJECT_0;
1.58 +}
1.59 +
1.60 +bool WaitableEvent::TimedWait(const TimeDelta& max_time) {
1.61 + DCHECK(max_time >= TimeDelta::FromMicroseconds(0));
1.62 + // Be careful here. TimeDelta has a precision of microseconds, but this API
1.63 + // is in milliseconds. If there are 5.5ms left, should the delay be 5 or 6?
1.64 + // It should be 6 to avoid returning too early.
1.65 + double timeout = ceil(max_time.InMillisecondsF());
1.66 + DWORD result = WaitForSingleObject(handle_, static_cast<DWORD>(timeout));
1.67 + switch (result) {
1.68 + case WAIT_OBJECT_0:
1.69 + return true;
1.70 + case WAIT_TIMEOUT:
1.71 + return false;
1.72 + }
1.73 + // It is most unexpected that this should ever fail. Help consumers learn
1.74 + // about it if it should ever fail.
1.75 + NOTREACHED() << "WaitForSingleObject failed";
1.76 + return false;
1.77 +}
1.78 +
1.79 +// static
1.80 +size_t WaitableEvent::WaitMany(WaitableEvent** events, size_t count) {
1.81 + HANDLE handles[MAXIMUM_WAIT_OBJECTS];
1.82 + CHECK(count <= MAXIMUM_WAIT_OBJECTS)
1.83 + << "Can only wait on " << MAXIMUM_WAIT_OBJECTS << " with WaitMany";
1.84 +
1.85 + for (size_t i = 0; i < count; ++i)
1.86 + handles[i] = events[i]->handle();
1.87 +
1.88 + DWORD result =
1.89 + WaitForMultipleObjects(count, handles,
1.90 + FALSE, // don't wait for all the objects
1.91 + INFINITE); // no timeout
1.92 + if (result < WAIT_OBJECT_0 || result >= WAIT_OBJECT_0 + count) {
1.93 + NOTREACHED() << "WaitForMultipleObjects failed: " << GetLastError();
1.94 + return 0;
1.95 + }
1.96 +
1.97 + return result - WAIT_OBJECT_0;
1.98 +}
1.99 +
1.100 +} // namespace base
