File: waitable_event_win.cc

package info (click to toggle)
thunderbird 1:52.8.0-1~deb8u1
  • links: PTS, VCS
  • area: main
  • in suites: jessie
  • size: 1,710,120 kB
  • sloc: cpp: 5,081,109; ansic: 2,051,982; python: 458,727; java: 241,615; xml: 193,367; asm: 178,649; sh: 81,881; makefile: 24,703; perl: 16,874; objc: 4,389; yacc: 1,816; ada: 1,697; lex: 1,257; pascal: 1,251; cs: 879; exp: 499; php: 436; lisp: 258; awk: 152; sed: 51; ruby: 47; csh: 27
file content (88 lines) | stat: -rw-r--r-- 2,737 bytes parent folder | download | duplicates (5)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/waitable_event.h"

#include <math.h>
#include <windows.h>

#include "base/logging.h"
#include "base/time.h"

namespace base {

WaitableEvent::WaitableEvent(bool manual_reset, bool signaled)
    : handle_(CreateEvent(NULL, manual_reset, signaled, NULL)) {
  // We're probably going to crash anyways if this is ever NULL, so we might as
  // well make our stack reports more informative by crashing here.
  CHECK(handle_);
}

WaitableEvent::~WaitableEvent() {
  CloseHandle(handle_);
}

void WaitableEvent::Reset() {
  ResetEvent(handle_);
}

void WaitableEvent::Signal() {
  SetEvent(handle_);
}

bool WaitableEvent::IsSignaled() {
  return TimedWait(TimeDelta::FromMilliseconds(0));
}

bool WaitableEvent::Wait() {
  DWORD result = WaitForSingleObject(handle_, INFINITE);
  // It is most unexpected that this should ever fail.  Help consumers learn
  // about it if it should ever fail.
  DCHECK(result == WAIT_OBJECT_0) << "WaitForSingleObject failed";
  return result == WAIT_OBJECT_0;
}

bool WaitableEvent::TimedWait(const TimeDelta& max_time) {
  DCHECK(max_time >= TimeDelta::FromMicroseconds(0));
  // Be careful here.  TimeDelta has a precision of microseconds, but this API
  // is in milliseconds.  If there are 5.5ms left, should the delay be 5 or 6?
  // It should be 6 to avoid returning too early.
  double timeout = ceil(max_time.InMillisecondsF());
  DWORD result = WaitForSingleObject(handle_, static_cast<DWORD>(timeout));
  switch (result) {
    case WAIT_OBJECT_0:
      return true;
    case WAIT_TIMEOUT:
      return false;
  }
  // It is most unexpected that this should ever fail.  Help consumers learn
  // about it if it should ever fail.
  NOTREACHED() << "WaitForSingleObject failed";
  return false;
}

// static
size_t WaitableEvent::WaitMany(WaitableEvent** events, size_t count) {
  HANDLE handles[MAXIMUM_WAIT_OBJECTS];
  CHECK(count <= MAXIMUM_WAIT_OBJECTS)
      << "Can only wait on " << MAXIMUM_WAIT_OBJECTS << " with WaitMany";

  for (size_t i = 0; i < count; ++i)
    handles[i] = events[i]->handle();

  DWORD result =
      WaitForMultipleObjects(count, handles,
                             FALSE,      // don't wait for all the objects
                             INFINITE);  // no timeout
  if (result >= WAIT_OBJECT_0 + count) {
    NOTREACHED() << "WaitForMultipleObjects failed: " << GetLastError();
    return 0;
  }

  return result - WAIT_OBJECT_0;
}

}  // namespace base