1// Copyright (c) 2012, Google Inc.
2// All rights reserved.
3//
4// Redistribution and use in source and binary forms, with or without
5// modification, are permitted provided that the following conditions are
6// met:
7//
8//     * Redistributions of source code must retain the above copyright
9// notice, this list of conditions and the following disclaimer.
10//     * Redistributions in binary form must reproduce the above
11// copyright notice, this list of conditions and the following disclaimer
12// in the documentation and/or other materials provided with the
13// distribution.
14//     * Neither the name of Google Inc. nor the names of its
15// contributors may be used to endorse or promote products derived from
16// this software without specific prior written permission.
17//
18// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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28// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29
30// This contains Pthread-related functions not provided by the Android NDK
31// but required by the Breakpad unit test. The functions are inlined here
32// in a C++ anonymous namespace in order to keep the build files simples.
33
34#ifndef GOOGLE_BREAKPAD_COMMON_ANDROID_TESTING_PTHREAD_FIXES_H
35#define GOOGLE_BREAKPAD_COMMON_ANDROID_TESTING_PTHREAD_FIXES_H
36
37#include <pthread.h>
38
39namespace {
40
41// Android doesn't provide pthread_barrier_t for now.
42#ifndef PTHREAD_BARRIER_SERIAL_THREAD
43
44// Anything except 0 will do here.
45#define PTHREAD_BARRIER_SERIAL_THREAD  0x12345
46
47typedef struct {
48  pthread_mutex_t  mutex;
49  pthread_cond_t   cond;
50  unsigned         count;
51} pthread_barrier_t;
52
53int pthread_barrier_init(pthread_barrier_t* barrier,
54                         const void* /* barrier_attr */,
55                         unsigned count) {
56  barrier->count = count;
57  pthread_mutex_init(&barrier->mutex, NULL);
58  pthread_cond_init(&barrier->cond, NULL);
59  return 0;
60}
61
62int pthread_barrier_wait(pthread_barrier_t* barrier) {
63  // Lock the mutex
64  pthread_mutex_lock(&barrier->mutex);
65  // Decrement the count. If this is the first thread to reach 0, wake up
66  // waiters, unlock the mutex, then return PTHREAD_BARRIER_SERIAL_THREAD.
67  if (--barrier->count == 0) {
68    // First thread to reach the barrier
69    pthread_cond_broadcast(&barrier->cond);
70    pthread_mutex_unlock(&barrier->mutex);
71    return PTHREAD_BARRIER_SERIAL_THREAD;
72  }
73  // Otherwise, wait for other threads until the count reaches 0, then
74  // return 0 to indicate this is not the first thread.
75  do {
76    pthread_cond_wait(&barrier->cond, &barrier->mutex);
77  } while (barrier->count > 0);
78
79  pthread_mutex_unlock(&barrier->mutex);
80  return 0;
81}
82
83int pthread_barrier_destroy(pthread_barrier_t *barrier) {
84  barrier->count = 0;
85  pthread_cond_destroy(&barrier->cond);
86  pthread_mutex_destroy(&barrier->mutex);
87  return 0;
88}
89
90#endif  // defined(PTHREAD_BARRIER_SERIAL_THREAD)
91
92int pthread_yield(void) {
93  sched_yield();
94  return 0;
95}
96
97}  // namespace
98
99#endif  // GOOGLE_BREAKPAD_COMMON_ANDROID_TESTING_PTHREAD_FIXES_H
100