platform_thread_android.cc revision 5f1c94371a64b3196d4be9466099bb892df9b88e 
1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "base/threading/platform_thread.h"
6
7#include <errno.h>
8#include <sys/prctl.h>
9#include <sys/resource.h>
10
11#include "base/android/jni_android.h"
12#include "base/android/thread_utils.h"
13#include "base/lazy_instance.h"
14#include "base/logging.h"
15#include "base/threading/thread_id_name_manager.h"
16#include "base/tracked_objects.h"
17#include "jni/ThreadUtils_jni.h"
18
19namespace base {
20
21namespace {
22int ThreadNiceValue(ThreadPriority priority) {
23  // These nice values are taken from Android, which uses nice
24  // values like linux, but defines some preset nice values.
25  //   Process.THREAD_PRIORITY_AUDIO = -16
26  //   Process.THREAD_PRIORITY_BACKGROUND = 10
27  //   Process.THREAD_PRIORITY_DEFAULT = 0;
28  //   Process.THREAD_PRIORITY_DISPLAY = -4;
29  //   Process.THREAD_PRIORITY_FOREGROUND = -2;
30  //   Process.THREAD_PRIORITY_LESS_FAVORABLE = 1;
31  //   Process.THREAD_PRIORITY_LOWEST = 19;
32  //   Process.THREAD_PRIORITY_MORE_FAVORABLE = -1;
33  //   Process.THREAD_PRIORITY_URGENT_AUDIO = -19;
34  //   Process.THREAD_PRIORITY_URGENT_DISPLAY = -8;
35  // We use -6 for display, but we may want to split this
36  // into urgent (-8) and non-urgent (-4).
37  static const int threadPriorityAudio = -16;
38  static const int threadPriorityBackground = 10;
39  static const int threadPriorityDefault = 0;
40  static const int threadPriorityDisplay = -6;
41  switch (priority) {
42    case kThreadPriority_RealtimeAudio:
43      return threadPriorityAudio;
44    case kThreadPriority_Background:
45      return threadPriorityBackground;
46    case kThreadPriority_Normal:
47      return threadPriorityDefault;
48    case kThreadPriority_Display:
49      return threadPriorityDisplay;
50    default:
51      NOTREACHED() << "Unknown priority.";
52      return 0;
53  }
54}
55} // namespace
56
57//static
58void PlatformThread::SetThreadPriority(PlatformThreadHandle handle,
59                                       ThreadPriority priority) {
60  // On Android, we set the Audio priority through JNI as Audio priority
61  // will also allow the process to run while it is backgrounded.
62  if (priority == kThreadPriority_RealtimeAudio) {
63    JNIEnv* env = base::android::AttachCurrentThread();
64    Java_ThreadUtils_setThreadPriorityAudio(env, PlatformThread::CurrentId());
65    return;
66  }
67
68  // setpriority(2) should change the whole thread group's (i.e. process)
69  // priority. however, on linux it will only change the target thread's
70  // priority. see the bugs section in
71  // http://man7.org/linux/man-pages/man2/getpriority.2.html.
72  // we prefer using 0 rather than the current thread id since they are
73  // equivalent but it makes sandboxing easier (https://crbug.com/399473).
74  DCHECK_NE(handle.id_, kInvalidThreadId);
75  int kNiceSetting = ThreadNiceValue(priority);
76  const PlatformThreadId current_id = PlatformThread::CurrentId();
77  if (setpriority(PRIO_PROCESS,
78                  handle.id_ == current_id ? 0 : handle.id_,
79                  kNiceSetting)) {
80    LOG(ERROR) << "Failed to set nice value of thread to " << kNiceSetting;
81  }
82}
83
84void PlatformThread::SetName(const char* name) {
85  ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
86  tracked_objects::ThreadData::InitializeThreadContext(name);
87
88  // Like linux, on android we can get the thread names to show up in the
89  // debugger by setting the process name for the LWP.
90  // We don't want to do this for the main thread because that would rename
91  // the process, causing tools like killall to stop working.
92  if (PlatformThread::CurrentId() == getpid())
93    return;
94
95  // Set the name for the LWP (which gets truncated to 15 characters).
96  int err = prctl(PR_SET_NAME, name);
97  if (err < 0 && errno != EPERM)
98    DPLOG(ERROR) << "prctl(PR_SET_NAME)";
99}
100
101
102void InitThreading() {
103}
104
105void InitOnThread() {
106  // Threads on linux/android may inherit their priority from the thread
107  // where they were created. This sets all new threads to the default.
108  PlatformThread::SetThreadPriority(PlatformThread::CurrentHandle(),
109                                    kThreadPriority_Normal);
110}
111
112void TerminateOnThread() {
113  base::android::DetachFromVM();
114}
115
116size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes) {
117#if !defined(ADDRESS_SANITIZER)
118  return 0;
119#else
120  // AddressSanitizer bloats the stack approximately 2x. Default stack size of
121  // 1Mb is not enough for some tests (see http://crbug.com/263749 for example).
122  return 2 * (1 << 20);  // 2Mb
123#endif
124}
125
126bool RegisterThreadUtils(JNIEnv* env) {
127  return RegisterNativesImpl(env);
128}
129
130}  // namespace base
131