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) will set a thread's priority if it is passed a tid as
69  // the 'process identifier', not affecting the rest of the threads in the
70  // process. Setting this priority will only succeed if the user has been
71  // granted permission to adjust nice values on the system.
72  DCHECK_NE(handle.id_, kInvalidThreadId);
73  int kNiceSetting = ThreadNiceValue(priority);
74  if (setpriority(PRIO_PROCESS, handle.id_, kNiceSetting))
75    LOG(ERROR) << "Failed to set nice value of thread to " << kNiceSetting;
76}
77
78void PlatformThread::SetName(const char* name) {
79  ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
80  tracked_objects::ThreadData::InitializeThreadContext(name);
81
82  // Like linux, on android we can get the thread names to show up in the
83  // debugger by setting the process name for the LWP.
84  // We don't want to do this for the main thread because that would rename
85  // the process, causing tools like killall to stop working.
86  if (PlatformThread::CurrentId() == getpid())
87    return;
88
89  // Set the name for the LWP (which gets truncated to 15 characters).
90  int err = prctl(PR_SET_NAME, name);
91  if (err < 0 && errno != EPERM)
92    DPLOG(ERROR) << "prctl(PR_SET_NAME)";
93}
94
95
96void InitThreading() {
97}
98
99void InitOnThread() {
100  // Threads on linux/android may inherit their priority from the thread
101  // where they were created. This sets all new threads to the default.
102  PlatformThread::SetThreadPriority(PlatformThread::CurrentHandle(),
103                                    kThreadPriority_Normal);
104}
105
106void TerminateOnThread() {
107  base::android::DetachFromVM();
108}
109
110size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes) {
111  return 0;
112}
113
114bool RegisterThreadUtils(JNIEnv* env) {
115  return RegisterNativesImpl(env);
116}
117
118}  // namespace base
119