base/threading/platform_thread_android.cc

   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
  19 namespace base {
  20
  21 namespace {
  22 int 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
  58 void 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
  84 void 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
 102 void InitThreading() {
 103 }
 104
 105 void 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
 112 void TerminateOnThread() {
 113   base::android::DetachFromVM();
 114 }
 115
 116 size_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
 126 bool RegisterThreadUtils(JNIEnv* env) {
 127   return RegisterNativesImpl(env);
 128 }
 129
 130 }  // namespace base