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) 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
  78 void 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
  96 void InitThreading() {
  97 }
  98
  99 void 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
 106 void TerminateOnThread() {
 107   base::android::DetachFromVM();
 108 }
 109
 110 size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes) {
 111 #if !defined(ADDRESS_SANITIZER)
 112   return 0;
 113 #else
 114   // AddressSanitizer bloats the stack approximately 2x. Default stack size of
 115   // 1Mb is not enough for some tests (see http://crbug.com/263749 for example).
 116   return 2 * (1 << 20);  // 2Mb
 117 #endif
 118 }
 119
 120 bool RegisterThreadUtils(JNIEnv* env) {
 121   return RegisterNativesImpl(env);
 122 }
 123
 124 }  // namespace base