text: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #include "base/threading/platform_thread.h"
  
  #include <errno.h>
  #include <stddef.h>
  #include <sys/prctl.h>
  #include <sys/resource.h>
  #include <sys/types.h>
  #include <unistd.h>
  
  #include "base/android/jni_android.h"
  #include "base/lazy_instance.h"
  #include "base/logging.h"
  #include "base/threading/platform_thread_internal_posix.h"
  #include "base/threading/thread_id_name_manager.h"
  #include "jni/ThreadUtils_jni.h"
  
  namespace base {
  
  namespace internal {
  
  // - BACKGROUND corresponds to Android's PRIORITY_BACKGROUND = 10 value and can
  // result in heavy throttling and force the thread onto a little core on
  // big.LITTLE devices.
  // - DISPLAY corresponds to Android's PRIORITY_DISPLAY = -4 value.
  // - REALTIME_AUDIO corresponds to Android's PRIORITY_AUDIO = -16 value.
  const ThreadPriorityToNiceValuePair kThreadPriorityToNiceValueMap[4] = {
      {ThreadPriority::BACKGROUND, 10},
      {ThreadPriority::NORMAL, 0},
      {ThreadPriority::DISPLAY, -4},
      {ThreadPriority::REALTIME_AUDIO, -16},
  };
  
  bool SetCurrentThreadPriorityForPlatform(ThreadPriority priority) {
    // On Android, we set the Audio priority through JNI as Audio priority
    // will also allow the process to run while it is backgrounded.
    if (priority == ThreadPriority::REALTIME_AUDIO) {
      JNIEnv* env = base::android::AttachCurrentThread();
      Java_ThreadUtils_setThreadPriorityAudio(env, PlatformThread::CurrentId());
      return true;
    }
    return false;
  }
  
  bool GetCurrentThreadPriorityForPlatform(ThreadPriority* priority) {
    DCHECK(priority);
    *priority = ThreadPriority::NORMAL;
    JNIEnv* env = base::android::AttachCurrentThread();
    if (Java_ThreadUtils_isThreadPriorityAudio(
        env, PlatformThread::CurrentId())) {
      *priority = ThreadPriority::REALTIME_AUDIO;
      return true;
    }
    return false;
  }
  
  }  // namespace internal
  
  void PlatformThread::SetName(const std::string& name) {
    ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
  
    // Like linux, on android we can get the thread names to show up in the
    // debugger by setting the process name for the LWP.
    // We don't want to do this for the main thread because that would rename
    // the process, causing tools like killall to stop working.
    if (PlatformThread::CurrentId() == getpid())
      return;
  
    // Set the name for the LWP (which gets truncated to 15 characters).
    int err = prctl(PR_SET_NAME, name.c_str());
    if (err < 0 && errno != EPERM)
      DPLOG(ERROR) << "prctl(PR_SET_NAME)";
  }
  
  
  void InitThreading() {
  }
  
  void TerminateOnThread() {
    base::android::DetachFromVM();
  }
  
  size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes) {
  #if !defined(ADDRESS_SANITIZER)
    return 0;
  #else
    // AddressSanitizer bloats the stack approximately 2x. Default stack size of
    // 1Mb is not enough for some tests (see http://crbug.com/263749 for example).
    return 2 * (1 << 20);  // 2Mb
  #endif
  }
  
  }  // namespace base
  