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// All rights reserved.
//
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// modification, are permitted provided that the following conditions are
// met:
//
//    * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//    * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
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// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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#include "base/platform_thread.h"

#if defined(OS_POSIX)
#include <errno.h>
#include <sched.h>
#endif

#if defined(OS_MACOSX)
#include <mach/mach.h>
#elif defined(OS_LINUX)
#include <sys/syscall.h>
#include <unistd.h>
#endif

// static
PlatformThread PlatformThread::Current() {
  PlatformThread thread;

#if defined(OS_WIN)
  thread.thread_ = GetCurrentThread();
#elif defined(OS_POSIX)
  thread.thread_ = pthread_self();
#endif

  return thread;
}

// static
void PlatformThread::YieldCurrentThread() {
#if defined(OS_WIN)
  ::Sleep(0);
#elif defined(OS_POSIX)
  sched_yield();
#endif
}

// static
void PlatformThread::Sleep(int duration_ms) {
#if defined(OS_WIN)
  ::Sleep(duration_ms);
#elif defined (OS_POSIX)
  struct timespec sleep_time, remaining;
  // Contains the portion of duration_ms >= 1 sec.
  sleep_time.tv_sec = duration_ms / 1000;
  duration_ms -= sleep_time.tv_sec * 1000;
  // Contains the portion of duration_ms < 1 sec.
  sleep_time.tv_nsec = duration_ms * 1000 * 1000;  // nanoseconds.
  while (nanosleep(&sleep_time, &remaining) == -1 && errno == EINTR) {
    sleep_time = remaining;
  }
#endif
}

// static
int PlatformThread::CurrentId() {
#if defined(OS_WIN)
  return GetCurrentThreadId();
#elif defined(OS_MACOSX)
  return mach_thread_self();
#elif defined(OS_LINUX)
  return syscall(__NR_gettid);
#endif
}

bool PlatformThread::operator==(const PlatformThread& other_thread) {
#if defined(OS_WIN)
  return thread_ == other_thread.thread_;
#elif defined(OS_POSIX)
  return pthread_equal(thread_, other_thread.thread_);
#endif
}