Revert of Use sched_yield on all POSIX platforms in PlatformThread.

webrtc/base/platform_thread.cc

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 203 matching lines @@
   // Attach the worker thread checker to this thread.
   RTC_DCHECK(spawned_thread_checker_.CalledOnValidThread());
   rtc::SetCurrentThreadName(name_.c_str());
 
   if (run_function_) {
     SetPriority(priority_);
     run_function_(obj_);
     return;
   }
 // TODO(tommi): Delete the below.
+#if !defined(WEBRTC_MAC) && !defined(WEBRTC_WIN)
+  const struct timespec ts_null = {0};
+#endif
   do {
     // The interface contract of Start/Stop is that for a successful call to
     // Start, there should be at least one call to the run function.  So we
     // call the function before checking |stop_|.
     if (!run_function_deprecated_(obj_))
       break;
 #if defined(WEBRTC_WIN)
     // Alertable sleep to permit RaiseFlag to run and update |stop_|.
     SleepEx(0, true);
   } while (!stop_);
 #else
+#if defined(WEBRTC_MAC)
     sched_yield();
+#else
+    nanosleep(&ts_null, nullptr);
+#endif
   } while (!AtomicOps::AcquireLoad(&stop_flag_));
 #endif  // defined(WEBRTC_WIN)
 }
 
 bool PlatformThread::SetPriority(ThreadPriority priority) {
 #if RTC_DCHECK_IS_ON
   if (run_function_) {
     // The non-deprecated way of how this function gets called, is that it must
     // be called on the worker thread itself.
     RTC_DCHECK(spawned_thread_checker_.CalledOnValidThread());
@@ skipping 59 matching lines @@
 #if defined(WEBRTC_WIN)
 bool PlatformThread::QueueAPC(PAPCFUNC function, ULONG_PTR data) {
   RTC_DCHECK(thread_checker_.CalledOnValidThread());
   RTC_DCHECK(IsRunning());
 
   return QueueUserAPC(function, thread_, data) != FALSE;
 }
 #endif
 
 }  // namespace rtc