Deduplicate PlatformThread's POSIX implementations of SetThreadPriority.

base/threading/platform_thread_freebsd.cc

 // Copyright 2014 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 <sched.h>
 
 #include "base/lazy_instance.h"
 #include "base/logging.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/safe_strerror_posix.h"
 #include "base/threading/thread_id_name_manager.h"
-#include "base/threading/thread_restrictions.h"
 #include "base/tracked_objects.h"
 
 #if !defined(OS_NACL)
-#include <sys/resource.h>
-#include <sys/syscall.h>
-#include <sys/time.h>
+#include <pthread.h>
+#include <sys/prctl.h>
 #include <sys/types.h>
 #include <unistd.h>
 #endif
 
 namespace base {
 
+namespace internal {
+
 namespace {
-int ThreadNiceValue(ThreadPriority priority) {
-  switch (priority) {
-    case kThreadPriority_RealtimeAudio:
-      return -10;
-    case kThreadPriority_Background:
-      return 10;
-    case kThreadPriority_Normal:
-      return 0;
-    case kThreadPriority_Display:
-      return -6;
-    default:
-      NOTREACHED() << "Unknown priority.";
-      return 0;
-  }
+const struct sched_param kRealTimePrio = {8};

[rvargas (doing something else), 2015/03/17 22:15:21]

nit: { 8 }

[gab, 2015/03/18 19:01:05]

As mentioned in another comment, this is the output of "git cl format" (up to
you..)

+}  // namespace
+
+const ThreadPriorityToNiceValuePair kThreadPriorityToNiceValueMap[4] = {
+  {kThreadPriority_RealtimeAudio, -10},
+  {kThreadPriority_Background, 10},
+  {kThreadPriority_Normal, 0},
+  {kThreadPriority_Display, -6},
 }
-} // namespace
+
+bool HandleSetThreadPriorityForPlatform(PlatformThreadHandle handle,
+                                        ThreadPriority priority) {
+#if !defined(OS_NACL)
+  // Handle real time priority the Linux way if possible.

[rvargas (doing something else), 2015/03/17 22:15:21]

nit: This comment sounds weird. Why is pthread_setschedparam the linux way?

[gab, 2015/03/18 19:01:05]

Removed comment, was trying to justify it somehow, but I don't actually know why
this special handling is required beyond that the previous code did it.

+  return priority == kThreadPriority_RealtimeAudio &&
+         pthread_setschedparam(pthread_self(), SCHED_RR, &kRealTimePrio);
+#else
+  return false;
+#endif
+}
+
+}  // namespace internal
 
 // static
 void PlatformThread::SetName(const char* name) {
   ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
   tracked_objects::ThreadData::InitializeThreadContext(name);
 
 #if !defined(OS_NACL)
   // On FreeBSD 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;
   setproctitle("%s", name);
 #endif  //  !defined(OS_NACL)
 }
 
-// static
-void PlatformThread::SetThreadPriority(PlatformThreadHandle handle,
-                                       ThreadPriority priority) {
-#if !defined(OS_NACL)
-  if (priority == kThreadPriority_RealtimeAudio) {
-    const struct sched_param kRealTimePrio = { 8 };
-    if (pthread_setschedparam(pthread_self(), SCHED_RR, &kRealTimePrio) == 0) {
-      // Got real time priority, no need to set nice level.
-      return;
-    }
-  }
-
-  // setpriority(2) will set a thread's priority if it is passed a tid as
-  // the 'process identifier', not affecting the rest of the threads in the
-  // process. Setting this priority will only succeed if the user has been
-  // granted permission to adjust nice values on the system.
-  DCHECK_NE(handle.id_, kInvalidThreadId);
-  const int kNiceSetting = ThreadNiceValue(priority);
-  if (setpriority(PRIO_PROCESS, handle.id_, kNiceSetting)) {
-    DVPLOG(1) << "Failed to set nice value of thread ("
-              << handle.id_ << ") to " << kNiceSetting;
-  }
-#endif  //  !defined(OS_NACL)
-}
-
 void InitThreading() {}
 
 void InitOnThread() {}
 
 void TerminateOnThread() {}
 
 size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes) {
 #if !defined(THREAD_SANITIZER)
   return 0;
 #else
   // ThreadSanitizer bloats the stack heavily. Evidence has been that the
   // default stack size isn't enough for some browser tests.
   return 2 * (1 << 23);  // 2 times 8192K (the default stack size on Linux).
 #endif
 }
 
 }  // namespace base