Add full SetThreadPriority support to Windows.

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"
@@ skipping 28 matching lines @@
 bool HandleSetThreadPriorityForPlatform(PlatformThreadHandle handle,
                                         ThreadPriority priority) {
 #if !defined(OS_NACL)
   return priority == kThreadPriority_RealtimeAudio &&
          pthread_setschedparam(pthread_self(), SCHED_RR, &kRealTimePrio) == 0;
 #else
   return false;
 #endif
 }
 
+bool HandleGetThreadPriorityForPlatform(PlatformThreadHandle handle,
+                                        ThreadPriority* priority) {
+#if !defined(OS_NACL)
+  // Mirrors HandleSetThreadPriorityForPlatform()'s implementation.

[rvargas (doing something else), 2015/03/19 22:19:21]

Do we need this comment?

[gab, 2015/03/30 20:14:45]

I like it, if anything it answers your question below :-)

[rvargas (doing something else), 2015/03/30 22:31:22]

It doesn't answer my question :p. I noticed you were following the other
function, and both seem buggy... but this comment seems too general for my taste
(we have tons of methods that are a logical complement to others so we could add
the same comment everywhere).

If what you want to point out is that the bug is not really yours, then the
comment is way too subtle.

Up to you.

+  int maybe_sched_rr = 0;
+  struct sched_param maybe_realtime_prio = {0};
+  if (pthread_getschedparam(pthread_self(), &maybe_sched_rr,

[rvargas (doing something else), 2015/03/19 22:19:21]

why self() and not handle?

[gab, 2015/03/30 20:14:45]

Because it mirrors HandleSetThreadPriorityForPlatform()'s implementation.

I agree that this looks broken (or at least doesn't respect the existing API --
filed http://crbug.com/468793 for someoen to investigate POSIX thread priority
once this lands)

[rvargas (doing something else), 2015/03/30 22:31:22]

I don't think that's a strong enough justification (unless of course the code is
correct). We should clarify this behavior before checking in more code, or at
least add a clear TODO pointing to the bug you filed.

[gab, 2015/03/31 14:02:33]

Added a TODO, will find an owner once this lands.

+                            &maybe_realtime_prio) == 0 &&
+      maybe_sched_rr == SCHED_RR &&
+      maybe_realtime_prio.sched_priority == kRealTimePrio.sched_priority) {
+    *priority = kThreadPriority_RealtimeAudio;
+    return true;
+  }
+#endif
+  return false;
+}
+
 }  // 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
@@ skipping 15 matching lines @@
 #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