base/threading: restrict to set only current thread priority

base/threading/platform_thread_win.cc

 // 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 "base/debug/alias.h"
 #include "base/debug/profiler.h"
 #include "base/logging.h"
 #include "base/threading/thread_id_name_manager.h"
@@ skipping 177 matching lines @@
   DCHECK(thread_handle);
   return CreateThreadInternal(stack_size, delegate, thread_handle);
 }
 
 // static
 bool PlatformThread::CreateWithPriority(size_t stack_size, Delegate* delegate,
                                         PlatformThreadHandle* thread_handle,
                                         ThreadPriority priority) {
   bool result = Create(stack_size, delegate, thread_handle);
   if (result)
-    SetThreadPriority(*thread_handle, priority);
+    SetCurrentThreadPriority(priority);

[gab, 2015/06/23 17:01:32]

Hmm, this is incorrect no? This code runs on the thread creating the thread of
interest, not on that thread itself.

I think we may need something like StartWithOptions in the Windows
implementation as well (as a precursor CL).

[Takashi Toyoshima, 2015/06/24 04:15:39]

Oops, thank you for catching this.
Yes, definitely I should fix it in a separate CL.
Thanks!

   return result;
 }
 
 // static
 bool PlatformThread::CreateNonJoinable(size_t stack_size, Delegate* delegate) {
   return CreateThreadInternal(stack_size, delegate, NULL);
 }
 
 // static
 void PlatformThread::Join(PlatformThreadHandle thread_handle) {
@@ skipping 15 matching lines @@
     DWORD error = GetLastError();
     debug::Alias(&error);
     debug::Alias(&result);
     CHECK(false);
   }
 
   CloseHandle(thread_handle.platform_handle());
 }
 
 // static
-void PlatformThread::SetThreadPriority(PlatformThreadHandle handle,
-                                       ThreadPriority priority) {
-  DCHECK(!handle.is_null());
-
+void PlatformThread::SetCurrentThreadPriority(ThreadPriority priority) {
   int desired_priority = THREAD_PRIORITY_ERROR_RETURN;
   switch (priority) {
     case ThreadPriority::BACKGROUND:
       desired_priority = THREAD_PRIORITY_LOWEST;
       break;
     case ThreadPriority::NORMAL:
       desired_priority = THREAD_PRIORITY_NORMAL;
       break;
     case ThreadPriority::DISPLAY:
       desired_priority = THREAD_PRIORITY_ABOVE_NORMAL;
       break;
     case ThreadPriority::REALTIME_AUDIO:
       desired_priority = THREAD_PRIORITY_TIME_CRITICAL;
       break;
     default:
       NOTREACHED() << "Unknown priority.";
       break;
   }
   DCHECK_NE(desired_priority, THREAD_PRIORITY_ERROR_RETURN);
 
 #ifndef NDEBUG
   const BOOL success =
 #endif
-      ::SetThreadPriority(handle.platform_handle(), desired_priority);
+      ::SetThreadPriority(PlatformThread::CurrentHandle().platform_handle(),
+                          desired_priority);
   DPLOG_IF(ERROR, !success) << "Failed to set thread priority to "
                             << desired_priority;
 }
 
 // static
-ThreadPriority PlatformThread::GetThreadPriority(PlatformThreadHandle handle) {
-  DCHECK(!handle.is_null());
-
-  int priority = ::GetThreadPriority(handle.platform_handle());
+ThreadPriority PlatformThread::GetCurrentThreadPriority() {
+  int priority =
+      ::GetThreadPriority(PlatformThread::CurrentHandle().platform_handle());
   switch (priority) {
     case THREAD_PRIORITY_LOWEST:
       return ThreadPriority::BACKGROUND;
     case THREAD_PRIORITY_NORMAL:
       return ThreadPriority::NORMAL;
     case THREAD_PRIORITY_ABOVE_NORMAL:
       return ThreadPriority::DISPLAY;
     case THREAD_PRIORITY_TIME_CRITICAL:
       return ThreadPriority::REALTIME_AUDIO;
     case THREAD_PRIORITY_ERROR_RETURN:
       DPCHECK(false) << "GetThreadPriority error";  // Falls through.
     default:
       NOTREACHED() << "Unexpected priority: " << priority;
       return ThreadPriority::NORMAL;
   }
 }
 
 }  // namespace base