Apply the initial thread priority on the starting thread on Windows

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 28 matching lines @@
   __try {
     RaiseException(kVCThreadNameException, 0, sizeof(info)/sizeof(DWORD),
                    reinterpret_cast<DWORD_PTR*>(&info));
   } __except(EXCEPTION_CONTINUE_EXECUTION) {
   }
 }
 
 struct ThreadParams {
   PlatformThread::Delegate* delegate;
   bool joinable;
+  ThreadPriority priority;
 };
 
 DWORD __stdcall ThreadFunc(void* params) {
   ThreadParams* thread_params = static_cast<ThreadParams*>(params);
   PlatformThread::Delegate* delegate = thread_params->delegate;
   if (!thread_params->joinable)
     base::ThreadRestrictions::SetSingletonAllowed(false);
 
+  if (thread_params->priority != ThreadPriority::NORMAL) {
+    PlatformThread::SetThreadPriority(
+        PlatformThread::CurrentHandle(), thread_params->priority);
+  }
+
   // Retrieve a copy of the thread handle to use as the key in the
   // thread name mapping.
   PlatformThreadHandle::Handle platform_handle;
   BOOL did_dup = DuplicateHandle(GetCurrentProcess(),
                                 GetCurrentThread(),
                                 GetCurrentProcess(),
                                 &platform_handle,
                                 0,
                                 FALSE,
                                 DUPLICATE_SAME_ACCESS);
@@ skipping 12 matching lines @@
 
   if (did_dup) {
     ThreadIdNameManager::GetInstance()->RemoveName(
         scoped_platform_handle.Get(),
         PlatformThread::CurrentId());
   }
 
   return NULL;
 }
 
-// CreateThreadInternal() matches PlatformThread::Create(), except that
-// |out_thread_handle| may be NULL, in which case a non-joinable thread is
+// CreateThreadInternal() matches PlatformThread::CreateWithPriority(), except
+// that |out_thread_handle| may be NULL, in which case a non-joinable thread is
 // created.
 bool CreateThreadInternal(size_t stack_size,
                           PlatformThread::Delegate* delegate,
-                          PlatformThreadHandle* out_thread_handle) {
+                          PlatformThreadHandle* out_thread_handle,
+                          ThreadPriority priority) {
   unsigned int flags = 0;
   if (stack_size > 0 && base::win::GetVersion() >= base::win::VERSION_XP) {
     flags = STACK_SIZE_PARAM_IS_A_RESERVATION;
   } else {
     stack_size = 0;
   }
 
   ThreadParams* params = new ThreadParams;
   params->delegate = delegate;
   params->joinable = out_thread_handle != NULL;
+  params->priority = priority;
 
   // Using CreateThread here vs _beginthreadex makes thread creation a bit
   // faster and doesn't require the loader lock to be available.  Our code will
   // have to work running on CreateThread() threads anyway, since we run code
   // on the Windows thread pool, etc.  For some background on the difference:
   //   http://www.microsoft.com/msj/1099/win32/win321099.aspx
   PlatformThreadId thread_id;
   void* thread_handle = CreateThread(
       NULL, stack_size, ThreadFunc, params, flags, &thread_id);
   if (!thread_handle) {
@@ skipping 63 matching lines @@
 }
 
 // static
 const char* PlatformThread::GetName() {
   return ThreadIdNameManager::GetInstance()->GetName(CurrentId());
 }
 
 // static
 bool PlatformThread::Create(size_t stack_size, Delegate* delegate,
                             PlatformThreadHandle* thread_handle) {
-  DCHECK(thread_handle);
-  return CreateThreadInternal(stack_size, delegate, thread_handle);
+  return CreateWithPriority(
+      stack_size, delegate, thread_handle, ThreadPriority::NORMAL);
 }
 
 // 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);
-  return result;
+  DCHECK(thread_handle);
+  return CreateThreadInternal(stack_size, delegate, thread_handle, priority);
 }
 
 // static
 bool PlatformThread::CreateNonJoinable(size_t stack_size, Delegate* delegate) {
-  return CreateThreadInternal(stack_size, delegate, NULL);
+  return CreateThreadInternal(
+      stack_size, delegate, NULL, ThreadPriority::NORMAL);
 }
 
 // static
 void PlatformThread::Join(PlatformThreadHandle thread_handle) {
   DCHECK(thread_handle.platform_handle());
   // TODO(willchan): Enable this check once I can get it to work for Windows
   // shutdown.
   // Joining another thread may block the current thread for a long time, since
   // the thread referred to by |thread_handle| may still be running long-lived /
   // blocking tasks.
@@ skipping 64 matching lines @@
       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