Switch MessagePumpForIO to use completion ports on Windows....

net/disk_cache/cache_util_win.cc

 // Copyright (c) 2006-2008 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 "net/disk_cache/cache_util.h"
 
 #include <windows.h>
 
 #include "base/logging.h"
+#include "base/message_loop.h"
 #include "base/scoped_handle.h"
 #include "base/file_util.h"
 
 namespace {
 
 // Deletes all the files on path that match search_name pattern.
 void DeleteFiles(const wchar_t* path, const wchar_t* search_name) {
   std::wstring name(path);
   file_util::AppendToPath(&name, search_name);
 
@@ skipping 11 matching lines @@
     std::wstring current(adjusted_path);
     current += data.cFileName;
     DeleteFile(current.c_str());
   } while (FindNextFile(handle, &data));
 }
 
 }  // namespace
 
 namespace disk_cache {
 
+// Implemented in file_win.cc.
+MessageLoopForIO::IOHandler* GetFileIOHandler();
+
 bool MoveCache(const std::wstring& from_path, const std::wstring& to_path) {
   // I don't want to use the shell version of move because if something goes
   // wrong, that version will attempt to move file by file and fail at the end.
   if (!MoveFileEx(from_path.c_str(), to_path.c_str(), 0)) {
     LOG(ERROR) << "Unable to move the cache: " << GetLastError();
     return false;
   }
   return true;
 }
 
 void DeleteCache(const std::wstring& path, bool remove_folder) {
   DeleteFiles(path.c_str(), L"*");
   if (remove_folder)
     RemoveDirectory(path.c_str());
 }
 
 bool DeleteCacheFile(const std::wstring& name) {
   // We do a simple delete, without ever falling back to SHFileOperation, as the
   // version from base does.
   return DeleteFile(name.c_str()) ? true : false;
 }
 
 void WaitForPendingIO(int* num_pending_io) {
   while (*num_pending_io) {
     // Asynchronous IO operations may be in flight and the completion may end
-    // up calling us back so let's wait for them (we need an alertable wait).
-    // The idea is to let other threads do usefull work and at the same time
-    // allow more than one IO to finish... 20 mS later, we process all queued
-    // APCs and see if we have to repeat the wait.
-    Sleep(20);
-    SleepEx(0, TRUE);
+    // up calling us back so let's wait for them.
+    MessageLoopForIO::current()->WaitForIOCompletion(100, GetFileIOHandler());
   }
 }
 
 }  // namespace disk_cache