net: Implement canceling of all async operations in FileStream.

net/base/file_stream_posix.h

 // 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.
 
 // This file implements FileStream for POSIX.
 
 #ifndef NET_BASE_FILE_STREAM_POSIX_H_
 #define NET_BASE_FILE_STREAM_POSIX_H_
 
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/weak_ptr.h"
 #include "base/platform_file.h"
 #include "net/base/completion_callback.h"
 #include "net/base/file_stream_whence.h"
 #include "net/base/net_export.h"
 #include "net/base/net_log.h"
 
 class FilePath;
 
 namespace base {
 class WaitableEvent;
@@ skipping 25 matching lines @@
   int ReadUntilComplete(char *buf, int buf_len);
   int Write(IOBuffer* buf, int buf_len, const CompletionCallback& callback);
   int WriteSync(const char* buf, int buf_len);
   int64 Truncate(int64 bytes);
   int Flush();
   void EnableErrorStatistics();
   void SetBoundNetLogSource(
       const net::BoundNetLog& owner_bound_net_log);
   base::PlatformFile GetPlatformFileForTesting();
 
-  // Resets on_io_complete_ and WeakPtr's.
-  // Called when Read() or Write() is completed.
-  void ResetOnIOComplete();
+ private:
+  class AsyncContext;
 
- private:
-  // Called when the file_ is closed asynchronously.
-  void OnClosed(const CompletionCallback& callback);
+  bool is_async() { return !!(open_flags_ & base::PLATFORM_FILE_ASYNC); }
 
-  // Waits until the in-flight async open/close/read/write operation is
-  // complete.
-  void WaitForIOCompletion();
+  // Context performing I/O operations. Despite its name the context is used
+  // for synchronous operations too, but it was extracted into separate class
+  // to perform asynchronous operations correctly.
+  AsyncContext* context_;
 
-  base::PlatformFile file_;
   int open_flags_;
-  bool auto_closed_;
-  bool record_uma_;
   net::BoundNetLog bound_net_log_;
-  base::WeakPtrFactory<FileStreamPosix> weak_ptr_factory_;
-  scoped_ptr<base::WaitableEvent> on_io_complete_;
 
   DISALLOW_COPY_AND_ASSIGN(FileStreamPosix);
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_FILE_STREAM_POSIX_H