Http cache: Implement a timeout for the cache lock.

net/http/http_cache_transaction.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 declares HttpCache::Transaction, a private class of HttpCache so
 // it should only be included by http_cache.cc
 
 #ifndef NET_HTTP_HTTP_CACHE_TRANSACTION_H_
 #define NET_HTTP_HTTP_CACHE_TRANSACTION_H_
 
@@ skipping 85 matching lines @@
   // Returns the LoadState of the writer transaction of a given ActiveEntry. In
   // other words, returns the LoadState of this transaction without asking the
   // http cache, because this transaction should be the one currently writing
   // to the cache entry.
   LoadState GetWriterLoadState() const;
 
   const CompletionCallback& io_callback() { return io_callback_; }
 
   const BoundNetLog& net_log() const;
 
+  // Bypasses the cache lock whenever there is lock contention.
+  void BypassLockForTest() {
+    bypass_lock_for_test_ = true;
+  }
+
   // HttpTransaction methods:
   virtual int Start(const HttpRequestInfo* request_info,
                     const CompletionCallback& callback,
                     const BoundNetLog& net_log) OVERRIDE;
   virtual int RestartIgnoringLastError(
       const CompletionCallback& callback) OVERRIDE;
   virtual int RestartWithCertificate(
       X509Certificate* client_cert,
       const CompletionCallback& callback) OVERRIDE;
   virtual int RestartWithAuth(const AuthCredentials& credentials,
@@ skipping 227 matching lines @@
                                 const CompletionCallback& callback);
 
   // Called when we are done writing to the cache entry.
   void DoneWritingToEntry(bool success);
 
   // Returns an error to signal the caller that the current read failed. The
   // current operation |result| is also logged. If |restart| is true, the
   // transaction should be restarted.
   int OnCacheReadError(int result, bool restart);
 
+  // Called when the cache lock timeout fires.
+  void OnAddToEntryTimeout(base::TimeTicks start_time);
+
   // Deletes the current partial cache entry (sparse), and optionally removes
   // the control object (partial_).
   void DoomPartialEntry(bool delete_object);
 
   // Performs the needed work after receiving data from the network, when
   // working with range requests.
   int DoPartialNetworkReadCompleted(int result);
 
   // Performs the needed work after receiving data from the cache, when
   // working with range requests.
@@ skipping 42 matching lines @@
   bool reading_;  // We are already reading. Never reverts to false once set.
   bool invalid_range_;  // We may bypass the cache for this request.
   bool truncated_;  // We don't have all the response data.
   bool is_sparse_;  // The data is stored in sparse byte ranges.
   bool range_requested_;  // The user requested a byte range.
   bool handling_206_;  // We must deal with this 206 response.
   bool cache_pending_;  // We are waiting for the HttpCache.
   bool done_reading_;  // All available data was read.
   bool vary_mismatch_;  // The request doesn't match the stored vary data.
   bool couldnt_conditionalize_request_;
+  bool bypass_lock_for_test_;  // A test is exercising the cache lock.
   scoped_refptr<IOBuffer> read_buf_;
   int io_buf_len_;
   int read_offset_;
   int effective_load_flags_;
   int write_len_;
   scoped_ptr<PartialData> partial_;  // We are dealing with range requests.
   UploadProgress final_upload_progress_;
   base::WeakPtrFactory<Transaction> weak_factory_;
   CompletionCallback io_callback_;
 
@@ skipping 18 matching lines @@
       websocket_handshake_stream_base_create_helper_;
 
   BeforeNetworkStartCallback before_network_start_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(Transaction);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_CACHE_TRANSACTION_H_