Race Create vs SendRequest on cache misses.

net/http/http_cache.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 "net/http/http_cache.h"
 
 #include <algorithm>
 
 #include "base/compiler_specific.h"
 
@@ skipping 12 matching lines @@
 #include "base/pickle.h"
 #include "base/stl_util.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/stringprintf.h"
 #include "net/base/io_buffer.h"
 #include "net/base/load_flags.h"
 #include "net/base/net_errors.h"
 #include "net/base/upload_data_stream.h"
 #include "net/disk_cache/disk_cache.h"
+#include "net/disk_cache/pending_create_entry.h"
 #include "net/http/http_cache_transaction.h"
 #include "net/http/http_network_layer.h"
 #include "net/http/http_network_session.h"
 #include "net/http/http_request_info.h"
 #include "net/http/http_response_headers.h"
 #include "net/http/http_response_info.h"
 #include "net/http/http_util.h"
 
 namespace net {
 
@@ skipping 661 matching lines @@
   if (rv != ERR_IO_PENDING) {
     item->ClearTransaction();
     pending_op->callback.Run(rv);
   }
 
   return rv;
 }
 
 int HttpCache::CreateEntry(const std::string& key, ActiveEntry** entry,
                            Transaction* trans) {
-  DCHECK(!FindActiveEntry(key));
+  if (FindActiveEntry(key)) {
+    return ERR_CACHE_RACE;
+  }
 
   WorkItem* item = new WorkItem(WI_CREATE_ENTRY, trans, entry);
   PendingOp* pending_op = GetPendingOp(key);
   if (pending_op->writer) {
     pending_op->pending_queue.push_back(item);
     return ERR_IO_PENDING;
   }
 
   DCHECK(pending_op->pending_queue.empty());
 
   pending_op->writer = item;
   pending_op->callback = base::Bind(&HttpCache::OnPendingOpComplete,
                                     AsWeakPtr(), pending_op);
 
-  int rv = disk_cache_->CreateEntry(key, &(pending_op->disk_entry),
-                                    pending_op->callback);
+  int rv = disk_cache::PendingCreateEntry(disk_cache_.get(), key,
+                                          &(pending_op->disk_entry));
   if (rv != ERR_IO_PENDING) {
     item->ClearTransaction();
     pending_op->callback.Run(rv);
   }
 
   return rv;
 }
 
 void HttpCache::DestroyEntry(ActiveEntry* entry) {
   if (entry->doomed) {
@@ skipping 375 matching lines @@
     building_backend_ = false;
     DeletePendingOp(pending_op);
   }
 
   // The cache may be gone when we return from the callback.
   if (!item->DoCallback(result, backend))
     item->NotifyTransaction(result, NULL);
 }
 
 }  // namespace net