When cancelling a pending request, release any outstanding SharedIOBuffer objects

chrome/common/resource_dispatcher.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.
 
 // See http://dev.chromium.org/developers/design-documents/multi-process-resource-loading
 
 #include "chrome/common/resource_dispatcher.h"
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
@@ skipping 466 matching lines @@
   pending_requests_[id] =
       PendingRequestInfo(callback, resource_type, request_url);
   return id;
 }
 
 bool ResourceDispatcher::RemovePendingRequest(int request_id) {
   PendingRequestList::iterator it = pending_requests_.find(request_id);
   if (it == pending_requests_.end())
     return false;
 
-  // Iterate through the deferred message queue and clean up the messages.
   PendingRequestInfo& request_info = it->second;
-  MessageQueue& q = request_info.deferred_message_queue;
-  while (!q.empty()) {
-    IPC::Message* m = q.front();
-    ReleaseResourcesInDataMessage(*m);
-    q.pop_front();
-    delete m;
-  }
+  ReleaseResourcesInMessageQueue(&request_info.deferred_message_queue);
+  pending_requests_.erase(it);
 
-  pending_requests_.erase(it);
   return true;
 }
 
 void ResourceDispatcher::CancelPendingRequest(int routing_id,
                                               int request_id) {
   PendingRequestList::iterator it = pending_requests_.find(request_id);
   if (it == pending_requests_.end()) {
-    DLOG(ERROR) << "unknown request";
+    DLOG(WARNING) << "unknown request";
     return;
   }
+
   PendingRequestInfo& request_info = it->second;
-  // Avoid spamming the host with cancel messages.
-  if (request_info.is_cancelled)
-    return;
-  request_info.is_cancelled = true;
+  ReleaseResourcesInMessageQueue(&request_info.deferred_message_queue);
+  pending_requests_.erase(it);
+
   message_sender()->Send(
       new ViewHostMsg_CancelRequest(routing_id, request_id));
 }
 
 void ResourceDispatcher::SetDefersLoading(int request_id, bool value) {
   PendingRequestList::iterator it = pending_requests_.find(request_id);
   if (it == pending_requests_.end()) {
     DLOG(ERROR) << "unknown request";
     return;
   }
@@ skipping 68 matching lines @@
     case ViewMsg_Resource_RequestComplete::ID:
       return true;
 
     default:
       break;
   }
 
   return false;
 }
 
+// static
 void ResourceDispatcher::ReleaseResourcesInDataMessage(
     const IPC::Message& message) {
   void* iter = NULL;
   int request_id;
   if (!message.ReadInt(&iter, &request_id)) {
     NOTREACHED() << "malformed resource message";
     return;
   }
 
   // If the message contains a shared memory handle, we should close the
   // handle or there will be a memory leak.
   if (message.type() == ViewMsg_Resource_DataReceived::ID) {
     base::SharedMemoryHandle shm_handle;
     if (IPC::ParamTraits<base::SharedMemoryHandle>::Read(&message,
                                                          &iter,
                                                          &shm_handle)) {
       base::SharedMemory::CloseHandle(shm_handle);
     }
   }
 }
+
+// static
+void ResourceDispatcher::ReleaseResourcesInMessageQueue(MessageQueue* queue) {
+  while (!queue->empty()) {
+    IPC::Message* message = queue->front();
+    ReleaseResourcesInDataMessage(*message);
+    queue->pop_front();
+    delete message;
+  }
+}