Add a ResourceScheduler to ResourceDispatcherHost.

content/browser/renderer_host/resource_dispatcher_host_impl.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 is the browser side of the resource dispatcher, it receives requests
 // from the child process (i.e. [Renderer, Plugin, Worker]ProcessHost), and
 // dispatches them to URLRequests. It then forwards the messages from the
 // URLRequests back to the correct process for handling.
 //
 // See http://dev.chromium.org/developers/design-documents/multi-process-resource-loading
 
 #ifndef CONTENT_BROWSER_RENDERER_HOST_RESOURCE_DISPATCHER_HOST_IMPL_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RESOURCE_DISPATCHER_HOST_IMPL_H_
 
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time.h"
 #include "base/timer.h"
 #include "content/browser/download/download_resource_handler.h"
 #include "content/browser/renderer_host/resource_loader.h"
 #include "content/browser/renderer_host/resource_loader_delegate.h"
+#include "content/browser/renderer_host/resource_scheduler.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/child_process_data.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/resource_dispatcher_host.h"
 #include "ipc/ipc_message.h"
 #include "net/cookies/canonical_cookie.h"
 #include "net/url_request/url_request.h"
 #include "webkit/glue/resource_type.h"
 
 class ResourceHandler;
@@ skipping 153 matching lines @@
   bool Send(IPC::Message* message);
 
   // Indicates whether third-party sub-content can pop-up HTTP basic auth
   // dialog boxes.
   bool allow_cross_origin_auth_prompt();
 
   ResourceDispatcherHostDelegate* delegate() {
     return delegate_;
   }
 
+  ResourceScheduler* scheduler() {
+    return resource_scheduler_.get();
+  }
+
   // Must be called after the ResourceRequestInfo has been created
   // and associated with the request.
   scoped_ptr<ResourceHandler> CreateResourceHandlerForDownload(
       net::URLRequest* request,
       bool is_content_initiated,
       scoped_ptr<DownloadSaveInfo> save_info,
       const DownloadResourceHandler::OnStartedCallback& started_cb);
 
   void ClearSSLClientAuthHandlerForRequest(net::URLRequest* request);
 
@@ skipping 56 matching lines @@
   // data structures supporting this request (net::URLRequest object,
   // HttpNetworkTransaction, etc...).
   // The value of |cost| is added to the running total, and the resulting
   // sum is returned.
   int IncrementOutstandingRequestsMemoryCost(int cost,
                                              int child_id);
 
   // Estimate how much heap space |request| will consume to run.
   static int CalculateApproximateMemoryCost(net::URLRequest* request);
 
-  // The list of all requests that we have pending. This list is not really
+  // The list of all requests that we have scheduled. This list is not really
   // optimized, and assumes that we have relatively few requests pending at once
   // since some operations require brute-force searching of the list.
   //
-  // It may be enhanced in the future to provide some kind of prioritization
-  // mechanism. We should also consider a hashtable or binary tree if it turns
-  // out we have a lot of things here.
-  typedef std::map<GlobalRequestID, linked_ptr<ResourceLoader> > LoaderMap;
+  // We should also consider a hashtable or binary tree if it turns out we have
+  // a lot of things here.
+  typedef std::map<
+      GlobalRequestID, linked_ptr<ResourceScheduler::LoadHandle> > LoaderMap;
 
   // Deletes the pending request identified by the iterator passed in.
   // This function will invalidate the iterator passed in. Callers should
   // not rely on this iterator being valid on return.
   void RemovePendingLoader(const LoaderMap::iterator& iter);
 
   // Checks all pending requests and updates the load states and upload
   // progress if necessary.
   void UpdateLoadStates();
 
@@ skipping 74 matching lines @@
   // start at -2 and go down from there. (We need to start at -2 because -1 is
   // used as a special value all over the resource_dispatcher_host for
   // uninitialized variables.) This way, we no longer have the unlikely (but
   // observed in the real world!) event where we have two requests with the same
   // request_id_.
   int request_id_;
 
   // True if the resource dispatcher host has been shut down.
   bool is_shutdown_;
 
   typedef std::vector<linked_ptr<ResourceLoader> > BlockedLoadersList;

[willchan no longer on Chromium, 2012/11/21 09:04:30]

This confuses me. Who owns the ResourceLoader? Why is there a linked_ptr to it
here and in ResourceScheduler's load handles?

[James Simonsen, 2012/11/27 02:20:51]

Both, but only one at a time. A loader is either blocked or  pending.

[willchan no longer on Chromium, 2012/12/03 02:30:16]

I think we should use ScopedVector instead, and weak_erase()/erase().

   typedef std::pair<int, int> ProcessRouteIDs;
   typedef std::map<ProcessRouteIDs, BlockedLoadersList*> BlockedLoadersMap;
   BlockedLoadersMap blocked_loaders_map_;
 
   // Maps the child_ids to the approximate number of bytes
   // being used to service its resource requests. No entry implies 0 cost.
   typedef std::map<int, int> OutstandingRequestsMemoryCostMap;
   OutstandingRequestsMemoryCostMap outstanding_requests_memory_cost_map_;
 
   // |max_outstanding_requests_cost_per_process_| is the upper bound on how
@@ skipping 15 matching lines @@
   ResourceMessageFilter* filter_;
 
   ResourceDispatcherHostDelegate* delegate_;
 
   bool allow_cross_origin_auth_prompt_;
 
   // http://crbug.com/90971 - Assists in tracking down use-after-frees on
   // shutdown.
   std::set<const ResourceContext*> active_resource_contexts_;
 
+  scoped_ptr<ResourceScheduler> resource_scheduler_;

[willchan no longer on Chromium, 2012/11/21 09:04:30]

Why bother with a scoped_ptr?

[James Simonsen, 2012/11/27 02:20:51]

I thought the leak checker would complain during the unit tests. Maybe not.

[willchan no longer on Chromium, 2012/11/30 10:16:20]

No, I mean, why isn't the whole object just embedded as a member variable. Why
use a pointer?

+
   DISALLOW_COPY_AND_ASSIGN(ResourceDispatcherHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RESOURCE_DISPATCHER_HOST_IMPL_H_