Add UMA that periodically logs number of outstanding requests

content/browser/loader/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
@@ skipping 439 matching lines @@
       int count,
       const ResourceRequestInfoImpl& info);
 
   // Called when an in flight request allocates or releases a shared memory
   // buffer. |count| indicates whether the request is issuing or finishing.
   // |count| must be 1 or -1.
   OustandingRequestsStats IncrementOutstandingRequestsCount(
       int count,
       ResourceRequestInfoImpl* info);
 
+  // Called from IncrementOutstandingRequestsCount to update the per-tab
+  // request stats in |outstanding_requests_per_tab_map_|.
+  // TODO(ksakamoto): This is just for temporary metrics collection for the
+  // Loading Dispatcher v0 (crbug.com/723233), and will be removed soon.
+  void IncrementOutstandingRequestsPerTab(int count,
+                                          const ResourceRequestInfoImpl& info);
+
   // Estimate how much heap space |request| will consume to run.
   static int CalculateApproximateMemoryCost(net::URLRequest* request);
 
   // Force cancels any pending requests for the given route id.  This method
   // acts like CancelRequestsForProcess when the |route_id| member of
   // |routing_id| is MSG_ROUTING_NONE.
   void CancelRequestsForRoute(const GlobalFrameRoutingId& global_routing_id);
 
   // The list of all requests that we have pending. This list is not really
   // optimized, and assumes that we have relatively few requests pending at once
@@ skipping 36 matching lines @@
   // WebContents.
   static std::unique_ptr<LoadInfoMap> PickMoreInterestingLoadInfos(
       std::unique_ptr<LoadInfoList> infos);
 
   // Gets all the LoadInfos for each pending request.
   std::unique_ptr<LoadInfoList> GetLoadInfoForAllRoutes();
 
   // Checks all pending requests and updates the load info if necessary.
   void UpdateLoadInfo();
 
+  // Records statistics about outstanding requests since the last call, and
+  // reset the stats.
+  void RecordOutstandingRequestsStats();
+
   // Resumes or cancels (if |cancel_requests| is true) any blocked requests.
   void ProcessBlockedRequestsForRoute(
       const GlobalFrameRoutingId& global_routing_id,
       bool cancel_requests);
 
   void OnRequestResource(ResourceRequesterInfo* requester_info,
                          int routing_id,
                          int request_id,
                          const ResourceRequest& request_data);
 
@@ skipping 162 matching lines @@
   // is not throttled. If the download is to be throttled (Decided by the
   // delegate) the function returns a ThrottlingResourceHandler to handle the
   // download.
   std::unique_ptr<ResourceHandler> HandleDownloadStarted(
       net::URLRequest* request,
       std::unique_ptr<ResourceHandler> handler,
       bool is_content_initiated,
       bool must_download,
       bool is_new_request);
 
+  // Returns true if there are two or more tabs that are not network 2-quiet
+  // (i.e. have at least three outstanding requests).
+  bool HasRequestsFromMultipleActiveTabs();
+
   LoaderMap pending_loaders_;
 
   // Collection of temp files downloaded for child processes via
   // the download_to_file mechanism. We avoid deleting them until
   // the client no longer needs them.
   typedef std::map<int, scoped_refptr<storage::ShareableFileReference> >
       DeletableFilesMap;  // key is request id
   typedef std::map<int, DeletableFilesMap>
       RegisteredTempFiles;  // key is child process id
   RegisteredTempFiles registered_temp_files_;
 
   // A timer that periodically calls UpdateLoadInfo while pending_loaders_ is
   // not empty and at least one RenderViewHost is loading.
   std::unique_ptr<base::RepeatingTimer> update_load_states_timer_;
 
+  // A timer that periodically calls RecordOutstandingRequestsStats.
+  std::unique_ptr<base::RepeatingTimer>
+      record_outstanding_requests_stats_timer_;
+
   // Request ID for browser initiated requests. request_ids generated by
   // child processes are counted up from 0, while browser created requests
   // 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_;
 
   using BlockedLoadersList = std::vector<std::unique_ptr<ResourceLoader>>;
   using BlockedLoadersMap =
       std::map<GlobalFrameRoutingId, std::unique_ptr<BlockedLoadersList>>;
   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, OustandingRequestsStats> OutstandingRequestsStatsMap;
   OutstandingRequestsStatsMap outstanding_requests_stats_map_;
 
+  // Maps (child_id, route_id) to the number of outstanding requests.
+  // Used only when OOPIF is not enabled, since in OOPIF modes routing_id
+  // doesn't represent tabs.
+  // TODO(ksakamoto): This is just for temporary metrics collection for the
+  // Loading Dispatcher v0 (crbug.com/723233), and will be removed soon.
+  typedef std::map<std::pair<int, int>, int> OutstandingRequestsPerTabMap;
+  OutstandingRequestsPerTabMap outstanding_requests_per_tab_map_;
+
   // |num_in_flight_requests_| is the total number of requests currently issued
   // summed across all renderers.
   int num_in_flight_requests_;
 
   // |max_num_in_flight_requests_| is the upper bound on how many requests
   // can be in flight at once. It's based on the maximum number of file
   // descriptors open per process. We need a global limit for the browser
   // process.
   int max_num_in_flight_requests_;
 
@@ skipping 11 matching lines @@
   //   (max_outstanding_requests_cost_per_process_ /
   //       kAvgBytesPerOutstandingRequest)
   int max_outstanding_requests_cost_per_process_;
 
   // Largest number of outstanding requests seen so far across all processes.
   int largest_outstanding_request_count_seen_;
 
   // Largest number of outstanding requests seen so far in any single process.
   int largest_outstanding_request_per_process_count_seen_;
 
+  // Largest number of outstanding requests seen since the last call to
+  // RecordOutstandingRequestsStats.
+  int peak_outstanding_request_count_;

[Charlie Harrison, 2017/06/22 12:33:46]

= 0

[Kunihiko Sakamoto, 2017/06/23 04:22:06]

Done.

+
+  // Largest number of outstanding requests seen while there are outstanding
+  // requests from two or more tabs, since the last call to
+  // RecordOutstandingRequestsStats.
+  int peak_outstanding_request_count_multitab_ = 0;
+
   // Time of the last user gesture. Stored so that we can add a load
   // flag to requests occurring soon after a gesture to indicate they
   // may be because of explicit user action.
   base::TimeTicks last_user_gesture_time_;
 
   ResourceDispatcherHostDelegate* delegate_;
 
   LoaderDelegate* loader_delegate_;
 
   bool allow_cross_origin_auth_prompt_;
@@ skipping 18 matching lines @@
 
   // Whether experimental web platform features are enabled.
   bool experimental_web_features_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourceDispatcherHostImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_RESOURCE_DISPATCHER_HOST_IMPL_H_