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 495 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 last call, and reset

[Takashi Toyoshima, 2017/06/20 07:39:22]

s/last/the last/ ?

[Kunihiko Sakamoto, 2017/06/20 08:39:28]

Done.

+  // 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 177 matching lines @@
   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.
@@ skipping 33 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 last call to

[Takashi Toyoshima, 2017/06/20 07:39:22]

the last

[Kunihiko Sakamoto, 2017/06/20 08:39:28]

Done.

+  // RecordOutstandingRequestsStats.
+  int peak_outstanding_request_count_;
+
+  // Largest number of outstanding requests seen while there are outstanding
+  // requests from two or more processes, since last call to

[Takashi Toyoshima, 2017/06/20 07:39:21]

the last

[Kunihiko Sakamoto, 2017/06/20 08:39:28]

Done.

+  // 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_