| // 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. |
| |
| #ifndef CONTENT_BROWSER_HISTOGRAM_CONTROLLER_H_ |
| #define CONTENT_BROWSER_HISTOGRAM_CONTROLLER_H_ |
| |
| #include <string> |
| #include <vector> |
| |
| #include "base/memory/singleton.h" |
| |
| namespace content { |
| |
| class HistogramSubscriber; |
| |
| // HistogramController is used on the browser process to collect histogram data. |
| // Only the browser UI thread is allowed to interact with the |
| // HistogramController object. |
| class HistogramController { |
| public: |
| // Returns the HistogramController object for the current process, or NULL if |
| // none. |
| static HistogramController* GetInstance(); |
| |
| // Normally instantiated when the child process is launched. Only one instance |
| // should be created per process. |
| HistogramController(); |
| virtual ~HistogramController(); |
| |
| // Register the subscriber so that it will be called when for example |
| // OnHistogramDataCollected is returning histogram data from a child process. |
| // This is called on UI thread. |
| void Register(HistogramSubscriber* subscriber); |
| |
| // Unregister the subscriber so that it will not be called when for example |
| // OnHistogramDataCollected is returning histogram data from a child process. |
| // Safe to call even if caller is not the current subscriber. |
| void Unregister(const HistogramSubscriber* subscriber); |
| |
| // Contact all processes and get their histogram data. |
| void GetHistogramData(int sequence_number); |
| |
| // Notify the |subscriber_| that it should expect at least |pending_processes| |
| // additional calls to OnHistogramDataCollected(). OnPendingProcess() may be |
| // called repeatedly; the last call will have |end| set to true, indicating |
| // that there is no longer a possibility for the count of pending processes to |
| // increase. This is called on the UI thread. |
| void OnPendingProcesses(int sequence_number, int pending_processes, bool end); |
| |
| // Send the |histogram| back to the |subscriber_|. |
| // This can be called from any thread. |
| void OnHistogramDataCollected( |
| int sequence_number, |
| const std::vector<std::string>& pickled_histograms); |
| |
| private: |
| friend struct DefaultSingletonTraits<HistogramController>; |
| |
| // Contact PLUGIN and GPU child processes and get their histogram data. |
| // TODO(rtenneti): Enable getting histogram data for other processes like |
| // PPAPI and NACL. |
| void GetHistogramDataFromChildProcesses(int sequence_number); |
| |
| HistogramSubscriber* subscriber_; |
| |
| DISALLOW_COPY_AND_ASSIGN(HistogramController); |
| }; |
| |
| } // namespace content |
| |
| #endif // CONTENT_BROWSER_HISTOGRAM_CONTROLLER_H_ |