components/browser_watcher/exit_funnel_win.h

   1 // Copyright (c) 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_BROWSER_WATCHER_EXIT_FUNNEL_WIN_H_
   6 #define COMPONENTS_BROWSER_WATCHER_EXIT_FUNNEL_WIN_H_
   7
   8 #include "base/macros.h"
   9 #include "base/process/process_handle.h"
  10 #include "base/strings/string16.h"
  11 #include "base/win/registry.h"
  12
  13 namespace browser_watcher {
  14
  15 // A wrapper class that takes care of persistently recording a trace of named,
  16 // timed events in registry, associated with a process instance. This allows
  17 // reconstructing and reporting an event trace on a subsequent launch.
  18 // The event trace is stored in registry under a new key named
  19 // <pid>-<uniquifier>, where each event is a value named after the event, with
  20 // an associated QWORD value noting the event time.
  21 class ExitFunnel {
  22  public:
  23   ExitFunnel();
  24   ~ExitFunnel();
  25
  26   // Initializes the exit funnel with |registry_path| and |process|.
  27   // |process| must be open for PROCESS_QUERY_INFORMATION at least.
  28   // Returns false on failure to create or open the registry path corresponding
  29   // to |process|.
  30   bool Init(const base::char16* registry_path, base::ProcessHandle process);
  31
  32   // Records |event_name| at the current time in the registry for the process
  33   // this instance is associated with. Returns false on failure to record the
  34   // event.
  35   bool RecordEvent(const base::char16* event_name);
  36
  37   // Records |event_name| at the current time in the registry at |registry_path|
  38   // for this process.
  39   static bool RecordSingleEvent(const base::char16* registry_path,
  40                                 const base::char16* event_name);
  41
  42  private:
  43   base::win::RegKey key_;
  44
  45   DISALLOW_COPY_AND_ASSIGN(ExitFunnel);
  46 };
  47
  48 }  // namespace browser_watcher
  49
  50 #endif  // COMPONENTS_BROWSER_WATCHER_EXIT_FUNNEL_WIN_H_