ui/events/latency_info.h

   1 // Copyright 2013 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 UI_EVENTS_LATENCY_INFO_H_
   6 #define UI_EVENTS_LATENCY_INFO_H_
   7
   8 #include <utility>
   9 #include <vector>
  10
  11 #include "base/basictypes.h"
  12 #include "base/containers/small_map.h"
  13 #include "base/time/time.h"
  14 #include "ui/events/events_base_export.h"
  15
  16 namespace ui {
  17
  18 enum LatencyComponentType {
  19   // ---------------------------BEGIN COMPONENT-------------------------------
  20   // BEGIN COMPONENT is when we show the latency begin in chrome://tracing.
  21   // Timestamp when the input event is sent from RenderWidgetHost to renderer.
  22   INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT,
  23   // Timestamp when the input event is received in plugin.
  24   INPUT_EVENT_LATENCY_BEGIN_PLUGIN_COMPONENT,
  25   // ---------------------------NORMAL COMPONENT-------------------------------
  26   // Timestamp when the scroll update gesture event is sent from RWH to
  27   // renderer. In Aura, touch event's LatencyInfo is carried over to the gesture
  28   // event. So gesture event's INPUT_EVENT_LATENCY_RWH_COMPONENT is the
  29   // timestamp when its original touch events is sent from RWH to renderer.
  30   // In non-aura platform, INPUT_EVENT_LATENCY_SCROLL_UPDATE_RWH_COMPONENT
  31   // is the same as INPUT_EVENT_LATENCY_RWH_COMPONENT.
  32   INPUT_EVENT_LATENCY_SCROLL_UPDATE_RWH_COMPONENT,
  33   // The original timestamp of the touch event which converts to scroll update.
  34   INPUT_EVENT_LATENCY_SCROLL_UPDATE_ORIGINAL_COMPONENT,
  35   // Original timestamp for input event (e.g. timestamp from kernel).
  36   INPUT_EVENT_LATENCY_ORIGINAL_COMPONENT,
  37   // Timestamp when the UI event is created.
  38   INPUT_EVENT_LATENCY_UI_COMPONENT,
  39   // This is special component indicating there is rendering scheduled for
  40   // the event associated with this LatencyInfo.
  41   INPUT_EVENT_LATENCY_RENDERING_SCHEDULED_COMPONENT,
  42   // Timestamp when the touch event is acked.
  43   INPUT_EVENT_LATENCY_ACKED_TOUCH_COMPONENT,
  44   // Frame number when a window snapshot was requested. The snapshot
  45   // is taken when the rendering results actually reach the screen.
  46   WINDOW_SNAPSHOT_FRAME_NUMBER_COMPONENT,
  47   // ---------------------------TERMINAL COMPONENT-----------------------------
  48   // TERMINAL COMPONENT is when we show the latency end in chrome://tracing.
  49   // Timestamp when the mouse event is acked from renderer and it does not
  50   // cause any rendering scheduled.
  51   INPUT_EVENT_LATENCY_TERMINATED_MOUSE_COMPONENT,
  52   // Timestamp when the touch event is acked from renderer and it does not
  53   // cause any rendering schedueld and does not generate any gesture event.
  54   INPUT_EVENT_LATENCY_TERMINATED_TOUCH_COMPONENT,
  55   // Timestamp when the gesture event is acked from renderer, and it does not
  56   // cause any rendering schedueld.
  57   INPUT_EVENT_LATENCY_TERMINATED_GESTURE_COMPONENT,
  58   // Timestamp when the frame is swapped (i.e. when the rendering caused by
  59   // input event actually takes effect).
  60   INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT,
  61   // This component indicates that the input causes a commit to be scheduled
  62   // but the commit failed.
  63   INPUT_EVENT_LATENCY_TERMINATED_COMMIT_FAILED_COMPONENT,
  64   // This component indicates that the input causes a swap to be scheduled
  65   // but the swap failed.
  66   INPUT_EVENT_LATENCY_TERMINATED_SWAP_FAILED_COMPONENT,
  67   // This component indicates that the cached LatencyInfo number exceeds the
  68   // maximal allowed size.
  69   LATENCY_INFO_LIST_TERMINATED_OVERFLOW_COMPONENT,
  70   // Timestamp when the input event is considered not cause any rendering
  71   // damage in plugin and thus terminated.
  72   INPUT_EVENT_LATENCY_TERMINATED_PLUGIN_COMPONENT,
  73   LATENCY_COMPONENT_TYPE_LAST = INPUT_EVENT_LATENCY_TERMINATED_PLUGIN_COMPONENT
  74 };
  75
  76 struct EVENTS_BASE_EXPORT LatencyInfo {
  77   struct LatencyComponent {
  78     // Nondecreasing number that can be used to determine what events happened
  79     // in the component at the time this struct was sent on to the next
  80     // component.
  81     int64 sequence_number;
  82     // Average time of events that happened in this component.
  83     base::TimeTicks event_time;
  84     // Count of events that happened in this component
  85     uint32 event_count;
  86   };
  87
  88   // Empirically determined constant based on a typical scroll sequence.
  89   enum { kTypicalMaxComponentsPerLatencyInfo = 6 };
  90
  91   // Map a Latency Component (with a component-specific int64 id) to a
  92   // component info.
  93   typedef base::SmallMap<
  94       std::map<std::pair<LatencyComponentType, int64>, LatencyComponent>,
  95       kTypicalMaxComponentsPerLatencyInfo> LatencyMap;
  96
  97   LatencyInfo();
  98
  99   ~LatencyInfo();
 100
 101   // Returns true if the vector |latency_info| is valid. Returns false
 102   // if it is not valid and log the |referring_msg|.
 103   // This function is mainly used to check the latency_info vector that
 104   // is passed between processes using IPC message has reasonable size
 105   // so that we are confident the IPC message is not corrupted/compromised.
 106   // This check will go away once the IPC system has better built-in scheme
 107   // for corruption/compromise detection.
 108   static bool Verify(const std::vector<LatencyInfo>& latency_info,
 109                      const char* referring_msg);
 110
 111   // Copy LatencyComponents with type |type| from |other| into |this|.
 112   void CopyLatencyFrom(const LatencyInfo& other, LatencyComponentType type);
 113
 114   // Add LatencyComponents that are in |other| but not in |this|.
 115   void AddNewLatencyFrom(const LatencyInfo& other);
 116
 117   // Modifies the current sequence number for a component, and adds a new
 118   // sequence number with the current timestamp.
 119   void AddLatencyNumber(LatencyComponentType component,
 120                         int64 id,
 121                         int64 component_sequence_number);
 122
 123   // Modifies the current sequence number and adds a certain number of events
 124   // for a specific component.
 125   void AddLatencyNumberWithTimestamp(LatencyComponentType component,
 126                                      int64 id,
 127                                      int64 component_sequence_number,
 128                                      base::TimeTicks time,
 129                                      uint32 event_count);
 130
 131   // Returns true if the a component with |type| and |id| is found in
 132   // the latency_components and the component is stored to |output| if
 133   // |output| is not NULL. Returns false if no such component is found.
 134   bool FindLatency(LatencyComponentType type,
 135                    int64 id,
 136                    LatencyComponent* output) const;
 137
 138   void RemoveLatency(LatencyComponentType type);
 139
 140   void Clear();
 141
 142   // Records the |event_type| in trace buffer as TRACE_EVENT_ASYNC_STEP.
 143   void TraceEventType(const char* event_type);
 144
 145   LatencyMap latency_components;
 146   // The unique id for matching the ASYNC_BEGIN/END trace event.
 147   int64 trace_id;
 148   // Whether a terminal component has been added.
 149   bool terminated;
 150 };
 151
 152 }  // namespace ui
 153
 154 #endif  // UI_EVENTS_LATENCY_INFO_H_