ui/gl/gpu_timing.h

   1 // Copyright (c) 2015 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_GL_GPU_TIMING_H_
   6 #define UI_GL_GPU_TIMING_H_
   7
   8 #include <queue>
   9
  10 #include "base/callback.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "ui/gl/gl_export.h"
  13
  14 // The gpu_timing classes handles the abstraction of GL GPU Timing extensions
  15 // into a common set of functions. Currently the different timer extensions that
  16 // are supported are EXT_timer_query, ARB_timer_query and
  17 // EXT_disjoint_timer_query.
  18 //
  19 // Explanation of Classes:
  20 //   GPUTiming - GPU Timing is a private class which is only owned by the
  21 //     underlying GLContextReal class. This class handles any GL Context level
  22 //     states which may need to be redistributed to users of GPUTiming. For
  23 //     example, there exists only a single disjoint flag for each real GL
  24 //     Context. Once the disjoint flag is checked, internally it is reset to
  25 //     false. In order to support multiple virtual contexts each checking the
  26 //     disjoint flag seperately, GPUTiming is in charge of checking the
  27 //     disjoint flag and broadcasting out the disjoint state to all the
  28 //     various users of GPUTiming (GPUTimingClient below).
  29 //   GPUTimingClient - The GLContextReal holds the GPUTiming class and is the
  30 //     factory that creates GPUTimingClient objects. If a user would like to
  31 //     obtain various GPU times they would access CreateGPUTimingClient() from
  32 //     their GLContext and use the returned object for their timing calls.
  33 //     Each virtual context as well as any other classes which need GPU times
  34 //     will hold one of these. When they want to time a set of GL commands they
  35 //     will create GPUTimer objects.
  36 //   GPUTimer - Once a user decides to time something, the user creates a new
  37 //     GPUTimer object from a GPUTimingClient and issue Start() and Stop() calls
  38 //     around various GL calls. Once IsAvailable() returns true, the GPU times
  39 //     will be available through the various time stamp related functions.
  40 //     The constructor and destructor of this object handles the actual
  41 //     creation and deletion of the GL Queries within GL.
  42
  43 namespace gfx {
  44
  45 class GLContextReal;
  46 class GPUTiming;
  47 class GPUTimingClient;
  48 class GPUTimingImpl;
  49 class QueryResult;
  50 class TimeElapsedTimerQuery;
  51 class TimerQuery;
  52
  53 class GPUTiming {
  54  public:
  55   enum TimerType {
  56     kTimerTypeInvalid = -1,
  57
  58     kTimerTypeEXT,      // EXT_timer_query
  59     kTimerTypeARB,      // ARB_timer_query
  60     kTimerTypeDisjoint  // EXT_disjoint_timer_query
  61   };
  62
  63  protected:
  64   friend struct base::DefaultDeleter<GPUTiming>;
  65   friend class GLContextReal;
  66
  67   static GPUTiming* CreateGPUTiming(GLContextReal* context);
  68
  69   GPUTiming();
  70   virtual ~GPUTiming();
  71
  72   virtual scoped_refptr<GPUTimingClient> CreateGPUTimingClient() = 0;
  73
  74   DISALLOW_COPY_AND_ASSIGN(GPUTiming);
  75 };
  76
  77 // Class to compute the amount of time it takes to fully
  78 // complete a set of GL commands
  79 class GL_EXPORT GPUTimer {
  80  public:
  81   static void DisableTimestampQueries();
  82
  83   ~GPUTimer();
  84
  85   // Destroy the timer object. This must be explicitly called before destroying
  86   // this object.
  87   void Destroy(bool have_context);
  88
  89   // Start an instant timer, start and end will be equal.
  90   void Instant();
  91
  92   // Start a timer range.
  93   void Start();
  94   void End();
  95
  96   bool IsAvailable();
  97
  98   void GetStartEndTimestamps(int64* start, int64* end);
  99   int64 GetDeltaElapsed();
 100
 101  private:
 102   friend class GPUTimingClient;
 103
 104   explicit GPUTimer(scoped_refptr<GPUTimingClient> gpu_timing_client,
 105                     bool use_elapsed_timer);
 106
 107   bool use_elapsed_timer_ = false;
 108   bool end_requested_ = false;
 109   bool end_available_ = false;
 110   scoped_refptr<GPUTimingClient> gpu_timing_client_;
 111   scoped_refptr<QueryResult> time_stamp_result_;
 112   scoped_refptr<QueryResult> elapsed_timer_result_;
 113
 114   DISALLOW_COPY_AND_ASSIGN(GPUTimer);
 115 };
 116
 117 // GPUTimingClient contains all the gl timing logic that is not specific
 118 // to a single GPUTimer.
 119 class GL_EXPORT GPUTimingClient
 120     : public base::RefCounted<GPUTimingClient> {
 121  public:
 122   explicit GPUTimingClient(GPUTimingImpl* gpu_timing = nullptr);
 123
 124   scoped_ptr<GPUTimer> CreateGPUTimer(bool prefer_elapsed_time);
 125   bool IsAvailable();
 126
 127   const char* GetTimerTypeName() const;
 128
 129   // CheckAndResetTimerErrors has to be called before reading timestamps
 130   // from GPUTimers instances and after making sure all the timers
 131   // were available.
 132   // If the returned value is false, all the previous timers should be
 133   // discarded.
 134   bool CheckAndResetTimerErrors();
 135
 136   int64 GetCurrentCPUTime();
 137   void SetCpuTimeForTesting(const base::Callback<int64(void)>& cpu_time);
 138
 139   bool IsForceTimeElapsedQuery();
 140   void ForceTimeElapsedQuery();
 141
 142  private:
 143   friend class base::RefCounted<GPUTimingClient>;
 144   friend class GPUTimer;
 145
 146   virtual ~GPUTimingClient();
 147
 148   GPUTimingImpl* gpu_timing_;
 149   GPUTiming::TimerType timer_type_ = GPUTiming::kTimerTypeInvalid;
 150   uint32_t disjoint_counter_ = 0;
 151
 152   DISALLOW_COPY_AND_ASSIGN(GPUTimingClient);
 153 };
 154
 155 }  // namespace gfx
 156
 157 #endif  // UI_GL_GPU_TIMING_H_