1 /*
2  * Copyright (C) 2014 Google Inc. All rights reserved.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #ifndef SkEventTracer_DEFINED
9 #define SkEventTracer_DEFINED
10 
11 // The class in this header defines the interface between Skia's internal
12 // tracing macros and an external entity (e.g., Chrome) that will consume them.
13 // Such an entity should subclass SkEventTracer and provide an instance of
14 // that event to SkEventTracer::SetInstance.
15 
16 // If you're looking for the tracing macros to instrument Skia itself, those
17 // live in src/core/SkTraceEvent.h
18 
19 #include "SkTypes.h"
20 
21 // This will mark the trace event as disabled by default. The user will need
22 // to explicitly enable the event.
23 #define TRACE_DISABLED_BY_DEFAULT(name) "disabled-by-default-" name
24 
25 class SK_API SkEventTracer {
26 public:
27 
28     typedef uint64_t Handle;
29 
30     static SkEventTracer* GetInstance();
31 
32     static void SetInstance(SkEventTracer*);
33 
~SkEventTracer()34     virtual ~SkEventTracer() { }
35 
36     // The pointer returned from GetCategoryGroupEnabled() points to a
37     // value with zero or more of the following bits. Used in this class only.
38     // The TRACE_EVENT macros should only use the value as a bool.
39     // These values must be in sync with macro values in trace_event.h in chromium.
40     enum CategoryGroupEnabledFlags {
41         // Category group enabled for the recording mode.
42         kEnabledForRecording_CategoryGroupEnabledFlags = 1 << 0,
43         // Category group enabled for the monitoring mode.
44         kEnabledForMonitoring_CategoryGroupEnabledFlags = 1 << 1,
45         // Category group enabled by SetEventCallbackEnabled().
46         kEnabledForEventCallback_CategoryGroupEnabledFlags = 1 << 2,
47     };
48 
49     virtual const uint8_t* getCategoryGroupEnabled(const char* name) = 0;
50     virtual const char* getCategoryGroupName(
51       const uint8_t* categoryEnabledFlag) = 0;
52 
53     virtual SkEventTracer::Handle
54         addTraceEvent(char phase,
55                       const uint8_t* categoryEnabledFlag,
56                       const char* name,
57                       uint64_t id,
58                       int32_t numArgs,
59                       const char** argNames,
60                       const uint8_t* argTypes,
61                       const uint64_t* argValues,
62                       uint8_t flags) = 0;
63 
64     virtual void
65         updateTraceEventDuration(const uint8_t* categoryEnabledFlag,
66                                  const char* name,
67                                  SkEventTracer::Handle handle) = 0;
68 };
69 
70 #endif // SkEventTracer_DEFINED
71