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
25class SK_API SkEventTracer {
26public:
27
28    typedef uint64_t Handle;
29
30    static SkEventTracer* GetInstance();
31
32    static void SetInstance(SkEventTracer* tracer) {
33        SkDELETE(SkEventTracer::gInstance);
34        SkEventTracer::gInstance = tracer;
35    }
36
37    virtual ~SkEventTracer() { }
38
39    // The pointer returned from GetCategoryGroupEnabled() points to a
40    // value with zero or more of the following bits. Used in this class only.
41    // The TRACE_EVENT macros should only use the value as a bool.
42    // These values must be in sync with macro values in trace_event.h in chromium.
43    enum CategoryGroupEnabledFlags {
44        // Category group enabled for the recording mode.
45        kEnabledForRecording_CategoryGroupEnabledFlags = 1 << 0,
46        // Category group enabled for the monitoring mode.
47        kEnabledForMonitoring_CategoryGroupEnabledFlags = 1 << 1,
48        // Category group enabled by SetEventCallbackEnabled().
49        kEnabledForEventCallback_CategoryGroupEnabledFlags = 1 << 2,
50    };
51
52    virtual const uint8_t* getCategoryGroupEnabled(const char* name) = 0;
53    virtual const char* getCategoryGroupName(
54      const uint8_t* categoryEnabledFlag) = 0;
55
56    virtual SkEventTracer::Handle
57        addTraceEvent(char phase,
58                      const uint8_t* categoryEnabledFlag,
59                      const char* name,
60                      uint64_t id,
61                      int32_t numArgs,
62                      const char** argNames,
63                      const uint8_t* argTypes,
64                      const uint64_t* argValues,
65                      uint8_t flags) = 0;
66
67    virtual void
68        updateTraceEventDuration(const uint8_t* categoryEnabledFlag,
69                                 const char* name,
70                                 SkEventTracer::Handle handle) = 0;
71private:
72    static SkEventTracer *gInstance;
73};
74
75#endif // SkEventTracer_DEFINED
76