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
21class SK_API SkEventTracer {
22public:
23
24    typedef uint64_t Handle;
25
26    /**
27     * If this is the first call to SetInstance or GetInstance then the passed instance is
28     * installed and true is returned. Otherwise, false is returned. In either case ownership of the
29     * tracer is transferred and it will be deleted when no longer needed.
30     */
31    static bool SetInstance(SkEventTracer*);
32
33    /**
34     * Gets the event tracer. If this is the first call to SetInstance or GetIntance then a default
35     * event tracer is installed and returned.
36     */
37    static SkEventTracer* GetInstance();
38
39    virtual ~SkEventTracer() { }
40
41    // The pointer returned from GetCategoryGroupEnabled() points to a
42    // value with zero or more of the following bits. Used in this class only.
43    // The TRACE_EVENT macros should only use the value as a bool.
44    // These values must be in sync with macro values in trace_event.h in chromium.
45    enum CategoryGroupEnabledFlags {
46        // Category group enabled for the recording mode.
47        kEnabledForRecording_CategoryGroupEnabledFlags = 1 << 0,
48        // Category group enabled for the monitoring mode.
49        kEnabledForMonitoring_CategoryGroupEnabledFlags = 1 << 1,
50        // Category group enabled by SetEventCallbackEnabled().
51        kEnabledForEventCallback_CategoryGroupEnabledFlags = 1 << 2,
52    };
53
54    virtual const uint8_t* getCategoryGroupEnabled(const char* name) = 0;
55    virtual const char* getCategoryGroupName(const uint8_t* categoryEnabledFlag) = 0;
56
57    virtual SkEventTracer::Handle
58        addTraceEvent(char phase,
59                      const uint8_t* categoryEnabledFlag,
60                      const char* name,
61                      uint64_t id,
62                      int32_t numArgs,
63                      const char** argNames,
64                      const uint8_t* argTypes,
65                      const uint64_t* argValues,
66                      uint8_t flags) = 0;
67
68    virtual void
69        updateTraceEventDuration(const uint8_t* categoryEnabledFlag,
70                                 const char* name,
71                                 SkEventTracer::Handle handle) = 0;
72};
73
74#endif // SkEventTracer_DEFINED
75