xref: /aosp_15_r20/external/skia/tools/trace/EventTracingPriv.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1 /*
2  * Copyright 2017 Google Inc.
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 #include "tools/trace/EventTracingPriv.h"
9 
10 #include "include/utils/SkEventTracer.h"
11 #include "src/core/SkATrace.h"
12 #include "src/core/SkTraceEvent.h"
13 #include "tools/flags/CommandLineFlags.h"
14 #include "tools/trace/ChromeTracingTracer.h"
15 #include "tools/trace/SkDebugfTracer.h"
16 
17 // SkPerfettoTrace is only relevant when Perfetto is requested, and for in-process tracing. It is
18 // incompatible with the alternate "direct macro override" approach to using Perfetto, which is
19 // currently used for SK_BUILD_FOR_ANDROID_FRAMEWORK. Skia's Perfetto integration is currently in
20 // in a transitionary period, see go/skia-perfetto for details.
21 #if defined(SK_USE_PERFETTO)
22   #if defined(SK_ANDROID_FRAMEWORK_USE_PERFETTO)
23     #error "SK_USE_PERFETTO and SK_ANDROID_FRAMEWORK_USE_PERFETTO are mutually exclusive"
24   #endif
25 
26   #include "tools/trace/SkPerfettoTrace.h"
27 #endif
28 
29 static DEFINE_string(trace,
30               "",
31               "Log trace events in one of several modes:\n"
32               "  debugf     : Show events using SkDebugf\n"
33               "  atrace     : Send events to Android ATrace\n"
34               "  perfetto   : Send events to Perfetto (Linux, Android, and Mac only)\n"
35               "  <filename> : Any other string is interpreted as a filename. Writes\n"
36               "               trace events to specified file as JSON, for viewing\n"
37               "               with chrome://tracing");
38 
39 static DEFINE_string(traceMatch,
40               "",
41               "Filter which categories are traced.\n"
42               "Uses same format as --match\n");
43 
initializeEventTracingForTools(const char * traceFlag)44 void initializeEventTracingForTools(const char* traceFlag) {
45     if (!traceFlag) {
46         if (FLAGS_trace.isEmpty()) {
47             return;
48         }
49         traceFlag = FLAGS_trace[0];
50     }
51 
52     SkEventTracer* eventTracer = nullptr;
53     if (0 == strcmp(traceFlag, "atrace")) {
54         eventTracer = new SkATrace();
55     } else if (0 == strcmp(traceFlag, "debugf")) {
56         eventTracer = new SkDebugfTracer();
57     } else if (0 == strcmp(traceFlag, "perfetto")) {
58       #if defined(SK_USE_PERFETTO)
59           eventTracer = new SkPerfettoTrace();
60       #else
61           // TODO(b/259248961): update this explanation (and associated docs) as the Perfetto
62           // transition progresses.
63           SkDebugf("Perfetto is not enabled (SK_USE_PERFETTO is false). Perfetto tracing will not "
64                    "be performed.\nTracing tools with Perfetto is only enabled for Linux, Android, "
65                    "and Mac.\n");
66           return;
67       #endif
68     }
69     else {
70         eventTracer = new ChromeTracingTracer(traceFlag);
71     }
72 
73     SkAssertResult(SkEventTracer::SetInstance(eventTracer));
74 }
75 
getCategoryGroupEnabled(const char * name)76 uint8_t* SkEventTracingCategories::getCategoryGroupEnabled(const char* name) {
77     static_assert(0 == offsetof(CategoryState, fEnabled), "CategoryState");
78 
79     // We ignore the "disabled-by-default-" prefix in our internal tools
80     if (SkStrStartsWith(name, TRACE_CATEGORY_PREFIX)) {
81         name += strlen(TRACE_CATEGORY_PREFIX);
82     }
83 
84     // Chrome's implementation of this API does a two-phase lookup (once without a lock, then again
85     // with a lock. But the tracing macros avoid calling these functions more than once per site,
86     // so just do something simple (and easier to reason about):
87     SkAutoMutexExclusive lock(fMutex);
88     for (int i = 0; i < fNumCategories; ++i) {
89         if (0 == strcmp(name, fCategories[i].fName)) {
90             return reinterpret_cast<uint8_t*>(&fCategories[i]);
91         }
92     }
93 
94     if (fNumCategories >= kMaxCategories) {
95         SkDEBUGFAIL("Exhausted event tracing categories. Increase kMaxCategories.");
96         return reinterpret_cast<uint8_t*>(&fCategories[0]);
97     }
98 
99     fCategories[fNumCategories].fEnabled =
100             CommandLineFlags::ShouldSkip(FLAGS_traceMatch, name)
101                     ? 0
102                     : SkEventTracer::kEnabledForRecording_CategoryGroupEnabledFlags;
103 
104     fCategories[fNumCategories].fName = name;
105     return reinterpret_cast<uint8_t*>(&fCategories[fNumCategories++]);
106 }
107 
getCategoryGroupName(const uint8_t * categoryEnabledFlag)108 const char* SkEventTracingCategories::getCategoryGroupName(const uint8_t* categoryEnabledFlag) {
109     if (categoryEnabledFlag) {
110         return reinterpret_cast<const CategoryState*>(categoryEnabledFlag)->fName;
111     }
112     return nullptr;
113 }
114