1 /* 2 * Copyright 2014 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 "SkAtomics.h" 9 #include "SkEventTracer.h" 10 #include "SkOnce.h" 11 12 #include <stdlib.h> 13 14 class SkDefaultEventTracer : public SkEventTracer { 15 SkEventTracer::Handle 16 addTraceEvent(char phase, 17 const uint8_t* categoryEnabledFlag, 18 const char* name, 19 uint64_t id, 20 int numArgs, 21 const char** argNames, 22 const uint8_t* argTypes, 23 const uint64_t* argValues, 24 uint8_t flags) override { return 0; } 25 26 void 27 updateTraceEventDuration(const uint8_t* categoryEnabledFlag, 28 const char* name, 29 SkEventTracer::Handle handle) override {} 30 31 const uint8_t* getCategoryGroupEnabled(const char* name) override { 32 static uint8_t no = 0; 33 return &no; 34 } 35 const char* getCategoryGroupName( 36 const uint8_t* categoryEnabledFlag) override { 37 static const char* dummy = "dummy"; 38 return dummy; 39 } 40 }; 41 42 // We prefer gUserTracer if it's been set, otherwise we fall back on a default tracer; 43 static SkEventTracer* gUserTracer = nullptr; 44 45 bool SkEventTracer::SetInstance(SkEventTracer* tracer) { 46 SkEventTracer* expected = nullptr; 47 if (!sk_atomic_compare_exchange(&gUserTracer, &expected, tracer)) { 48 delete tracer; 49 return false; 50 } 51 // An atomic load during process shutdown is probably overkill, but safe overkill. 52 atexit([]() { delete sk_atomic_load(&gUserTracer); }); 53 return true; 54 } 55 56 SkEventTracer* SkEventTracer::GetInstance() { 57 if (SkEventTracer* tracer = sk_atomic_load(&gUserTracer, sk_memory_order_acquire)) { 58 return tracer; 59 } 60 static SkOnce once; 61 static SkDefaultEventTracer* defaultTracer; 62 once([] { defaultTracer = new SkDefaultEventTracer; }); 63 return defaultTracer; 64 } 65
