third_party/pigweed/repo/pw_trace_tokenized/example/trigger.cc

   1 // Copyright 2020 The Pigweed Authors
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
   4 // use this file except in compliance with the License. You may obtain a copy of
   5 // the License at
   6 //
   7 //     https://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  12 // License for the specific language governing permissions and limitations under
  13 // the License.
  14 //==============================================================================
  15 // BUID
  16 // ninja -C out
  17 // host_clang_debug/obj/pw_trace_tokenized/bin/trace_tokenized_example_trigger
  18 //
  19 // RUN
  20 // .out/host_clang_debug/obj/pw_trace_tokenized/bin/trace_tokenized_example_trigger
  21 // trace.bin
  22 //
  23 // DECODE
  24 // python pw_trace_tokenized/py/trace_tokenized.py -i trace.bin -o trace.json
  25 // ./out/host_clang_debug/obj/pw_trace_tokenized/bin/trace_tokenized_example_basic
  26 //
  27 // VIEW
  28 // In chrome navigate to chrome://tracing, and load the trace.json file.
  29
  30 #include "pw_log/log.h"
  31 #include "pw_trace/example/sample_app.h"
  32 #include "pw_trace/trace.h"
  33 #include "pw_trace_tokenized/example/trace_to_file.h"
  34 #include "pw_trace_tokenized/trace_callback.h"
  35 #include "pw_trace_tokenized/trace_tokenized.h"
  36
  37 namespace {
  38
  39 constexpr uint32_t kTriggerId = 3;
  40 constexpr uint32_t kTriggerStartTraceRef =
  41     PW_TRACE_REF_DATA(PW_TRACE_TYPE_ASYNC_START,
  42                       "Processing",  // Module
  43                       "Job",         // Label
  44                       PW_TRACE_FLAGS_DEFAULT,
  45                       "Process",
  46                       "@pw_py_struct_fmt:B");
  47 constexpr uint32_t kTriggerEndTraceRef = PW_TRACE_REF(PW_TRACE_TYPE_ASYNC_END,
  48                                                       "Processing",  // Module
  49                                                       "Job",         // Label
  50                                                       PW_TRACE_FLAGS_DEFAULT,
  51                                                       "Process");
  52
  53 }  // namespace
  54
  55 pw_trace_TraceEventReturnFlags TraceEventCallback(void* user_data,
  56                                                   uint32_t trace_ref,
  57                                                   pw_trace_EventType event_type,
  58                                                   const char* module,
  59                                                   uint32_t trace_id,
  60                                                   uint8_t flags) {
  61   PW_UNUSED(user_data);
  62   PW_UNUSED(event_type);
  63   PW_UNUSED(module);
  64   PW_UNUSED(flags);
  65   if (trace_ref == kTriggerStartTraceRef && trace_id == kTriggerId) {
  66     PW_LOG_INFO("Trace capture started!");
  67     PW_TRACE_SET_ENABLED(true);
  68   }
  69   if (trace_ref == kTriggerEndTraceRef && trace_id == kTriggerId) {
  70     PW_LOG_INFO("Trace capture ended!");
  71     return PW_TRACE_EVENT_RETURN_FLAGS_DISABLE_AFTER_PROCESSING;
  72   }
  73   return 0;
  74 }
  75
  76 int main(int argc, char** argv) {  // Take filename as arg
  77   if (argc != 2) {
  78     PW_LOG_ERROR("Expected output file name as argument.\n");
  79     return -1;
  80   }
  81
  82   // Register trigger callback
  83   pw::trace::Callbacks::Instance().RegisterEventCallback(
  84       TraceEventCallback, pw::trace::CallbacksImpl::kCallOnEveryEvent);
  85
  86   // Ensure tracing is off at start, the trigger will turn it on.
  87   PW_TRACE_SET_ENABLED(false);
  88
  89   // Dump trace data to the file passed in.
  90   pw::trace::TraceToFile trace_to_file(argv[1]);
  91
  92   PW_LOG_INFO("Running trigger example...");
  93   RunTraceSampleApp();
  94   return 0;
  95 }