examples/usdt_sample/usdt_sample_lib1/src/lib1.cpp

   1 #include "usdt_sample_lib1/lib1.h"
   2
   3 // std
   4 #include <atomic>
   5 #include <chrono>
   6 #include <iostream>
   7 #include <thread>
   8
   9 // usdt_sample_lib1
  10 #include "folly/tracing/StaticTracepoint.h"
  11
  12 // When using systemtap-sdt-devel, the following file should be included:
  13 // #include "usdt_sample_lib1/lib1_sdt.h"
  14
  15 OperationRequest::OperationRequest(const std::string& input_)
  16     : _input(input_)
  17 {
  18 }
  19
  20 OperationResponse::OperationResponse(const std::string& output_)
  21     : _output(output_)
  22 {
  23 }
  24
  25 OperationProvider::OperationProvider(std::uint32_t minLatencyMs_, std::uint32_t maxLatencyMs_)
  26     : _gen(std::random_device()())
  27     , _dis(minLatencyMs_, maxLatencyMs_)
  28 {
  29 }
  30
  31 std::shared_future<OperationResponse> OperationProvider::executeAsync(const OperationRequest& request)
  32 {
  33     static std::atomic<std::uint64_t> operationIdCounter(0);
  34     std::uint64_t operationId = operationIdCounter++;
  35
  36     FOLLY_SDT(usdt_sample_lib1, operation_start, operationId, request.input().c_str());
  37
  38 /* Below an example of how to use this sample with systemtap-sdt-devel:
  39     if (USDT_SAMPLE_LIB1_OPERATION_START_ENABLED()) {
  40         //std::cout << "operation_start probe enabled." << std::endl;
  41         USDT_SAMPLE_LIB1_OPERATION_START(operationId, &inputBuf);
  42     }
  43 */
  44
  45     auto latencyMs = _dis(_gen);
  46
  47     return std::async(std::launch::async, [latencyMs, operationId, request]() {
  48         std::this_thread::sleep_for(std::chrono::milliseconds(latencyMs));
  49
  50         auto output = std::string("resp_") + request.input();
  51         OperationResponse response(output);
  52
  53         FOLLY_SDT(usdt_sample_lib1, operation_end, operationId, response.output().c_str());
  54
  55 /* Below an example of how to use this sample with systemtap-sdt-devel:
  56         if (USDT_SAMPLE_LIB1_OPERATION_END_ENABLED()) {
  57             //std::cout << "operation_end probe enabled." << std::endl;
  58             USDT_SAMPLE_LIB1_OPERATION_END(operationId, &outputBuf);
  59         }
  60 */
  61
  62         return response;
  63     });
  64 }