test/stubs/TestTBBTasksAnalyzer.cc

0001 // -*- C++ -*-
0002 //
0003 // Package:    Framework
0004 // Class:      TestTBBTasksAnalyzer
0005 //
0006 /**\class TestTBBTasksAnalyzer TestTBBTasksAnalyzer.cc FWCore/Framework/test/stubs/TestTBBTasksAnalyzer.cc
0007
0008  Description: <one line class summary>
0009
0010  Implementation:
0011      <Notes on implementation>
0012 */
0013 //
0014 // Original Author:  Chris Jones
0015 //         Created:  Thu Jan 03 11:02:00 EST 2013
0016 //
0017 //
0018
0019 // system include files
0020 #include <memory>
0021 #include <atomic>
0022 #include <chrono>
0023 #include "oneapi/tbb/task_group.h"
0024 #include "oneapi/tbb/task_arena.h"
0025
0026 // user include files
0027 #include "FWCore/Framework/interface/one/EDAnalyzer.h"
0028
0029 #include "FWCore/Framework/interface/MakerMacros.h"
0030
0031 #include "FWCore/ParameterSet/interface/ParameterSet.h"
0032
0033 #include "FWCore/Utilities/interface/Exception.h"
0034
0035 //
0036 // class decleration
0037 //
0038
0039 class TestTBBTasksAnalyzer : public edm::one::EDAnalyzer<> {
0040 public:
0041   explicit TestTBBTasksAnalyzer(const edm::ParameterSet&);
0042   ~TestTBBTasksAnalyzer() override;
0043
0044   virtual void analyze(const edm::Event&, const edm::EventSetup&) override;
0045
0046 private:
0047   virtual void endJob() override;
0048   unsigned int startTasks(unsigned int iNTasks, unsigned int iSleepTime) const;
0049   unsigned int m_nTasksToRun;
0050   unsigned int m_expectedNumberOfSimultaneousTasks;
0051   unsigned int m_maxCountedTasks;
0052   unsigned int m_usecondsToSleep;
0053   // ----------member data ---------------------------
0054 };
0055
0056 //
0057 // constants, enums and typedefs
0058 //
0059
0060 //
0061 // static data member definitions
0062 //
0063
0064 //
0065 // constructors and destructor
0066 //
0067 TestTBBTasksAnalyzer::TestTBBTasksAnalyzer(const edm::ParameterSet& iConfig)
0068     : m_nTasksToRun(iConfig.getUntrackedParameter<unsigned int>("numTasksToRun")),
0069       m_expectedNumberOfSimultaneousTasks(iConfig.getUntrackedParameter<unsigned int>("nExpectedThreads")),
0070       m_maxCountedTasks(0),
0071       m_usecondsToSleep(iConfig.getUntrackedParameter<unsigned int>("usecondsToSleep", 100000)) {
0072   //now do what ever initialization is needed
0073 }
0074
0075 TestTBBTasksAnalyzer::~TestTBBTasksAnalyzer() {
0076   // do anything here that needs to be done at desctruction time
0077   // (e.g. close files, deallocate resources etc.)
0078 }
0079
0080 //
0081 // member functions
0082 //
0083
0084 // ------------ method called to produce the data  ------------
0085 void TestTBBTasksAnalyzer::analyze(const edm::Event&, const edm::EventSetup& iSetup) {
0086   unsigned int max = startTasks(m_nTasksToRun, m_usecondsToSleep);
0087
0088   if (max > m_maxCountedTasks) {
0089     m_maxCountedTasks = max;
0090   }
0091 }
0092
0093 unsigned int TestTBBTasksAnalyzer::startTasks(unsigned int iNTasks, unsigned int iSleepTime) const {
0094   std::atomic<unsigned int> count{0};
0095   std::atomic<unsigned int> maxCount{0};
0096   oneapi::tbb::task_group grp;
0097
0098   for (unsigned int i = 0; i < iNTasks; ++i) {
0099     grp.run([&]() {
0100       unsigned int c = ++count;
0101       while (true) {
0102         unsigned int mc = maxCount.load();
0103         if (c > mc) {
0104           if (maxCount.compare_exchange_strong(mc, c)) {
0105             break;
0106           }
0107         } else {
0108           break;
0109         }
0110       }
0111       std::this_thread::sleep_for(std::chrono::microseconds(m_usecondsToSleep));
0112       --(count);
0113     });
0114   }
0115   grp.wait();
0116   return maxCount.load();
0117 }
0118
0119 void TestTBBTasksAnalyzer::endJob() {
0120   if (((m_expectedNumberOfSimultaneousTasks - 1) > m_maxCountedTasks) ||
0121       (m_maxCountedTasks > m_expectedNumberOfSimultaneousTasks)) {
0122     throw cms::Exception("WrongNumberOfTasks")
0123         << "expected " << m_expectedNumberOfSimultaneousTasks << " but instead saw " << m_maxCountedTasks << "\n";
0124   }
0125 }
0126 //define this as a plug-in
0127 DEFINE_FWK_MODULE(TestTBBTasksAnalyzer);