include/Pythia8/PythiaParallel.h

0001 // PythiaParallel.h is a part of the PYTHIA event generator.
0002 // Copyright (C) 2025 Marius Utheim, Torbjorn Sjostrand.
0003 // PYTHIA is licenced under the GNU GPL v2 or later, see COPYING for details.
0004 // Please respect the MCnet Guidelines, see GUIDELINES for details.
0005
0006 #ifndef PYTHIA_PARALLEL_H
0007 #define PYTHIA_PARALLEL_H
0008
0009 #include "Pythia8/Pythia.h"
0010 #include "Pythia8/PythiaStdlib.h"
0011
0012 namespace Pythia8 {
0013
0014 //==========================================================================
0015
0016 // Class for doing Pythia runs in parallel.
0017
0018 class PythiaParallel {
0019
0020 public:
0021
0022   // Constructor.
0023   PythiaParallel(string xmlDir = "../share/Pythia8/xmldoc",
0024     bool printBanner = true);
0025
0026   // Read in one update for a setting or particle data from a single line.
0027   bool readString(string setting, bool warn = true) {
0028     return pythiaHelper.readString(setting, warn); }
0029
0030   // Read in updates for settings or particle data from user-defined file.
0031   bool readFile(string fileName, bool warn = true,
0032     int subrun = SUBRUNDEFAULT);
0033   bool readFile(string fileName, int subrun) {
0034     return readFile(fileName, true, subrun); }
0035   bool readFile(istream& is = cin, bool warn = true,
0036     int subrun = SUBRUNDEFAULT);
0037   bool readFile(istream& is, int subrun) {
0038     return readFile(is, true, subrun);}
0039
0040   // Initialize all Pythia objects.
0041   bool init();
0042   bool init(function<bool(Pythia*)> additionalSetup);
0043
0044   // Perform the specified action for each Pythia instance.
0045   void foreach(function<void(Pythia*)> action);
0046
0047   // Perform the specified action for each instance in parallel.
0048   void foreachAsync(function<void(Pythia*)> action);
0049
0050   // Write final statistics, combining errors from each Pythia instance.
0051   // For all PhysicsBase objects, combine that PhysicsBase object
0052   // across all threads, if onStat is defined for that specific
0053   // PhysicsBase type.
0054   void stat(bool combine = true);
0055
0056   // Generate events in parallel.
0057   vector<long> run(long nEvents, function<void(Pythia*)> callback);
0058   vector<long> run(function<void(Pythia*)> callback) {
0059     return run(settings.mode("Main:numberOfEvents"), callback); }
0060
0061   // Pythia object used for loading data.
0062   Pythia pythiaHelper;
0063
0064   // Weighted average of the generated cross section for each Pythia instance.
0065   double sigmaGen() const { return sigmaGenSave; }
0066
0067   // Sum of weights from all Pythia instances.
0068   double weightSum() const { return weightSumSave; }
0069
0070   // The settings that will be used to initialize Pythia instances.
0071   Settings& settings;
0072
0073   // The particle database that will be used to initialize Pythia instances.
0074   ParticleData& particleData;
0075
0076 private:
0077
0078   // Object used for logging.
0079   Logger& logger;
0080
0081   // Flag if initialized.
0082   bool isInit = false;
0083
0084   // Sum of weights and weighted cross section.
0085   double weightSumSave, sigmaGenSave;
0086
0087   // Configuration flags.
0088   int numThreads;
0089   bool processAsync;
0090   bool balanceLoad;
0091   bool doNext;
0092
0093   // Internal Pythia objects.
0094   vector<unique_ptr<Pythia> > pythiaObjects;
0095
0096   // Mutex that can be used by each internal Pythia object.
0097   mutex mainMutex;
0098
0099 };
0100
0101 //==========================================================================
0102
0103 } // end namespace Pythia8
0104
0105 #endif // Pythia8_PythiaParallel_H