Herwig6Instance.cc

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#include <iostream>
#include <sstream>
#include <cstdlib>
#include <cstring>
#include <cctype>
#include <string>
#include <cassert>

#ifdef _POSIX_C_SOURCE
#   include <sys/time.h>
#   include <csignal>
#   include <csetjmp>
#endif

#include <CLHEP/Random/RandomEngine.h>

#include <HepMC/HerwigWrapper.h>

#include "FWCore/ParameterSet/interface/FileInPath.h"
#include "FWCore/Utilities/interface/Exception.h"
#include "FWCore/MessageLogger/interface/MessageLogger.h"

#include "GeneratorInterface/Herwig6Interface/interface/herwig.h"
#include "GeneratorInterface/Herwig6Interface/interface/Herwig6Instance.h"

#include "params.inc"

extern "C" void jminit_();
__attribute__((visibility("hidden"))) void dummy()
{
  int dummyInt = 0;
  jminit_();
  jimmin_();
  jminit_();
  hwmsct_(&dummyInt);
  jmefin_();
}

// Added for reading in the paremeter files (orig. L. Sonnenschein)
extern "C" void lunread_(const char filename[], const int length);

using namespace gen;

// implementation for the Fortran callbacks from Herwig

// this gets a random number from the currently running instance
// so, if the have separate instances for let's say decayers based on
// Herwig than the Herwig pp collision instance, we get independent
// random numbers.  Also true for FastSim, since FastSim uses its own
// random numbers.  This means FastSim needs take a Herwig6Instance
// instance of its own instead of calling into Herwig directly.
double gen::hwrgen_(int *idummy)
{ 
  Herwig6Instance *instance = FortranInstance::getInstance<Herwig6Instance>();
  assert(instance != nullptr);
  assert(instance->randomEngine != nullptr);
  return instance->randomEngine->flat();
}

void gen::cms_hwwarn_(char fn[6], int *code, int *exit)
{
    std::string function(fn, 6);
    *exit = FortranInstance::getInstance<Herwig6Instance>()->hwwarn(function, *code);
}

extern "C" {
    void hwaend_()
    {}

    void cmsending_(int *ecode)
    {
        throw cms::Exception("Herwig6Error")
            << "Herwig6 stopped run with error code " << *ecode
            << "." << std::endl;
    }
}

struct gen::TimeoutHolder {
  sigjmp_buf buf;
};

// Herwig6Instance methods

Herwig6Instance::Herwig6Instance() :
    randomEngine(nullptr),
    timeoutPrivate()
{
}

Herwig6Instance::~Herwig6Instance()
{
}

// timeout tool

#ifdef _POSIX_C_SOURCE
// some deep POSIX hackery to catch HERWIG sometimes (O(10k events) with
// complicated topologies) getting caught in and endless loop :-(

void Herwig6Instance::_timeout_sighandler(int signr)
{
  Herwig6Instance *instance = FortranInstance::getInstance<Herwig6Instance>();
  assert(instance != nullptr);
  assert(instance->timeoutPrivate);
  siglongjmp(instance->timeoutPrivate->buf, 1);
}

bool Herwig6Instance::timeout(unsigned int secs, void (*fn)())
{
    if (timeoutPrivate)
        throw cms::Exception("ReentrancyProblem")
            << "Herwig6Instance::timeout() called recursively."
            << std::endl;
    struct sigaction saOld;
    std::memset(&saOld, 0, sizeof saOld);

    struct itimerval itv;
    timerclear(&itv.it_value);
    timerclear(&itv.it_interval);
    itv.it_value.tv_sec = 0;
    itv.it_interval.tv_sec = 0;
    setitimer(ITIMER_VIRTUAL, &itv, nullptr);

    sigset_t ss;
    sigemptyset(&ss);
    sigaddset(&ss, SIGVTALRM);

    sigprocmask(SIG_UNBLOCK, &ss, nullptr);
    sigprocmask(SIG_BLOCK, &ss, nullptr);

    timeoutPrivate = std::make_unique<TimeoutHolder>();
    if (sigsetjmp(timeoutPrivate->buf, 1)) {
        timeoutPrivate.reset();

        itv.it_value.tv_sec = 0;
        itv.it_interval.tv_sec = 0;
        setitimer(ITIMER_VIRTUAL, &itv, nullptr);
        sigprocmask(SIG_UNBLOCK, &ss, nullptr);
        return true;
    }

    itv.it_value.tv_sec = secs;
    itv.it_interval.tv_sec = secs;
    setitimer(ITIMER_VIRTUAL, &itv, nullptr);

    struct sigaction sa;
    std::memset(&sa, 0, sizeof sa);
    sa.sa_handler = &Herwig6Instance::_timeout_sighandler;
    sa.sa_flags = SA_ONESHOT;
    sigemptyset(&sa.sa_mask);

    sigaction(SIGVTALRM, &sa, &saOld);
    sigprocmask(SIG_UNBLOCK, &ss, nullptr);

    try {
        fn();
    } catch(...) {

        timeoutPrivate.reset();

        itv.it_value.tv_sec = 0;
        itv.it_interval.tv_sec = 0;
        setitimer(ITIMER_VIRTUAL, &itv, nullptr);

        sigaction(SIGVTALRM, &saOld, nullptr);

        throw;
    }

    timeoutPrivate.reset();

    itv.it_value.tv_sec = 0;
    itv.it_interval.tv_sec = 0;
    setitimer(ITIMER_VIRTUAL, &itv, nullptr);

    sigaction(SIGVTALRM, &saOld, nullptr);

    return false;
}
#else
bool Herwig6Instance::timeout(unsigned int secs, void (*fn)())
{
    fn();
    return false;
}
#endif

bool Herwig6Instance::hwwarn(const std::string &fn, int code)
{
    return false;
}

// regular Herwig6Instance methods

bool Herwig6Instance::give(const std::string &line)
{   
    typedef std::istringstream::traits_type traits;

    const char *p = line.c_str(), *q;
    p += std::strspn(p, " \t\r\n");

    for(q = p; std::isalnum(*q); q++);
    std::string name(p, q - p);

    const ConfigParam *param;
    for(param = configParams; param->name; param++)
        if (name == param->name)
            break;
    if (!param->name)
        return false;

    p = q + std::strspn(q, " \t\r\n");  

    std::size_t pos = 0;
    std::size_t mult = 1;
    for(unsigned int i = 0; i < 3; i++) {
        if (!param->dim[i].size)
            break;

        if (*p++ != (i ? ',' : '('))
            return false;

        p += std::strspn(p, " \t\r\n");

        for(q = p; std::isdigit(*q); q++);
        std::istringstream ss(std::string(p, q - p));
        std::size_t index;
        ss >> index;
        if (ss.bad() || ss.peek() != traits::eof())
            return false;

        if (index < param->dim[i].offset)
            return false;
        index -= param->dim[i].offset;
        if (index >= param->dim[i].size)
            return false;

        p = q + std::strspn(q, " \t\r\n");

        pos += mult * index;
        mult *= param->dim[i].size;
    }

    if (param->dim[0].size) {
        if (*p++ != ')')
            return false;
        p += std::strspn(p, " \t\r\n");
    }

    if (*p++ != '=')
        return false;
    p += std::strspn(p, " \t\r\n");

    for(q = p; *q && (std::isalnum(*q) || std::strchr(".-+", *q)); q++);
    std::istringstream ss(std::string(p, q - p));

    p = q + std::strspn(q, " \t\r\n");
    if (*p && *p != '!')
        return false;

    switch(param->type) {
        case kInt: {
        int value;
        ss >> value;
        if (ss.bad() || ss.peek() != traits::eof())
            return false;

        ((int*)param->ptr)[pos] = value;
        break;
        }
        case kDouble: {
        double value;
        ss >> value;
        if (ss.bad() || ss.peek() != traits::eof())
            return false;

        ((double*)param->ptr)[pos] = value;
        break;
        }
        case kLogical: {
        std::string value_;
        ss >> value_;
        if (ss.bad() || ss.peek() != traits::eof())
            return false;

        for(std::string::iterator iter = value_.begin();
            iter != value_.end(); ++iter)
            *iter = std::tolower(*iter);
        bool value;
        if (value_ == "yes" || value_ == "true" || value_ == "1")
            value = true;
        else if (value_ == "no" || value_ == "false" || value_ == "0")
            value = false;
        else
            return false;

        ((int*)param->ptr)[pos] = value;
        break;
        }
    }

    return true;
}

void Herwig6Instance::openParticleSpecFile(const std::string fileName) {

  edm::FileInPath fileAndPath( fileName );
  // WARING : This will call HWWARN if file does not exist.
  lunread_( fileAndPath.fullPath().c_str(),strlen(fileAndPath.fullPath().c_str()) );
  
  return;
}