RandomGenerator.cpp

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#include  <utils/RandomGenerator.hpp>

#include <logger/Log.hpp>

namespace mic {
namespace utils {

// Init generator instance - as NULL.
boost::atomic<RandomGenerator*> RandomGenerator::instance_(NULL);

// Initilize mutex.
boost::mutex RandomGenerator::instantiation_mutex;


RandomGenerator* RandomGenerator::getInstance() {
    // Try to load the instance - first check.
    RandomGenerator* tmp = instance_.load(boost::memory_order_consume);
    // If instance does not exist.
    if (!tmp) {
        // Enter critical section.
        boost::mutex::scoped_lock guard(instantiation_mutex);
        // Try to load the instance - second check.
        tmp = instance_.load(boost::memory_order_consume);
        // If still does not exist - create new instance.
        if (!tmp) {
            tmp = new RandomGenerator;
            instance_.store(tmp, boost::memory_order_release);
        }//: if
        // Exit critical section.
    }//: if
    // Return instance.
    return tmp;
}


RandomGenerator::RandomGenerator() :
        rng_mt19937_64(rd()),
        uniform_int_dist(0, RAND_MAX),
        uniform_real_dist(0, 1),
        normal_real_dist(0, 1)
{
    // TODO Auto-generated constructor stub

}


uint64_t RandomGenerator::uniRandInt(int min, int max) {
    LOG(LTRACE)<<"uniRandInt";
    std::uniform_int_distribution<> dist(min, max);
    return dist(rng_mt19937_64);
    //return uniform_int_dist(rng_mt19937_64);
}

double RandomGenerator::uniRandReal(double min, double max) {
    LOG(LTRACE)<<"uniRandReal";
    return (uniform_real_dist(rng_mt19937_64) + min)/(max - min);
}

double RandomGenerator::normRandReal(double mean, double variance) {
    LOG(LTRACE)<<"normRandReal";
    return (normal_real_dist(rng_mt19937_64) * variance + mean);
}


} /* namespace utils */
} /* namespace mic */