OpenMP Implementation of a Team of AD Threads
Keywords: openmp implementation team ad threads

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OpenMP Implementation of a Team of AD Threads
See team_thread.hpp for this routines specifications. `

    # include <omp.h>
    # include <cppad/cppad.hpp>
    # include "../team_thread.hpp"

    namespace {
    	using CppAD::thread_alloc;

    	// number of threads in this team
    	size_t num_threads_;

    	// used to inform CppAD when we are in parallel execution mode
    	bool in_parallel(void)
    	{	return omp_in_parallel() != 0; }

    	// used to inform CppAD of the current thread number
    	size_t thread_num(void)
    	{	return static_cast<size_t>( omp_get_thread_num() ); }
    }

    bool team_create(size_t num_threads)
    {
    	bool ok = ! in_parallel();
    	ok     &= thread_num() == 0;;
    	ok     &= num_threads > 0;

    	// Turn off dynamic thread adjustment
    	omp_set_dynamic(0);

    	// Set the number of OpenMP threads
    	omp_set_num_threads( int(num_threads) );

    	// setup for using CppAD::AD<double> in parallel
    	thread_alloc::parallel_setup(num_threads, in_parallel, thread_num);
    	thread_alloc::hold_memory(true);
    	CppAD::parallel_ad<double>();

    	// inform team_work of number of threads
    	num_threads_ = num_threads;

    	return ok;
    }

    bool team_work(void worker(void))
    {	bool ok = ! in_parallel();
    	ok     &= thread_num() == 0;;
    	ok     &= num_threads_ > 0;

    	int number_threads = int(num_threads_);
    	int thread_num;
    # pragma omp parallel for
    	for(thread_num = 0; thread_num < number_threads; thread_num++)
    		worker();
    // end omp parallel for

    	return ok;
    }

    bool team_destroy(void)
    {	bool ok = ! in_parallel();
    	ok     &= thread_num() == 0;;
    	ok     &= num_threads_ > 0;

    	// inform team_work of number of threads
    	num_threads_ = 1;

    	// Set the number of OpenMP threads to one
    	omp_set_num_threads(num_threads_);

    	// inform CppAD no longer in multi-threading mode
    	thread_alloc::parallel_setup(num_threads_, CPPAD_NULL, CPPAD_NULL);
    	thread_alloc::hold_memory(false);
    	CppAD::parallel_ad<double>();

    	return ok;
    }

    const char* team_name(void)
    {	return "openmp"; }

`

Input File: multi_thread/openmp/team_openmp.cpp