\(\newcommand{\W}[1]{ \; #1 \; }\) \(\newcommand{\R}[1]{ {\rm #1} }\) \(\newcommand{\B}[1]{ {\bf #1} }\) \(\newcommand{\D}[2]{ \frac{\partial #1}{\partial #2} }\) \(\newcommand{\DD}[3]{ \frac{\partial^2 #1}{\partial #2 \partial #3} }\) \(\newcommand{\Dpow}[2]{ \frac{\partial^{#1}}{\partial {#2}^{#1}} }\) \(\newcommand{\dpow}[2]{ \frac{ {\rm d}^{#1}}{{\rm d}\, {#2}^{#1}} }\)
team_openmp.cpp¶
View page sourceOpenMP 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( int(num_threads_) );
// inform CppAD no longer in multi-threading mode
thread_alloc::parallel_setup(num_threads_, nullptr, nullptr);
thread_alloc::hold_memory(false);
CppAD::parallel_ad<double>();
return ok;
}
const char* team_name(void)
{ return "openmp"; }