AuxThreads.c

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#include <stdio.h>
#include <stdlib.h>
 
#ifdef _OPENMP
#include <omp.h>
#endif
 
#include "fasp.h"
#include "fasp_functs.h"
 
/*---------------------------------*/
/*--      Public Functions       --*/
/*---------------------------------*/
 
#ifdef _OPENMP
 
INT thread_ini_flag = 0;
 
INT fasp_get_num_threads ( void )
{
    static INT nthreads;
    
    if ( thread_ini_flag == 0 ) {
        nthreads = 1;
#pragma omp parallel
        nthreads = omp_get_num_threads();
        
        printf("\nFASP is running on %d thread(s).\n\n", nthreads);
        thread_ini_flag = 1;
    }
    
    return nthreads;
}
 
INT fasp_set_num_threads (const INT nthreads)
{
    omp_set_num_threads( nthreads );
    
    return nthreads;
}
 
#endif
 
void fasp_get_start_end (const INT  procid,
                         const INT  nprocs,
                         const INT  n,
                         INT       *start,
                         INT       *end)
{
    INT chunk_size = n / nprocs;
    INT mod =  n % nprocs;
    INT start_loc, end_loc;
    
    if ( procid < mod) {
        end_loc = chunk_size + 1;
        start_loc = end_loc * procid;
    }
    else {
        end_loc = chunk_size;
        start_loc = end_loc * procid + mod;
    }
    end_loc = end_loc + start_loc;
    
    *start = start_loc;
    *end = end_loc;
}
 
INT THDs_AMG_GS=0;  
INT THDs_CPR_lGS=0; 
INT THDs_CPR_gGS=0; 
void fasp_set_gs_threads (const INT mythreads,
                          const INT its)
{
#ifdef _OPENMP
    
#if 1
    
    if (its <=8) {
        THDs_AMG_GS =  mythreads;
        THDs_CPR_lGS = mythreads ;
        THDs_CPR_gGS = mythreads ;
    }
    else if (its <=12) {
        THDs_AMG_GS =  mythreads;
        THDs_CPR_lGS = (6 < mythreads) ? 6 : mythreads;
        THDs_CPR_gGS = (4 < mythreads) ? 4 : mythreads;
    }
    else if (its <=15) {
        THDs_AMG_GS =  (3 < mythreads) ? 3 : mythreads;
        THDs_CPR_lGS = (3 < mythreads) ? 3 : mythreads;
        THDs_CPR_gGS = (2 < mythreads) ? 2 : mythreads;
    }
    else if (its <=18) {
        THDs_AMG_GS =  (2 < mythreads) ? 2 : mythreads;
        THDs_CPR_lGS = (2 < mythreads) ? 2 : mythreads;
        THDs_CPR_gGS = (1 < mythreads) ? 1 : mythreads;
    }
    else {
        THDs_AMG_GS =  1;
        THDs_CPR_lGS = 1;
        THDs_CPR_gGS = 1;
    }
    
#else
    
    THDs_AMG_GS =  mythreads;
    THDs_CPR_lGS = mythreads ;
    THDs_CPR_gGS = mythreads ;
    
#endif
    
#endif // _OPENMP
}
 
/*---------------------------------*/
/*--        End of File          --*/
/*---------------------------------*/