Messages synchrones avec MPI (simples et bloquants ou securises et non bloquants)

#include <stdio.h>

#define SIZE 1000

int main(int argc; char *argv[])

{

double startwtime, endwtime;

int namelen, numprocs, myid, size ;

char processor_name[MPI_MAX_PROCESSOR_NAME], buff[SIZE], msg[SIZE] ;

MPI_Init(&argc,&argv);

startwtime = MPI_Wtime();

MPI_Comm_size(MPI_COMM_WORLD,&numprocs);

MPI_Comm_rank(MPI_COMM_WORLD,&myid);

MPI_Get_processor_name(processor_name,&namelen);

fprintf(stderr,"\nProcessus %d sur la machine %s parmi %d processus.\n", myid, processor_name, numprocs);

if (numprocs != 3) fprintf(stderr,"Il me faut 3 processus !\n") ;

if (myid==0)

{

strcpy(msg,"Message 1") ;

size=sizeof(char)*strlen(msg) ;

fprintf(stderr,"%d envoie <%s>\n",myid, msg) ;

MPI_Ssend((void*) msg, size, MPI_CHAR, 1, 1, MPI_COMM_WORLD) ;

strcpy(msg,"Message 2") ;

fprintf(stderr,"%d envoie <%s>\n",myid,msg) ;

MPI_Ssend((void*) msg, 15, MPI_CHAR, 2, 1, MPI_COMM_WORLD) ;

} else

{

strcpy(msg,"") ;

if (myid==1) system("sleep 2") ;

else system("sleep 5") ;

MPI_Recv(msg, 15, MPI_CHAR, 0, MPI_ANY_TAG, MPI_COMM_WORLD, &status) ;

fprintf(stderr,"%d recoit [%s]\n",myid,msg) ;

}

endwtime = MPI_Wtime();

printf("Temps ecoule sur %d = %f\n", myid, endwtime-startwtime);

MPI_Finalize();

return 0;

}

0 envoie <Message 1>

Processus 2 sur la machine lil. parmi 3 processus.

Processus 1 sur la machine lil. parmi 3 processus.

0 envoie <Message 2>

1 recoit [message 1]

Temps ecoule sur 1 = 2.060022

Temps ecoule sur 0 = 5.071701

2 recoit [Message 2]

Temps ecoule sur 2 = 5.060516