JNIEXPORT jstring JNICALL Java_devmap_DevMap_getDevMaps(JNIEnv *env, jclass cls)
{
jstring content;
char *res = "";
char buf[4096];
/* Step 1: open the shm */
int fd = open_shm();
if (fd < 0) {
goto out;
}
/* Step 2: read in the content */
memset(buf, 0, sizeof(buf));
read(fd, buf, 4096);
printf("buf %s\n", buf);
close_shm(fd);
res = buf;
out:
content = (*env)->NewStringUTF(env, res);
return content;
}
int main(int argc, char **argv)
{
int i, rc, status, np, nr_prog_arg, size_structure_shm, size_np_shm;
int fd_structure_shm, fd_np_shm;
char *prog, *command;
char **arguments;
void *structure_mem, *np_mem;
mqd_t local_queue;
char local_queue_name[MAX_NAME_LEN];
if(argc < 4)
{
printf("Wrong parameters!\n");
return -1;
}
np = atoi(argv[2]);
prog = argv[3];
nr_prog_arg = argc - 4;
arguments = calloc(nr_prog_arg + 2, sizeof(char*));
arguments[0] = prog;
for(i = 0; i < nr_prog_arg; i++)
{
arguments[i + 1] = argv[i + 4];
}
arguments[i + 1] = NULL;
//alloc memory for the mpi_comm_world structure
mpi_comm_world = calloc(np, sizeof(struct mpi_comm));
//create the first shared memory for the processes number
size_structure_shm = np * sizeof(struct mpi_comm);
fd_structure_shm = open_shm(SHM_STRUCTURE_NAME, size_structure_shm, O_CREAT | O_RDWR, &structure_mem);
memcpy(structure_mem, mpi_comm_world, size_structure_shm);
//create the shared memory for the mpi_comm_world structure
size_np_shm = sizeof(int);
fd_np_shm = open_shm(SHM_NP_NAME, size_np_shm, O_CREAT | O_RDWR, &np_mem);
((int*)np_mem)[0] = np;
//create queues for all the processes
for(i = 0; i < np; i ++) {
sprintf(local_queue_name, "/%i", i);
local_queue = mq_open(local_queue_name, O_CREAT | O_RDWR, 0666, NULL);
DIE(local_queue == (mqd_t)-1, "mq_open");
mpi_comm_world[i].local_queue = local_queue;
}
//create the processes
for(i = 0; i < np; i++)
{
pid_t pid = fork();
switch(pid) {
case -1:
return EXIT_FAILURE;
case 0:
((struct mpi_comm*)structure_mem)[i].pid = getpid();
((struct mpi_comm*)structure_mem)[i].rank = i;
command = calloc(strlen(prog) + 2, sizeof(char));
sprintf(command, "./%s", prog);
execvp(command, (char*const*) arguments);
free(command);
free(arguments);
exit(EXIT_FAILURE);
default:
break;
}
}
free(arguments);
for(i = 0; i < np; i++)
waitpid(mpi_comm_world[i].pid, &status, 0);
//close the shared memories and the queues
close_shm(SHM_STRUCTURE_NAME, structure_mem, fd_structure_shm, size_structure_shm);
close_shm(SHM_NP_NAME, np_mem, fd_np_shm, size_np_shm);
for(i = 0; i < np; i++) {
rc = mq_close(mpi_comm_world[i].local_queue);
DIE(rc == -1, "mq_close");
sprintf(local_queue_name, "/%i", i);
rc = mq_unlink(local_queue_name);
DIE(rc == -1, "mq_unlink");
}
free(mpi_comm_world);
return 0;
}
