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#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ipc.h>
#include <sys/select.h>
#include <sys/shm.h>
#include <sys/types.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
char *mem;
void quit(signum)
int signum;
{
shmdt(mem);
exit(1);
}
int main(argc, argv)
int argc;
char **argv;
{
printf("\tW STARTING\n");
int shmid, i, pid, id;
char *mem;
if (argc < 2) {
printf("usage: writer [id]\n");
exit(1);
}
id = atoi(argv[1]);
printf("\tW%d. started...\n", id);
if ((shmid = shmget(52, 1<<14, IPC_CREAT | 0666)) == -1){
perror("shmget: shmget failed");
exit(1);
}
if ((mem = shmat(shmid, NULL, 0)) == (char *) -1) {
perror("shmat");
exit(1);
}
signal(SIGQUIT, quit);
printf("\tW%d. SHMID: %d\n", id, shmid);
srand(time(NULL));
while (1) {
printf("\tW%d. testing...\n", id);
rand() % id;
printf("\tW%d. writing...\n", id);
for (i = 0; i < 1<<14; i++) {
mem[i]= 0x30 + id;
}
printf("\tW%d. waiting...\n");
sleep(rand() % ((id * 2) + 1));
}
}
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