From e8b1808eaf87a49e4c34ebbfb66854baa627418c Mon Sep 17 00:00:00 2001 From: Tucker Evans Date: Mon, 18 Feb 2019 07:35:54 -0500 Subject: Moves assignments to given course folder. --- CS3871/sync/sync.c | 118 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) create mode 100644 CS3871/sync/sync.c (limited to 'CS3871/sync/sync.c') diff --git a/CS3871/sync/sync.c b/CS3871/sync/sync.c new file mode 100644 index 0000000..23d6ba1 --- /dev/null +++ b/CS3871/sync/sync.c @@ -0,0 +1,118 @@ +#include +#include +#include +#include +#include +#include +#include +#include + +#define NSEM 3 + +union semun { + int val; + struct semid_ds *buf; + ushort *array; +}; + + +int shmid, semid; + +void quit(signum) +int signum; +{ + shmctl(shmid, IPC_RMID, NULL); + semctl(semid, IPC_RMID, 0); +} + + +int main(argc, argv) +int argc; +char **argv; +{ + int i, pid, n_read, n_write, w; + char *mem, **arg_r, **arg_w; + union semun semarg; + + if (argc < 2) { + printf("usage: sync [number readers] [number writers]\n"); + exit(1); + } + n_read = atoi(argv[1]); + n_write = atoi(argv[2]); + + 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); + } +printf("Sshmid: %x\n", shmid); + signal(SIGQUIT, quit); + + for (i = 0; i < 1<<14; i++) { + *(mem + i) = 0x30; + } + + if ((semid = semget(shmid, NSEM, 0666 | IPC_CREAT)) == -1) { + perror("Ssemget: "); + exit(1); + } + + semarg.val = 1; + for (i = 0; i < NSEM; i++) { + if ((semctl(semid, i, SETVAL, semarg)) == -1) { + perror("semctl: "); + exit(1); + } + } + + + arg_r = malloc(sizeof(char*) * 3); + arg_w = malloc(sizeof(char*) * 3); + *arg_r = malloc(sizeof(char) * 10); + *arg_w = malloc(sizeof(char) * 10); + + *(arg_r + 1) = malloc(sizeof(char) * 50); + *(arg_w + 1) = malloc(sizeof(char) * 50); + + *arg_r = "reader"; + *arg_w = "writer"; + + *(arg_r + 2) = NULL; + *(arg_w + 2) = NULL; + + for (i = 0; i < n_read; i++){ + sprintf(*(arg_r + 1), "%d", i); + if (pid = fork()) { + /* printf("starting reader %d...\n", i); */ + } else { + int ret = execv("./reader", arg_r); + printf("exec retern %d", ret); + } + } + + for (i = 0; i < n_write; i++) { + sprintf(*(arg_w + 1), "%d", i); + if (pid = fork()) { + /* printf("starting writer %d...\n", i); */ + } else { + execvp("./writer", arg_w); + } + + } + + shmdt(mem); +printf("sync done...\n"); +/* TODO + * why is this returning 8 + */ + for (i = 0; i < (n_write + n_read); i++) { + wait(&w); + printf("\nReturned with code:%d\n", WEXITSTATUS(w)); + } + quit(); +} -- cgit v1.1