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-rw-r--r--sync/reader.c26
-rw-r--r--sync/sync.c39
-rw-r--r--sync/writer.c26
3 files changed, 69 insertions, 22 deletions
diff --git a/sync/reader.c b/sync/reader.c
index 66ee57b..929eba1 100644
--- a/sync/reader.c
+++ b/sync/reader.c
@@ -4,11 +4,15 @@
#include <stdlib.h>
#include <sys/ipc.h>
#include <sys/select.h>
+#include <sys/sem.h>
#include <sys/shm.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
+#define NSEM 3
+#define KEY 52
+
char *mem;
void quit(signum)
@@ -22,10 +26,10 @@ int main(argc, argv)
int argc;
char **argv;
{
-printf("\tR STARTING\n");
- int shmid, i, pid, id;
+ int shmid, semid, i, pid, id;
char filename[50];
FILE *fd;
+ struct sembuf sb;
if (argc < 2) {
printf("usage: reader [id]\n");
@@ -33,7 +37,6 @@ printf("\tR STARTING\n");
}
id = atoi(argv[1]);
-printf("\tR%d. started...\n", id);
if ((shmid = shmget(52, 1<<14, IPC_CREAT | 0666)) == -1){
@@ -45,12 +48,16 @@ printf("\tR%d. started...\n", id);
perror("shmat");
exit(1);
}
+
+ if ((semid = semget(shmid, NSEM, 0)) == -1) {
+ perror("Rsemget: ");
+ exit(1);
+ }
+
signal(SIGQUIT, quit);
-printf("\tR%d. SHMID: %d\n", id, shmid);
sprintf(filename, "reader.%d", id);
-printf("\tR%d. opening file \"%s\"...\n", id, filename);
fd = fopen(filename, "a");
if (!fd) {
@@ -60,7 +67,9 @@ printf("\tR%d. opening file \"%s\"...\n", id, filename);
srand(time(NULL));
while (1) {
-printf("\tR%d. reading...\n", id);
+ sb.sem_num = 0; sb.sem_op = -1; sb.sem_flg = 0;
+ semop(semid, &sb, 1);
+
for (i = 0; i < 1<<14; i++) {
fprintf(fd, "%c", *(mem + i));
fflush(fd);
@@ -68,7 +77,10 @@ printf("\tR%d. reading...\n", id);
fprintf(fd, "\n");
fflush(fd);
-printf("\tR%d. waiting...\n", id);
+ sb.sem_op = 1;
+ semop(semid, &sb, 1);
+
+
sleep(rand() % (id + 1));
}
}
diff --git a/sync/sync.c b/sync/sync.c
index 66574a1..23d6ba1 100644
--- a/sync/sync.c
+++ b/sync/sync.c
@@ -1,15 +1,28 @@
#include <stdio.h>
#include <stdlib.h>
#include <sys/ipc.h>
+#include <sys/sem.h>
#include <sys/shm.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
+#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);
}
@@ -17,8 +30,9 @@ int main(argc, argv)
int argc;
char **argv;
{
- int shmid, i, pid, n_read, n_write, w;
+ 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");
@@ -36,13 +50,27 @@ char **argv;
perror("shmat");
exit(1);
}
+printf("Sshmid: %x\n", shmid);
signal(SIGQUIT, quit);
-printf("\nSHMID: %d\nsetting initial memory values...\n", shmid);
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);
@@ -57,11 +85,8 @@ printf("\nSHMID: %d\nsetting initial memory values...\n", shmid);
*(arg_r + 2) = NULL;
*(arg_w + 2) = NULL;
-printf("forking readers...\n");
for (i = 0; i < n_read; i++){
-printf("sprintf...\n");
sprintf(*(arg_r + 1), "%d", i);
-printf("\t%d\n",i);
if (pid = fork()) {
/* printf("starting reader %d...\n", i); */
} else {
@@ -70,10 +95,8 @@ printf("\t%d\n",i);
}
}
-printf("forking writers...\n");
for (i = 0; i < n_write; i++) {
sprintf(*(arg_w + 1), "%d", i);
-printf("\t%d\n", i);
if (pid = fork()) {
/* printf("starting writer %d...\n", i); */
} else {
@@ -89,7 +112,7 @@ printf("sync done...\n");
*/
for (i = 0; i < (n_write + n_read); i++) {
wait(&w);
- printf("\nReturned with code:%d\n", WTERMSIG(w));
+ printf("\nReturned with code:%d\n", WEXITSTATUS(w));
}
quit();
}
diff --git a/sync/writer.c b/sync/writer.c
index b1ab9ed..d38dd70 100644
--- a/sync/writer.c
+++ b/sync/writer.c
@@ -4,12 +4,15 @@
#include <stdlib.h>
#include <sys/ipc.h>
#include <sys/select.h>
+#include <sys/sem.h>
#include <sys/shm.h>
#include <sys/types.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
+#define NSEM 3
+
char *mem;
void quit(signum)
@@ -23,9 +26,9 @@ int main(argc, argv)
int argc;
char **argv;
{
-printf("\tW STARTING\n");
- int shmid, i, pid, id;
+ int shmid, semid, i, pid, id;
char *mem;
+ struct sembuf sb;
if (argc < 2) {
printf("usage: writer [id]\n");
@@ -34,7 +37,6 @@ printf("\tW STARTING\n");
id = atoi(argv[1]);
-printf("\tW%d. started...\n", id);
if ((shmid = shmget(52, 1<<14, IPC_CREAT | 0666)) == -1){
perror("shmget: shmget failed");
@@ -45,20 +47,30 @@ printf("\tW%d. started...\n", id);
perror("shmat");
exit(1);
}
+printf("Wshmid: %x\n", shmid);
+
+ if ((semid = semget(shmid, NSEM, 0)) == -1) {
+ perror("Wsemget: ");
+ 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);
+
+ sb.sem_num = 0; sb.sem_op = -1; sb.sem_flg = 0;
+ semop(semid, &sb, 1);
+
for (i = 0; i < 1<<14; i++) {
mem[i]= 0x30 + id;
}
-printf("\tW%d. waiting...\n");
+
+ sb.sem_op = 1;
+ semop(semid, &sb, 1);
+
sleep(rand() % ((id * 2) + 1));
}
}
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