IPCS, IPCRM, IPC_NOWAIT currently working

programs/tests/CMakeLists.txt

@@ -88,6 +88,7 @@ set(TESTS
     # Test semaphores.
     t_semget.c
     t_sem1.c
+    t_semflg.c
     # Test scheduling feedback tests.
     t_schedfb.c
 )

programs/tests/t_semflg.c

@@ -0,0 +1,65 @@
+//test
+#include "ipc/sem.h"
+#include "stdio.h"
+#include "ipc/ipc.h"
+#include "sys/errno.h"
+#include "stdlib.h"
+#include "sys/unistd.h"
+
+/*
+Testing IPC_NOWAIT flag.
+*/
+
+void semid_print(struct semid_ds *temp)
+{
+    printf("pid, IPC_KEY, Semid, semop, change: %d, %d, %d, %d, %d\n", temp->owner, temp->key, temp->semid, temp->sem_otime, temp->sem_ctime);
+    for (int i = 0; i < (temp->sem_nsems); i++) {
+        printf("%d semaphore:\n", i + 1);
+        printf("value: %d, pid %d, process waiting %d\n", temp->sems[i].sem_val, temp->sems[i].sem_pid, temp->sems[i].sem_zcnt);
+    }
+}
+
+int main()
+{
+    struct sembuf op[2];
+    union semun arg;
+    long ret, id;
+
+    // Create the first semaphore.
+    id = semget(IPC_PRIVATE, 1, IPC_CREAT);
+    printf("Id: %d\n", id);
+
+    // Set the value of the semaphore in the structure.
+    arg.val = 0;
+    // Setting the semaphore value.
+    printf("Set Value (%d): %d\n", id, arg.val);
+    ret = semctl(id, 0, SETVAL, &arg);
+    if (ret == -1) {
+        perror("Failed to set value of semaphore.");
+        return 1;
+    }
+
+    op[0].sem_num = 0;
+    op[0].sem_op = 1;
+    op[0].sem_flg = IPC_NOWAIT;
+    
+    op[1].sem_num = 0;
+    op[1].sem_op = -2;
+    op[1].sem_flg = IPC_NOWAIT;
+
+    // Check the value of the semaphore.
+    ret = semctl(id, 0, GETVAL, &arg);
+    printf("Check Value before(%d): %d\n", id, ret);
+
+    sleep(1);
+    if((ret = semop(id, op, 2)) == -1){
+        perror("Failed to perform the operations on the value of semaphore.");
+        return 1;
+    }
+    
+    // Check the value of the semaphore.
+    ret = semctl(id, 0, GETVAL, &arg);
+    printf("Check Value after(%d): %d\n", id, ret);
+
+    return 0;
+}