feat: update structure

cs2106/labs/lab3/progs/part2/test_barrier.c

@@ -0,0 +1,48 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <time.h>
+#include <sys/wait.h>
+#include "barrier.h"
+
+#define NUM_PROCESSES   6
+#define MAX_SLEEP       1000000  // Maximum sleep period in microseconds
+
+int main() {
+    int i, pid;
+    int sleep_time[NUM_PROCESSES];
+
+    init_barrier(NUM_PROCESSES+1);
+
+    srand(time(NULL));
+    for(i=0; i<NUM_PROCESSES; i++) {
+
+        // The children will all slip at different amounts of time
+        sleep_time[i] = (int) (((float) rand() / RAND_MAX) * MAX_SLEEP);
+        if((pid = fork()) == 0) {
+            srand(time(NULL));
+            break;
+        }
+    }
+
+    if(pid == 0) {
+        usleep(sleep_time[i]);
+
+        // Reach the barrier.
+        printf("\tChild %d slept for %3.2f seconds and has now reached the barrier\n", i, sleep_time[i]/1000000.0);
+        reach_barrier();
+    }
+    else {
+        // Parent will just wait at barrier for all children to return
+        printf("**Parent waiting for children**\n\n");
+        reach_barrier();
+        printf("\n**All the children have returned**\n");
+        
+        // Clean up the process table
+        for(i=0; i<NUM_PROCESSES; i++)
+            wait(NULL);
+
+        destroy_barrier(pid);
+    }
+}
+