Create 5

5_Multithreaded-Programming/thread_reverse_order.c

@@ -0,0 +1,75 @@
+#include <stdio.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <time.h>
+#include <semaphore.h>
+
+#define NUM_THREADS 5
+
+// Semaphores to control output order
+sem_t semaphores[NUM_THREADS];
+
+// Thread function
+void* thread_function(void* arg) {
+    int thread_num = *(int*)arg;
+    int thread_creation_number = thread_num + 1;
+    
+    // Random delay between 1-5 seconds
+    int delay = rand() % 5 + 1;
+    printf("Thread %d created, will delay for %d seconds\n", thread_creation_number, delay);
+    sleep(delay);
+    
+    // Wait for signal to ensure proper output order
+    sem_wait(&semaphores[thread_num]);
+    
+    // Output thread information
+    printf("Thread ID: %lu, Creation Number: %d\n", pthread_self(), thread_creation_number);
+    
+    // Signal the next thread in reverse order
+    if (thread_num > 0) {
+        sem_post(&semaphores[thread_num - 1]);
+    }
+    
+    free(arg);
+    return NULL;
+}
+
+int main() {
+    pthread_t threads[NUM_THREADS];
+    int i;
+    
+    // Seed the random number generator
+    srand(time(NULL));
+    
+    // Initialize all semaphores
+    for (i = 0; i < NUM_THREADS; i++) {
+        sem_init(&semaphores[i], 0, 0);
+    }
+    
+    // Create all threads
+    printf("Creating threads...\n");
+    for (i = 0; i < NUM_THREADS; i++) {
+        int* thread_num = malloc(sizeof(int));
+        *thread_num = i;
+        pthread_create(&threads[i], NULL, thread_function, thread_num);
+        usleep(100000); // Small delay between thread creation for clarity
+    }
+    
+    // Signal the last created thread to start the reverse order output
+    sem_post(&semaphores[NUM_THREADS - 1]);
+    
+    // Wait for all threads to complete
+    for (i = 0; i < NUM_THREADS; i++) {
+        pthread_join(threads[i], NULL);
+    }
+    
+    // Clean up semaphores
+    for (i = 0; i < NUM_THREADS; i++) {
+        sem_destroy(&semaphores[i]);
+    }
+    
+    printf("All threads completed execution.\n");
+    
+    return 0;
+}