POSIX Mutex

Thread_sync/mutex_example/mutex_example.c

@@ -0,0 +1,101 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>	/* for working with posix threads */
+#include <unistd.h>		/* for pause() and sleep() */
+#include <errno.h>		/* for using global variable errno */
+#include <assert.h>
+
+int arr[] = { 1,2,3,4,5 };
+
+void
+print_array() {
+
+	int i = 0;
+	int arr_size = sizeof(arr) / sizeof(arr[0]);
+
+	for (; i < arr_size - 1; i++) {
+
+		printf("%d ", arr[i]);
+	}
+
+	printf("%d\n", arr[i]);
+}
+
+/* a thread callback fn must have following prototypes
+	void *(*thread_fn)(void *) */
+
+static void *
+thread_fn_callback_sum(void* arg) {
+
+	int i;
+	int sum;
+
+	int arr_size = sizeof(arr) / sizeof(arr[0]);
+
+	do {
+		sum = 0;
+		i = 0;
+		while (i < arr_size) {
+			sum += arr[i];
+			i++;
+		}
+
+		printf("sum = %d\n", sum);
+
+	} while (1);
+}
+
+static void *
+thread_fn_callback_swap(void* arg) {
+
+	int temp;
+	int arr_size = sizeof(arr) / sizeof(arr[0]);
+
+	do {
+		temp = arr[0];
+		arr[0] = arr[arr_size - 1];
+		arr[arr_size - 1] = temp;
+	} while (1);
+}
+
+void
+sum_thread_create() {
+
+	pthread_t pthread1;
+
+	int rc = pthread_create(&pthread1,
+		NULL,
+		thread_fn_callback_sum,
+		NULL);
+
+	if (rc != 0) {
+		printf("error occured, thread could not be created, errno = %d\n", rc);
+		exit(EXIT_FAILURE);
+	}
+}
+
+void
+swap_thread_create() {
+
+	pthread_t pthread2;
+
+	int rc = pthread_create(&pthread2,
+		NULL,
+		thread_fn_callback_swap,
+		NULL);
+
+	if (rc != 0) {
+		printf("error occured, thread could not be created, errno = %d\n", rc);
+		exit(EXIT_FAILURE);
+	}
+}
+
+int
+main(int argc, char* argv[]) {
+
+	sum_thread_create();
+	swap_thread_create();
+
+	pthread_exit(0);
+	return 0;
+}