deadlock simple example

threads-bugs/deadlock.c

@@ -0,0 +1,54 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <unistd.h>
+
+#include "common.h"
+#include "common_threads.h"
+
+pthread_mutex_t L1 = PTHREAD_MUTEX_INITIALIZER;
+pthread_mutex_t L2 = PTHREAD_MUTEX_INITIALIZER;
+
+void *thread1(void *arg) {
+    printf("t1: begin\n");
+    printf("t1: try to acquire L1...\n");
+    Pthread_mutex_lock(&L1);
+    printf("t1: L1 acquired\n");
+    printf("t1: try to acquire L2...\n");
+    Pthread_mutex_lock(&L2);
+    printf("t1: L2 acquired\n");
+    Pthread_mutex_unlock(&L1);
+    Pthread_mutex_unlock(&L2);
+    return NULL;
+}
+
+void *thread2(void *arg) {
+    printf("                           t2: begin\n");
+    printf("                           t2: try to acquire L2...\n");
+    Pthread_mutex_lock(&L2);
+    printf("                           t2: L2 acquired\n");
+    printf("                           t2: try to acquire L1...\n");
+    Pthread_mutex_lock(&L1);
+    printf("                           t2: L1 acquired\n");
+    Pthread_mutex_unlock(&L1);
+    Pthread_mutex_unlock(&L2);
+
+    return NULL;
+}
+
+int main(int argc, char *argv[]) {                    
+    if (argc != 1) {
+	fprintf(stderr, "usage: main\n");
+	exit(1);
+    }
+    pthread_t p1, p2;
+    printf("main: begin\n");
+    Pthread_create(&p1, NULL, thread1, NULL); 
+    Pthread_create(&p2, NULL, thread2, NULL);
+    // join waits for the threads to finish
+    Pthread_join(p1, NULL); 
+    Pthread_join(p2, NULL); 
+    printf("main: end\n");
+    return 0;
+}
+