Producer Consumer TAS Sample code

Practice_07/Producer_Consumer_TAS.c

@@ -0,0 +1,55 @@
+#include <stdio.h>
+#include <stdatomic.h>
+#include <pthread.h>
+
+atomic_int lock = 0;     //원자적 변수
+int counter = 5;
+
+int TestAndSet(atomic_int *target){
+    // atomic으로 비슷하게 흉내.
+    // 어셈블리어 수준의 원자적 표현이 없음
+    return atomic_exchange(target, 1);
+}
+
+void acquire_lock(atomic_int *lock){
+    while(TestAndSet(lock) == 1){
+        // 바쁜대기중...
+    }
+}
+
+void release_lock(atomic_int *lock){
+    atomic_store(lock, 0);
+}
+
+void* producer(void* arg){
+    for(int i = 0; i < 1000000; i++){
+        acquire_lock(&lock);
+        counter++;
+        release_lock(&lock);
+    }
+
+    return NULL;
+}
+
+void *consumer(void* arg){
+    for(int i = 0; i < 1000000; i++){
+        acquire_lock(&lock);
+        counter--;
+        release_lock(&lock);
+    }
+
+    return NULL;
+}
+
+int main(){
+    pthread_t t1, t2;
+
+    pthread_create(&t1, NULL, producer, NULL);
+    pthread_create(&t2, NULL, consumer, NULL);
+
+    pthread_join(t1, NULL);
+    pthread_join(t2, NULL);
+
+    printf("최종 Counter 값 : %d\n", counter);
+    return 0;
+}