Post #1003

// gcc -O2 -pthread -std=gnu11 -Wall -Wextra main.c #include <pthread.h> #include <stdint.h> #include <stdio.h> #define u64 uint64_t #define N 1000000000ULL static volatile u64 counter = 0; static volatile int done = 0; static void *reader() { while (!done) { counter; } return NULL; } static void *writer() { for (u64 i = 0; i < N; i++) { counter++; } done = 1; return NULL; } int main(void) { pthread_t rth, wth; if (pthread_create(&rth, NULL, reader, NULL) != 0) return 1; if (pthread_create(&wth, NULL, writer, NULL) != 0) return 1; pthread_join(wth, NULL); pthread_join(rth, NULL); u64 final = counter; printf("final=%lu expected=%llu %s\n", final, N, (final == N ? "OK" : "MISMATCH")); return (final == N) ? 0 : 2; }