#include #include #include #include #include #include #include #define RUNS 4096 #define THREADS 4 #define DATA_TEXT_SIZE 1024 #define BUFFER_SIZE 1024 struct data { char text[DATA_TEXT_SIZE]; }; bool are_same(struct data* a, struct data* b) { for (int i = 0; i < DATA_TEXT_SIZE; i++) if (a->text[i] != b->text[i]) return false; return true; } struct data buffer[BUFFER_SIZE] = { 0 }; struct data produced[RUNS] = { 0 }; // used to check correctness struct data consumed[RUNS] = { 0 }; // used to check correctness void* produce(void* null) { for (int r = 0; r < RUNS; r++) { for (int i = 0; i < DATA_TEXT_SIZE; i++) produced[r].text[i] = rand(); buffer[r % BUFFER_SIZE] = produced[r]; // Super wrong: Overwritting data being read by the consumer. } } void* consume(void* null) { for (int r = 0; r < RUNS; r++) { consumed[r] = buffer[r % BUFFER_SIZE]; // Super wrong: Reading data concurrently (or not even) written by the // producer. } } int main() { int res; pthread_t producer; res = pthread_create(&producer, NULL, produce, NULL); assert(!res); pthread_t consumer; res = pthread_create(&consumer, NULL, consume, NULL); assert(!res); res = pthread_join(consumer, NULL); assert(!res); res = pthread_join(producer, NULL); assert(!res); int r = 0; for (; r < RUNS; r++) { if (!are_same(&produced[r], &consumed[r])) { printf("Consumed the wrong data on round %d.\n", r); break; } } if (r == RUNS) { printf("Looks correct to me! :)\n"); } }