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Unix Threads in C

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Deadlocks in C

#include <pthread.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #include <time.h> #define THREAD_NUM 8 pthread_mutex_t mutexFuel; int fuel = 50; pthread_mutex_t mutexWater; int water = 10; void* routine(void* args) { if (rand() % 2 == 0) { pthread_mutex_lock(&mutexFuel); sleep(1); pthread_mutex_lock(&mutexWater); } else { pthread_mutex_lock(&mutexWater); sleep(1); pthread_mutex_lock(&mutexFuel); } fuel += 50; water = fuel; printf("Incremented fuel to: %d set water to %d\n", fuel, water); pthread_mutex_unlock(&mutexFuel); pthread_mutex_unlock(&mutexWater); } int main(int argc, char *argv[]) { pthread_t th[THREAD_NUM]; pthread_mutex_init(&mutexFuel, NULL); pthread_mutex_init(&mutexWater, NULL); int i; for (i = 0; i < THREAD_NUM; i++) { if (pthread_create(&th[i], NULL, &routine, NULL) != 0) { perror("Failed to create thread"); } } for (i = 0; i < THREAD_NUM; i++) { if (pthread_join(th[i], NULL) != 0) { perror("Failed to join thread"); } } printf("Fuel: %d\n", fuel); printf("Water: %d\n", water); pthread_mutex_destroy(&mutexFuel); pthread_mutex_destroy(&mutexWater); return 0; }