static pthread_mutex_t write_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t write_cond = PTHREAD_COND_INITIALIZER;
static pthread_t *write_threads = NULL;
static pthread_mutex_t write_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t write_cond = PTHREAD_COND_INITIALIZER;
static pthread_t *write_threads = NULL;