#include "pthread_impl.h"
#include <threads.h>

int mtx_lock(mtx_t* m) {
  if (m->_m_type == PTHREAD_MUTEX_NORMAL && !a_cas(&m->_m_lock, 0, EBUSY))
    return thrd_success;
  /* Calling mtx_timedlock with a null pointer is an extension.
   * It is convenient, here to avoid duplication of the logic
   * for return values. */
  return mtx_timedlock(m, 0);
}