fusl/src/thread/mtx_trylock.c

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

int __pthread_mutex_trylock(mtx_t*);

int mtx_trylock(mtx_t* m) {
  if (m->_m_type == PTHREAD_MUTEX_NORMAL)
    return (a_cas(&m->_m_lock, 0, EBUSY) & EBUSY) ? thrd_busy : thrd_success;

  int ret = __pthread_mutex_trylock(m);
  switch (ret) {
    default:
      return thrd_error;
    case 0:
      return thrd_success;
    case EBUSY:
      return thrd_busy;
  }
}