__wait.c raw

   1  #include "pthread_impl.h"
   2  
   3  void __wait(volatile int *addr, volatile int *waiters, int val, int priv)
   4  {
   5  	int spins=100;
   6  	if (priv) priv = FUTEX_PRIVATE;
   7  	while (spins-- && (!waiters || !*waiters)) {
   8  		if (*addr==val) a_spin();
   9  		else return;
  10  	}
  11  	if (waiters) a_inc(waiters);
  12  	while (*addr==val) {
  13  		__syscall(SYS_futex, addr, FUTEX_WAIT|priv, val, 0) != -ENOSYS
  14  		|| __syscall(SYS_futex, addr, FUTEX_WAIT, val, 0);
  15  	}
  16  	if (waiters) a_dec(waiters);
  17  }
  18