| #include "pthread_impl.h" | |
| static int vmlock[2]; | |
| void __vm_lock(int inc) | |
| { | |
| for (;;) { | |
| int v = vmlock[0]; | |
| if (inc*v < 0) __wait(vmlock, vmlock+1, v, 1); | |
| else if (a_cas(vmlock, v, v+inc)==v) break; | |
| } | |
| } | |
| void __vm_unlock(void) | |
| { | |
| int inc = vmlock[0]>0 ? -1 : 1; | |
| if (a_fetch_add(vmlock, inc)==-inc && vmlock[1]) | |
| __wake(vmlock, -1, 1); | |
| } | |
| weak_alias(__vm_lock, __vm_lock_impl); | |
| weak_alias(__vm_unlock, __vm_unlock_impl); |