#define _LOCK_EXTENSION #include "../plan9/sys9.h" #include int tas(int*); void lockinit(void) { } void lock(Lock *lk) { while(tas(&lk->val)) _SLEEP(0); } int canlock(Lock *lk) { if(tas(&lk->val)) return 0; return 1; } void unlock(Lock *lk) { lk->val = 0; }