ref: 3b7e03a30ed29ee0666c00568bf67b8179c28d12
dir: /sys/src/cmd/dossrv/lock.c/
#include <u.h> #include <libc.h> #include "iotrack.h" #include "dat.h" #include "fns.h" void mlock(MLock *l) { if(l->key != 0 && l->key != 1) panic("uninitialized lock"); if (l->key) panic("lock"); l->key = 1; } void unmlock(MLock *l) { if(l->key != 0 && l->key != 1) panic("uninitialized unlock"); if (!l->key) panic("unlock"); l->key = 0; } int canmlock(MLock *l) { if(l->key != 0 && l->key != 1) panic("uninitialized canlock"); if (l->key) return 0; l->key = 1; return 1; }