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- /*
- * This file is part of the UCB release of Plan 9. It is subject to the license
- * terms in the LICENSE file found in the top-level directory of this
- * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
- * part of the UCB release of Plan 9, including this file, may be copied,
- * modified, propagated, or distributed except according to the terms contained
- * in the LICENSE file.
- */
- #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;
- }
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