diff options
Diffstat (limited to 'kern/kmutex.h')
| -rw-r--r-- | kern/kmutex.h | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/kern/kmutex.h b/kern/kmutex.h new file mode 100644 index 00000000..29815156 --- /dev/null +++ b/kern/kmutex.h @@ -0,0 +1,52 @@ +/* Copyright (C) 2017 Free Software Foundation, Inc. + Contributed by Agustina Arzille <avarzille@riseup.net>, 2017. + + This program is free software; you can redistribute it and/or + modify it under the terms of the GNU General Public License + as published by the Free Software Foundation; either + version 2 of the license, or (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public + License along with this program; if not, see + <http://www.gnu.org/licenses/>. +*/ + +#ifndef _KERN_KMUTEX_H_ +#define _KERN_KMUTEX_H_ 1 + +#include <kern/lock.h> +#include <mach/kern_return.h> + +struct kmutex +{ + unsigned int state; + decl_simple_lock_data (, lock) +}; + +/* Possible values for the mutex state. */ +#define KMUTEX_AVAIL 0 +#define KMUTEX_LOCKED 1 +#define KMUTEX_CONTENDED 2 + +/* Initialize mutex in *MTXP. */ +extern void kmutex_init (struct kmutex *mtxp); + +/* Acquire lock MTXP. If INTERRUPTIBLE is true, the sleep may be + * prematurely terminated, in which case the function returns + * KERN_INTERRUPTED. Otherwise, KERN_SUCCESS is returned. */ +extern kern_return_t kmutex_lock (struct kmutex *mtxp, + boolean_t interruptible); + +/* Try to acquire the lock MTXP without sleeping. + * Returns KERN_SUCCESS if successful, KERN_FAILURE otherwise. */ +extern kern_return_t kmutex_trylock (struct kmutex *mtxp); + +/* Unlock the mutex MTXP. */ +extern void kmutex_unlock (struct kmutex *mtxp); + +#endif |