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is check if semaphore is actually locked, which can be trivially done in portable way. Code gets more reabable, while we are at it... SGI-PV: 953915 SGI-Modid: xfs-linux-melb:xfs-kern:26274a Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Nathan Scott <nathans@sgi.com>
55 lines
1.6 KiB
C
55 lines
1.6 KiB
C
/*
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* Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
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* All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it would be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#ifndef __XFS_SUPPORT_SEMA_H__
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#define __XFS_SUPPORT_SEMA_H__
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#include <linux/time.h>
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#include <linux/wait.h>
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#include <asm/atomic.h>
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#include <asm/semaphore.h>
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/*
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* sema_t structure just maps to struct semaphore in Linux kernel.
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*/
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typedef struct semaphore sema_t;
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#define init_sema(sp, val, c, d) sema_init(sp, val)
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#define initsema(sp, val) sema_init(sp, val)
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#define initnsema(sp, val, name) sema_init(sp, val)
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#define psema(sp, b) down(sp)
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#define vsema(sp) up(sp)
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#define freesema(sema) do { } while (0)
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static inline int issemalocked(sema_t *sp)
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{
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return down_trylock(sp) || (up(sp), 0);
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}
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/*
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* Map cpsema (try to get the sema) to down_trylock. We need to switch
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* the return values since cpsema returns 1 (acquired) 0 (failed) and
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* down_trylock returns the reverse 0 (acquired) 1 (failed).
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*/
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static inline int cpsema(sema_t *sp)
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{
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return down_trylock(sp) ? 0 : 1;
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}
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#endif /* __XFS_SUPPORT_SEMA_H__ */
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