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Diffstat (limited to 'include/os/linux/spl/sys/condvar.h')
| -rw-r--r-- | include/os/linux/spl/sys/condvar.h | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/include/os/linux/spl/sys/condvar.h b/include/os/linux/spl/sys/condvar.h new file mode 100644 index 000000000000..22408824f85b --- /dev/null +++ b/include/os/linux/spl/sys/condvar.h @@ -0,0 +1,113 @@ +/* + * Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC. + * Copyright (C) 2007 The Regents of the University of California. + * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER). + * Written by Brian Behlendorf <behlendorf1@llnl.gov>. + * UCRL-CODE-235197 + * + * This file is part of the SPL, Solaris Porting Layer. + * For details, see <http://zfsonlinux.org/>. + * + * The SPL 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. + * + * The SPL 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 the SPL. If not, see <http://www.gnu.org/licenses/>. + */ + +#ifndef _SPL_CONDVAR_H +#define _SPL_CONDVAR_H + +#include <linux/module.h> +#include <sys/kmem.h> +#include <sys/mutex.h> +#include <sys/callo.h> +#include <sys/wait.h> +#include <sys/time.h> + +/* + * cv_timedwait() is similar to cv_wait() except that it additionally expects + * a timeout value specified in ticks. When woken by cv_signal() or + * cv_broadcast() it returns 1, otherwise when the timeout is reached -1 is + * returned. + * + * cv_timedwait_sig() behaves the same as cv_timedwait() but blocks + * interruptibly and can be woken by a signal (EINTR, ERESTART). When + * this occurs 0 is returned. + * + * cv_timedwait_io() and cv_timedwait_sig_io() are variants of cv_timedwait() + * and cv_timedwait_sig() which should be used when waiting for outstanding + * IO to complete. They are responsible for updating the iowait accounting + * when this is supported by the platform. + * + * cv_timedwait_hires() and cv_timedwait_sig_hires() are high resolution + * versions of cv_timedwait() and cv_timedwait_sig(). They expect the timeout + * to be specified as a hrtime_t allowing for timeouts of less than a tick. + * + * N.B. The return values differ slightly from the illumos implementation + * which returns the time remaining, instead of 1, when woken. They both + * return -1 on timeout. Consumers which need to know the time remaining + * are responsible for tracking it themselves. + */ + + +/* + * The kcondvar_t struct is protected by mutex taken externally before + * calling any of the wait/signal funs, and passed into the wait funs. + */ +#define CV_MAGIC 0x346545f4 +#define CV_DESTROY 0x346545f5 + +typedef struct { + int cv_magic; + spl_wait_queue_head_t cv_event; + spl_wait_queue_head_t cv_destroy; + atomic_t cv_refs; + atomic_t cv_waiters; + kmutex_t *cv_mutex; +} kcondvar_t; + +typedef enum { CV_DEFAULT = 0, CV_DRIVER } kcv_type_t; + +extern void __cv_init(kcondvar_t *, char *, kcv_type_t, void *); +extern void __cv_destroy(kcondvar_t *); +extern void __cv_wait(kcondvar_t *, kmutex_t *); +extern void __cv_wait_io(kcondvar_t *, kmutex_t *); +extern int __cv_wait_io_sig(kcondvar_t *, kmutex_t *); +extern int __cv_wait_sig(kcondvar_t *, kmutex_t *); +extern int __cv_timedwait(kcondvar_t *, kmutex_t *, clock_t); +extern int __cv_timedwait_io(kcondvar_t *, kmutex_t *, clock_t); +extern int __cv_timedwait_sig(kcondvar_t *, kmutex_t *, clock_t); +extern int cv_timedwait_hires(kcondvar_t *, kmutex_t *, hrtime_t, + hrtime_t res, int flag); +extern int cv_timedwait_sig_hires(kcondvar_t *, kmutex_t *, hrtime_t, + hrtime_t res, int flag); +extern void __cv_signal(kcondvar_t *); +extern void __cv_broadcast(kcondvar_t *c); + +#define cv_init(cvp, name, type, arg) __cv_init(cvp, name, type, arg) +#define cv_destroy(cvp) __cv_destroy(cvp) +#define cv_wait(cvp, mp) __cv_wait(cvp, mp) +#define cv_wait_io(cvp, mp) __cv_wait_io(cvp, mp) +#define cv_wait_io_sig(cvp, mp) __cv_wait_io_sig(cvp, mp) +#define cv_wait_sig(cvp, mp) __cv_wait_sig(cvp, mp) +#define cv_signal(cvp) __cv_signal(cvp) +#define cv_broadcast(cvp) __cv_broadcast(cvp) + +/* + * NB: There is no way to reliably distinguish between having been signalled + * and having timed out on Linux. If the client code needs to reliably + * distinguish between the two it should use the hires variant. + */ +#define cv_timedwait(cvp, mp, t) __cv_timedwait(cvp, mp, t) +#define cv_timedwait_io(cvp, mp, t) __cv_timedwait_io(cvp, mp, t) +#define cv_timedwait_sig(cvp, mp, t) __cv_timedwait_sig(cvp, mp, t) + +#endif /* _SPL_CONDVAR_H */ |