diff options
Diffstat (limited to 'include/os')
| -rw-r--r-- | include/os/freebsd/spl/sys/condvar.h | 36 | ||||
| -rw-r--r-- | include/os/linux/spl/sys/condvar.h | 48 |
2 files changed, 68 insertions, 16 deletions
diff --git a/include/os/freebsd/spl/sys/condvar.h b/include/os/freebsd/spl/sys/condvar.h index ff5f308e2..4375bd6a3 100644 --- a/include/os/freebsd/spl/sys/condvar.h +++ b/include/os/freebsd/spl/sys/condvar.h @@ -37,6 +37,31 @@ #include <sys/time.h> #include <sys/kmem.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. + */ + static __inline sbintime_t zfs_nstosbt(int64_t _ns) { @@ -120,7 +145,7 @@ cv_timedwait_sig(kcondvar_t *cvp, kmutex_t *mp, clock_t timo) #define cv_timedwait_io cv_timedwait #define cv_timedwait_sig_io cv_timedwait_sig -static inline clock_t +static inline int cv_timedwait_hires(kcondvar_t *cvp, kmutex_t *mp, hrtime_t tim, hrtime_t res, int flag) { @@ -135,7 +160,6 @@ cv_timedwait_hires(kcondvar_t *cvp, kmutex_t *mp, hrtime_t tim, hrtime_t res, if (hrtime >= tim) return (-1); - rc = cv_timedwait_sbt(cvp, mp, zfs_nstosbt(tim), zfs_nstosbt(res), C_ABSOLUTE); @@ -143,11 +167,10 @@ cv_timedwait_hires(kcondvar_t *cvp, kmutex_t *mp, hrtime_t tim, hrtime_t res, return (-1); KASSERT(rc == 0, ("unexpected rc value %d", rc)); - hrtime = tim - gethrtime(); - return ((hrtime > 0) ? hrtime : -1); + return (1); } -static inline clock_t +static inline int cv_timedwait_sig_hires(kcondvar_t *cvp, kmutex_t *mp, hrtime_t tim, hrtime_t res, int flag) { @@ -175,8 +198,7 @@ cv_timedwait_sig_hires(kcondvar_t *cvp, kmutex_t *mp, hrtime_t tim, return (0); default: KASSERT(rc == 0, ("unexpected rc value %d", rc)); - hrtime = tim - gethrtime(); - return ((hrtime > 0) ? hrtime : -1); + return (1); } } diff --git a/include/os/linux/spl/sys/condvar.h b/include/os/linux/spl/sys/condvar.h index f1438c4e2..22408824f 100644 --- a/include/os/linux/spl/sys/condvar.h +++ b/include/os/linux/spl/sys/condvar.h @@ -33,6 +33,32 @@ #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. */ @@ -56,12 +82,12 @@ 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 clock_t __cv_timedwait(kcondvar_t *, kmutex_t *, clock_t); -extern clock_t __cv_timedwait_io(kcondvar_t *, kmutex_t *, clock_t); -extern clock_t __cv_timedwait_sig(kcondvar_t *, kmutex_t *, clock_t); -extern clock_t cv_timedwait_hires(kcondvar_t *, kmutex_t *, hrtime_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 clock_t cv_timedwait_sig_hires(kcondvar_t *, kmutex_t *, hrtime_t, +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); @@ -72,12 +98,16 @@ extern void __cv_broadcast(kcondvar_t *c); #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_wait_interruptible(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) -#define cv_timedwait_interruptible(cvp, mp, t) cv_timedwait_sig(cvp, mp, t) -#define cv_signal(cvp) __cv_signal(cvp) -#define cv_broadcast(cvp) __cv_broadcast(cvp) #endif /* _SPL_CONDVAR_H */ |