diff options
author | jhb <jhb@FreeBSD.org> | 2007-03-09 22:41:01 +0000 |
---|---|---|
committer | jhb <jhb@FreeBSD.org> | 2007-03-09 22:41:01 +0000 |
commit | f5e396934025920e30b32a3eef21d05548f16898 (patch) | |
tree | 343c44631b470578282dfd1c1d3fb73ed2833f3c /share/man/man9/sx.9 | |
parent | b470e17165153afeed8259afb043250b76f64e76 (diff) | |
download | FreeBSD-src-f5e396934025920e30b32a3eef21d05548f16898.zip FreeBSD-src-f5e396934025920e30b32a3eef21d05548f16898.tar.gz |
Allow threads to atomically release rw and sx locks while waiting for an
event. Locking primitives that support this (mtx, rw, and sx) now each
include their own foo_sleep() routine.
- Rename msleep() to _sleep() and change it's 'struct mtx' object to a
'struct lock_object' pointer. _sleep() uses the recently added
lc_unlock() and lc_lock() function pointers for the lock class of the
specified lock to release the lock while the thread is suspended.
- Add wrappers around _sleep() for mutexes (mtx_sleep()), rw locks
(rw_sleep()), and sx locks (sx_sleep()). msleep() still exists and
is now identical to mtx_sleep(), but it is deprecated.
- Rename SLEEPQ_MSLEEP to SLEEPQ_SLEEP.
- Rewrite much of sleep.9 to not be msleep(9) centric.
- Flesh out the 'RETURN VALUES' section in sleep.9 and add an 'ERRORS'
section.
- Add __nonnull(1) to _sleep() and msleep_spin() so that the compiler will
warn if you try to pass a NULL wait channel. The functions already have
a KASSERT to that effect.
Diffstat (limited to 'share/man/man9/sx.9')
-rw-r--r-- | share/man/man9/sx.9 | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/share/man/man9/sx.9 b/share/man/man9/sx.9 index a204ad5..50c0bc4 100644 --- a/share/man/man9/sx.9 +++ b/share/man/man9/sx.9 @@ -42,6 +42,7 @@ .Nm sx_unlock , .Nm sx_try_upgrade , .Nm sx_downgrade , +.Nm sx_sleep , .Nm sx_xlocked , .Nm sx_assert , .Nm SX_SYSINIT @@ -73,6 +74,8 @@ .Ft void .Fn sx_downgrade "struct sx *sx" .Ft int +.Fn sx_sleep "void *chan" "struct sx *sx" "int priority" "const char *wmesg" "int timo" +.Ft int .Fn sx_xlocked "struct sx *sx" .Pp .Cd "options INVARIANTS" @@ -134,6 +137,13 @@ will return 0 if the shared lock cannot be upgraded to an exclusive lock immediately; otherwise the exclusive lock will be acquired and a non-zero value will be returned. .Pp +A thread can atomically release a shared/exclusive lock while waiting for an +event by calling +.Fn sx_sleep . +For more details on the parameters to this function, +see +.Xr sleep 9 . +.Pp When compiled with .Cd "options INVARIANTS" and @@ -169,7 +179,7 @@ by the first argument. .El .Pp .Fn sx_xlocked -will return non-zero if the current process holds the exclusive lock; +will return non-zero if the current thread holds the exclusive lock; otherwise, it will return zero. .Pp For ease of programming, |