* [PATCH 1/1] futex.2: explanation of blocking
@ 2015-03-29 19:13 Heinrich Schuchardt
[not found] ` <1427656383-8779-1-git-send-email-xypron.glpk-Mmb7MZpHnFY@public.gmane.org>
0 siblings, 1 reply; 3+ messages in thread
From: Heinrich Schuchardt @ 2015-03-29 19:13 UTC (permalink / raw)
To: Michael Kerrisk; +Cc: linux-man-u79uwXL29TY76Z2rM5mHXA, Heinrich Schuchardt
Use shorter sentences.
Signed-off-by: Heinrich Schuchardt <xypron.glpk-Mmb7MZpHnFY@public.gmane.org>
---
man2/futex.2 | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/man2/futex.2 b/man2/futex.2
index dea50ea..6a4d45c 100644
--- a/man2/futex.2
+++ b/man2/futex.2
@@ -85,14 +85,18 @@ In the uncontended case,
a thread can access or modify the lock state with atomic instructions,
for example atomically changing it from not acquired to acquired
using an atomic compare-and-exchange instruction.
-If a thread cannot acquire a lock because
-it is already acquired by another thread,
-it can request to block if and only the lock is still acquired by
-using the lock's flag as futex word and expecting a value that
-represents the acquired state.
+A thread maybe unable acquire a lock because
+it is already acquired by another thread.
+It then may pass the lock's flag as futex word and the value
+representing the acquired state as expected value to a
+.BR futex ()
+wait operation.
+.BR futex ()
+will block if and only if the lock is still acquired.
When releasing the lock, a thread has to first reset the
-lock state to not acquired and then execute the futex operation that
-wakes one thread blocked on the futex word that is the lock's flag
+lock state to not acquired and then execute a
+.BR futex ()
+operation that wakes threads blocked on the lock flag used as futex word.
(this can be be further optimized to avoid unnecessary wake-ups).
See
.BR futex (7)
--
2.1.4
--
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^ permalink raw reply related [flat|nested] 3+ messages in thread[parent not found: <1427656383-8779-1-git-send-email-xypron.glpk-Mmb7MZpHnFY@public.gmane.org>]
* Re: [PATCH 1/1] futex.2: explanation of blocking [not found] ` <1427656383-8779-1-git-send-email-xypron.glpk-Mmb7MZpHnFY@public.gmane.org> @ 2015-04-11 7:02 ` Michael Kerrisk (man-pages) [not found] ` <5528C6F6.7050300-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> 0 siblings, 1 reply; 3+ messages in thread From: Michael Kerrisk (man-pages) @ 2015-04-11 7:02 UTC (permalink / raw) To: Heinrich Schuchardt Cc: mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w, linux-man-u79uwXL29TY76Z2rM5mHXA On 03/29/2015 09:13 PM, Heinrich Schuchardt wrote: > Use shorter sentences. Thanks, Heinrich. Applied. Cheers, Michael > Signed-off-by: Heinrich Schuchardt <xypron.glpk-Mmb7MZpHnFY@public.gmane.org> > --- > man2/futex.2 | 18 +++++++++++------- > 1 file changed, 11 insertions(+), 7 deletions(-) > > diff --git a/man2/futex.2 b/man2/futex.2 > index dea50ea..6a4d45c 100644 > --- a/man2/futex.2 > +++ b/man2/futex.2 > @@ -85,14 +85,18 @@ In the uncontended case, > a thread can access or modify the lock state with atomic instructions, > for example atomically changing it from not acquired to acquired > using an atomic compare-and-exchange instruction. > -If a thread cannot acquire a lock because > -it is already acquired by another thread, > -it can request to block if and only the lock is still acquired by > -using the lock's flag as futex word and expecting a value that > -represents the acquired state. > +A thread maybe unable acquire a lock because > +it is already acquired by another thread. > +It then may pass the lock's flag as futex word and the value > +representing the acquired state as expected value to a > +.BR futex () > +wait operation. > +.BR futex () > +will block if and only if the lock is still acquired. > When releasing the lock, a thread has to first reset the > -lock state to not acquired and then execute the futex operation that > -wakes one thread blocked on the futex word that is the lock's flag > +lock state to not acquired and then execute a > +.BR futex () > +operation that wakes threads blocked on the lock flag used as futex word. > (this can be be further optimized to avoid unnecessary wake-ups). > See > .BR futex (7) > -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 3+ messages in thread
[parent not found: <5528C6F6.7050300-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]
* Re: [PATCH 1/1] futex.2: explanation of blocking [not found] ` <5528C6F6.7050300-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> @ 2015-04-11 7:09 ` Michael Kerrisk (man-pages) 0 siblings, 0 replies; 3+ messages in thread From: Michael Kerrisk (man-pages) @ 2015-04-11 7:09 UTC (permalink / raw) To: Heinrich Schuchardt; +Cc: Michael Kerrisk, linux-man Hi Heinrich, On 11 April 2015 at 09:02, Michael Kerrisk (man-pages) <mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote: > On 03/29/2015 09:13 PM, Heinrich Schuchardt wrote: >> Use shorter sentences. > > > Thanks, Heinrich. Applied. Those changes are now pushed to kernel.org in the draft_futex branch. I made a few tweaks to the page in commit 4d5a782726b1, some of which included small changes to your patches (just formatting changes, really). Cheers, Michael >> Signed-off-by: Heinrich Schuchardt <xypron.glpk-Mmb7MZpHnFY@public.gmane.org> >> --- >> man2/futex.2 | 18 +++++++++++------- >> 1 file changed, 11 insertions(+), 7 deletions(-) >> >> diff --git a/man2/futex.2 b/man2/futex.2 >> index dea50ea..6a4d45c 100644 >> --- a/man2/futex.2 >> +++ b/man2/futex.2 >> @@ -85,14 +85,18 @@ In the uncontended case, >> a thread can access or modify the lock state with atomic instructions, >> for example atomically changing it from not acquired to acquired >> using an atomic compare-and-exchange instruction. >> -If a thread cannot acquire a lock because >> -it is already acquired by another thread, >> -it can request to block if and only the lock is still acquired by >> -using the lock's flag as futex word and expecting a value that >> -represents the acquired state. >> +A thread maybe unable acquire a lock because >> +it is already acquired by another thread. >> +It then may pass the lock's flag as futex word and the value >> +representing the acquired state as expected value to a >> +.BR futex () >> +wait operation. >> +.BR futex () >> +will block if and only if the lock is still acquired. >> When releasing the lock, a thread has to first reset the >> -lock state to not acquired and then execute the futex operation that >> -wakes one thread blocked on the futex word that is the lock's flag >> +lock state to not acquired and then execute a >> +.BR futex () >> +operation that wakes threads blocked on the lock flag used as futex word. >> (this can be be further optimized to avoid unnecessary wake-ups). >> See >> .BR futex (7) >> > > > -- > Michael Kerrisk > Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ > Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html ^ permalink raw reply [flat|nested] 3+ messages in thread
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2015-03-29 19:13 [PATCH 1/1] futex.2: explanation of blocking Heinrich Schuchardt
[not found] ` <1427656383-8779-1-git-send-email-xypron.glpk-Mmb7MZpHnFY@public.gmane.org>
2015-04-11 7:02 ` Michael Kerrisk (man-pages)
[not found] ` <5528C6F6.7050300-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-04-11 7:09 ` Michael Kerrisk (man-pages)
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