* [PATCH] Cygwin: sigproc: Do not send signal to myself if exiting.
@ 2021-11-19 11:50 Takashi Yano
2021-11-19 15:51 ` Corinna Vinschen
0 siblings, 1 reply; 6+ messages in thread
From: Takashi Yano @ 2021-11-19 11:50 UTC (permalink / raw)
To: cygwin-patches
- This patch fixes the issue that process sometimes hangs for 60
seconds with the following scenario.
1) Open command prompt.
2) Run "c:\cygwin64\bin\bash -l"
3) Compipe the following source with mingw compiler.
/*--- Begin ---*/
#include <stdio.h>
int main() {return getchar();}
/*---- End ----*/
3) Run "tcsh -c ./a.exe"
4) Hit Ctrl-C.
---
winsup/cygwin/sigproc.cc | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc
index 97211edcf..9160dd160 100644
--- a/winsup/cygwin/sigproc.cc
+++ b/winsup/cygwin/sigproc.cc
@@ -603,6 +603,10 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls)
its_me = false;
}
+ /* Do not send signal to myself if exiting. */
+ if (its_me && exit_state > ES_EXIT_STARTING && si.si_signo > 0)
+ goto out;
+
if (its_me)
sendsig = my_sendsig;
else
--
2.33.0
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] Cygwin: sigproc: Do not send signal to myself if exiting.
2021-11-19 11:50 [PATCH] Cygwin: sigproc: Do not send signal to myself if exiting Takashi Yano
@ 2021-11-19 15:51 ` Corinna Vinschen
2021-11-19 15:53 ` Corinna Vinschen
0 siblings, 1 reply; 6+ messages in thread
From: Corinna Vinschen @ 2021-11-19 15:51 UTC (permalink / raw)
To: cygwin-patches
Hi Takashi,
On Nov 19 20:50, Takashi Yano wrote:
> - This patch fixes the issue that process sometimes hangs for 60
> seconds with the following scenario.
> 1) Open command prompt.
> 2) Run "c:\cygwin64\bin\bash -l"
> 3) Compipe the following source with mingw compiler.
> /*--- Begin ---*/
> #include <stdio.h>
> int main() {return getchar();}
> /*---- End ----*/
> 3) Run "tcsh -c ./a.exe"
> 4) Hit Ctrl-C.
> ---
> winsup/cygwin/sigproc.cc | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc
> index 97211edcf..9160dd160 100644
> --- a/winsup/cygwin/sigproc.cc
> +++ b/winsup/cygwin/sigproc.cc
> @@ -603,6 +603,10 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls)
> its_me = false;
> }
>
> + /* Do not send signal to myself if exiting. */
> + if (its_me && exit_state > ES_EXIT_STARTING && si.si_signo > 0)
> + goto out;
> +
> if (its_me)
> sendsig = my_sendsig;
> else
> --
> 2.33.0
Isn't that already handled in wait_sig? What's the difference here?
Thx,
Corinna
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] Cygwin: sigproc: Do not send signal to myself if exiting.
2021-11-19 15:51 ` Corinna Vinschen
@ 2021-11-19 15:53 ` Corinna Vinschen
2021-11-19 17:14 ` Takashi Yano
0 siblings, 1 reply; 6+ messages in thread
From: Corinna Vinschen @ 2021-11-19 15:53 UTC (permalink / raw)
To: cygwin-patches
On Nov 19 16:51, Corinna Vinschen wrote:
> Hi Takashi,
>
> On Nov 19 20:50, Takashi Yano wrote:
> > - This patch fixes the issue that process sometimes hangs for 60
> > seconds with the following scenario.
> > 1) Open command prompt.
> > 2) Run "c:\cygwin64\bin\bash -l"
> > 3) Compipe the following source with mingw compiler.
> > /*--- Begin ---*/
> > #include <stdio.h>
> > int main() {return getchar();}
> > /*---- End ----*/
> > 3) Run "tcsh -c ./a.exe"
> > 4) Hit Ctrl-C.
> > ---
> > winsup/cygwin/sigproc.cc | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc
> > index 97211edcf..9160dd160 100644
> > --- a/winsup/cygwin/sigproc.cc
> > +++ b/winsup/cygwin/sigproc.cc
> > @@ -603,6 +603,10 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls)
> > its_me = false;
> > }
> >
> > + /* Do not send signal to myself if exiting. */
> > + if (its_me && exit_state > ES_EXIT_STARTING && si.si_signo > 0)
> > + goto out;
> > +
> > if (its_me)
> > sendsig = my_sendsig;
> > else
> > --
> > 2.33.0
>
> Isn't that already handled in wait_sig? What's the difference here?
...and where exactly is it waiting 60 secs?
>
>
> Thx,
> Corinna
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] Cygwin: sigproc: Do not send signal to myself if exiting.
2021-11-19 15:53 ` Corinna Vinschen
@ 2021-11-19 17:14 ` Takashi Yano
2021-11-19 17:22 ` Corinna Vinschen
0 siblings, 1 reply; 6+ messages in thread
From: Takashi Yano @ 2021-11-19 17:14 UTC (permalink / raw)
To: cygwin-patches
On Fri, 19 Nov 2021 16:53:57 +0100
Corinna Vinschen wrote:
> On Nov 19 16:51, Corinna Vinschen wrote:
> > Hi Takashi,
> >
> > On Nov 19 20:50, Takashi Yano wrote:
> > > - This patch fixes the issue that process sometimes hangs for 60
> > > seconds with the following scenario.
> > > 1) Open command prompt.
> > > 2) Run "c:\cygwin64\bin\bash -l"
> > > 3) Compipe the following source with mingw compiler.
> > > /*--- Begin ---*/
> > > #include <stdio.h>
> > > int main() {return getchar();}
> > > /*---- End ----*/
> > > 3) Run "tcsh -c ./a.exe"
> > > 4) Hit Ctrl-C.
> > > ---
> > > winsup/cygwin/sigproc.cc | 4 ++++
> > > 1 file changed, 4 insertions(+)
> > >
> > > diff --git a/winsup/cygwin/sigproc.cc b/winsup/cygwin/sigproc.cc
> > > index 97211edcf..9160dd160 100644
> > > --- a/winsup/cygwin/sigproc.cc
> > > +++ b/winsup/cygwin/sigproc.cc
> > > @@ -603,6 +603,10 @@ sig_send (_pinfo *p, siginfo_t& si, _cygtls *tls)
> > > its_me = false;
> > > }
> > >
> > > + /* Do not send signal to myself if exiting. */
> > > + if (its_me && exit_state > ES_EXIT_STARTING && si.si_signo > 0)
> > > + goto out;
> > > +
> > > if (its_me)
> > > sendsig = my_sendsig;
> > > else
> > > --
> > > 2.33.0
> >
> > Isn't that already handled in wait_sig? What's the difference here?
>
> ...and where exactly is it waiting 60 secs?
If sending signal to myself with exit_state > ES_EXIT_STARGING,
wait_for_completion in sig_send() is set to true. Therefore,
sig_send() waits for pack.wakeup event for WSSC (60000 msec) here:
/* No need to wait for signal completion unless this was a signal to
this process.
If it was a signal to this process, wait for a dispatched signal.
Otherwise just wait for the wait_sig to signal that it has finished
processing the signal. */
if (wait_for_completion)
{
sigproc_printf ("Waiting for pack.wakeup %p", pack.wakeup);
rc = WaitForSingleObject (pack.wakeup, WSSC);
ForceCloseHandle (pack.wakeup);
}
However, thread wait_sig ignores the signal here:
/* Don't process signals when we start exiting */
if (exit_state > ES_EXIT_STARTING && pack.si.si_signo > 0)
continue;
and does not call SetEvent (pack.wakeup).
As a result, sig_send() hangs for 60 secs.
With this patch, sig_send() does not send signal which will
be ignored in wait_sig().
--
Takashi Yano <takashi.yano@nifty.ne.jp>
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] Cygwin: sigproc: Do not send signal to myself if exiting.
2021-11-19 17:14 ` Takashi Yano
@ 2021-11-19 17:22 ` Corinna Vinschen
2021-11-19 18:14 ` Takashi Yano
0 siblings, 1 reply; 6+ messages in thread
From: Corinna Vinschen @ 2021-11-19 17:22 UTC (permalink / raw)
To: cygwin-patches
On Nov 20 02:14, Takashi Yano wrote:
> On Fri, 19 Nov 2021 16:53:57 +0100
> Corinna Vinschen wrote:
> > On Nov 19 16:51, Corinna Vinschen wrote:
> > > Isn't that already handled in wait_sig? What's the difference here?
> >
> > ...and where exactly is it waiting 60 secs?
>
> If sending signal to myself with exit_state > ES_EXIT_STARGING,
> wait_for_completion in sig_send() is set to true. Therefore,
> sig_send() waits for pack.wakeup event for WSSC (60000 msec) here:
>
> /* No need to wait for signal completion unless this was a signal to
> this process.
>
> If it was a signal to this process, wait for a dispatched signal.
> Otherwise just wait for the wait_sig to signal that it has finished
> processing the signal. */
> if (wait_for_completion)
> {
> sigproc_printf ("Waiting for pack.wakeup %p", pack.wakeup);
> rc = WaitForSingleObject (pack.wakeup, WSSC);
> ForceCloseHandle (pack.wakeup);
> }
>
> However, thread wait_sig ignores the signal here:
> /* Don't process signals when we start exiting */
> if (exit_state > ES_EXIT_STARTING && pack.si.si_signo > 0)
> continue;
> and does not call SetEvent (pack.wakeup).
>
> As a result, sig_send() hangs for 60 secs.
>
> With this patch, sig_send() does not send signal which will
> be ignored in wait_sig().
Ah, ok, that makes sense. Thanks for the explanation. Please push.
Thanks,
Corinna
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH] Cygwin: sigproc: Do not send signal to myself if exiting.
2021-11-19 17:22 ` Corinna Vinschen
@ 2021-11-19 18:14 ` Takashi Yano
0 siblings, 0 replies; 6+ messages in thread
From: Takashi Yano @ 2021-11-19 18:14 UTC (permalink / raw)
To: cygwin-patches
On Fri, 19 Nov 2021 18:22:40 +0100
Corinna Vinschen wrote:
> On Nov 20 02:14, Takashi Yano wrote:
> > On Fri, 19 Nov 2021 16:53:57 +0100
> > Corinna Vinschen wrote:
> > > On Nov 19 16:51, Corinna Vinschen wrote:
> > > > Isn't that already handled in wait_sig? What's the difference here?
> > >
> > > ...and where exactly is it waiting 60 secs?
> >
> > If sending signal to myself with exit_state > ES_EXIT_STARGING,
> > wait_for_completion in sig_send() is set to true. Therefore,
> > sig_send() waits for pack.wakeup event for WSSC (60000 msec) here:
> >
> > /* No need to wait for signal completion unless this was a signal to
> > this process.
> >
> > If it was a signal to this process, wait for a dispatched signal.
> > Otherwise just wait for the wait_sig to signal that it has finished
> > processing the signal. */
> > if (wait_for_completion)
> > {
> > sigproc_printf ("Waiting for pack.wakeup %p", pack.wakeup);
> > rc = WaitForSingleObject (pack.wakeup, WSSC);
> > ForceCloseHandle (pack.wakeup);
> > }
> >
> > However, thread wait_sig ignores the signal here:
> > /* Don't process signals when we start exiting */
> > if (exit_state > ES_EXIT_STARTING && pack.si.si_signo > 0)
> > continue;
> > and does not call SetEvent (pack.wakeup).
> >
> > As a result, sig_send() hangs for 60 secs.
> >
> > With this patch, sig_send() does not send signal which will
> > be ignored in wait_sig().
>
> Ah, ok, that makes sense. Thanks for the explanation. Please push.
Ah, this patch may cause race issue regarding exit_state.
I will submit another patch which overrides this patch.
--
Takashi Yano <takashi.yano@nifty.ne.jp>
^ permalink raw reply [flat|nested] 6+ messages in thread
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2021-11-19 11:50 [PATCH] Cygwin: sigproc: Do not send signal to myself if exiting Takashi Yano
2021-11-19 15:51 ` Corinna Vinschen
2021-11-19 15:53 ` Corinna Vinschen
2021-11-19 17:14 ` Takashi Yano
2021-11-19 17:22 ` Corinna Vinschen
2021-11-19 18:14 ` Takashi Yano
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