Re: [patch] Fix testsuite annotate-quit race (PR 544)

Jan Kratochvil
2008-03-21T20:45:36Z

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On Wed, 19 Mar 2008 09:10:56 +0100, Jan Kratochvil wrote:
> On Wed, 19 Mar 2008 00:17:38 +0100, Daniel Jacobowitz wrote:
> > On Tue, Mar 18, 2008 at 11:54:36PM +0100, Jan Kratochvil wrote:
> > > Hi,
> > >
> > > PR 544 des gdb.cp/annota2.exp and gdb.cp/annota3.exp sometimes FAIL with:
> > > FAIL: gdb.cp/annota3.exp: annotate-quit (pattern 1)
> ...
> > Isn't this a bug in GDB, not a bug in the test?
>
> You are right it is probably better to fix it in readline.

The patch was approved by the readline maintainer:

On Fri, 21 Mar 2008 19:37:31 +0100, Chet Ramey wrote:
> I will add something like your block_sigint/release_sigint changes around
> the guts of rl_redisplay. That's the right thing to do anyway. It will
> probably not come out as a patch for readline-5.2; you can use your
> current patch (though the names will change to _rl_block_sigint and
> _rl_release_sigint -- fair warning).

It could be probably also coded only in GDB by modifying the function pointer
RL_REDISPLAY_FUNCTION instead to a custom wrapper calling RL_REDISPLAY but it
would need the SIGINT blocking/handling done in GDB.

OK to commit as a readline fork before readline-6 is here?

Regards,
Jan

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2008-03-21 Jan Kratochvil <jan.kratochvil@redhat.com>

PR gdb/544
* display.c (rl_redisplay): Wrap the function by the calls to
BLOCK_SIGINT and RELEASE_SIGINT.
* rltty.c (block_sigint, release_sigint): Make the functions global.
* rltty.h (block_sigint, release_sigint): New prototypes.

--- ./readline/display.c 5 May 2006 18:26:12 -0000 1.11
+++ ./readline/display.c 19 Mar 2008 05:10:16 -0000
@@ -463,6 +463,10 @@ rl_redisplay ()
if (!readline_echoing_p)
return;

+ /* Signals are blocked through this function as the global data structures
+ could get corrupted upon modifications from an invoked signal handler. */
+ block_sigint ();
+
if (!rl_display_prompt)
rl_display_prompt = "";

@@ -1139,6 +1143,8 @@ rl_redisplay ()
else
visible_wrap_offset = wrap_offset;
}
+
+ release_sigint ();
}

/* PWP: update_line() is based on finding the middle difference of each
--- ./readline/rltty.c 5 May 2006 18:26:12 -0000 1.9
+++ ./readline/rltty.c 19 Mar 2008 05:10:16 -0000
@@ -52,8 +52,8 @@ extern int errno;
rl_vintfunc_t *rl_prep_term_function = rl_prep_terminal;
rl_voidfunc_t *rl_deprep_term_function = rl_deprep_terminal;

-static void block_sigint PARAMS((void));
-static void release_sigint PARAMS((void));
+void block_sigint PARAMS((void));
+void release_sigint PARAMS((void));

static void set_winsize PARAMS((int));

@@ -75,7 +75,7 @@ static int sigint_blocked;

/* Cause SIGINT to not be delivered until the corresponding call to
release_sigint(). */
-static void
+void
block_sigint ()
{
if (sigint_blocked)
@@ -100,7 +100,7 @@ block_sigint ()
}

/* Allow SIGINT to be delivered. */
-static void
+void
release_sigint ()
{
if (sigint_blocked == 0)
--- ./readline/rltty.h 5 May 2006 18:26:12 -0000 1.5
+++ ./readline/rltty.h 19 Mar 2008 05:10:16 -0000
@@ -79,4 +79,7 @@ typedef struct _rl_tty_chars {
unsigned char t_status;
} _RL_TTY_CHARS;

+extern void block_sigint PARAMS((void));
+extern void release_sigint PARAMS((void));
+
#endif /* _RLTTY_H_ */