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From: Tom Tromey <tromey@redhat.com>
To: Gary Benson <gbenson@redhat.com>
Cc: "gdb-patches\@sourceware.org" <gdb-patches@sourceware.org>
Subject: Re: [PATCH 0/2] Demangler crash handler
References: <20140509100656.GA4760@blade.nx>	<201405091120.s49BKO1f010622@glazunov.sibelius.xs4all.nl>	<20140509153305.GA13345@blade.nx>	<CAP9bCMRmZOcMtdKfZZHVCdYat3MqiaK8-RWGzJ3SQW7MViSr6w@mail.gmail.com>	<20140513102035.GA17805@blade.nx>
Date: Tue, 13 May 2014 19:39:00 -0000
In-Reply-To: <20140513102035.GA17805@blade.nx> (Gary Benson's message of "Tue,	13 May 2014 11:20:35 +0100")
Message-ID: <87vbt9foyc.fsf@fleche.redhat.com>
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>>>>> "Gary" == Gary Benson <gbenson@redhat.com> writes:

Gary>  char *
Gary>  gdb_demangle (const char *name, int options)
Gary>  {
[...]
Gary> +  sigaction (SIGSEGV, &sa, &old_sa);
[...]
Gary> +  crash_signal = SIGSETJMP (gdb_demangle_jmp_buf);
[...]
Gary> +  sigaction (SIGSEGV, &old_sa, NULL);

This adds two calls to sigaction and a call to sigsetjmp to every
demangling invocation.

I wonder whether the performance cost of this is noticeable; and if so,
how large the effect is.

If it is too large we could perhaps arrange to do the sigaction calls
just once and see if that helps.

Tom