Mailing-List: contact cygwin-developers-help AT sourceware DOT cygnus DOT com; run by ezmlm
List-Unsubscribe: <mailto:cygwin-developers-unsubscribe-archive-cygwin-developers=delorie DOT com AT sourceware DOT cygnus DOT com>
List-Subscribe: <mailto:cygwin-developers-subscribe AT sourceware DOT cygnus DOT com>
List-Archive: <http://sourceware.cygnus.com/ml/cygwin-developers/>
List-Post: <mailto:cygwin-developers AT sourceware DOT cygnus DOT com>
List-Help: <mailto:cygwin-developers-help AT sourceware DOT cygnus DOT com>,
	<http://sourceware.cygnus.com/ml/#faqs>
Sender: cygwin-developers-owner AT sourceware DOT cygnus DOT com
Delivered-To: mailing list cygwin-developers AT sourceware DOT cygnus DOT com
Message-ID: <37C65CF3.50E89A09@1c.ru>
Date: Fri, 27 Aug 1999 13:40:03 +0400
From: Vadim Egorov <egorovv AT 1c DOT ru>
X-Mailer: Mozilla 4.61 [en] (WinNT; I)
X-Accept-Language: ru,en
MIME-Version: 1.0
To: "cygwin-developers AT sourceware DOT cygnus DOT com" 
 <cygwin-developers AT sourceware DOT cygnus DOT com>
Subject: longjmp problem
Content-Type: text/plain; charset=koi8-r
Content-Transfer-Encoding: 8bit
X-MDaemon-Deliver-To: cygwin-developers AT sourceware DOT cygnus DOT com
X-Return-Path: EgorovV AT 1c DOT ru

Hello,

There is a problem with setjmp/longjmp/signals/exceptions that can be
demonstrated by the following code:

static jmp_buf	env;
static sigset_t set = {0};

static void sig_handler(int sig)
{
    sigprocmask(SIG_UNBLOCK, &set, 0);
    longjmp(env, sig);
}

int main(int argc, char * * argv)
{
    sigaddset(&set, SIGSEGV);

    for ( int i = 0 ; i < 2; i++)
    {
        if ( setjmp(env) == 0 ) 
        {
            signal(SIGSEGV, ssig_handler);
            printf("exception ...");
            *(int*)0 = 1;
        }
        else
        {
            printf("trapped\n");
        }
    }
    return 0;

}

It traps exception only once and than hangs. The problem seems to be in
longjmp code. 
If I load CRTDLL.DLL dynamically and use setjmp/longjmp from 
there all works. I traced MS longjmp and noticed that it calls RtlUnwind 
which seems do the trick.
In addition this code works on Linux without signal unblocking - it is
necessary only if SIGSEGV is signaled by raise.

Does anyone have any opinion about this matter?

Regards
Vadim

-- 
*********************************************
Vadim Egorov, 1C      *       Вадим Егоров,1C
egorovv AT 1c DOT ru         *         egorovv AT 1c DOT ru
*********************************************