freebsd-skq/usr.sbin/ppp/sig.h
brian e9c44757c3 Maintain a `necessary' marker to indicate that we *probably*
need to process a signal (usually a SIGALRM).  Check to see
if we need to process a signal both before *and* after calling
select() as older (pre-2.0) versions of ppp used to.

This handles the possibility that ppp may block at some
point (maybe due to an open() of a misconfigured device).
Previously, we'd potentially lock up in select().

The `necessary' marker reduces the increased signal checking
overhead so that at full speed with no compression transferring
an 83Mb file via a ``!ppp -direct'' device, we get a 1%
throughput gain.
1999-03-30 00:44:57 +00:00

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C

/*-
* Copyright (c) 1997 Brian Somers <brian@Awfulhak.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: sig.h,v 1.12 1998/05/21 21:48:23 brian Exp $
*/
typedef void (*sig_type)(int);
/* Call this instead of signal() */
extern sig_type sig_signal(int, sig_type);
/* Call this when you want things to *actually* happen */
extern int sig_Handle(void);