486105bcb0
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.
108 lines
2.9 KiB
C
108 lines
2.9 KiB
C
/*-
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* Copyright (c) 1997 Brian Somers <brian@Awfulhak.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $Id: sig.c,v 1.13 1998/05/21 21:48:20 brian Exp $
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*/
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#include <sys/types.h>
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#include <signal.h>
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#include "log.h"
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#include "sig.h"
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static int caused[NSIG]; /* An array of pending signals */
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static int necessary; /* Anything set ? */
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static sig_type handler[NSIG]; /* all start at SIG_DFL */
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/* Record a signal in the "caused" array */
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static void
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signal_recorder(int sig)
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{
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caused[sig - 1]++;
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necessary = 1;
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}
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/*
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* Set up signal_recorder, and record handler as the function to ultimately
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* call in handle_signal()
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*/
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sig_type
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sig_signal(int sig, sig_type fn)
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{
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sig_type Result;
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if (sig <= 0 || sig > NSIG) {
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/* Oops - we must be a bit out of date (too many sigs ?) */
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log_Printf(LogALERT, "Eeek! %s:%d: I must be out of date!\n",
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__FILE__, __LINE__);
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return signal(sig, fn);
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}
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Result = handler[sig - 1];
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if (fn == SIG_DFL || fn == SIG_IGN) {
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signal(sig, fn);
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handler[sig - 1] = (sig_type) 0;
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} else {
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handler[sig - 1] = fn;
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signal(sig, signal_recorder);
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}
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caused[sig - 1] = 0;
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return Result;
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}
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/* Call the handlers for any pending signals */
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int
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sig_Handle()
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{
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int sig;
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int got;
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int result;
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result = 0;
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if (necessary) {
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/* We've *probably* got something in `caused' set */
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necessary = 0;
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/* `necessary' might go back to 1 while we're in here.... */
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do {
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got = 0;
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for (sig = 0; sig < NSIG; sig++)
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if (caused[sig]) {
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caused[sig]--;
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got++;
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result++;
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(*handler[sig])(sig + 1);
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}
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} while (got);
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}
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return result;
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}
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