Markus Armbruster
bfb558dee3
lwpSigWait() clears LwpSigCheck even when signals remain in
LwpSigCaught. The next empth_wait_for_signal() will then wait until
another one gets caught. Broken in commit fe2de3d74, v4.3.10.
Fix by clearing it only when LwpSigCaught is empty.
Signed-off-by: Markus Armbruster <armbru@pond.sub.org>
153 lines
3.4 KiB
C
153 lines
3.4 KiB
C
/*
|
|
* Empire - A multi-player, client/server Internet based war game.
|
|
* Copyright (C) 1994-2020, Dave Pare, Jeff Bailey, Thomas Ruschak,
|
|
* Ken Stevens, Steve McClure, Markus Armbruster
|
|
*
|
|
* Empire is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*
|
|
* ---
|
|
*
|
|
* See files README, COPYING and CREDITS in the root of the source
|
|
* tree for related information and legal notices. It is expected
|
|
* that future projects/authors will amend these files as needed.
|
|
*
|
|
* ---
|
|
*
|
|
* sig.c: Wait for signals
|
|
*
|
|
* Known contributors to this file:
|
|
* Markus Armbruster, 2006-2020
|
|
*/
|
|
|
|
#include <config.h>
|
|
|
|
#include <errno.h>
|
|
#include <stddef.h>
|
|
#include <signal.h>
|
|
#include "lwp.h"
|
|
#include "lwpint.h"
|
|
|
|
/*
|
|
* Signals caught so far.
|
|
* Access only with signals blocked!
|
|
*/
|
|
static sigset_t LwpSigCaught;
|
|
|
|
/*
|
|
* LwpSigCaught changed since last
|
|
*/
|
|
static sig_atomic_t LwpSigCheck;
|
|
|
|
/* The thread waiting for signals in lwpSigWait() */
|
|
static struct lwpProc *LwpSigWaiter;
|
|
|
|
static void lwpCatchAwaitedSig(int);
|
|
|
|
/*
|
|
* Initialize waiting for signals in @set.
|
|
*/
|
|
void
|
|
lwpInitSigWait(sigset_t *set)
|
|
{
|
|
struct sigaction act;
|
|
int i;
|
|
|
|
sigemptyset(&LwpSigCaught);
|
|
|
|
act.sa_flags = 0;
|
|
act.sa_mask = *set;
|
|
act.sa_handler = lwpCatchAwaitedSig;
|
|
for (i = 0; i < NSIG; i++) {
|
|
if (sigismember(set, i) > 0)
|
|
sigaction(i, &act, NULL);
|
|
}
|
|
}
|
|
|
|
static void
|
|
lwpCatchAwaitedSig(int sig)
|
|
{
|
|
sigaddset(&LwpSigCaught, sig);
|
|
LwpSigCheck = 1;
|
|
}
|
|
|
|
/*
|
|
* Test whether a signal from @set has been caught.
|
|
* If yes, delete that signal from the set of caught signals, and
|
|
* return its number.
|
|
* Else return 0.
|
|
*/
|
|
static int
|
|
lwpGetSig(sigset_t *set)
|
|
{
|
|
sigset_t save;
|
|
int i, j;
|
|
|
|
sigprocmask(SIG_BLOCK, set, &save);
|
|
|
|
for (i = NSIG - 1; i > 0; i--) {
|
|
if (sigismember(set, i) > 0 && sigismember(&LwpSigCaught, i) > 0) {
|
|
lwpStatus(LwpCurrent, "Got awaited signal %d", i);
|
|
sigdelset(&LwpSigCaught, i);
|
|
break;
|
|
}
|
|
}
|
|
|
|
for (j = i;
|
|
sigismember(set, i) > 0 && sigismember(&LwpSigCaught, i) > 0;
|
|
j--)
|
|
;
|
|
if (!j)
|
|
LwpSigCheck = 0;
|
|
|
|
sigprocmask(SIG_SETMASK, &save, NULL);
|
|
return i;
|
|
}
|
|
|
|
/*
|
|
* Wait until a signal from @set arrives.
|
|
* Assign its number to *@sig and return 0.
|
|
* If another thread is already waiting for signals, return EBUSY
|
|
* without waiting.
|
|
*/
|
|
int
|
|
lwpSigWait(sigset_t *set, int *sig)
|
|
{
|
|
int res;
|
|
|
|
if (LwpSigWaiter)
|
|
return EBUSY;
|
|
for (;;) {
|
|
res = lwpGetSig(set);
|
|
if (res > 0)
|
|
break;
|
|
lwpStatus(LwpCurrent, "Waiting for signals");
|
|
LwpSigWaiter = LwpCurrent;
|
|
lwpReschedule();
|
|
}
|
|
*sig = res;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Wake up the thread awaiting signals if one arrived.
|
|
* To be called from lwpReschedule().
|
|
*/
|
|
void
|
|
lwpSigWakeup(void)
|
|
{
|
|
if (LwpSigWaiter && LwpSigCheck) {
|
|
lwpReady(LwpSigWaiter);
|
|
LwpSigWaiter = NULL;
|
|
}
|
|
}
|