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/* Linuxthreads - a simple clone()-based implementation of Posix */
/* threads for Linux. */
/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
/* */
/* This program is free software; you can redistribute it and/or */
/* modify it under the terms of the GNU Library General Public License */
/* as published by the Free Software Foundation; either version 2 */
/* 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 Library General Public License for more details. */
/* Handling of signals */
#include <errno.h>
#include <signal.h>
#include "pthread.h"
#include "internals.h"
#include "spinlock.h"
int pthread_sigmask(int how, const sigset_t * newmask, sigset_t * oldmask)
{
sigset_t mask;
if (newmask != NULL) {
mask = *newmask;
/* Don't allow PTHREAD_SIG_RESTART to be unmasked.
Don't allow PTHREAD_SIG_CANCEL to be masked. */
switch(how) {
case SIG_SETMASK:
sigaddset(&mask, PTHREAD_SIG_RESTART);
sigdelset(&mask, PTHREAD_SIG_CANCEL);
break;
case SIG_BLOCK:
sigdelset(&mask, PTHREAD_SIG_CANCEL);
break;
case SIG_UNBLOCK:
sigdelset(&mask, PTHREAD_SIG_RESTART);
break;
}
newmask = &mask;
}
if (sigprocmask(how, newmask, oldmask) == -1)
return errno;
else
return 0;
}
int pthread_kill(pthread_t thread, int signo)
{
pthread_handle handle = thread_handle(thread);
int pid;
acquire(&handle->h_spinlock);
if (invalid_handle(handle, thread)) {
release(&handle->h_spinlock);
return ESRCH;
}
pid = handle->h_descr->p_pid;
release(&handle->h_spinlock);
if (kill(pid, signo) == -1)
return errno;
else
return 0;
}
/* The set of signals on which some thread is doing a sigwait */
static sigset_t sigwaited;
static pthread_mutex_t sigwaited_mut = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t sigwaited_changed = PTHREAD_COND_INITIALIZER;
int sigwait(const sigset_t * set, int * sig)
{
volatile pthread_descr self = thread_self();
sigset_t mask;
int s;
struct sigaction action, saved_signals[NSIG];
sigjmp_buf jmpbuf;
pthread_mutex_lock(&sigwaited_mut);
/* Make sure no other thread is waiting on our signals */
test_again:
for (s = 1; s < NSIG; s++) {
if (sigismember(set, s) && sigismember(&sigwaited, s)) {
pthread_cond_wait(&sigwaited_changed, &sigwaited_mut);
goto test_again;
}
}
/* Get ready to block all signals except those in set
and the cancellation signal */
sigfillset(&mask);
sigdelset(&mask, PTHREAD_SIG_CANCEL);
/* Signals in set are assumed blocked on entrance */
/* Install our signal handler on all signals in set,
and unblock them in mask.
Also mark those signals as being sigwaited on */
for (s = 1; s < NSIG; s++) {
if (sigismember(set, s) && s != PTHREAD_SIG_CANCEL) {
sigdelset(&mask, s);
action.sa_handler = __pthread_sighandler;
sigemptyset(&action.sa_mask);
action.sa_flags = 0;
sigaction(s, &action, &(saved_signals[s]));
sigaddset(&sigwaited, s);
}
}
pthread_mutex_unlock(&sigwaited_mut);
/* Test for cancellation */
if (sigsetjmp(jmpbuf, 1) == 0) {
self->p_cancel_jmp = &jmpbuf;
if (! (self->p_canceled && self->p_cancelstate == PTHREAD_CANCEL_ENABLE)) {
/* Reset the signal count */
self->p_signal = 0;
/* Unblock the signals and wait for them */
sigsuspend(&mask);
}
}
self->p_cancel_jmp = NULL;
/* The signals are now reblocked. Restore the sighandlers. */
pthread_mutex_lock(&sigwaited_mut);
for (s = 1; s < NSIG; s++) {
if (sigismember(set, s) && s != PTHREAD_SIG_CANCEL) {
sigaction(s, &(saved_signals[s]), NULL);
sigdelset(&sigwaited, s);
}
}
pthread_cond_broadcast(&sigwaited_changed);
pthread_mutex_unlock(&sigwaited_mut);
/* Check for cancellation */
pthread_testcancel();
/* We should have self->p_signal != 0 and equal to the signal received */
*sig = self->p_signal;
return 0;
}
int raise (int sig)
{
int retcode = pthread_kill(pthread_self(), sig);
if (retcode == 0)
return 0;
else {
errno = retcode;
return -1;
}
}
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