1 files changed, 385 insertions, 0 deletions
diff --git a/lib/libthr/thread/thr_sig.c b/lib/libthr/thread/thr_sig.c
new file mode 100644
index 0000000..1be544b
--- /dev/null
+++ b/lib/libthr/thread/thr_sig.c
@@ -0,0 +1,385 @@
+/*
+ * Copyright (c) 2005, David Xu <davidxu@freebsd.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 unmodified, 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 ``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 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.
+ *
+ * $FreeBSD$
+ */
+
+#include "namespace.h"
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/signalvar.h>
+#include <signal.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <pthread.h>
+#include "un-namespace.h"
+
+#include "thr_private.h"
+
+/* #define DEBUG_SIGNAL */
+#ifdef DEBUG_SIGNAL
+#define DBG_MSG		stdout_debug
+#else
+#define DBG_MSG(x...)
+#endif
+
+extern int	__pause(void);
+int	___pause(void);
+int	_raise(int);
+int	__sigtimedwait(const sigset_t *set, siginfo_t *info,
+	const struct timespec * timeout);
+int	__sigwaitinfo(const sigset_t *set, siginfo_t *info);
+int	__sigwait(const sigset_t *set, int *sig);
+
+static void
+sigcancel_handler(int sig __unused,
+	siginfo_t *info __unused, ucontext_t *ucp __unused)
+{
+	struct pthread *curthread = _get_curthread();
+
+	if (curthread->cancel_defer && curthread->cancel_pending)
+		thr_wake(curthread->tid);
+	_thr_ast(curthread);
+}
+
+void
+_thr_ast(struct pthread *curthread)
+{
+	if (!THR_IN_CRITICAL(curthread)) {
+		_thr_testcancel(curthread);
+		if (__predict_false((curthread->flags &
+		    (THR_FLAGS_NEED_SUSPEND | THR_FLAGS_SUSPENDED))
+			== THR_FLAGS_NEED_SUSPEND))
+			_thr_suspend_check(curthread);
+	}
+}
+
+void
+_thr_suspend_check(struct pthread *curthread)
+{
+	umtx_t cycle;
+	int err;
+
+	err = errno;
+	/* 
+	 * Blocks SIGCANCEL which other threads must send.
+	 */
+	_thr_signal_block(curthread);
+
+	/*
+	 * Increase critical_count, here we don't use THR_LOCK/UNLOCK
+	 * because we are leaf code, we don't want to recursively call
+	 * ourself.
+	 */
+	curthread->critical_count++;
+	THR_UMUTEX_LOCK(curthread, &(curthread)->lock);
+	while ((curthread->flags & (THR_FLAGS_NEED_SUSPEND |
+		THR_FLAGS_SUSPENDED)) == THR_FLAGS_NEED_SUSPEND) {
+		curthread->cycle++;
+		cycle = curthread->cycle;
+
+		/* Wake the thread suspending us. */
+		_thr_umtx_wake(&curthread->cycle, INT_MAX);
+
+		/*
+		 * if we are from pthread_exit, we don't want to
+		 * suspend, just go and die.
+		 */
+		if (curthread->state == PS_DEAD)
+			break;
+		curthread->flags |= THR_FLAGS_SUSPENDED;
+		THR_UMUTEX_UNLOCK(curthread, &(curthread)->lock);
+		_thr_umtx_wait(&curthread->cycle, cycle, NULL);
+		THR_UMUTEX_LOCK(curthread, &(curthread)->lock);
+		curthread->flags &= ~THR_FLAGS_SUSPENDED;
+	}
+	THR_UMUTEX_UNLOCK(curthread, &(curthread)->lock);
+	curthread->critical_count--;
+
+	/* 
+	 * Unblocks SIGCANCEL, it is possible a new SIGCANCEL is ready and
+	 * a new signal frame will nest us, this seems a problem because 
+	 * stack will grow and overflow, but because kernel will automatically
+	 * mask the SIGCANCEL when delivering the signal, so we at most only
+	 * have one nesting signal frame, this should be fine.
+	 */
+	_thr_signal_unblock(curthread);
+	errno = err;
+}
+
+void
+_thr_signal_init(void)
+{
+	struct sigaction act;
+
+	/* Install cancel handler. */
+	SIGEMPTYSET(act.sa_mask);
+	act.sa_flags = SA_SIGINFO | SA_RESTART;
+	act.sa_sigaction = (__siginfohandler_t *)&sigcancel_handler;
+	__sys_sigaction(SIGCANCEL, &act, NULL);
+}
+
+void
+_thr_signal_deinit(void)
+{
+}
+
+__weak_reference(___pause, pause);
+
+int
+___pause(void)
+{
+	struct pthread *curthread = _get_curthread();
+	int	ret;
+
+	_thr_cancel_enter(curthread);
+	ret = __pause();
+	_thr_cancel_leave(curthread);
+	
+	return ret;
+}
+
+__weak_reference(_raise, raise);
+
+int
+_raise(int sig)
+{
+	int ret;
+
+	if (!_thr_isthreaded())
+		ret = kill(getpid(), sig);
+	else
+		ret = _thr_send_sig(_get_curthread(), sig);
+	return (ret);
+}
+
+__weak_reference(_sigaction, sigaction);
+
+int
+_sigaction(int sig, const struct sigaction * act, struct sigaction * oact)
+{
+	/* Check if the signal number is out of range: */
+	if (sig < 1 || sig > _SIG_MAXSIG || sig == SIGCANCEL) {
+		/* Return an invalid argument: */
+		errno = EINVAL;
+		return (-1);
+	}
+
+	return __sys_sigaction(sig, act, oact);
+}
+
+__weak_reference(_sigprocmask, sigprocmask);
+
+int
+_sigprocmask(int how, const sigset_t *set, sigset_t *oset)
+{
+	const sigset_t *p = set;
+	sigset_t newset;
+
+	if (how != SIG_UNBLOCK) {
+		if (set != NULL) {
+			newset = *set;
+			SIGDELSET(newset, SIGCANCEL);
+			p = &newset;
+		}
+	}
+	return (__sys_sigprocmask(how, p, oset));
+}
+
+__weak_reference(_pthread_sigmask, pthread_sigmask);
+
+int
+_pthread_sigmask(int how, const sigset_t *set, sigset_t *oset)
+{
+	if (_sigprocmask(how, set, oset))
+		return (errno);
+	return (0);
+}
+
+__weak_reference(__sigsuspend, sigsuspend);
+
+int
+_sigsuspend(const sigset_t * set)
+{
+	sigset_t newset;
+	const sigset_t *pset;
+	int ret;
+
+	if (SIGISMEMBER(*set, SIGCANCEL)) {
+		newset = *set;
+		SIGDELSET(newset, SIGCANCEL);
+		pset = &newset;
+	} else
+		pset = set;
+
+	ret = __sys_sigsuspend(pset);
+
+	return (ret);
+}
+
+int
+__sigsuspend(const sigset_t * set)
+{
+	struct pthread *curthread = _get_curthread();
+	sigset_t newset;
+	const sigset_t *pset;
+	int ret;
+
+	if (SIGISMEMBER(*set, SIGCANCEL)) {
+		newset = *set;
+		SIGDELSET(newset, SIGCANCEL);
+		pset = &newset;
+	} else
+		pset = set;
+
+	_thr_cancel_enter(curthread);
+	ret = __sys_sigsuspend(pset);
+	_thr_cancel_leave(curthread);
+
+	return (ret);
+}
+
+__weak_reference(__sigwait, sigwait);
+__weak_reference(__sigtimedwait, sigtimedwait);
+__weak_reference(__sigwaitinfo, sigwaitinfo);
+
+int
+_sigtimedwait(const sigset_t *set, siginfo_t *info,
+	const struct timespec * timeout)
+{
+	sigset_t newset;
+	const sigset_t *pset;
+	int ret;
+
+	if (SIGISMEMBER(*set, SIGCANCEL)) {
+		newset = *set;
+		SIGDELSET(newset, SIGCANCEL);
+		pset = &newset;
+	} else
+		pset = set;
+	ret = __sys_sigtimedwait(pset, info, timeout);
+	return (ret);
+}
+
+int
+__sigtimedwait(const sigset_t *set, siginfo_t *info,
+	const struct timespec * timeout)
+{
+	struct pthread	*curthread = _get_curthread();
+	sigset_t newset;
+	const sigset_t *pset;
+	int ret;
+
+	if (SIGISMEMBER(*set, SIGCANCEL)) {
+		newset = *set;
+		SIGDELSET(newset, SIGCANCEL);
+		pset = &newset;
+	} else
+		pset = set;
+	_thr_cancel_enter(curthread);
+	ret = __sys_sigtimedwait(pset, info, timeout);
+	_thr_cancel_leave(curthread);
+	return (ret);
+}
+
+int
+_sigwaitinfo(const sigset_t *set, siginfo_t *info)
+{
+	sigset_t newset;
+	const sigset_t *pset;
+	int ret;
+
+	if (SIGISMEMBER(*set, SIGCANCEL)) {
+		newset = *set;
+		SIGDELSET(newset, SIGCANCEL);
+		pset = &newset;
+	} else
+		pset = set;
+
+	ret = __sys_sigwaitinfo(pset, info);
+	return (ret);
+}
+
+int
+__sigwaitinfo(const sigset_t *set, siginfo_t *info)
+{
+	struct pthread	*curthread = _get_curthread();
+	sigset_t newset;
+	const sigset_t *pset;
+	int ret;
+
+	if (SIGISMEMBER(*set, SIGCANCEL)) {
+		newset = *set;
+		SIGDELSET(newset, SIGCANCEL);
+		pset = &newset;
+	} else
+		pset = set;
+
+	_thr_cancel_enter(curthread);
+	ret = __sys_sigwaitinfo(pset, info);
+	_thr_cancel_leave(curthread);
+	return (ret);
+}
+
+int
+_sigwait(const sigset_t *set, int *sig)
+{
+	sigset_t newset;
+	const sigset_t *pset;
+	int ret;
+
+	if (SIGISMEMBER(*set, SIGCANCEL)) {
+		newset = *set;
+		SIGDELSET(newset, SIGCANCEL);
+		pset = &newset;
+	} else 
+		pset = set;
+
+	ret = __sys_sigwait(pset, sig);
+	return (ret);
+}
+
+int
+__sigwait(const sigset_t *set, int *sig)
+{
+	struct pthread	*curthread = _get_curthread();
+	sigset_t newset;
+	const sigset_t *pset;
+	int ret;
+
+	if (SIGISMEMBER(*set, SIGCANCEL)) {
+		newset = *set;
+		SIGDELSET(newset, SIGCANCEL);
+		pset = &newset;
+	} else 
+		pset = set;
+
+	_thr_cancel_enter(curthread);
+	ret = __sys_sigwait(pset, sig);
+	_thr_cancel_leave(curthread);
+	return (ret);
+}