Deliver signals posted via an upcall to the appropriate thread.

12 files changed, 548 insertions, 1050 deletions

diff --git a/lib/libkse/thread/thr_cancel.c b/lib/libkse/thread/thr_cancel.c
index e4e0216..8b0b4c0 100644
--- a/lib/libkse/thread/thr_cancel.c
+++ b/lib/libkse/thread/thr_cancel.c
@@ -51,6 +51,8 @@ _pthread_cancel(pthread_t pthread)
 				/* Fall through: */
 			case PS_SLEEP_WAIT:
 			case PS_WAIT_WAIT:
+			case PS_SIGSUSPEND:
+			case PS_SIGWAIT:
 				/* Interrupt and resume: */
 				pthread->interrupted = 1;
 				pthread->cancelflags |= PTHREAD_CANCELLING;
diff --git a/lib/libkse/thread/thr_init.c b/lib/libkse/thread/thr_init.c
index 9f2f894..8e19924 100644
--- a/lib/libkse/thread/thr_init.c
+++ b/lib/libkse/thread/thr_init.c
@@ -162,6 +162,12 @@ _thread_init(void)
 	int		sched_stack_size;	/* Size of scheduler stack. */
 
 	struct clockinfo clockinfo;
+	struct sigaction act;
+
+	/* Check if this function has already been called: */
+	if (_thread_initial)
+		/* Only initialise the threaded application once. */
+		return;
 
 	_pthread_page_size = getpagesize();
 	_pthread_guard_default = getpagesize();
@@ -338,6 +344,31 @@ _thread_init(void)
 		TAILQ_INSERT_HEAD(&_thread_list, _thread_initial, tle);
 		_set_curthread(_thread_initial);
 
+		/* Clear the pending signals for the process. */
+		sigemptyset(&_thread_sigpending);
+
+		/* Enter a loop to get the existing signal status: */
+		for (i = 1; i < NSIG; i++) {
+			/* Check for signals which cannot be trapped. */
+			if (i == SIGKILL || i == SIGSTOP)
+				continue;
+
+			/* Get the signal handler details. */
+			if (__sys_sigaction(i, NULL,
+			    &_thread_sigact[i - 1]) != 0)
+				PANIC("Cannot read signal handler info");
+		}
+
+		/* Register SIGCHLD (needed for wait(2)). */
+		sigfillset(&act.sa_mask);
+		act.sa_handler = (void (*) ()) _thread_sig_handler;
+		act.sa_flags = SA_SIGINFO | SA_RESTART;
+		if (__sys_sigaction(SIGCHLD, &act, NULL) != 0)
+			PANIC("Can't initialize signal handler");
+
+		/* Get the process signal mask. */
+		__sys_sigprocmask(SIG_SETMASK, NULL, &_thread_sigmask);
+
 		/* Get the kernel clockrate: */
 		mib[0] = CTL_KERN;
 		mib[1] = KERN_CLOCKRATE;
diff --git a/lib/libkse/thread/thr_kern.c b/lib/libkse/thread/thr_kern.c
index 0747cff..c14d44a 100644
--- a/lib/libkse/thread/thr_kern.c
+++ b/lib/libkse/thread/thr_kern.c
@@ -248,6 +248,8 @@ _thread_kern_scheduler(struct kse_mailbox *km)
 	pthread_t	td, pthread, pthread_h;
 	unsigned int	current_tick;
 	struct kse_thr_mailbox	*tm, *p;
+	sigset_t	sigset;
+	int		i;
 
 	DBG_MSG("entering\n");
 	while (!TAILQ_EMPTY(&_thread_list)) {
@@ -280,8 +282,13 @@ _thread_kern_scheduler(struct kse_mailbox *km)
 		}
 
 		/* Deliver posted signals. */
-		/* XXX: Not yet. */
 		DBG_MSG("Picking up signals\n");
+		bcopy(&km->km_sigscaught, &sigset, sizeof(sigset_t));
+		sigemptyset(&km->km_sigscaught); /* XXX */
+		if (SIGNOTEMPTY(sigset))
+			for (i = 1; i < NSIG; i++)
+				if (sigismember(&sigset, i) != 0)
+					_thread_sig_dispatch(i);
 
 		if (_spinblock_count != 0) {
 			/*
diff --git a/lib/libkse/thread/thr_private.h b/lib/libkse/thread/thr_private.h
index 8aacdc0..7c5cc87 100644
--- a/lib/libkse/thread/thr_private.h
+++ b/lib/libkse/thread/thr_private.h
@@ -426,6 +426,8 @@ enum pthread_state {
 	PS_COND_WAIT,
 	PS_SLEEP_WAIT,
 	PS_WAIT_WAIT,
+	PS_SIGSUSPEND,
+	PS_SIGWAIT,
 	PS_SPINBLOCK,
 	PS_JOIN,
 	PS_SUSPENDED,
@@ -445,6 +447,7 @@ enum pthread_state {
 union pthread_wait_data {
 	pthread_mutex_t	mutex;
 	pthread_cond_t	cond;
+	const sigset_t	*sigwait;	/* Waiting on a signal in sigwait */
 	spinlock_t	*spinlock;
 	struct pthread	*thread;
 };
@@ -461,6 +464,15 @@ struct join_status {
 	int		error;
 };
 
+struct pthread_state_data {
+	struct timespec		psd_wakeup_time;
+	union pthread_wait_data psd_wait_data;
+	enum pthread_state	psd_state;
+	int			psd_flags;
+	int			psd_interrupted;
+	int			psd_sig_defer_count;
+};
+
 struct pthread_specific_elem {
 	const void	*data;
 	int		seqno;
@@ -515,6 +527,9 @@ struct pthread {
 
 	thread_continuation_t	continuation;
 
+	/* Currently pending signals. */
+	sigset_t	sigpend;
+
 	/* Thread state: */
 	enum pthread_state	state;
 
@@ -590,6 +605,9 @@ struct pthread {
 	 */
 	int		interrupted;
 
+	/* Signal number when in state PS_SIGWAIT: */
+	int		signo;
+
 	/*
 	 * Set to non-zero when this thread has deferred signals.
 	 * We allow for recursive deferral.
@@ -774,6 +792,11 @@ SCLASS	pthread_cond_t  _gc_cond
 ;
 
 /*
+ * Array of signal actions for this process.
+ */
+SCLASS struct  sigaction _thread_sigact[NSIG];
+
+/*
  * Scheduling queues:
  */
 SCLASS pq_queue_t		_readyq;
@@ -799,6 +822,12 @@ SCLASS pthread_switch_routine_t _sched_switch_hook
 ;
 
 /*
+ * Signals pending and masked.
+ */
+SCLASS sigset_t		_thread_sigpending;
+SCLASS sigset_t		_thread_sigmask;
+
+/*
  * Declare the kernel scheduler jump buffer and stack:
  */
 SCLASS struct kse_mailbox	_thread_kern_kse_mailbox;
@@ -893,6 +922,7 @@ void	_thread_kern_sched_state_unlock(enum pthread_state state,
 void    _thread_kern_set_timeout(const struct timespec *);
 void    _thread_kern_sig_defer(void);
 void    _thread_kern_sig_undefer(void);
+void	_thread_sig_handler(int, siginfo_t *, ucontext_t *);
 void	_thread_printf(int fd, const char *, ...);
 void    _thread_start(void);
 void	_thread_seterrno(pthread_t, int);
diff --git a/lib/libkse/thread/thr_sig.c b/lib/libkse/thread/thr_sig.c
index 5baaab9..a93b406 100644
--- a/lib/libkse/thread/thr_sig.c
+++ b/lib/libkse/thread/thr_sig.c
@@ -43,262 +43,62 @@
 #include "thr_private.h"
 
 /* Prototypes: */
+static void	thread_sig_handle_special(int sig);
+
 static void	thread_sig_add(struct pthread *pthread, int sig, int has_args);
 static void	thread_sig_check_state(struct pthread *pthread, int sig);
 static struct pthread *thread_sig_find(int sig);
-static void	thread_sig_handle_special(int sig);
 static void	thread_sigframe_add(struct pthread *thread, int sig,
 		    int has_args);
 static void	thread_sigframe_save(struct pthread *thread,
-		    struct pthread_signal_frame *psf);
-static void	thread_sig_invoke_handler(int sig, siginfo_t *info,
-		    ucontext_t *ucp);
+		    struct pthread_state_data *psd);
+static void	thread_sigframe_restore(struct pthread *thread,
+		    struct pthread_state_data *psd);
 
-/*#define DEBUG_SIGNAL*/
+/* #define DEBUG_SIGNAL */
 #ifdef DEBUG_SIGNAL
 #define DBG_MSG		stdout_debug
 #else
 #define DBG_MSG(x...)
 #endif
 
-#if defined(_PTHREADS_INVARIANTS)
-#define SIG_SET_ACTIVE()	_sig_in_handler = 1
-#define SIG_SET_INACTIVE()	_sig_in_handler = 0
-#else
-#define SIG_SET_ACTIVE()
-#define SIG_SET_INACTIVE()
-#endif
-
+/*
+ * Dispatch a signal to a thread, if appropriate.
+ */
 void
-_thread_sig_handler(int sig, siginfo_t *info, ucontext_t *ucp)
+_thread_sig_dispatch(int sig)
 {
-	struct pthread	*curthread = _get_curthread();
-	struct pthread	*pthread, *pthread_h;
-	int		in_sched = _thread_kern_in_sched;
-	char		c;
-
-	if (ucp == NULL)
-		PANIC("Thread signal handler received null context");
-	DBG_MSG("Got signal %d, current thread %p\n", sig, curthread);
-
-	/* Check if an interval timer signal: */
-	if (sig == _SCHED_SIGNAL) {
-		/* Update the scheduling clock: */
-		gettimeofday((struct timeval *)&_sched_tod, NULL);
-		_sched_ticks++;
-
-		if (in_sched != 0) {
-			/*
-			 * The scheduler is already running; ignore this
-			 * signal.
-			 */
-		}
-		/*
-		 * Check if the scheduler interrupt has come when
-		 * the currently running thread has deferred thread
-		 * signals.
-		 */
-		else if (curthread->sig_defer_count > 0)
-			curthread->yield_on_sig_undefer = 1;
-		else {
-			/* Schedule the next thread: */
-			_thread_kern_sched(ucp);
-
-			/*
-			 * This point should not be reached, so abort the
-			 * process:
-			 */
-			PANIC("Returned to signal function from scheduler");
-		}
-	}
-	/*
-	 * Check if the kernel has been interrupted while the scheduler
-	 * is accessing the scheduling queues or if there is a currently
-	 * running thread that has deferred signals.
-	 */
-	else if ((in_sched != 0) || (curthread->sig_defer_count > 0)) {
-		/* Cast the signal number to a character variable: */
-		c = sig;
-
-		/*
-		 * Write the signal number to the kernel pipe so that it will
-		 * be ready to read when this signal handler returns.
-		 */
-		if (_queue_signals != 0) {
-			__sys_write(_thread_kern_pipe[1], &c, 1);
-			DBG_MSG("Got signal %d, queueing to kernel pipe\n", sig);
-		}
-		if (_thread_sigq[sig - 1].blocked == 0) {
-			DBG_MSG("Got signal %d, adding to _thread_sigq\n", sig);
-			/*
-			 * Do not block this signal; it will be blocked
-			 * when the pending signals are run down.
-			 */
-			/* _thread_sigq[sig - 1].blocked = 1; */
-
-			/*
-			 * Queue the signal, saving siginfo and sigcontext
-			 * (ucontext).
-			 *
-			 * XXX - Do we need to copy siginfo and ucp?
-			 */
-			_thread_sigq[sig - 1].signo = sig;
-			if (info != NULL)
-				memcpy(&_thread_sigq[sig - 1].siginfo, info,
-				    sizeof(*info));
-			memcpy(&_thread_sigq[sig - 1].uc, ucp, sizeof(*ucp));
-
-			/* Indicate that there are queued signals: */
-			_thread_sigq[sig - 1].pending = 1;
-			_sigq_check_reqd = 1;
-		}
-		/* These signals need special handling: */
-		else if (sig == SIGCHLD || sig == SIGTSTP ||
-		    sig == SIGTTIN || sig == SIGTTOU) {
-			_thread_sigq[sig - 1].pending = 1;
-			_thread_sigq[sig - 1].signo = sig;
-			_sigq_check_reqd = 1;
-		}
-		else
-			DBG_MSG("Got signal %d, ignored.\n", sig);
-	}
-	/*
-	 * The signal handlers should have been installed so that they
-	 * cannot be interrupted by other signals.
-	 */
-	else if (_thread_sigq[sig - 1].blocked == 0) {
-		/*
-		 * The signal is not blocked; handle the signal.
-		 *
-		 * Ignore subsequent occurrences of this signal
-		 * until the current signal is handled:
-		 */
-		_thread_sigq[sig - 1].blocked = 1;
-
-		/* This signal will be handled; clear the pending flag: */
-		_thread_sigq[sig - 1].pending = 0;
-
-		/*
-		 * Save siginfo and sigcontext (ucontext).
-		 *
-		 * XXX - Do we need to copy siginfo and ucp?
-		 */
-		_thread_sigq[sig - 1].signo = sig;
-
-		if (info != NULL)
-			memcpy(&_thread_sigq[sig - 1].siginfo, info,
-			    sizeof(*info));
-		memcpy(&_thread_sigq[sig - 1].uc, ucp, sizeof(*ucp));
-		SIG_SET_ACTIVE();
-
-		/* Handle special signals: */
-		thread_sig_handle_special(sig);
-
-		pthread_h = NULL;
-		if ((pthread = thread_sig_find(sig)) == NULL)
-			DBG_MSG("No thread to handle signal %d\n", sig);
-		else if (pthread == curthread) {
-			/*
-			 * Unblock the signal and restore the process signal
-			 * mask in case we don't return from the handler:
-			 */
-			_thread_sigq[sig - 1].blocked = 0;
-			__sys_sigprocmask(SIG_SETMASK, &_process_sigmask, NULL);
-
-			/* Call the signal handler for the current thread: */
-			thread_sig_invoke_handler(sig, info, ucp);
-
-			/*
-			 * Set the process signal mask in the context; it
-			 * could have changed by the handler.
- 			 */
-			ucp->uc_sigmask = _process_sigmask;
- 
-			/* Resume the interrupted thread: */
-			__sys_sigreturn(ucp);
-		} else {
-			DBG_MSG("Got signal %d, adding frame to thread %p\n",
-			    sig, pthread);
-
-			/* Setup the target thread to receive the signal: */
-			thread_sig_add(pthread, sig, /*has_args*/ 1);
-
-			/* Take a peek at the next ready to run thread: */
-			pthread_h = PTHREAD_PRIOQ_FIRST();
-			DBG_MSG("Finished adding frame, head of prio list %p\n",
-			    pthread_h);
-		}
-		SIG_SET_INACTIVE();
+	struct pthread	*pthread;
 
-		/*
-		 * Switch to a different context if the currently running
-		 * thread takes a signal, or if another thread takes a
-		 * signal and the currently running thread is not in a
-		 * signal handler.
-		 */
-		if ((pthread_h != NULL) &&
-		    (pthread_h->active_priority > curthread->active_priority)) {
-			/* Enter the kernel scheduler: */
-			_thread_kern_sched(ucp);
-		}
-	}
-	else {
-		SIG_SET_ACTIVE();
-		thread_sig_handle_special(sig);
-		SIG_SET_INACTIVE();
-	}
-}
+	DBG_MSG(">>> _thread_sig_dispatch(%d)\n", sig);
 
-static void
-thread_sig_invoke_handler(int sig, siginfo_t *info, ucontext_t *ucp)
- {
-	struct pthread	*curthread = _get_curthread();
-	void (*sigfunc)(int, siginfo_t *, void *);
-	int		saved_seqno;
-	sigset_t	saved_sigmask;
+	thread_sig_handle_special(sig);
+	if (sigismember(&_thread_sigmask, sig))
+		/* Don't deliver the signal if it's masked. */
+		return;
+	/* Mask the signal until it's handled.  */
+	sigaddset(&_thread_sigmask, sig);
+	/* This signal will be handled; clear the pending flag. */
+	sigdelset(&_thread_sigpending, sig);
 
-	/* Invoke the signal handler without going through the scheduler:
-	 */
-	DBG_MSG("Got signal %d, calling handler for current thread %p\n",
-	    sig, curthread);
-
-	/* Save the threads signal mask: */
-	saved_sigmask = curthread->sigmask;
-	saved_seqno = curthread->sigmask_seqno;
- 
-	/* Setup the threads signal mask: */
-	SIGSETOR(curthread->sigmask, _thread_sigact[sig - 1].sa_mask);
-	sigaddset(&curthread->sigmask, sig);
- 
 	/*
-	 * Check that a custom handler is installed and if
-	 * the signal is not blocked:
+	 * Deliver the signal to a thread.
 	 */
-	sigfunc = _thread_sigact[sig - 1].sa_sigaction;
-	if (((__sighandler_t *)sigfunc != SIG_DFL) &&
-	    ((__sighandler_t *)sigfunc != SIG_IGN)) {
-		if (((_thread_sigact[sig - 1].sa_flags & SA_SIGINFO) != 0) ||
-		    (info == NULL))
-			(*(sigfunc))(sig, info, ucp);
-		else
-			(*(sigfunc))(sig, (siginfo_t *)info->si_code, ucp);
+	if ((pthread = thread_sig_find(sig)) == NULL) {
+		DBG_MSG("No thread to handle signal %d\n", sig);
+		return;
 	}
-	/*
-	 * Only restore the signal mask if it hasn't been changed by the
-	 * application during invocation of the signal handler:
-	 */
-	if (curthread->sigmask_seqno == saved_seqno)
-		curthread->sigmask = saved_sigmask;
+	DBG_MSG("Got signal %d, selecting thread %p\n", sig, pthread);
+	thread_sig_add(pthread, sig, /*has_args*/ 1);
 }
 
 /*
  * Find a thread that can handle the signal.
  */
-struct pthread *
+static struct pthread *
 thread_sig_find(int sig)
 {
 	struct pthread	*curthread = _get_curthread();
-	int		handler_installed;
 	struct pthread	*pthread, *pthread_next;
 	struct pthread	*suspended_thread, *signaled_thread;
 
@@ -309,138 +109,116 @@ thread_sig_find(int sig)
 		_thread_dump_info();
 
 		/* Unblock this signal to allow further dumps: */
-		_thread_sigq[sig - 1].blocked = 0;
+		sigdelset(&_thread_sigmask, sig);
 	}
-	/* Check if an interval timer signal: */
-	else if (sig == _SCHED_SIGNAL) {
-		/*
-		 * This shouldn't ever occur (should this panic?).
-		 */
-	} else {
+
+	/*
+	 * Enter a loop to look for threads that have the signal
+	 * unmasked.  POSIX specifies that a thread in a sigwait
+	 * will get the signal over any other threads.  Second
+	 * preference will be threads in in a sigsuspend.  Third
+	 * preference will be the current thread.  If none of the
+	 * above, then the signal is delivered to the first thread
+	 * that is found.  Note that if a custom handler is not
+	 * installed, the signal only affects threads in sigwait.
+	 */
+	suspended_thread = NULL;
+	if ((curthread != &_thread_kern_thread) &&
+	    !sigismember(&curthread->mailbox.tm_context.uc_sigmask, sig))
+		signaled_thread = curthread;
+	else
+		signaled_thread = NULL;
+
+	for (pthread = TAILQ_FIRST(&_waitingq);
+	    pthread != NULL; pthread = pthread_next) {
 		/*
-		 * Enter a loop to look for threads that have the signal
-		 * unmasked.  POSIX specifies that a thread in a sigwait
-		 * will get the signal over any other threads.  Second
-		 * preference will be threads in in a sigsuspend.  Third
-		 * preference will be the current thread.  If none of the
-		 * above, then the signal is delivered to the first thread
-		 * that is found.  Note that if a custom handler is not
-		 * installed, the signal only affects threads in sigwait.
+		 * Grab the next thread before possibly destroying
+		 * the link entry.
 		 */
-		suspended_thread = NULL;
-		if ((curthread != &_thread_kern_thread) &&
-		    !sigismember(&curthread->sigmask, sig))
-			signaled_thread = curthread;
-		else
-			signaled_thread = NULL;
-		if ((_thread_sigact[sig - 1].sa_handler == SIG_IGN) ||
-		    (_thread_sigact[sig - 1].sa_handler == SIG_DFL))
-			handler_installed = 0;
-		else
-			handler_installed = 1;
+		pthread_next = TAILQ_NEXT(pthread, pqe);
+
+		if ((pthread->state == PS_SIGWAIT) &&
+		    sigismember(pthread->data.sigwait, sig)) {
+			/* Change the state of the thread to run: */
+			PTHREAD_NEW_STATE(pthread, PS_RUNNING);
 
-		for (pthread = TAILQ_FIRST(&_waitingq);
-		    pthread != NULL; pthread = pthread_next) {
 			/*
-			 * Grab the next thread before possibly destroying
-			 * the link entry.
+			 * A signal handler is not invoked for threads
+			 * in sigwait.  Clear the blocked and pending
+			 * flags.
 			 */
-			pthread_next = TAILQ_NEXT(pthread, pqe);
+			sigdelset(&_thread_sigmask, sig);
+			sigdelset(&_thread_sigpending, sig);
 
-			if ((pthread->state == PS_SIGWAIT) &&
-			    sigismember(pthread->data.sigwait, sig)) {
-				/* Change the state of the thread to run: */
-				PTHREAD_NEW_STATE(pthread,PS_RUNNING);
-				/*
-				 * A signal handler is not invoked for threads
-				 * in sigwait.  Clear the blocked and pending
-				 * flags.
-				 */
-				_thread_sigq[sig - 1].blocked = 0;
-				_thread_sigq[sig - 1].pending = 0;
-
-				/* Return the signal number: */
-				pthread->signo = sig;
+			/* Return the signal number: */
+			pthread->signo = sig;
 
-				/*
-				 * POSIX doesn't doesn't specify which thread
-				 * will get the signal if there are multiple
-				 * waiters, so we give it to the first thread
-				 * we find.
-				 *
-				 * Do not attempt to deliver this signal
-				 * to other threads and do not add the signal
-				 * to the process pending set.
-				 */
-				return (NULL);
-			}
-			else if ((handler_installed != 0) &&
-			    !sigismember(&pthread->sigmask, sig) &&
-			    ((pthread->flags & PTHREAD_FLAGS_SUSPENDED) == 0)) {
-				if (pthread->state == PS_SIGSUSPEND) {
-					if (suspended_thread == NULL)
-						suspended_thread = pthread;
-				} else if (signaled_thread == NULL)
-					signaled_thread = pthread;
-			}
+			/*
+			 * POSIX doesn't doesn't specify which thread
+			 * will get the signal if there are multiple
+			 * waiters, so we give it to the first thread
+			 * we find.
+			 *
+			 * Do not attempt to deliver this signal
+			 * to other threads and do not add the signal
+			 * to the process pending set.
+			 */
+			return (NULL);
+		}
+		if (!sigismember(
+			&pthread->mailbox.tm_context.uc_sigmask, sig) &&
+		    ((pthread->flags & PTHREAD_FLAGS_SUSPENDED) == 0)) {
+			if (pthread->state == PS_SIGSUSPEND) {
+				if (suspended_thread == NULL)
+					suspended_thread = pthread;
+			} else if (signaled_thread == NULL)
+				signaled_thread = pthread;
 		}
+	}
 
+	/*
+	 * If we didn't find a thread in the waiting queue,
+	 * check the all threads queue:
+	 */
+	if (suspended_thread == NULL &&
+	    signaled_thread == NULL) {
 		/*
-		 * Only perform wakeups and signal delivery if there is a
-		 * custom handler installed:
+		 * Enter a loop to look for other threads
+		 * capable of receiving the signal:
 		 */
-		if (handler_installed == 0) {
-			/*
-			 * There is no handler installed.  Unblock the
-			 * signal so that if a handler _is_ installed, any
-			 * subsequent signals can be handled.
-			 */
-			_thread_sigq[sig - 1].blocked = 0;
-		} else {
-			/*
-			 * If we didn't find a thread in the waiting queue,
-			 * check the all threads queue:
-			 */
-			if (suspended_thread == NULL &&
-			    signaled_thread == NULL) {
-				/*
-				 * Enter a loop to look for other threads
-				 * capable of receiving the signal:
-				 */
-				TAILQ_FOREACH(pthread, &_thread_list, tle) {
-					if (!sigismember(&pthread->sigmask,
-					    sig)) {
-						signaled_thread = pthread;
-						break;
-					}
-				}
-			}
-
-			if (suspended_thread == NULL &&
-			    signaled_thread == NULL)
-				/*
-				 * Add it to the set of signals pending
-				 * on the process:
-				 */
-				sigaddset(&_process_sigpending, sig);
-			else {
-				/*
-				 * We only deliver the signal to one thread;
-				 * give preference to the suspended thread:
-				 */
-				if (suspended_thread != NULL)
-					pthread = suspended_thread;
-				else
-					pthread = signaled_thread;
-				return (pthread);
+		TAILQ_FOREACH(pthread, &_thread_list, tle) {
+			if (!sigismember(
+			    &pthread->mailbox.tm_context.uc_sigmask, sig)) {
+				signaled_thread = pthread;
+				break;
 			}
 		}
 	}
 
+	if (suspended_thread == NULL &&
+	    signaled_thread == NULL)
+		/*
+		 * Add it to the set of signals pending
+		 * on the process:
+		 */
+		sigaddset(&_thread_sigpending, sig);
+	else {
+		/*
+		 * We only deliver the signal to one thread;
+		 * give preference to the suspended thread:
+		 */
+		if (suspended_thread != NULL)
+			pthread = suspended_thread;
+		else
+			pthread = signaled_thread;
+		return (pthread);
+	}
+
 	/* Returns nothing. */
 	return (NULL);
 }
 
+#if __XXX_NOT_YET__
 void
 _thread_sig_check_pending(struct pthread *pthread)
 {
@@ -452,8 +230,9 @@ _thread_sig_check_pending(struct pthread *pthread)
 	 * thread or process that aren't blocked:
 	 */
 	sigset = pthread->sigpend;
-	SIGSETOR(sigset, _process_sigpending);
+	SIGSETOR(sigset, _thread_sigpending);
 	SIGSETNAND(sigset, pthread->sigmask);
+	SIGSETNAND(sigset, _thread_sigmask);
 	if (SIGNOTEMPTY(sigset)) {
 		for (i = 1; i < NSIG; i++) {
 			if (sigismember(&sigset, i) != 0) {
@@ -463,13 +242,15 @@ _thread_sig_check_pending(struct pthread *pthread)
 				else {
 					thread_sig_add(pthread, i,
 					    /*has_args*/ 1);
-					sigdelset(&_process_sigpending, i);
+					sigdelset(&_thread_sigpending, i);
 				}
 			}
 		}
 	}
 }
+#endif
 
+#if __XXX_NOT_YET__
 /*
  * This can only be called from the kernel scheduler.  It assumes that
  * all thread contexts are saved and that a signal frame can safely be
@@ -479,30 +260,20 @@ void
 _thread_sig_handle_pending(void)
 {
 	struct pthread	*pthread;
-	int		i, sig;
+	int		sig;
 
-	PTHREAD_ASSERT(_thread_kern_in_sched != 0,
-	    "_thread_sig_handle_pending called from outside kernel schedule");
 	/*
 	 * Check the array of pending signals:
 	 */
-	for (i = 0; i < NSIG; i++) {
-		if (_thread_sigq[i].pending != 0) {
+	for (sig = 1; sig <= NSIG; sig++) {
+		if (sigismember(&_thread_sigpending, sig)) {
 			/* This signal is no longer pending. */
-			_thread_sigq[i].pending = 0;
-
-			sig = _thread_sigq[i].signo;
-
-			/* Some signals need special handling: */
+			sigdelset(&_thread_sigpending, sig);
+			/* Some signals need special handling. */
 			thread_sig_handle_special(sig);
-
-			if (_thread_sigq[i].blocked == 0) {
-				/*
-				 * Block future signals until this one
-				 * is handled:
-				 */
-				_thread_sigq[i].blocked = 1;
-
+			/* Deliver the signal. */
+			if (sigismember(&_thread_sigmask, sig)) {
+				sigaddset(&_thread_sigmask, sig);
 				if ((pthread = thread_sig_find(sig)) != NULL) {
 					/*
 					 * Setup the target thread to receive
@@ -515,7 +286,12 @@ _thread_sig_handle_pending(void)
 		}
 	}
 }
+#endif
 
+/*
+ * Do special processing to the thread states before we deliver
+ * a signal to the application.
+ */
 static void
 thread_sig_handle_special(int sig)
 {
@@ -525,21 +301,6 @@ thread_sig_handle_special(int sig)
 	switch (sig) {
 	case SIGCHLD:
 		/*
-		 * Go through the file list and set all files
-		 * to non-blocking again in case the child
-		 * set some of them to block. Sigh.
-		 */
-		for (i = 0; i < _thread_dtablesize; i++) {
-			/* Check if this file is used: */
-			if (_thread_fd_table[i] != NULL) {
-				/*
-				 * Set the file descriptor to non-blocking:
-				 */
-				__sys_fcntl(i, F_SETFL,
-				    _thread_fd_getflags(i) | O_NONBLOCK);
-			}
-		}
-		/*
 		 * Enter a loop to wake up all threads waiting
 		 * for a process to complete:
 		 */
@@ -595,12 +356,9 @@ thread_sig_handle_special(int sig)
 static void
 thread_sig_add(struct pthread *pthread, int sig, int has_args)
 {
-	int	restart;
 	int	suppress_handler = 0;
 	int	thread_is_active = 0;
 
-	restart = _thread_sigact[sig - 1].sa_flags & SA_RESTART;
-
 	/* Make sure this signal isn't still in the pending set: */
 	sigdelset(&pthread->sigpend, sig);
 
@@ -614,7 +372,6 @@ thread_sig_add(struct pthread *pthread, int sig, int has_args)
 	case PS_DEAD:
 	case PS_DEADLOCK:
 	case PS_STATE_MAX:
-	case PS_SIGTHREAD:
 		/*
 		 * You can't call a signal handler for threads in these
 		 * states.
@@ -685,8 +442,6 @@ thread_sig_add(struct pthread *pthread, int sig, int has_args)
 			 * Mark the thread as interrupted only if the
 			 * restart flag is not set on the signal action:
 			 */
-			if (restart == 0)
-				pthread->interrupted = 1;
 			PTHREAD_WAITQ_REMOVE(pthread);
 			PTHREAD_SET_STATE(pthread, PS_RUNNING);
 		}
@@ -717,50 +472,10 @@ thread_sig_add(struct pthread *pthread, int sig, int has_args)
 		PTHREAD_SET_STATE(pthread, PS_RUNNING);
 		break;
 
-	/*
-	 * States which are interruptible but may need to be removed
-	 * from queues before any signal handler is called.
-	 *
-	 * XXX - We may not need to handle this condition, but will
-	 *       mark it as a potential problem.
-	 */
-	case PS_FDLR_WAIT:
-	case PS_FDLW_WAIT:
-	case PS_FILE_WAIT:
-		if (restart == 0)
-			pthread->interrupted = 1;
-		/*
-		 * Remove the thread from the wait queue.  Our
-		 * signal handler hook will remove this thread
-		 * from the fd or file queue before invoking
-		 * the actual handler.
-		 */
-		PTHREAD_WAITQ_REMOVE(pthread);
-		break;
-
-	/*
-	 * States which are interruptible:
-	 */
-	case PS_FDR_WAIT:
-	case PS_FDW_WAIT:
-		if (restart == 0) {
-			/*
-			 * Flag the operation as interrupted and
-			 * set the state to running:
-			 */
-			pthread->interrupted = 1;
-			PTHREAD_SET_STATE(pthread, PS_RUNNING);
-		}
-		PTHREAD_WORKQ_REMOVE(pthread);
-		PTHREAD_WAITQ_REMOVE(pthread);
-		break;
-
-	case PS_POLL_WAIT:
-	case PS_SELECT_WAIT:
 	case PS_SLEEP_WAIT:
 		/*
-		 * Unmasked signals always cause poll, select, and sleep
-		 * to terminate early, regardless of SA_RESTART:
+		 * Unmasked signals always cause sleep to terminate early,
+		 * regardless of SA_RESTART:
 		 */
 		pthread->interrupted = 1;
 		/* Remove threads in poll and select from the workq: */
@@ -776,6 +491,9 @@ thread_sig_add(struct pthread *pthread, int sig, int has_args)
 		break;
 	}
 
+	DBG_MSG(">>> suppress_handler = %d, thread_is_active = %d\n",
+	    suppress_handler, thread_is_active);
+
 	if (suppress_handler == 0) {
 		/* Setup a signal frame and save the current threads state: */
 		thread_sigframe_add(pthread, sig, has_args);
@@ -807,6 +525,7 @@ thread_sig_add(struct pthread *pthread, int sig, int has_args)
 	}
 }
 
+#if __XXX_NOT_YET__
 static void
 thread_sig_check_state(struct pthread *pthread, int sig)
 {
@@ -820,7 +539,6 @@ thread_sig_check_state(struct pthread *pthread, int sig)
 	case PS_DEAD:
 	case PS_DEADLOCK:
 	case PS_STATE_MAX:
-	case PS_SIGTHREAD:
 	case PS_RUNNING:
 	case PS_SUSPENDED:
 	case PS_SPINBLOCK:
@@ -893,7 +611,9 @@ thread_sig_check_state(struct pthread *pthread, int sig)
 		break;
 	}
 }
+#endif
 
+#if __XXX_NOT_YET__
 /*
  * Send a signal to a specific thread (ala pthread_kill):
  */
@@ -950,6 +670,7 @@ _thread_sig_send(struct pthread *pthread, int sig)
 		}
 	}
 }
+#endif
 
 /*
  * User thread signal handler wrapper.
@@ -957,45 +678,32 @@ _thread_sig_send(struct pthread *pthread, int sig)
  *   thread - current running thread
  */
 void
-_thread_sig_wrapper(void)
+_thread_sig_wrapper(int sig, siginfo_t *info, ucontext_t *context)
 {
-	struct pthread_signal_frame *psf;
+	struct pthread_state_data psd;
 	struct pthread	*thread = _get_curthread();
+	__siginfohandler_t *handler;
 
-	/* Get the current frame and state: */
-	psf = thread->curframe;
-	thread->curframe = NULL;
-	PTHREAD_ASSERT(psf != NULL, "Invalid signal frame in signal handler");
-
-	/*
-	 * We're coming from the kernel scheduler; clear the in
-	 * scheduler flag:
-	 */
-	_thread_kern_in_sched = 0;
+	/* Save the thread's previous state. */
+	thread_sigframe_save(thread, &psd);
 
 	/* Check the threads previous state: */
-	if (psf->saved_state.psd_state != PS_RUNNING) {
+	if (psd.psd_state != PS_RUNNING) {
 		/*
 		 * Do a little cleanup handling for those threads in
 		 * queues before calling the signal handler.  Signals
 		 * for these threads are temporarily blocked until
 		 * after cleanup handling.
 		 */
-		switch (psf->saved_state.psd_state) {
-		case PS_FDLR_WAIT:
-		case PS_FDLW_WAIT:
-			_fd_lock_backout(thread);
-			psf->saved_state.psd_state = PS_RUNNING;
-			break;
-
+		switch (psd.psd_state) {
 		case PS_COND_WAIT:
 			_cond_wait_backout(thread);
-			psf->saved_state.psd_state = PS_RUNNING;
+			psd.psd_state = PS_RUNNING;
 			break;
 
 		case PS_MUTEX_WAIT:
 			_mutex_lock_backout(thread);
-			psf->saved_state.psd_state = PS_RUNNING;
+			psd.psd_state = PS_RUNNING;
 			break;
 
 		default:
@@ -1003,8 +711,12 @@ _thread_sig_wrapper(void)
 		}
 	}
 
-	/* Unblock the signal in case we don't return from the handler: */
-	_thread_sigq[psf->signo - 1].blocked = 0;
+	/* Unblock the signal in case we don't return from the handler. */
+	/*
+ 	 * XXX - This is totally bogus. We need to lock the signal mask
+         * somehow.
+	 */
+	sigdelset(&_thread_sigmask, sig);
 
 	/*
 	 * Lower the priority before calling the handler in case
@@ -1014,23 +726,21 @@ _thread_sig_wrapper(void)
 
 	/*
 	 * Reenable interruptions without checking for the need to
-	 * context switch:
+	 * context switch.
 	 */
 	thread->sig_defer_count = 0;
 
-	/*
-	 * Dispatch the signal via the custom signal handler:
-	 */
-	if (psf->sig_has_args == 0)
-		thread_sig_invoke_handler(psf->signo, NULL, NULL);
-	else
-		thread_sig_invoke_handler(psf->signo, &psf->siginfo, &psf->uc);
+	if (_thread_sigact[sig -1].sa_handler != NULL) {
+		handler = (__siginfohandler_t *)
+			_thread_sigact[sig - 1].sa_handler;
+		handler(sig, info, context);
+	}
 
-	/*
-	 * Call the kernel scheduler to safely restore the frame and
-	 * schedule the next thread:
-	 */
-	_thread_kern_sched_frame(psf);
+        /* Restore the signal frame. */
+        thread_sigframe_restore(thread, &psd);
+
+        /* The signal mask was restored; check for any pending signals. */
+        /* XXX - thread->check_pending = 1; */
 }
 
 static void
@@ -1039,43 +749,20 @@ thread_sigframe_add(struct pthread *thread, int sig, int has_args)
 	struct pthread_signal_frame *psf = NULL;
 	unsigned long	stackp;
 
- 	/* Get the top of the threads stack: */
-	stackp = GET_STACK_JB(thread->ctx.jb);
-
-	/*
-	 * Leave a little space on the stack and round down to the
-	 * nearest aligned word:
-	 */
-	stackp -= sizeof(double);
-	stackp &= ~0x3UL;
-
-	/* Allocate room on top of the stack for a new signal frame: */
-	stackp -= sizeof(struct pthread_signal_frame);
-
-	psf = (struct pthread_signal_frame *) stackp;
-
-	/* Save the current context in the signal frame: */
-	thread_sigframe_save(thread, psf);
-
-	/* Set handler specific information: */
-	psf->sig_has_args = has_args;
-	psf->signo = sig;
-	if (has_args) {
-		/* Copy the signal handler arguments to the signal frame: */
-		memcpy(&psf->uc, &_thread_sigq[psf->signo - 1].uc,
-		    sizeof(psf->uc));
-		memcpy(&psf->siginfo, &_thread_sigq[psf->signo - 1].siginfo,
-		    sizeof(psf->siginfo));
-	}
-
-	/* Setup the signal mask: */
-	SIGSETOR(thread->sigmask, _thread_sigact[sig - 1].sa_mask);
-	sigaddset(&thread->sigmask, sig);
+	/* Add a signal frame to the stack, pointing to our signal wrapper. */
+	signalcontext(&thread->mailbox.tm_context, sig,
+	    (__sighandler_t *)_thread_sig_wrapper);
 
-	/* Set up the new frame: */
+	/* Setup the new signal mask. */
+	SIGSETOR(thread->mailbox.tm_context.uc_sigmask,
+	    _thread_sigact[sig - 1].sa_mask);
+	sigaddset(&thread->mailbox.tm_context.uc_sigmask, sig);
+#if 0
+	/* Set up the new frame. */
 	thread->curframe = psf;
 	thread->flags &= PTHREAD_FLAGS_PRIVATE | PTHREAD_FLAGS_TRACE |
 	    PTHREAD_FLAGS_IN_SYNCQ;
+
 	/*
 	 * Set up the context:
 	 */
@@ -1083,43 +770,35 @@ thread_sigframe_add(struct pthread *thread, int sig, int has_args)
 	_setjmp(thread->ctx.jb);
 	SET_STACK_JB(thread->ctx.jb, stackp);
 	SET_RETURN_ADDR_JB(thread->ctx.jb, _thread_sig_wrapper);
+#endif
 }
 
-void
-_thread_sigframe_restore(struct pthread *thread,
-    struct pthread_signal_frame *psf)
+static void
+thread_sigframe_restore(struct pthread *thread, struct pthread_state_data *psd)
 {
-	memcpy(&thread->ctx, &psf->ctx, sizeof(thread->ctx));
-	/*
-	 * Only restore the signal mask if it hasn't been changed
-	 * by the application during invocation of the signal handler:
-	 */
-	if (thread->sigmask_seqno == psf->saved_state.psd_sigmask_seqno)
-		thread->sigmask = psf->saved_state.psd_sigmask;
-	thread->curframe = psf->saved_state.psd_curframe;
-	thread->wakeup_time = psf->saved_state.psd_wakeup_time;
-	thread->data = psf->saved_state.psd_wait_data;
-	thread->state = psf->saved_state.psd_state;
-	thread->flags = psf->saved_state.psd_flags;
-	thread->interrupted = psf->saved_state.psd_interrupted;
-	thread->signo = psf->saved_state.psd_signo;
-	thread->sig_defer_count = psf->saved_state.psd_sig_defer_count;
+	thread->wakeup_time = psd->psd_wakeup_time;
+	thread->data = psd->psd_wait_data;
+	thread->state = psd->psd_state;
+	thread->flags = psd->psd_flags;
+	thread->interrupted = psd->psd_interrupted;
+	thread->sig_defer_count = psd->psd_sig_defer_count;
 }
 
 static void
-thread_sigframe_save(struct pthread *thread, struct pthread_signal_frame *psf)
+thread_sigframe_save(struct pthread *thread, struct pthread_state_data *psd)
 {
-	memcpy(&psf->ctx, &thread->ctx, sizeof(thread->ctx));
-	psf->saved_state.psd_sigmask = thread->sigmask;
-	psf->saved_state.psd_curframe = thread->curframe;
-	psf->saved_state.psd_wakeup_time = thread->wakeup_time;
-	psf->saved_state.psd_wait_data = thread->data;
-	psf->saved_state.psd_state = thread->state;
-	psf->saved_state.psd_flags = thread->flags &
+	psd->psd_wakeup_time = thread->wakeup_time;
+	psd->psd_wait_data = thread->data;
+	psd->psd_state = thread->state;
+	psd->psd_flags = thread->flags &
 	    (PTHREAD_FLAGS_PRIVATE | PTHREAD_FLAGS_TRACE);
-	psf->saved_state.psd_interrupted = thread->interrupted;
-	psf->saved_state.psd_sigmask_seqno = thread->sigmask_seqno;
-	psf->saved_state.psd_signo = thread->signo;
-	psf->saved_state.psd_sig_defer_count = thread->sig_defer_count;
+	psd->psd_interrupted = thread->interrupted;
+	psd->psd_sig_defer_count = thread->sig_defer_count;
 }
 
+void
+_thread_sig_handler(int sig, siginfo_t *info, ucontext_t *context)
+{
+
+	/* Nothing. */
+}
diff --git a/lib/libkse/thread/thr_sigpending.c b/lib/libkse/thread/thr_sigpending.c
index 71c6771..5b3c02f 100644
--- a/lib/libkse/thread/thr_sigpending.c
+++ b/lib/libkse/thread/thr_sigpending.c
@@ -54,7 +54,7 @@ _sigpending(sigset_t *set)
 	}
 	else {
 		*set = curthread->sigpend;
-		SIGSETOR(*set, _process_sigpending);
+		SIGSETOR(*set, _thread_sigpending);
 	}
 	/* Return the completion status: */
 	return (ret);
diff --git a/lib/libpthread/thread/thr_cancel.c b/lib/libpthread/thread/thr_cancel.c
index e4e0216..8b0b4c0 100644
--- a/lib/libpthread/thread/thr_cancel.c
+++ b/lib/libpthread/thread/thr_cancel.c
@@ -51,6 +51,8 @@ _pthread_cancel(pthread_t pthread)
 				/* Fall through: */
 			case PS_SLEEP_WAIT:
 			case PS_WAIT_WAIT:
+			case PS_SIGSUSPEND:
+			case PS_SIGWAIT:
 				/* Interrupt and resume: */
 				pthread->interrupted = 1;
 				pthread->cancelflags |= PTHREAD_CANCELLING;
diff --git a/lib/libpthread/thread/thr_init.c b/lib/libpthread/thread/thr_init.c
index 9f2f894..8e19924 100644
--- a/lib/libpthread/thread/thr_init.c
+++ b/lib/libpthread/thread/thr_init.c
@@ -162,6 +162,12 @@ _thread_init(void)
 	int		sched_stack_size;	/* Size of scheduler stack. */
 
 	struct clockinfo clockinfo;
+	struct sigaction act;
+
+	/* Check if this function has already been called: */
+	if (_thread_initial)
+		/* Only initialise the threaded application once. */
+		return;
 
 	_pthread_page_size = getpagesize();
 	_pthread_guard_default = getpagesize();
@@ -338,6 +344,31 @@ _thread_init(void)
 		TAILQ_INSERT_HEAD(&_thread_list, _thread_initial, tle);
 		_set_curthread(_thread_initial);
 
+		/* Clear the pending signals for the process. */
+		sigemptyset(&_thread_sigpending);
+
+		/* Enter a loop to get the existing signal status: */
+		for (i = 1; i < NSIG; i++) {
+			/* Check for signals which cannot be trapped. */
+			if (i == SIGKILL || i == SIGSTOP)
+				continue;
+
+			/* Get the signal handler details. */
+			if (__sys_sigaction(i, NULL,
+			    &_thread_sigact[i - 1]) != 0)
+				PANIC("Cannot read signal handler info");
+		}
+
+		/* Register SIGCHLD (needed for wait(2)). */
+		sigfillset(&act.sa_mask);
+		act.sa_handler = (void (*) ()) _thread_sig_handler;
+		act.sa_flags = SA_SIGINFO | SA_RESTART;
+		if (__sys_sigaction(SIGCHLD, &act, NULL) != 0)
+			PANIC("Can't initialize signal handler");
+
+		/* Get the process signal mask. */
+		__sys_sigprocmask(SIG_SETMASK, NULL, &_thread_sigmask);
+
 		/* Get the kernel clockrate: */
 		mib[0] = CTL_KERN;
 		mib[1] = KERN_CLOCKRATE;
diff --git a/lib/libpthread/thread/thr_kern.c b/lib/libpthread/thread/thr_kern.c
index 0747cff..c14d44a 100644
--- a/lib/libpthread/thread/thr_kern.c
+++ b/lib/libpthread/thread/thr_kern.c
@@ -248,6 +248,8 @@ _thread_kern_scheduler(struct kse_mailbox *km)
 	pthread_t	td, pthread, pthread_h;
 	unsigned int	current_tick;
 	struct kse_thr_mailbox	*tm, *p;
+	sigset_t	sigset;
+	int		i;
 
 	DBG_MSG("entering\n");
 	while (!TAILQ_EMPTY(&_thread_list)) {
@@ -280,8 +282,13 @@ _thread_kern_scheduler(struct kse_mailbox *km)
 		}
 
 		/* Deliver posted signals. */
-		/* XXX: Not yet. */
 		DBG_MSG("Picking up signals\n");
+		bcopy(&km->km_sigscaught, &sigset, sizeof(sigset_t));
+		sigemptyset(&km->km_sigscaught); /* XXX */
+		if (SIGNOTEMPTY(sigset))
+			for (i = 1; i < NSIG; i++)
+				if (sigismember(&sigset, i) != 0)
+					_thread_sig_dispatch(i);
 
 		if (_spinblock_count != 0) {
 			/*
diff --git a/lib/libpthread/thread/thr_private.h b/lib/libpthread/thread/thr_private.h
index 8aacdc0..7c5cc87 100644
--- a/lib/libpthread/thread/thr_private.h
+++ b/lib/libpthread/thread/thr_private.h
@@ -426,6 +426,8 @@ enum pthread_state {
 	PS_COND_WAIT,
 	PS_SLEEP_WAIT,
 	PS_WAIT_WAIT,
+	PS_SIGSUSPEND,
+	PS_SIGWAIT,
 	PS_SPINBLOCK,
 	PS_JOIN,
 	PS_SUSPENDED,
@@ -445,6 +447,7 @@ enum pthread_state {
 union pthread_wait_data {
 	pthread_mutex_t	mutex;
 	pthread_cond_t	cond;
+	const sigset_t	*sigwait;	/* Waiting on a signal in sigwait */
 	spinlock_t	*spinlock;
 	struct pthread	*thread;
 };
@@ -461,6 +464,15 @@ struct join_status {
 	int		error;
 };
 
+struct pthread_state_data {
+	struct timespec		psd_wakeup_time;
+	union pthread_wait_data psd_wait_data;
+	enum pthread_state	psd_state;
+	int			psd_flags;
+	int			psd_interrupted;
+	int			psd_sig_defer_count;
+};
+
 struct pthread_specific_elem {
 	const void	*data;
 	int		seqno;
@@ -515,6 +527,9 @@ struct pthread {
 
 	thread_continuation_t	continuation;
 
+	/* Currently pending signals. */
+	sigset_t	sigpend;
+
 	/* Thread state: */
 	enum pthread_state	state;
 
@@ -590,6 +605,9 @@ struct pthread {
 	 */
 	int		interrupted;
 
+	/* Signal number when in state PS_SIGWAIT: */
+	int		signo;
+
 	/*
 	 * Set to non-zero when this thread has deferred signals.
 	 * We allow for recursive deferral.
@@ -774,6 +792,11 @@ SCLASS	pthread_cond_t  _gc_cond
 ;
 
 /*
+ * Array of signal actions for this process.
+ */
+SCLASS struct  sigaction _thread_sigact[NSIG];
+
+/*
  * Scheduling queues:
  */
 SCLASS pq_queue_t		_readyq;
@@ -799,6 +822,12 @@ SCLASS pthread_switch_routine_t _sched_switch_hook
 ;
 
 /*
+ * Signals pending and masked.
+ */
+SCLASS sigset_t		_thread_sigpending;
+SCLASS sigset_t		_thread_sigmask;
+
+/*
  * Declare the kernel scheduler jump buffer and stack:
  */
 SCLASS struct kse_mailbox	_thread_kern_kse_mailbox;
@@ -893,6 +922,7 @@ void	_thread_kern_sched_state_unlock(enum pthread_state state,
 void    _thread_kern_set_timeout(const struct timespec *);
 void    _thread_kern_sig_defer(void);
 void    _thread_kern_sig_undefer(void);
+void	_thread_sig_handler(int, siginfo_t *, ucontext_t *);
 void	_thread_printf(int fd, const char *, ...);
 void    _thread_start(void);
 void	_thread_seterrno(pthread_t, int);
diff --git a/lib/libpthread/thread/thr_sig.c b/lib/libpthread/thread/thr_sig.c
index 5baaab9..a93b406 100644
--- a/lib/libpthread/thread/thr_sig.c
+++ b/lib/libpthread/thread/thr_sig.c
@@ -43,262 +43,62 @@
 #include "thr_private.h"
 
 /* Prototypes: */
+static void	thread_sig_handle_special(int sig);
+
 static void	thread_sig_add(struct pthread *pthread, int sig, int has_args);
 static void	thread_sig_check_state(struct pthread *pthread, int sig);
 static struct pthread *thread_sig_find(int sig);
-static void	thread_sig_handle_special(int sig);
 static void	thread_sigframe_add(struct pthread *thread, int sig,
 		    int has_args);
 static void	thread_sigframe_save(struct pthread *thread,
-		    struct pthread_signal_frame *psf);
-static void	thread_sig_invoke_handler(int sig, siginfo_t *info,
-		    ucontext_t *ucp);
+		    struct pthread_state_data *psd);
+static void	thread_sigframe_restore(struct pthread *thread,
+		    struct pthread_state_data *psd);
 
-/*#define DEBUG_SIGNAL*/
+/* #define DEBUG_SIGNAL */
 #ifdef DEBUG_SIGNAL
 #define DBG_MSG		stdout_debug
 #else
 #define DBG_MSG(x...)
 #endif
 
-#if defined(_PTHREADS_INVARIANTS)
-#define SIG_SET_ACTIVE()	_sig_in_handler = 1
-#define SIG_SET_INACTIVE()	_sig_in_handler = 0
-#else
-#define SIG_SET_ACTIVE()
-#define SIG_SET_INACTIVE()
-#endif
-
+/*
+ * Dispatch a signal to a thread, if appropriate.
+ */
 void
-_thread_sig_handler(int sig, siginfo_t *info, ucontext_t *ucp)
+_thread_sig_dispatch(int sig)
 {
-	struct pthread	*curthread = _get_curthread();
-	struct pthread	*pthread, *pthread_h;
-	int		in_sched = _thread_kern_in_sched;
-	char		c;
-
-	if (ucp == NULL)
-		PANIC("Thread signal handler received null context");
-	DBG_MSG("Got signal %d, current thread %p\n", sig, curthread);
-
-	/* Check if an interval timer signal: */
-	if (sig == _SCHED_SIGNAL) {
-		/* Update the scheduling clock: */
-		gettimeofday((struct timeval *)&_sched_tod, NULL);
-		_sched_ticks++;
-
-		if (in_sched != 0) {
-			/*
-			 * The scheduler is already running; ignore this
-			 * signal.
-			 */
-		}
-		/*
-		 * Check if the scheduler interrupt has come when
-		 * the currently running thread has deferred thread
-		 * signals.
-		 */
-		else if (curthread->sig_defer_count > 0)
-			curthread->yield_on_sig_undefer = 1;
-		else {
-			/* Schedule the next thread: */
-			_thread_kern_sched(ucp);
-
-			/*
-			 * This point should not be reached, so abort the
-			 * process:
-			 */
-			PANIC("Returned to signal function from scheduler");
-		}
-	}
-	/*
-	 * Check if the kernel has been interrupted while the scheduler
-	 * is accessing the scheduling queues or if there is a currently
-	 * running thread that has deferred signals.
-	 */
-	else if ((in_sched != 0) || (curthread->sig_defer_count > 0)) {
-		/* Cast the signal number to a character variable: */
-		c = sig;
-
-		/*
-		 * Write the signal number to the kernel pipe so that it will
-		 * be ready to read when this signal handler returns.
-		 */
-		if (_queue_signals != 0) {
-			__sys_write(_thread_kern_pipe[1], &c, 1);
-			DBG_MSG("Got signal %d, queueing to kernel pipe\n", sig);
-		}
-		if (_thread_sigq[sig - 1].blocked == 0) {
-			DBG_MSG("Got signal %d, adding to _thread_sigq\n", sig);
-			/*
-			 * Do not block this signal; it will be blocked
-			 * when the pending signals are run down.
-			 */
-			/* _thread_sigq[sig - 1].blocked = 1; */
-
-			/*
-			 * Queue the signal, saving siginfo and sigcontext
-			 * (ucontext).
-			 *
-			 * XXX - Do we need to copy siginfo and ucp?
-			 */
-			_thread_sigq[sig - 1].signo = sig;
-			if (info != NULL)
-				memcpy(&_thread_sigq[sig - 1].siginfo, info,
-				    sizeof(*info));
-			memcpy(&_thread_sigq[sig - 1].uc, ucp, sizeof(*ucp));
-
-			/* Indicate that there are queued signals: */
-			_thread_sigq[sig - 1].pending = 1;
-			_sigq_check_reqd = 1;
-		}
-		/* These signals need special handling: */
-		else if (sig == SIGCHLD || sig == SIGTSTP ||
-		    sig == SIGTTIN || sig == SIGTTOU) {
-			_thread_sigq[sig - 1].pending = 1;
-			_thread_sigq[sig - 1].signo = sig;
-			_sigq_check_reqd = 1;
-		}
-		else
-			DBG_MSG("Got signal %d, ignored.\n", sig);
-	}
-	/*
-	 * The signal handlers should have been installed so that they
-	 * cannot be interrupted by other signals.
-	 */
-	else if (_thread_sigq[sig - 1].blocked == 0) {
-		/*
-		 * The signal is not blocked; handle the signal.
-		 *
-		 * Ignore subsequent occurrences of this signal
-		 * until the current signal is handled:
-		 */
-		_thread_sigq[sig - 1].blocked = 1;
-
-		/* This signal will be handled; clear the pending flag: */
-		_thread_sigq[sig - 1].pending = 0;
-
-		/*
-		 * Save siginfo and sigcontext (ucontext).
-		 *
-		 * XXX - Do we need to copy siginfo and ucp?
-		 */
-		_thread_sigq[sig - 1].signo = sig;
-
-		if (info != NULL)
-			memcpy(&_thread_sigq[sig - 1].siginfo, info,
-			    sizeof(*info));
-		memcpy(&_thread_sigq[sig - 1].uc, ucp, sizeof(*ucp));
-		SIG_SET_ACTIVE();
-
-		/* Handle special signals: */
-		thread_sig_handle_special(sig);
-
-		pthread_h = NULL;
-		if ((pthread = thread_sig_find(sig)) == NULL)
-			DBG_MSG("No thread to handle signal %d\n", sig);
-		else if (pthread == curthread) {
-			/*
-			 * Unblock the signal and restore the process signal
-			 * mask in case we don't return from the handler:
-			 */
-			_thread_sigq[sig - 1].blocked = 0;
-			__sys_sigprocmask(SIG_SETMASK, &_process_sigmask, NULL);
-
-			/* Call the signal handler for the current thread: */
-			thread_sig_invoke_handler(sig, info, ucp);
-
-			/*
-			 * Set the process signal mask in the context; it
-			 * could have changed by the handler.
- 			 */
-			ucp->uc_sigmask = _process_sigmask;
- 
-			/* Resume the interrupted thread: */
-			__sys_sigreturn(ucp);
-		} else {
-			DBG_MSG("Got signal %d, adding frame to thread %p\n",
-			    sig, pthread);
-
-			/* Setup the target thread to receive the signal: */
-			thread_sig_add(pthread, sig, /*has_args*/ 1);
-
-			/* Take a peek at the next ready to run thread: */
-			pthread_h = PTHREAD_PRIOQ_FIRST();
-			DBG_MSG("Finished adding frame, head of prio list %p\n",
-			    pthread_h);
-		}
-		SIG_SET_INACTIVE();
+	struct pthread	*pthread;
 
-		/*
-		 * Switch to a different context if the currently running
-		 * thread takes a signal, or if another thread takes a
-		 * signal and the currently running thread is not in a
-		 * signal handler.
-		 */
-		if ((pthread_h != NULL) &&
-		    (pthread_h->active_priority > curthread->active_priority)) {
-			/* Enter the kernel scheduler: */
-			_thread_kern_sched(ucp);
-		}
-	}
-	else {
-		SIG_SET_ACTIVE();
-		thread_sig_handle_special(sig);
-		SIG_SET_INACTIVE();
-	}
-}
+	DBG_MSG(">>> _thread_sig_dispatch(%d)\n", sig);
 
-static void
-thread_sig_invoke_handler(int sig, siginfo_t *info, ucontext_t *ucp)
- {
-	struct pthread	*curthread = _get_curthread();
-	void (*sigfunc)(int, siginfo_t *, void *);
-	int		saved_seqno;
-	sigset_t	saved_sigmask;
+	thread_sig_handle_special(sig);
+	if (sigismember(&_thread_sigmask, sig))
+		/* Don't deliver the signal if it's masked. */
+		return;
+	/* Mask the signal until it's handled.  */
+	sigaddset(&_thread_sigmask, sig);
+	/* This signal will be handled; clear the pending flag. */
+	sigdelset(&_thread_sigpending, sig);
 
-	/* Invoke the signal handler without going through the scheduler:
-	 */
-	DBG_MSG("Got signal %d, calling handler for current thread %p\n",
-	    sig, curthread);
-
-	/* Save the threads signal mask: */
-	saved_sigmask = curthread->sigmask;
-	saved_seqno = curthread->sigmask_seqno;
- 
-	/* Setup the threads signal mask: */
-	SIGSETOR(curthread->sigmask, _thread_sigact[sig - 1].sa_mask);
-	sigaddset(&curthread->sigmask, sig);
- 
 	/*
-	 * Check that a custom handler is installed and if
-	 * the signal is not blocked:
+	 * Deliver the signal to a thread.
 	 */
-	sigfunc = _thread_sigact[sig - 1].sa_sigaction;
-	if (((__sighandler_t *)sigfunc != SIG_DFL) &&
-	    ((__sighandler_t *)sigfunc != SIG_IGN)) {
-		if (((_thread_sigact[sig - 1].sa_flags & SA_SIGINFO) != 0) ||
-		    (info == NULL))
-			(*(sigfunc))(sig, info, ucp);
-		else
-			(*(sigfunc))(sig, (siginfo_t *)info->si_code, ucp);
+	if ((pthread = thread_sig_find(sig)) == NULL) {
+		DBG_MSG("No thread to handle signal %d\n", sig);
+		return;
 	}
-	/*
-	 * Only restore the signal mask if it hasn't been changed by the
-	 * application during invocation of the signal handler:
-	 */
-	if (curthread->sigmask_seqno == saved_seqno)
-		curthread->sigmask = saved_sigmask;
+	DBG_MSG("Got signal %d, selecting thread %p\n", sig, pthread);
+	thread_sig_add(pthread, sig, /*has_args*/ 1);
 }
 
 /*
  * Find a thread that can handle the signal.
  */
-struct pthread *
+static struct pthread *
 thread_sig_find(int sig)
 {
 	struct pthread	*curthread = _get_curthread();
-	int		handler_installed;
 	struct pthread	*pthread, *pthread_next;
 	struct pthread	*suspended_thread, *signaled_thread;
 
@@ -309,138 +109,116 @@ thread_sig_find(int sig)
 		_thread_dump_info();
 
 		/* Unblock this signal to allow further dumps: */
-		_thread_sigq[sig - 1].blocked = 0;
+		sigdelset(&_thread_sigmask, sig);
 	}
-	/* Check if an interval timer signal: */
-	else if (sig == _SCHED_SIGNAL) {
-		/*
-		 * This shouldn't ever occur (should this panic?).
-		 */
-	} else {
+
+	/*
+	 * Enter a loop to look for threads that have the signal
+	 * unmasked.  POSIX specifies that a thread in a sigwait
+	 * will get the signal over any other threads.  Second
+	 * preference will be threads in in a sigsuspend.  Third
+	 * preference will be the current thread.  If none of the
+	 * above, then the signal is delivered to the first thread
+	 * that is found.  Note that if a custom handler is not
+	 * installed, the signal only affects threads in sigwait.
+	 */
+	suspended_thread = NULL;
+	if ((curthread != &_thread_kern_thread) &&
+	    !sigismember(&curthread->mailbox.tm_context.uc_sigmask, sig))
+		signaled_thread = curthread;
+	else
+		signaled_thread = NULL;
+
+	for (pthread = TAILQ_FIRST(&_waitingq);
+	    pthread != NULL; pthread = pthread_next) {
 		/*
-		 * Enter a loop to look for threads that have the signal
-		 * unmasked.  POSIX specifies that a thread in a sigwait
-		 * will get the signal over any other threads.  Second
-		 * preference will be threads in in a sigsuspend.  Third
-		 * preference will be the current thread.  If none of the
-		 * above, then the signal is delivered to the first thread
-		 * that is found.  Note that if a custom handler is not
-		 * installed, the signal only affects threads in sigwait.
+		 * Grab the next thread before possibly destroying
+		 * the link entry.
 		 */
-		suspended_thread = NULL;
-		if ((curthread != &_thread_kern_thread) &&
-		    !sigismember(&curthread->sigmask, sig))
-			signaled_thread = curthread;
-		else
-			signaled_thread = NULL;
-		if ((_thread_sigact[sig - 1].sa_handler == SIG_IGN) ||
-		    (_thread_sigact[sig - 1].sa_handler == SIG_DFL))
-			handler_installed = 0;
-		else
-			handler_installed = 1;
+		pthread_next = TAILQ_NEXT(pthread, pqe);
+
+		if ((pthread->state == PS_SIGWAIT) &&
+		    sigismember(pthread->data.sigwait, sig)) {
+			/* Change the state of the thread to run: */
+			PTHREAD_NEW_STATE(pthread, PS_RUNNING);
 
-		for (pthread = TAILQ_FIRST(&_waitingq);
-		    pthread != NULL; pthread = pthread_next) {
 			/*
-			 * Grab the next thread before possibly destroying
-			 * the link entry.
+			 * A signal handler is not invoked for threads
+			 * in sigwait.  Clear the blocked and pending
+			 * flags.
 			 */
-			pthread_next = TAILQ_NEXT(pthread, pqe);
+			sigdelset(&_thread_sigmask, sig);
+			sigdelset(&_thread_sigpending, sig);
 
-			if ((pthread->state == PS_SIGWAIT) &&
-			    sigismember(pthread->data.sigwait, sig)) {
-				/* Change the state of the thread to run: */
-				PTHREAD_NEW_STATE(pthread,PS_RUNNING);
-				/*
-				 * A signal handler is not invoked for threads
-				 * in sigwait.  Clear the blocked and pending
-				 * flags.
-				 */
-				_thread_sigq[sig - 1].blocked = 0;
-				_thread_sigq[sig - 1].pending = 0;
-
-				/* Return the signal number: */
-				pthread->signo = sig;
+			/* Return the signal number: */
+			pthread->signo = sig;
 
-				/*
-				 * POSIX doesn't doesn't specify which thread
-				 * will get the signal if there are multiple
-				 * waiters, so we give it to the first thread
-				 * we find.
-				 *
-				 * Do not attempt to deliver this signal
-				 * to other threads and do not add the signal
-				 * to the process pending set.
-				 */
-				return (NULL);
-			}
-			else if ((handler_installed != 0) &&
-			    !sigismember(&pthread->sigmask, sig) &&
-			    ((pthread->flags & PTHREAD_FLAGS_SUSPENDED) == 0)) {
-				if (pthread->state == PS_SIGSUSPEND) {
-					if (suspended_thread == NULL)
-						suspended_thread = pthread;
-				} else if (signaled_thread == NULL)
-					signaled_thread = pthread;
-			}
+			/*
+			 * POSIX doesn't doesn't specify which thread
+			 * will get the signal if there are multiple
+			 * waiters, so we give it to the first thread
+			 * we find.
+			 *
+			 * Do not attempt to deliver this signal
+			 * to other threads and do not add the signal
+			 * to the process pending set.
+			 */
+			return (NULL);
+		}
+		if (!sigismember(
+			&pthread->mailbox.tm_context.uc_sigmask, sig) &&
+		    ((pthread->flags & PTHREAD_FLAGS_SUSPENDED) == 0)) {
+			if (pthread->state == PS_SIGSUSPEND) {
+				if (suspended_thread == NULL)
+					suspended_thread = pthread;
+			} else if (signaled_thread == NULL)
+				signaled_thread = pthread;
 		}
+	}
 
+	/*
+	 * If we didn't find a thread in the waiting queue,
+	 * check the all threads queue:
+	 */
+	if (suspended_thread == NULL &&
+	    signaled_thread == NULL) {
 		/*
-		 * Only perform wakeups and signal delivery if there is a
-		 * custom handler installed:
+		 * Enter a loop to look for other threads
+		 * capable of receiving the signal:
 		 */
-		if (handler_installed == 0) {
-			/*
-			 * There is no handler installed.  Unblock the
-			 * signal so that if a handler _is_ installed, any
-			 * subsequent signals can be handled.
-			 */
-			_thread_sigq[sig - 1].blocked = 0;
-		} else {
-			/*
-			 * If we didn't find a thread in the waiting queue,
-			 * check the all threads queue:
-			 */
-			if (suspended_thread == NULL &&
-			    signaled_thread == NULL) {
-				/*
-				 * Enter a loop to look for other threads
-				 * capable of receiving the signal:
-				 */
-				TAILQ_FOREACH(pthread, &_thread_list, tle) {
-					if (!sigismember(&pthread->sigmask,
-					    sig)) {
-						signaled_thread = pthread;
-						break;
-					}
-				}
-			}
-
-			if (suspended_thread == NULL &&
-			    signaled_thread == NULL)
-				/*
-				 * Add it to the set of signals pending
-				 * on the process:
-				 */
-				sigaddset(&_process_sigpending, sig);
-			else {
-				/*
-				 * We only deliver the signal to one thread;
-				 * give preference to the suspended thread:
-				 */
-				if (suspended_thread != NULL)
-					pthread = suspended_thread;
-				else
-					pthread = signaled_thread;
-				return (pthread);
+		TAILQ_FOREACH(pthread, &_thread_list, tle) {
+			if (!sigismember(
+			    &pthread->mailbox.tm_context.uc_sigmask, sig)) {
+				signaled_thread = pthread;
+				break;
 			}
 		}
 	}
 
+	if (suspended_thread == NULL &&
+	    signaled_thread == NULL)
+		/*
+		 * Add it to the set of signals pending
+		 * on the process:
+		 */
+		sigaddset(&_thread_sigpending, sig);
+	else {
+		/*
+		 * We only deliver the signal to one thread;
+		 * give preference to the suspended thread:
+		 */
+		if (suspended_thread != NULL)
+			pthread = suspended_thread;
+		else
+			pthread = signaled_thread;
+		return (pthread);
+	}
+
 	/* Returns nothing. */
 	return (NULL);
 }
 
+#if __XXX_NOT_YET__
 void
 _thread_sig_check_pending(struct pthread *pthread)
 {
@@ -452,8 +230,9 @@ _thread_sig_check_pending(struct pthread *pthread)
 	 * thread or process that aren't blocked:
 	 */
 	sigset = pthread->sigpend;
-	SIGSETOR(sigset, _process_sigpending);
+	SIGSETOR(sigset, _thread_sigpending);
 	SIGSETNAND(sigset, pthread->sigmask);
+	SIGSETNAND(sigset, _thread_sigmask);
 	if (SIGNOTEMPTY(sigset)) {
 		for (i = 1; i < NSIG; i++) {
 			if (sigismember(&sigset, i) != 0) {
@@ -463,13 +242,15 @@ _thread_sig_check_pending(struct pthread *pthread)
 				else {
 					thread_sig_add(pthread, i,
 					    /*has_args*/ 1);
-					sigdelset(&_process_sigpending, i);
+					sigdelset(&_thread_sigpending, i);
 				}
 			}
 		}
 	}
 }
+#endif
 
+#if __XXX_NOT_YET__
 /*
  * This can only be called from the kernel scheduler.  It assumes that
  * all thread contexts are saved and that a signal frame can safely be
@@ -479,30 +260,20 @@ void
 _thread_sig_handle_pending(void)
 {
 	struct pthread	*pthread;
-	int		i, sig;
+	int		sig;
 
-	PTHREAD_ASSERT(_thread_kern_in_sched != 0,
-	    "_thread_sig_handle_pending called from outside kernel schedule");
 	/*
 	 * Check the array of pending signals:
 	 */
-	for (i = 0; i < NSIG; i++) {
-		if (_thread_sigq[i].pending != 0) {
+	for (sig = 1; sig <= NSIG; sig++) {
+		if (sigismember(&_thread_sigpending, sig)) {
 			/* This signal is no longer pending. */
-			_thread_sigq[i].pending = 0;
-
-			sig = _thread_sigq[i].signo;
-
-			/* Some signals need special handling: */
+			sigdelset(&_thread_sigpending, sig);
+			/* Some signals need special handling. */
 			thread_sig_handle_special(sig);
-
-			if (_thread_sigq[i].blocked == 0) {
-				/*
-				 * Block future signals until this one
-				 * is handled:
-				 */
-				_thread_sigq[i].blocked = 1;
-
+			/* Deliver the signal. */
+			if (sigismember(&_thread_sigmask, sig)) {
+				sigaddset(&_thread_sigmask, sig);
 				if ((pthread = thread_sig_find(sig)) != NULL) {
 					/*
 					 * Setup the target thread to receive
@@ -515,7 +286,12 @@ _thread_sig_handle_pending(void)
 		}
 	}
 }
+#endif
 
+/*
+ * Do special processing to the thread states before we deliver
+ * a signal to the application.
+ */
 static void
 thread_sig_handle_special(int sig)
 {
@@ -525,21 +301,6 @@ thread_sig_handle_special(int sig)
 	switch (sig) {
 	case SIGCHLD:
 		/*
-		 * Go through the file list and set all files
-		 * to non-blocking again in case the child
-		 * set some of them to block. Sigh.
-		 */
-		for (i = 0; i < _thread_dtablesize; i++) {
-			/* Check if this file is used: */
-			if (_thread_fd_table[i] != NULL) {
-				/*
-				 * Set the file descriptor to non-blocking:
-				 */
-				__sys_fcntl(i, F_SETFL,
-				    _thread_fd_getflags(i) | O_NONBLOCK);
-			}
-		}
-		/*
 		 * Enter a loop to wake up all threads waiting
 		 * for a process to complete:
 		 */
@@ -595,12 +356,9 @@ thread_sig_handle_special(int sig)
 static void
 thread_sig_add(struct pthread *pthread, int sig, int has_args)
 {
-	int	restart;
 	int	suppress_handler = 0;
 	int	thread_is_active = 0;
 
-	restart = _thread_sigact[sig - 1].sa_flags & SA_RESTART;
-
 	/* Make sure this signal isn't still in the pending set: */
 	sigdelset(&pthread->sigpend, sig);
 
@@ -614,7 +372,6 @@ thread_sig_add(struct pthread *pthread, int sig, int has_args)
 	case PS_DEAD:
 	case PS_DEADLOCK:
 	case PS_STATE_MAX:
-	case PS_SIGTHREAD:
 		/*
 		 * You can't call a signal handler for threads in these
 		 * states.
@@ -685,8 +442,6 @@ thread_sig_add(struct pthread *pthread, int sig, int has_args)
 			 * Mark the thread as interrupted only if the
 			 * restart flag is not set on the signal action:
 			 */
-			if (restart == 0)
-				pthread->interrupted = 1;
 			PTHREAD_WAITQ_REMOVE(pthread);
 			PTHREAD_SET_STATE(pthread, PS_RUNNING);
 		}
@@ -717,50 +472,10 @@ thread_sig_add(struct pthread *pthread, int sig, int has_args)
 		PTHREAD_SET_STATE(pthread, PS_RUNNING);
 		break;
 
-	/*
-	 * States which are interruptible but may need to be removed
-	 * from queues before any signal handler is called.
-	 *
-	 * XXX - We may not need to handle this condition, but will
-	 *       mark it as a potential problem.
-	 */
-	case PS_FDLR_WAIT:
-	case PS_FDLW_WAIT:
-	case PS_FILE_WAIT:
-		if (restart == 0)
-			pthread->interrupted = 1;
-		/*
-		 * Remove the thread from the wait queue.  Our
-		 * signal handler hook will remove this thread
-		 * from the fd or file queue before invoking
-		 * the actual handler.
-		 */
-		PTHREAD_WAITQ_REMOVE(pthread);
-		break;
-
-	/*
-	 * States which are interruptible:
-	 */
-	case PS_FDR_WAIT:
-	case PS_FDW_WAIT:
-		if (restart == 0) {
-			/*
-			 * Flag the operation as interrupted and
-			 * set the state to running:
-			 */
-			pthread->interrupted = 1;
-			PTHREAD_SET_STATE(pthread, PS_RUNNING);
-		}
-		PTHREAD_WORKQ_REMOVE(pthread);
-		PTHREAD_WAITQ_REMOVE(pthread);
-		break;
-
-	case PS_POLL_WAIT:
-	case PS_SELECT_WAIT:
 	case PS_SLEEP_WAIT:
 		/*
-		 * Unmasked signals always cause poll, select, and sleep
-		 * to terminate early, regardless of SA_RESTART:
+		 * Unmasked signals always cause sleep to terminate early,
+		 * regardless of SA_RESTART:
 		 */
 		pthread->interrupted = 1;
 		/* Remove threads in poll and select from the workq: */
@@ -776,6 +491,9 @@ thread_sig_add(struct pthread *pthread, int sig, int has_args)
 		break;
 	}
 
+	DBG_MSG(">>> suppress_handler = %d, thread_is_active = %d\n",
+	    suppress_handler, thread_is_active);
+
 	if (suppress_handler == 0) {
 		/* Setup a signal frame and save the current threads state: */
 		thread_sigframe_add(pthread, sig, has_args);
@@ -807,6 +525,7 @@ thread_sig_add(struct pthread *pthread, int sig, int has_args)
 	}
 }
 
+#if __XXX_NOT_YET__
 static void
 thread_sig_check_state(struct pthread *pthread, int sig)
 {
@@ -820,7 +539,6 @@ thread_sig_check_state(struct pthread *pthread, int sig)
 	case PS_DEAD:
 	case PS_DEADLOCK:
 	case PS_STATE_MAX:
-	case PS_SIGTHREAD:
 	case PS_RUNNING:
 	case PS_SUSPENDED:
 	case PS_SPINBLOCK:
@@ -893,7 +611,9 @@ thread_sig_check_state(struct pthread *pthread, int sig)
 		break;
 	}
 }
+#endif
 
+#if __XXX_NOT_YET__
 /*
  * Send a signal to a specific thread (ala pthread_kill):
  */
@@ -950,6 +670,7 @@ _thread_sig_send(struct pthread *pthread, int sig)
 		}
 	}
 }
+#endif
 
 /*
  * User thread signal handler wrapper.
@@ -957,45 +678,32 @@ _thread_sig_send(struct pthread *pthread, int sig)
  *   thread - current running thread
  */
 void
-_thread_sig_wrapper(void)
+_thread_sig_wrapper(int sig, siginfo_t *info, ucontext_t *context)
 {
-	struct pthread_signal_frame *psf;
+	struct pthread_state_data psd;
 	struct pthread	*thread = _get_curthread();
+	__siginfohandler_t *handler;
 
-	/* Get the current frame and state: */
-	psf = thread->curframe;
-	thread->curframe = NULL;
-	PTHREAD_ASSERT(psf != NULL, "Invalid signal frame in signal handler");
-
-	/*
-	 * We're coming from the kernel scheduler; clear the in
-	 * scheduler flag:
-	 */
-	_thread_kern_in_sched = 0;
+	/* Save the thread's previous state. */
+	thread_sigframe_save(thread, &psd);
 
 	/* Check the threads previous state: */
-	if (psf->saved_state.psd_state != PS_RUNNING) {
+	if (psd.psd_state != PS_RUNNING) {
 		/*
 		 * Do a little cleanup handling for those threads in
 		 * queues before calling the signal handler.  Signals
 		 * for these threads are temporarily blocked until
 		 * after cleanup handling.
 		 */
-		switch (psf->saved_state.psd_state) {
-		case PS_FDLR_WAIT:
-		case PS_FDLW_WAIT:
-			_fd_lock_backout(thread);
-			psf->saved_state.psd_state = PS_RUNNING;
-			break;
-
+		switch (psd.psd_state) {
 		case PS_COND_WAIT:
 			_cond_wait_backout(thread);
-			psf->saved_state.psd_state = PS_RUNNING;
+			psd.psd_state = PS_RUNNING;
 			break;
 
 		case PS_MUTEX_WAIT:
 			_mutex_lock_backout(thread);
-			psf->saved_state.psd_state = PS_RUNNING;
+			psd.psd_state = PS_RUNNING;
 			break;
 
 		default:
@@ -1003,8 +711,12 @@ _thread_sig_wrapper(void)
 		}
 	}
 
-	/* Unblock the signal in case we don't return from the handler: */
-	_thread_sigq[psf->signo - 1].blocked = 0;
+	/* Unblock the signal in case we don't return from the handler. */
+	/*
+ 	 * XXX - This is totally bogus. We need to lock the signal mask
+         * somehow.
+	 */
+	sigdelset(&_thread_sigmask, sig);
 
 	/*
 	 * Lower the priority before calling the handler in case
@@ -1014,23 +726,21 @@ _thread_sig_wrapper(void)
 
 	/*
 	 * Reenable interruptions without checking for the need to
-	 * context switch:
+	 * context switch.
 	 */
 	thread->sig_defer_count = 0;
 
-	/*
-	 * Dispatch the signal via the custom signal handler:
-	 */
-	if (psf->sig_has_args == 0)
-		thread_sig_invoke_handler(psf->signo, NULL, NULL);
-	else
-		thread_sig_invoke_handler(psf->signo, &psf->siginfo, &psf->uc);
+	if (_thread_sigact[sig -1].sa_handler != NULL) {
+		handler = (__siginfohandler_t *)
+			_thread_sigact[sig - 1].sa_handler;
+		handler(sig, info, context);
+	}
 
-	/*
-	 * Call the kernel scheduler to safely restore the frame and
-	 * schedule the next thread:
-	 */
-	_thread_kern_sched_frame(psf);
+        /* Restore the signal frame. */
+        thread_sigframe_restore(thread, &psd);
+
+        /* The signal mask was restored; check for any pending signals. */
+        /* XXX - thread->check_pending = 1; */
 }
 
 static void
@@ -1039,43 +749,20 @@ thread_sigframe_add(struct pthread *thread, int sig, int has_args)
 	struct pthread_signal_frame *psf = NULL;
 	unsigned long	stackp;
 
- 	/* Get the top of the threads stack: */
-	stackp = GET_STACK_JB(thread->ctx.jb);
-
-	/*
-	 * Leave a little space on the stack and round down to the
-	 * nearest aligned word:
-	 */
-	stackp -= sizeof(double);
-	stackp &= ~0x3UL;
-
-	/* Allocate room on top of the stack for a new signal frame: */
-	stackp -= sizeof(struct pthread_signal_frame);
-
-	psf = (struct pthread_signal_frame *) stackp;
-
-	/* Save the current context in the signal frame: */
-	thread_sigframe_save(thread, psf);
-
-	/* Set handler specific information: */
-	psf->sig_has_args = has_args;
-	psf->signo = sig;
-	if (has_args) {
-		/* Copy the signal handler arguments to the signal frame: */
-		memcpy(&psf->uc, &_thread_sigq[psf->signo - 1].uc,
-		    sizeof(psf->uc));
-		memcpy(&psf->siginfo, &_thread_sigq[psf->signo - 1].siginfo,
-		    sizeof(psf->siginfo));
-	}
-
-	/* Setup the signal mask: */
-	SIGSETOR(thread->sigmask, _thread_sigact[sig - 1].sa_mask);
-	sigaddset(&thread->sigmask, sig);
+	/* Add a signal frame to the stack, pointing to our signal wrapper. */
+	signalcontext(&thread->mailbox.tm_context, sig,
+	    (__sighandler_t *)_thread_sig_wrapper);
 
-	/* Set up the new frame: */
+	/* Setup the new signal mask. */
+	SIGSETOR(thread->mailbox.tm_context.uc_sigmask,
+	    _thread_sigact[sig - 1].sa_mask);
+	sigaddset(&thread->mailbox.tm_context.uc_sigmask, sig);
+#if 0
+	/* Set up the new frame. */
 	thread->curframe = psf;
 	thread->flags &= PTHREAD_FLAGS_PRIVATE | PTHREAD_FLAGS_TRACE |
 	    PTHREAD_FLAGS_IN_SYNCQ;
+
 	/*
 	 * Set up the context:
 	 */
@@ -1083,43 +770,35 @@ thread_sigframe_add(struct pthread *thread, int sig, int has_args)
 	_setjmp(thread->ctx.jb);
 	SET_STACK_JB(thread->ctx.jb, stackp);
 	SET_RETURN_ADDR_JB(thread->ctx.jb, _thread_sig_wrapper);
+#endif
 }
 
-void
-_thread_sigframe_restore(struct pthread *thread,
-    struct pthread_signal_frame *psf)
+static void
+thread_sigframe_restore(struct pthread *thread, struct pthread_state_data *psd)
 {
-	memcpy(&thread->ctx, &psf->ctx, sizeof(thread->ctx));
-	/*
-	 * Only restore the signal mask if it hasn't been changed
-	 * by the application during invocation of the signal handler:
-	 */
-	if (thread->sigmask_seqno == psf->saved_state.psd_sigmask_seqno)
-		thread->sigmask = psf->saved_state.psd_sigmask;
-	thread->curframe = psf->saved_state.psd_curframe;
-	thread->wakeup_time = psf->saved_state.psd_wakeup_time;
-	thread->data = psf->saved_state.psd_wait_data;
-	thread->state = psf->saved_state.psd_state;
-	thread->flags = psf->saved_state.psd_flags;
-	thread->interrupted = psf->saved_state.psd_interrupted;
-	thread->signo = psf->saved_state.psd_signo;
-	thread->sig_defer_count = psf->saved_state.psd_sig_defer_count;
+	thread->wakeup_time = psd->psd_wakeup_time;
+	thread->data = psd->psd_wait_data;
+	thread->state = psd->psd_state;
+	thread->flags = psd->psd_flags;
+	thread->interrupted = psd->psd_interrupted;
+	thread->sig_defer_count = psd->psd_sig_defer_count;
 }
 
 static void
-thread_sigframe_save(struct pthread *thread, struct pthread_signal_frame *psf)
+thread_sigframe_save(struct pthread *thread, struct pthread_state_data *psd)
 {
-	memcpy(&psf->ctx, &thread->ctx, sizeof(thread->ctx));
-	psf->saved_state.psd_sigmask = thread->sigmask;
-	psf->saved_state.psd_curframe = thread->curframe;
-	psf->saved_state.psd_wakeup_time = thread->wakeup_time;
-	psf->saved_state.psd_wait_data = thread->data;
-	psf->saved_state.psd_state = thread->state;
-	psf->saved_state.psd_flags = thread->flags &
+	psd->psd_wakeup_time = thread->wakeup_time;
+	psd->psd_wait_data = thread->data;
+	psd->psd_state = thread->state;
+	psd->psd_flags = thread->flags &
 	    (PTHREAD_FLAGS_PRIVATE | PTHREAD_FLAGS_TRACE);
-	psf->saved_state.psd_interrupted = thread->interrupted;
-	psf->saved_state.psd_sigmask_seqno = thread->sigmask_seqno;
-	psf->saved_state.psd_signo = thread->signo;
-	psf->saved_state.psd_sig_defer_count = thread->sig_defer_count;
+	psd->psd_interrupted = thread->interrupted;
+	psd->psd_sig_defer_count = thread->sig_defer_count;
 }
 
+void
+_thread_sig_handler(int sig, siginfo_t *info, ucontext_t *context)
+{
+
+	/* Nothing. */
+}
diff --git a/lib/libpthread/thread/thr_sigpending.c b/lib/libpthread/thread/thr_sigpending.c
index 71c6771..5b3c02f 100644
--- a/lib/libpthread/thread/thr_sigpending.c
+++ b/lib/libpthread/thread/thr_sigpending.c
@@ -54,7 +54,7 @@ _sigpending(sigset_t *set)
 	}
 	else {
 		*set = curthread->sigpend;
-		SIGSETOR(*set, _process_sigpending);
+		SIGSETOR(*set, _thread_sigpending);
 	}
 	/* Return the completion status: */
 	return (ret);