save and restore fp state when switching threads. This, with

an arch/i386 patch previously commited and arch/sparc64 patches
from jason@ make the preemption_float test pass on those two
architectures.

Do not run signal handlers for a thread until the thread has
been made current, ensuring the proper context.   Solves several
(if not all) of the '_pq_insert_tail: Already in priority queue'
problems.

3 files changed, 46 insertions, 77 deletions

diff --git a/lib/libpthread/uthread/pthread_private.h b/lib/libpthread/uthread/pthread_private.h
index 83389b6008b..78d34b82804 100644
--- a/lib/libpthread/uthread/pthread_private.h
+++ b/lib/libpthread/uthread/pthread_private.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pthread_private.h,v 1.40 2002/12/11 23:21:19 marc Exp $	*/
+/*	$OpenBSD: pthread_private.h,v 1.41 2003/01/24 21:03:15 marc Exp $	*/
 /*
  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>.
  * All rights reserved.
@@ -1073,7 +1073,7 @@ struct pthread *_get_curthread(void);
 void	_set_curthread(struct pthread *);
 int     _thread_create(pthread_t *, const pthread_attr_t *,
 		       void *(*start_routine)(void *), void *,pthread_t);
-void    _dispatch_signals(pthread_t, struct sigcontext *);
+void    _dispatch_signals(struct sigcontext *);
 void    _thread_signal(pthread_t, int);
 int	_mutex_cv_lock(pthread_mutex_t *);
 int	_mutex_cv_unlock(pthread_mutex_t *);
diff --git a/lib/libpthread/uthread/uthread_kern.c b/lib/libpthread/uthread/uthread_kern.c
index cf1a6dcf6ac..9930098a974 100644
--- a/lib/libpthread/uthread/uthread_kern.c
+++ b/lib/libpthread/uthread/uthread_kern.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uthread_kern.c,v 1.23 2002/11/04 21:28:49 marc Exp $	*/
+/*	$OpenBSD: uthread_kern.c,v 1.24 2003/01/24 21:03:15 marc Exp $	*/
 /*
  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
  * All rights reserved.
@@ -115,11 +115,6 @@ _thread_kern_sched(struct sigcontext * scp)
 		memcpy(&curthread->saved_sigcontext, scp,
 		    sizeof(curthread->saved_sigcontext));
 
-		/*
-		 * Save floating point state.
-		 */
-		_thread_machdep_save_float_state(&curthread->_machdep);
-
 		/* Flag the signal context as the last state saved: */
 		curthread->sig_saved = 1;
 	} else
@@ -130,6 +125,9 @@ _thread_kern_sched(struct sigcontext * scp)
 	if ((curthread->flags & PTHREAD_FLAGS_PRIVATE) == 0)
 		_last_user_thread = curthread;
 
+	/* Save floating point state. */
+	_thread_machdep_save_float_state(&curthread->_machdep);
+
 	/* Save errno. */
 	curthread->error = errno;
 
@@ -501,41 +499,38 @@ _thread_kern_sched(struct sigcontext * scp)
 			/* Restore errno. */
 			errno = curthread->error;
 
+			/* Restore floating point state. */
+			_thread_machdep_restore_float_state(&curthread->_machdep);
+
 			/*
 			 * Restore the new thread, saving current.
 			 */
 			_thread_machdep_switch(&curthread->_machdep,
-			    &old_thread_run->_machdep);
-
-			/* Check if a signal context was saved: */
-			if (curthread->sig_saved == 1) {
-				/*
-				 * Restore floating point state.
-				 */
-				_thread_machdep_restore_float_state(&curthread->_machdep);
-
-				/*
-				 * Do a sigreturn to restart the thread that
-				 * was interrupted by a signal:
-				 */
-				_thread_kern_in_sched = 0;
+					       &old_thread_run->_machdep);
 
-				/*
-				 * If we had a context switch, run any
-				 * installed switch hooks.
-				 */
-				if ((_sched_switch_hook != NULL) &&
-				    (_last_user_thread != curthread)) {
-					_thread_run_switch_hook(_last_user_thread,
-					    curthread);
-				}
+			/*
+			 * Process any pending signals for the thread we
+			 * just switched to.
+			 */
+			_thread_kern_in_sched = 0;
+			_dispatch_signals(scp);
+
+			/* run any installed switch-hooks */
+			if ((_sched_switch_hook != NULL) &&
+			    (_last_user_thread != curthread)) {
+				_thread_run_switch_hook(_last_user_thread,
+							curthread);
+			}
 
-				if (((curthread->cancelflags &
-				    PTHREAD_AT_CANCEL_POINT) == 0) &&
-				    ((curthread->cancelflags &
-				     PTHREAD_CANCEL_ASYNCHRONOUS) != 0))
-					pthread_testcancel();
+			/* check for thread cancellation */
+			if (((curthread->cancelflags &
+			      PTHREAD_AT_CANCEL_POINT) == 0) &&
+			    ((curthread->cancelflags &
+			      PTHREAD_CANCEL_ASYNCHRONOUS) != 0))
+				pthread_testcancel();
 
+			/* Check if a signal context was saved: */
+			if (curthread->sig_saved == 1) {
 				/* return to signal handler.   This code
 				   should be:
 				   _thread_sys_sigreturn(&curthread->saved_sigcontext);
@@ -543,22 +538,7 @@ _thread_kern_sched(struct sigcontext * scp)
 				   sparc */
 				return;
 			} else {
-				/*
-				 * This is the normal way out of the scheduler.
-				 */
-				_thread_kern_in_sched = 0;
-
-				if (_sched_switch_hook != NULL) {
-					/* Run the installed switch hook: */
-					_thread_run_switch_hook(_last_user_thread,
-					    curthread);
-				}
-
-				if (((curthread->cancelflags &
-				    PTHREAD_AT_CANCEL_POINT) == 0) &&
-				    ((curthread->cancelflags &
-				     PTHREAD_CANCEL_ASYNCHRONOUS) != 0))
-					pthread_testcancel();
+				/* This is the normal way out */
 				return;
 			}
 
diff --git a/lib/libpthread/uthread/uthread_sig.c b/lib/libpthread/uthread/uthread_sig.c
index 1d64e077cde..17eef3fa38e 100644
--- a/lib/libpthread/uthread/uthread_sig.c
+++ b/lib/libpthread/uthread/uthread_sig.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uthread_sig.c,v 1.16 2002/11/08 23:18:25 todd Exp $	*/
+/*	$OpenBSD: uthread_sig.c,v 1.17 2003/01/24 21:03:15 marc Exp $	*/
 /*
  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
  * All rights reserved.
@@ -75,8 +75,8 @@ _thread_sig_process(int sig, struct sigcontext * scp)
 		locked = 1;
 
 	if (locked || _thread_sigact[sig - 1].sa_flags & SA_NODEFER) {
-		_thread_sig_handle(sig, scp);
 		pending_sigs[sig - 1] = 0;
+		_thread_sig_handle(sig, scp);
 	} else
 		check_pending = 1;
 	if (locked)
@@ -167,7 +167,7 @@ _thread_sig_handler(int sig, siginfo_t *info, struct sigcontext * scp)
 			signal_lock = _SPINLOCK_UNLOCKED;
 			for (i = 1; i < NSIG; i++)
 				if (pending_sigs[i - 1])
-				    _thread_sig_process(i, scp);
+					_thread_sig_process(i, scp);
 		}
 	}
 
@@ -268,22 +268,14 @@ _thread_sig_handle(int sig, struct sigcontext * scp)
 					pthread->sig_defer_count--;
 			}
 			/*
-			 * give each thread a chance to dispatch pending
-			 * signals.
+			 * Give the current thread a chance to dispatch
+			 * the signals.  Other threads will get thier
+			 * chance (if the signal is still pending) later.
 			 */
-			TAILQ_FOREACH(pthread, &_thread_list, tle) {
-				/* Current thread inside critical region? */
-				if (curthread->sig_defer_count > 0)
-					pthread->sig_defer_count++;
-				_dispatch_signals(pthread, scp);
-				if (curthread->sig_defer_count > 0)
-					pthread->sig_defer_count--;
-			}
+			_dispatch_signals(scp);
+
 		}
 	}
-
-	/* Returns nothing. */
-	return;
 }
 
 /* Perform thread specific actions in response to a signal: */
@@ -385,12 +377,12 @@ _thread_signal(pthread_t pthread, int sig)
 }
 
 /*
- * possibly dispatch a signal to the given thread.
+ * possibly dispatch a signal to the current thread.
  */
 void
-_dispatch_signals(pthread_t pthread, struct sigcontext * scp)
+_dispatch_signals(struct sigcontext * scp)
 {
-	pthread_t pthread_saved;
+	struct pthread	*curthread = _get_curthread();
 	struct sigaction act;
 	void (*action)(int, siginfo_t *, void *);
 	int i;
@@ -399,7 +391,7 @@ _dispatch_signals(pthread_t pthread, struct sigcontext * scp)
 	 * Check if there are pending signals for the running
 	 * thread that aren't blocked:
 	 */
-	if ((pthread->sigpend & ~pthread->sigmask) != 0)
+	if ((curthread->sigpend & ~curthread->sigmask) != 0)
 		/* Look for all possible pending signals: */
 		for (i = 1; i < NSIG; i++)
 			/*
@@ -408,8 +400,8 @@ _dispatch_signals(pthread_t pthread, struct sigcontext * scp)
 			 */
 			if (_thread_sigact[i - 1].sa_handler != SIG_DFL &&
 			    _thread_sigact[i - 1].sa_handler != SIG_IGN &&
-			    sigismember(&pthread->sigpend,i) &&
-			    !sigismember(&pthread->sigmask,i)) {
+			    sigismember(&curthread->sigpend,i) &&
+			    !sigismember(&curthread->sigmask,i)) {
 				action = _thread_sigact[i - 1].sa_sigaction;
 				_clear_pending_flag(i);
 
@@ -426,10 +418,7 @@ _dispatch_signals(pthread_t pthread, struct sigcontext * scp)
 				 * Dispatch the signal via the custom signal
 				 * handler.
 				 */
-				pthread_saved = _get_curthread();
-				_set_curthread(pthread);
 				(*action)(i, &info_queue[i - 1], scp);
-				_set_curthread(pthread_saved);
 			}
 }
 #endif