Move the cleanup code that frees memory allocated for a dead thread from

the thread kernel into a garbage collector thread which is started when
the fisrt thread is created (other than the initial thread). This
removes the window of opportunity where a context switch will cause a
thread that has locked the malloc spinlock, to enter the thread kernel,
find there is a dead thread and try to free memory, therefore trying
to lock the malloc spinlock against itself.

The garbage collector thread acts just like any other thread, so
instead of having a spinlock to control accesses to the dead thread
list, it uses a mutex and a condition variable so that it can happily
wait to be signalled when a thread exists.

20 files changed, 700 insertions, 390 deletions

diff --git a/lib/libc_r/uthread/Makefile.inc b/lib/libc_r/uthread/Makefile.inc
index 0c5c582..004982a 100644
--- a/lib/libc_r/uthread/Makefile.inc
+++ b/lib/libc_r/uthread/Makefile.inc
@@ -1,4 +1,4 @@
-#	$Id: Makefile.inc,v 1.14 1998/09/07 19:01:43 alex Exp $
+#	$Id: Makefile.inc,v 1.15 1998/09/12 22:03:20 dt Exp $
 
 # uthread sources
 .PATH: ${.CURDIR}/uthread
@@ -40,6 +40,7 @@ SRCS+= \
 	uthread_fstat.c \
 	uthread_fstatfs.c \
 	uthread_fsync.c \
+	uthread_gc.c \
 	uthread_getdirentries.c \
 	uthread_getpeername.c \
 	uthread_getprio.c \
diff --git a/lib/libc_r/uthread/uthread_create.c b/lib/libc_r/uthread/uthread_create.c
index 7603dd3..c7ddeb2 100644
--- a/lib/libc_r/uthread/uthread_create.c
+++ b/lib/libc_r/uthread/uthread_create.c
@@ -46,9 +46,11 @@ int
 pthread_create(pthread_t * thread, const pthread_attr_t * attr,
 	       void *(*start_routine) (void *), void *arg)
 {
+	int		f_gc = 0;
 	int             i;
 	int             ret = 0;
 	int             status;
+	pthread_t       gc_thread;
 	pthread_t       new_thread;
 	pthread_attr_t	pattr;
 	void           *stack;
@@ -185,6 +187,12 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr,
 			/* Lock the thread list: */
 			_lock_thread_list();
 
+			/*
+			 * Check if the garbage collector thread
+			 * needs to be started.
+			 */
+			f_gc = (_thread_link_list == _thread_initial);
+
 			/* Add the thread to the linked list of all threads: */
 			new_thread->nxt = _thread_link_list;
 			_thread_link_list = new_thread;
@@ -197,6 +205,14 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr,
 
 			/* Schedule the new user thread: */
 			_thread_kern_sched(NULL);
+
+			/*
+			 * Start a garbage collector thread
+			 * if necessary.
+			 */
+			if (f_gc && pthread_create(&gc_thread,NULL,
+				    _thread_gc,NULL) != 0)
+				PANIC("Can't create gc thread");
 		}
 	}
 
diff --git a/lib/libc_r/uthread/uthread_exit.c b/lib/libc_r/uthread/uthread_exit.c
index 0083f2b..a5fc400 100644
--- a/lib/libc_r/uthread/uthread_exit.c
+++ b/lib/libc_r/uthread/uthread_exit.c
@@ -133,56 +133,29 @@ pthread_exit(void *status)
 		PTHREAD_NEW_STATE(pthread,PS_RUNNING);
 	}
 
-	/* Lock the thread list: */
-	_lock_thread_list();
-
-	/* Check if the running thread is at the head of the linked list: */
-	if (_thread_link_list == _thread_run) {
-		/* There is no previous thread: */
-		_thread_link_list = _thread_run->nxt;
-	} else {
-		/* Point to the first thread in the list: */
-		pthread = _thread_link_list;
-
-		/*
-		 * Enter a loop to find the thread in the linked list before
-		 * the running thread: 
-		 */
-		while (pthread != NULL && pthread->nxt != _thread_run) {
-			/* Point to the next thread: */
-			pthread = pthread->nxt;
-		}
-
-		/* Check that a previous thread was found: */
-		if (pthread != NULL) {
-			/*
-			 * Point the previous thread to the one after the
-			 * running thread: 
-			 */
-			pthread->nxt = _thread_run->nxt;
-		}
-	}
-
-	/* Unlock the thread list: */
-	_unlock_thread_list();
-
-	/* Lock the dead thread list: */
-	_lock_dead_thread_list();
-
 	/*
-	 * This thread will never run again. Add it to the list of dead
-	 * threads: 
+	 * Lock the garbage collector mutex to ensure that the garbage
+	 * collector is not using the dead thread list.
 	 */
-	_thread_run->nxt = _thread_dead;
-	_thread_dead = _thread_run;
+	if (pthread_mutex_lock(&_gc_mutex) != 0)
+		PANIC("Cannot lock gc mutex");
 
-	/* Unlock the dead thread list: */
-	_unlock_dead_thread_list();
+	/* Add this thread to the list of dead threads. */
+	_thread_run->nxt_dead = _thread_dead;
+	_thread_dead = _thread_run;
 
 	/*
-	 * The running thread is no longer in the thread link list so it will
-	 * now die: 
+	 * Signal the garbage collector thread that there is something
+	 * to clean up.
 	 */
+	if (pthread_cond_signal(&_gc_cond) != 0)
+		PANIC("Cannot signal gc cond");
+
+	/* Unlock the garbage collector mutex: */
+	if (pthread_mutex_unlock(&_gc_mutex) != 0)
+		PANIC("Cannot lock gc mutex");
+
+	/* This this thread will never be re-scheduled. */
 	_thread_kern_sched_state(PS_DEAD, __FILE__, __LINE__);
 
 	/* This point should not be reached. */
diff --git a/lib/libc_r/uthread/uthread_find_thread.c b/lib/libc_r/uthread/uthread_find_thread.c
index 99e3023..e4a59a0 100644
--- a/lib/libc_r/uthread/uthread_find_thread.c
+++ b/lib/libc_r/uthread/uthread_find_thread.c
@@ -76,8 +76,12 @@ _find_dead_thread(pthread_t pthread)
 		/* Invalid thread: */
 		return(EINVAL);
 
-	/* Lock the dead thread list: */
-	_lock_dead_thread_list();
+	/*
+	 * Lock the garbage collector mutex to ensure that the garbage
+	 * collector is not using the dead thread list.
+	 */
+	if (pthread_mutex_lock(&_gc_mutex) != 0)
+		PANIC("Cannot lock gc mutex");
 
 	/* Point to the first thread in the list: */
 	pthread1 = _thread_dead;
@@ -85,11 +89,12 @@ _find_dead_thread(pthread_t pthread)
 	/* Search for the thread to join to: */
 	while (pthread1 != NULL && pthread1 != pthread) {
 		/* Point to the next thread: */
-		pthread1 = pthread1->nxt;
+		pthread1 = pthread1->nxt_dead;
 	}
 
-	/* Unlock the dead thread list: */
-	_unlock_dead_thread_list();
+	/* Unlock the garbage collector mutex: */
+	if (pthread_mutex_unlock(&_gc_mutex) != 0)
+		PANIC("Cannot lock gc mutex");
 
 	/* Return zero if the thread exists: */
 	return ((pthread1 != NULL) ? 0:ESRCH);
diff --git a/lib/libc_r/uthread/uthread_gc.c b/lib/libc_r/uthread/uthread_gc.c
new file mode 100644
index 0000000..faf1b5d
--- /dev/null
+++ b/lib/libc_r/uthread/uthread_gc.c
@@ -0,0 +1,272 @@
+/*
+ * Copyright (c) 1998 John Birrell <jb@cimlogic.com.au>
+ * 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, 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by John Birrell.
+ * 4. Neither the name of the author nor the names of any co-contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
+ *
+ *	$Id$
+ *
+ * Garbage collector thread. Frees memory allocated for dead threads.
+ *
+ */
+#include <errno.h>
+#include <time.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <pthread.h>
+#include "pthread_private.h"
+
+pthread_addr_t
+_thread_gc(pthread_addr_t arg)
+{
+	int		f_debug;
+	int		f_done = 0;
+	int		ret;
+	pthread_t	pthread;
+	pthread_t	pthread_cln;
+	pthread_t	pthread_nxt;
+	pthread_t	pthread_prv;
+	struct timespec	abstime;
+	void		*p_stack;
+
+	/* Set a debug flag based on an environment variable. */
+	f_debug = (getenv("LIBC_R_DEBUG") == NULL);
+
+	/* Set the name of this thread. */
+	pthread_set_name_np(_thread_run,"GC");
+
+	while (!f_done) {
+		/* Check if debugging this application. */
+		if (f_debug)
+			/* Dump thread info to file. */
+			_thread_dump_info();
+
+		/* Lock the thread list: */
+		_lock_thread_list();
+
+		/* Check if this is the last running thread: */
+		if (_thread_link_list == _thread_run &&
+		    _thread_link_list->nxt == NULL)
+			/*
+			 * This is the last thread, so it can exit
+			 * now.
+			 */
+			f_done = 1;
+
+		/* Unlock the thread list: */
+		_unlock_thread_list();
+
+		/*
+		 * Lock the garbage collector mutex which ensures that
+		 * this thread sees another thread exit:
+		 */
+		if (pthread_mutex_lock(&_gc_mutex) != 0)
+			PANIC("Cannot lock gc mutex");
+
+		/* No stack of thread structure to free yet: */
+		p_stack = NULL;
+		pthread_cln = NULL;
+
+		/* Point to the first dead thread (if there are any): */
+		pthread = _thread_dead;
+
+		/* There is no previous dead thread: */
+		pthread_prv = NULL;
+
+		/*
+		 * Enter a loop to search for the first dead thread that
+		 * has memory to free.
+		 */
+		while (p_stack == NULL && pthread_cln == NULL &&
+		    pthread != NULL) {
+			/* Save a pointer to the next thread: */
+			pthread_nxt = pthread->nxt_dead;
+
+			/* Check if the initial thread: */
+			if (pthread == _thread_initial)
+				/* Don't destroy the initial thread. */
+				pthread_prv = pthread;
+
+			/*
+			 * Check if this thread has detached:
+			 */
+			else if ((pthread->attr.flags &
+			    PTHREAD_DETACHED) != 0) {
+				/*
+				 * Check if there is no previous dead
+				 * thread:
+				 */
+				if (pthread_prv == NULL)
+					/*
+					 * The dead thread is at the head
+					 * of the list: 
+					 */
+					_thread_dead = pthread_nxt;
+				else
+					/*
+					 * The dead thread is not at the
+					 * head of the list: 
+					 */
+					pthread_prv->nxt_dead =
+					    pthread->nxt_dead;
+
+				/*
+				 * Check if the stack was not specified by
+				 * the caller to pthread_create and has not
+				 * been destroyed yet: 
+				 */
+				if (pthread->attr.stackaddr_attr == NULL &&
+				    pthread->stack != NULL) {
+					/*
+					 * Point to the stack that must
+					 * be freed outside the locks:
+					 */
+					p_stack = pthread->stack;
+				}
+
+				/*
+				 * Point to the thread structure that must
+				 * be freed outside the locks:
+				 */
+				pthread_cln = pthread;
+			} else {
+				/*
+				 * This thread has not detached, so do
+				 * not destroy it: 
+				 */
+				pthread_prv = pthread;
+
+				/*
+				 * Check if the stack was not specified by
+				 * the caller to pthread_create and has not
+				 * been destroyed yet: 
+				 */
+				if (pthread->attr.stackaddr_attr == NULL &&
+				    pthread->stack != NULL) {
+					/*
+					 * Point to the stack that must
+					 * be freed outside the locks:
+					 */
+					p_stack = pthread->stack;
+
+					/*
+					 * NULL the stack pointer now
+					 * that the memory has been freed: 
+					 */
+					pthread->stack = NULL;
+				}
+			}
+
+			/* Point to the next thread: */
+			pthread = pthread_nxt;
+		}
+
+		/*
+		 * Check if this is not the last thread and there is no
+		 * memory to free this time around.
+		 */
+		if (!f_done && p_stack == NULL && pthread_cln == NULL) {
+			/* Get the current time. */
+			if (clock_gettime(CLOCK_REALTIME,&abstime) != 0)
+				PANIC("gc cannot get time");
+
+			/*
+			 * Do a backup poll in 10 seconds if no threads
+			 * die before then.
+			 */
+			abstime.tv_sec += 10;
+
+			/*
+			 * Wait for a signal from a dying thread or a
+			 * timeout (for a backup poll).
+			 */
+			if ((ret = pthread_cond_timedwait(&_gc_cond,
+			    &_gc_mutex, &abstime)) != 0 && ret != ETIMEDOUT)
+				PANIC("gc cannot wait for a signal");
+		}
+
+		/* Unlock the garbage collector mutex: */
+		if (pthread_mutex_unlock(&_gc_mutex) != 0)
+			PANIC("Cannot unlock gc mutex");
+
+		/*
+		 * If there is memory to free, do it now. The call to
+		 * free() might block, so this must be done outside the
+		 * locks.
+		 */
+		if (p_stack != NULL)
+			free(p_stack);
+		if (pthread_cln != NULL) {
+			/* Lock the thread list: */
+			_lock_thread_list();
+
+			/*
+			 * Check if the thread is at the head of the
+			 * linked list.
+			 */
+			if (_thread_link_list == pthread_cln)
+				/* There is no previous thread: */
+				_thread_link_list = pthread_cln->nxt;
+			else {
+				/* Point to the first thread in the list: */
+				pthread = _thread_link_list;
+
+				/*
+				 * Enter a loop to find the thread in the
+				 * linked list before the thread that is
+				 * about to be freed.
+				 */
+				while (pthread != NULL &&
+				    pthread->nxt != pthread_cln)
+					/* Point to the next thread: */
+					pthread = pthread->nxt;
+
+				/* Check that a previous thread was found: */
+				if (pthread != NULL) {
+					/*
+					 * Point the previous thread to
+					 * the one after the thread being
+					 * freed: 
+					 */
+					pthread->nxt = pthread_cln->nxt;
+				}
+			}
+
+			/* Unlock the thread list: */
+			_unlock_thread_list();
+
+			/*
+			 * Free the memory allocated for the thread
+			 * structure.
+			 */
+			free(pthread_cln);
+		}
+		
+	}
+	return (NULL);
+}
diff --git a/lib/libc_r/uthread/uthread_init.c b/lib/libc_r/uthread/uthread_init.c
index 69b0fef..50f3bef 100644
--- a/lib/libc_r/uthread/uthread_init.c
+++ b/lib/libc_r/uthread/uthread_init.c
@@ -251,6 +251,11 @@ _thread_init(void)
 	__set_dynamic_handler_allocator( dynamic_allocator_handler_fn );
 #endif /* GCC_2_8_MADE_THREAD_AWARE */
 
+	/* Initialise the garbage collector mutex and condition variable. */
+	if (pthread_mutex_init(&_gc_mutex,NULL) != 0 ||
+	    pthread_cond_init(&_gc_cond,NULL) != 0)
+		PANIC("Failed to initialise garbage collector mutex or condvar");
+
 	return;
 }
 
diff --git a/lib/libc_r/uthread/uthread_kern.c b/lib/libc_r/uthread/uthread_kern.c
index ce17cf8..da125cd 100644
--- a/lib/libc_r/uthread/uthread_kern.c
+++ b/lib/libc_r/uthread/uthread_kern.c
@@ -29,7 +29,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: uthread_kern.c,v 1.11 1998/04/30 21:50:29 jb Exp $
+ * $Id: uthread_kern.c,v 1.12 1998/09/07 21:55:01 alex Exp $
  *
  */
 #include <errno.h>
@@ -62,8 +62,6 @@ _thread_kern_sched(struct sigcontext * scp)
 	int             prio = -1;
 	pthread_t       pthread;
 	pthread_t       pthread_h = NULL;
-	pthread_t       pthread_nxt = NULL;
-	pthread_t       pthread_prv = NULL;
 	pthread_t       pthread_s = NULL;
 	struct itimerval itimer;
 	struct timespec ts;
@@ -113,85 +111,9 @@ __asm__("fnsave %0": :"m"(*fdata));
 		 */
 		_dispatch_signals();
 		return;
-	} else {
+	} else
 		/* Flag the jump buffer was the last state saved: */
 		_thread_run->sig_saved = 0;
-	}
-
-	/* Point to the first dead thread (if there are any): */
-	pthread = _thread_dead;
-
-	/* There is no previous dead thread: */
-	pthread_prv = NULL;
-
-	/* Enter a loop to cleanup after dead threads: */
-	while (pthread != NULL) {
-		/* Save a pointer to the next thread: */
-		pthread_nxt = pthread->nxt;
-
-		/* Check if this thread is one which is running: */
-		if (pthread == _thread_run || pthread == _thread_initial) {
-			/*
-			 * Don't destroy the running thread or the initial
-			 * thread. 
-			 */
-			pthread_prv = pthread;
-		}
-		/*
-		 * Check if this thread has detached:
-		 */
-		else if ((pthread->attr.flags & PTHREAD_DETACHED) != 0) {
-			/* Check if there is no previous dead thread: */
-			if (pthread_prv == NULL) {
-				/*
-				 * The dead thread is at the head of the
-				 * list: 
-				 */
-				_thread_dead = pthread_nxt;
-			} else {
-				/*
-				 * The dead thread is not at the head of the
-				 * list: 
-				 */
-				pthread_prv->nxt = pthread->nxt;
-			}
-
-			/*
-			 * Check if the stack was not specified by the caller
-			 * to pthread_create and has not been destroyed yet: 
-			 */
-			if (pthread->attr.stackaddr_attr == NULL && pthread->stack != NULL) {
-				/* Free the stack of the dead thread: */
-				free(pthread->stack);
-			}
-			/* Free the memory allocated to the thread structure: */
-			free(pthread);
-		} else {
-			/*
-			 * This thread has not detached, so do not destroy
-			 * it: 
-			 */
-			pthread_prv = pthread;
-
-			/*
-			 * Check if the stack was not specified by the caller
-			 * to pthread_create and has not been destroyed yet: 
-			 */
-			if (pthread->attr.stackaddr_attr == NULL && pthread->stack != NULL) {
-				/* Free the stack of the dead thread: */
-				free(pthread->stack);
-
-				/*
-				 * NULL the stack pointer now that the memory
-				 * has been freed: 
-				 */
-				pthread->stack = NULL;
-			}
-		}
-
-		/* Point to the next thread: */
-		pthread = pthread_nxt;
-	}
 
 	/*
 	 * Enter a the scheduling loop that finds the next thread that is
diff --git a/lib/libkse/thread/Makefile.inc b/lib/libkse/thread/Makefile.inc
index 0c5c582..004982a 100644
--- a/lib/libkse/thread/Makefile.inc
+++ b/lib/libkse/thread/Makefile.inc
@@ -1,4 +1,4 @@
-#	$Id: Makefile.inc,v 1.14 1998/09/07 19:01:43 alex Exp $
+#	$Id: Makefile.inc,v 1.15 1998/09/12 22:03:20 dt Exp $
 
 # uthread sources
 .PATH: ${.CURDIR}/uthread
@@ -40,6 +40,7 @@ SRCS+= \
 	uthread_fstat.c \
 	uthread_fstatfs.c \
 	uthread_fsync.c \
+	uthread_gc.c \
 	uthread_getdirentries.c \
 	uthread_getpeername.c \
 	uthread_getprio.c \
diff --git a/lib/libkse/thread/thr_create.c b/lib/libkse/thread/thr_create.c
index 7603dd3..c7ddeb2 100644
--- a/lib/libkse/thread/thr_create.c
+++ b/lib/libkse/thread/thr_create.c
@@ -46,9 +46,11 @@ int
 pthread_create(pthread_t * thread, const pthread_attr_t * attr,
 	       void *(*start_routine) (void *), void *arg)
 {
+	int		f_gc = 0;
 	int             i;
 	int             ret = 0;
 	int             status;
+	pthread_t       gc_thread;
 	pthread_t       new_thread;
 	pthread_attr_t	pattr;
 	void           *stack;
@@ -185,6 +187,12 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr,
 			/* Lock the thread list: */
 			_lock_thread_list();
 
+			/*
+			 * Check if the garbage collector thread
+			 * needs to be started.
+			 */
+			f_gc = (_thread_link_list == _thread_initial);
+
 			/* Add the thread to the linked list of all threads: */
 			new_thread->nxt = _thread_link_list;
 			_thread_link_list = new_thread;
@@ -197,6 +205,14 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr,
 
 			/* Schedule the new user thread: */
 			_thread_kern_sched(NULL);
+
+			/*
+			 * Start a garbage collector thread
+			 * if necessary.
+			 */
+			if (f_gc && pthread_create(&gc_thread,NULL,
+				    _thread_gc,NULL) != 0)
+				PANIC("Can't create gc thread");
 		}
 	}
 
diff --git a/lib/libkse/thread/thr_exit.c b/lib/libkse/thread/thr_exit.c
index 0083f2b..a5fc400 100644
--- a/lib/libkse/thread/thr_exit.c
+++ b/lib/libkse/thread/thr_exit.c
@@ -133,56 +133,29 @@ pthread_exit(void *status)
 		PTHREAD_NEW_STATE(pthread,PS_RUNNING);
 	}
 
-	/* Lock the thread list: */
-	_lock_thread_list();
-
-	/* Check if the running thread is at the head of the linked list: */
-	if (_thread_link_list == _thread_run) {
-		/* There is no previous thread: */
-		_thread_link_list = _thread_run->nxt;
-	} else {
-		/* Point to the first thread in the list: */
-		pthread = _thread_link_list;
-
-		/*
-		 * Enter a loop to find the thread in the linked list before
-		 * the running thread: 
-		 */
-		while (pthread != NULL && pthread->nxt != _thread_run) {
-			/* Point to the next thread: */
-			pthread = pthread->nxt;
-		}
-
-		/* Check that a previous thread was found: */
-		if (pthread != NULL) {
-			/*
-			 * Point the previous thread to the one after the
-			 * running thread: 
-			 */
-			pthread->nxt = _thread_run->nxt;
-		}
-	}
-
-	/* Unlock the thread list: */
-	_unlock_thread_list();
-
-	/* Lock the dead thread list: */
-	_lock_dead_thread_list();
-
 	/*
-	 * This thread will never run again. Add it to the list of dead
-	 * threads: 
+	 * Lock the garbage collector mutex to ensure that the garbage
+	 * collector is not using the dead thread list.
 	 */
-	_thread_run->nxt = _thread_dead;
-	_thread_dead = _thread_run;
+	if (pthread_mutex_lock(&_gc_mutex) != 0)
+		PANIC("Cannot lock gc mutex");
 
-	/* Unlock the dead thread list: */
-	_unlock_dead_thread_list();
+	/* Add this thread to the list of dead threads. */
+	_thread_run->nxt_dead = _thread_dead;
+	_thread_dead = _thread_run;
 
 	/*
-	 * The running thread is no longer in the thread link list so it will
-	 * now die: 
+	 * Signal the garbage collector thread that there is something
+	 * to clean up.
 	 */
+	if (pthread_cond_signal(&_gc_cond) != 0)
+		PANIC("Cannot signal gc cond");
+
+	/* Unlock the garbage collector mutex: */
+	if (pthread_mutex_unlock(&_gc_mutex) != 0)
+		PANIC("Cannot lock gc mutex");
+
+	/* This this thread will never be re-scheduled. */
 	_thread_kern_sched_state(PS_DEAD, __FILE__, __LINE__);
 
 	/* This point should not be reached. */
diff --git a/lib/libkse/thread/thr_find_thread.c b/lib/libkse/thread/thr_find_thread.c
index 99e3023..e4a59a0 100644
--- a/lib/libkse/thread/thr_find_thread.c
+++ b/lib/libkse/thread/thr_find_thread.c
@@ -76,8 +76,12 @@ _find_dead_thread(pthread_t pthread)
 		/* Invalid thread: */
 		return(EINVAL);
 
-	/* Lock the dead thread list: */
-	_lock_dead_thread_list();
+	/*
+	 * Lock the garbage collector mutex to ensure that the garbage
+	 * collector is not using the dead thread list.
+	 */
+	if (pthread_mutex_lock(&_gc_mutex) != 0)
+		PANIC("Cannot lock gc mutex");
 
 	/* Point to the first thread in the list: */
 	pthread1 = _thread_dead;
@@ -85,11 +89,12 @@ _find_dead_thread(pthread_t pthread)
 	/* Search for the thread to join to: */
 	while (pthread1 != NULL && pthread1 != pthread) {
 		/* Point to the next thread: */
-		pthread1 = pthread1->nxt;
+		pthread1 = pthread1->nxt_dead;
 	}
 
-	/* Unlock the dead thread list: */
-	_unlock_dead_thread_list();
+	/* Unlock the garbage collector mutex: */
+	if (pthread_mutex_unlock(&_gc_mutex) != 0)
+		PANIC("Cannot lock gc mutex");
 
 	/* Return zero if the thread exists: */
 	return ((pthread1 != NULL) ? 0:ESRCH);
diff --git a/lib/libkse/thread/thr_init.c b/lib/libkse/thread/thr_init.c
index 69b0fef..50f3bef 100644
--- a/lib/libkse/thread/thr_init.c
+++ b/lib/libkse/thread/thr_init.c
@@ -251,6 +251,11 @@ _thread_init(void)
 	__set_dynamic_handler_allocator( dynamic_allocator_handler_fn );
 #endif /* GCC_2_8_MADE_THREAD_AWARE */
 
+	/* Initialise the garbage collector mutex and condition variable. */
+	if (pthread_mutex_init(&_gc_mutex,NULL) != 0 ||
+	    pthread_cond_init(&_gc_cond,NULL) != 0)
+		PANIC("Failed to initialise garbage collector mutex or condvar");
+
 	return;
 }
 
diff --git a/lib/libkse/thread/thr_kern.c b/lib/libkse/thread/thr_kern.c
index ce17cf8..da125cd 100644
--- a/lib/libkse/thread/thr_kern.c
+++ b/lib/libkse/thread/thr_kern.c
@@ -29,7 +29,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: uthread_kern.c,v 1.11 1998/04/30 21:50:29 jb Exp $
+ * $Id: uthread_kern.c,v 1.12 1998/09/07 21:55:01 alex Exp $
  *
  */
 #include <errno.h>
@@ -62,8 +62,6 @@ _thread_kern_sched(struct sigcontext * scp)
 	int             prio = -1;
 	pthread_t       pthread;
 	pthread_t       pthread_h = NULL;
-	pthread_t       pthread_nxt = NULL;
-	pthread_t       pthread_prv = NULL;
 	pthread_t       pthread_s = NULL;
 	struct itimerval itimer;
 	struct timespec ts;
@@ -113,85 +111,9 @@ __asm__("fnsave %0": :"m"(*fdata));
 		 */
 		_dispatch_signals();
 		return;
-	} else {
+	} else
 		/* Flag the jump buffer was the last state saved: */
 		_thread_run->sig_saved = 0;
-	}
-
-	/* Point to the first dead thread (if there are any): */
-	pthread = _thread_dead;
-
-	/* There is no previous dead thread: */
-	pthread_prv = NULL;
-
-	/* Enter a loop to cleanup after dead threads: */
-	while (pthread != NULL) {
-		/* Save a pointer to the next thread: */
-		pthread_nxt = pthread->nxt;
-
-		/* Check if this thread is one which is running: */
-		if (pthread == _thread_run || pthread == _thread_initial) {
-			/*
-			 * Don't destroy the running thread or the initial
-			 * thread. 
-			 */
-			pthread_prv = pthread;
-		}
-		/*
-		 * Check if this thread has detached:
-		 */
-		else if ((pthread->attr.flags & PTHREAD_DETACHED) != 0) {
-			/* Check if there is no previous dead thread: */
-			if (pthread_prv == NULL) {
-				/*
-				 * The dead thread is at the head of the
-				 * list: 
-				 */
-				_thread_dead = pthread_nxt;
-			} else {
-				/*
-				 * The dead thread is not at the head of the
-				 * list: 
-				 */
-				pthread_prv->nxt = pthread->nxt;
-			}
-
-			/*
-			 * Check if the stack was not specified by the caller
-			 * to pthread_create and has not been destroyed yet: 
-			 */
-			if (pthread->attr.stackaddr_attr == NULL && pthread->stack != NULL) {
-				/* Free the stack of the dead thread: */
-				free(pthread->stack);
-			}
-			/* Free the memory allocated to the thread structure: */
-			free(pthread);
-		} else {
-			/*
-			 * This thread has not detached, so do not destroy
-			 * it: 
-			 */
-			pthread_prv = pthread;
-
-			/*
-			 * Check if the stack was not specified by the caller
-			 * to pthread_create and has not been destroyed yet: 
-			 */
-			if (pthread->attr.stackaddr_attr == NULL && pthread->stack != NULL) {
-				/* Free the stack of the dead thread: */
-				free(pthread->stack);
-
-				/*
-				 * NULL the stack pointer now that the memory
-				 * has been freed: 
-				 */
-				pthread->stack = NULL;
-			}
-		}
-
-		/* Point to the next thread: */
-		pthread = pthread_nxt;
-	}
 
 	/*
 	 * Enter a the scheduling loop that finds the next thread that is
diff --git a/lib/libpthread/thread/Makefile.inc b/lib/libpthread/thread/Makefile.inc
index 0c5c582..004982a 100644
--- a/lib/libpthread/thread/Makefile.inc
+++ b/lib/libpthread/thread/Makefile.inc
@@ -1,4 +1,4 @@
-#	$Id: Makefile.inc,v 1.14 1998/09/07 19:01:43 alex Exp $
+#	$Id: Makefile.inc,v 1.15 1998/09/12 22:03:20 dt Exp $
 
 # uthread sources
 .PATH: ${.CURDIR}/uthread
@@ -40,6 +40,7 @@ SRCS+= \
 	uthread_fstat.c \
 	uthread_fstatfs.c \
 	uthread_fsync.c \
+	uthread_gc.c \
 	uthread_getdirentries.c \
 	uthread_getpeername.c \
 	uthread_getprio.c \
diff --git a/lib/libpthread/thread/thr_create.c b/lib/libpthread/thread/thr_create.c
index 7603dd3..c7ddeb2 100644
--- a/lib/libpthread/thread/thr_create.c
+++ b/lib/libpthread/thread/thr_create.c
@@ -46,9 +46,11 @@ int
 pthread_create(pthread_t * thread, const pthread_attr_t * attr,
 	       void *(*start_routine) (void *), void *arg)
 {
+	int		f_gc = 0;
 	int             i;
 	int             ret = 0;
 	int             status;
+	pthread_t       gc_thread;
 	pthread_t       new_thread;
 	pthread_attr_t	pattr;
 	void           *stack;
@@ -185,6 +187,12 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr,
 			/* Lock the thread list: */
 			_lock_thread_list();
 
+			/*
+			 * Check if the garbage collector thread
+			 * needs to be started.
+			 */
+			f_gc = (_thread_link_list == _thread_initial);
+
 			/* Add the thread to the linked list of all threads: */
 			new_thread->nxt = _thread_link_list;
 			_thread_link_list = new_thread;
@@ -197,6 +205,14 @@ pthread_create(pthread_t * thread, const pthread_attr_t * attr,
 
 			/* Schedule the new user thread: */
 			_thread_kern_sched(NULL);
+
+			/*
+			 * Start a garbage collector thread
+			 * if necessary.
+			 */
+			if (f_gc && pthread_create(&gc_thread,NULL,
+				    _thread_gc,NULL) != 0)
+				PANIC("Can't create gc thread");
 		}
 	}
 
diff --git a/lib/libpthread/thread/thr_exit.c b/lib/libpthread/thread/thr_exit.c
index 0083f2b..a5fc400 100644
--- a/lib/libpthread/thread/thr_exit.c
+++ b/lib/libpthread/thread/thr_exit.c
@@ -133,56 +133,29 @@ pthread_exit(void *status)
 		PTHREAD_NEW_STATE(pthread,PS_RUNNING);
 	}
 
-	/* Lock the thread list: */
-	_lock_thread_list();
-
-	/* Check if the running thread is at the head of the linked list: */
-	if (_thread_link_list == _thread_run) {
-		/* There is no previous thread: */
-		_thread_link_list = _thread_run->nxt;
-	} else {
-		/* Point to the first thread in the list: */
-		pthread = _thread_link_list;
-
-		/*
-		 * Enter a loop to find the thread in the linked list before
-		 * the running thread: 
-		 */
-		while (pthread != NULL && pthread->nxt != _thread_run) {
-			/* Point to the next thread: */
-			pthread = pthread->nxt;
-		}
-
-		/* Check that a previous thread was found: */
-		if (pthread != NULL) {
-			/*
-			 * Point the previous thread to the one after the
-			 * running thread: 
-			 */
-			pthread->nxt = _thread_run->nxt;
-		}
-	}
-
-	/* Unlock the thread list: */
-	_unlock_thread_list();
-
-	/* Lock the dead thread list: */
-	_lock_dead_thread_list();
-
 	/*
-	 * This thread will never run again. Add it to the list of dead
-	 * threads: 
+	 * Lock the garbage collector mutex to ensure that the garbage
+	 * collector is not using the dead thread list.
 	 */
-	_thread_run->nxt = _thread_dead;
-	_thread_dead = _thread_run;
+	if (pthread_mutex_lock(&_gc_mutex) != 0)
+		PANIC("Cannot lock gc mutex");
 
-	/* Unlock the dead thread list: */
-	_unlock_dead_thread_list();
+	/* Add this thread to the list of dead threads. */
+	_thread_run->nxt_dead = _thread_dead;
+	_thread_dead = _thread_run;
 
 	/*
-	 * The running thread is no longer in the thread link list so it will
-	 * now die: 
+	 * Signal the garbage collector thread that there is something
+	 * to clean up.
 	 */
+	if (pthread_cond_signal(&_gc_cond) != 0)
+		PANIC("Cannot signal gc cond");
+
+	/* Unlock the garbage collector mutex: */
+	if (pthread_mutex_unlock(&_gc_mutex) != 0)
+		PANIC("Cannot lock gc mutex");
+
+	/* This this thread will never be re-scheduled. */
 	_thread_kern_sched_state(PS_DEAD, __FILE__, __LINE__);
 
 	/* This point should not be reached. */
diff --git a/lib/libpthread/thread/thr_find_thread.c b/lib/libpthread/thread/thr_find_thread.c
index 99e3023..e4a59a0 100644
--- a/lib/libpthread/thread/thr_find_thread.c
+++ b/lib/libpthread/thread/thr_find_thread.c
@@ -76,8 +76,12 @@ _find_dead_thread(pthread_t pthread)
 		/* Invalid thread: */
 		return(EINVAL);
 
-	/* Lock the dead thread list: */
-	_lock_dead_thread_list();
+	/*
+	 * Lock the garbage collector mutex to ensure that the garbage
+	 * collector is not using the dead thread list.
+	 */
+	if (pthread_mutex_lock(&_gc_mutex) != 0)
+		PANIC("Cannot lock gc mutex");
 
 	/* Point to the first thread in the list: */
 	pthread1 = _thread_dead;
@@ -85,11 +89,12 @@ _find_dead_thread(pthread_t pthread)
 	/* Search for the thread to join to: */
 	while (pthread1 != NULL && pthread1 != pthread) {
 		/* Point to the next thread: */
-		pthread1 = pthread1->nxt;
+		pthread1 = pthread1->nxt_dead;
 	}
 
-	/* Unlock the dead thread list: */
-	_unlock_dead_thread_list();
+	/* Unlock the garbage collector mutex: */
+	if (pthread_mutex_unlock(&_gc_mutex) != 0)
+		PANIC("Cannot lock gc mutex");
 
 	/* Return zero if the thread exists: */
 	return ((pthread1 != NULL) ? 0:ESRCH);
diff --git a/lib/libpthread/thread/thr_gc.c b/lib/libpthread/thread/thr_gc.c
new file mode 100644
index 0000000..faf1b5d
--- /dev/null
+++ b/lib/libpthread/thread/thr_gc.c
@@ -0,0 +1,272 @@
+/*
+ * Copyright (c) 1998 John Birrell <jb@cimlogic.com.au>
+ * 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, 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by John Birrell.
+ * 4. Neither the name of the author nor the names of any co-contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
+ *
+ *	$Id$
+ *
+ * Garbage collector thread. Frees memory allocated for dead threads.
+ *
+ */
+#include <errno.h>
+#include <time.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <pthread.h>
+#include "pthread_private.h"
+
+pthread_addr_t
+_thread_gc(pthread_addr_t arg)
+{
+	int		f_debug;
+	int		f_done = 0;
+	int		ret;
+	pthread_t	pthread;
+	pthread_t	pthread_cln;
+	pthread_t	pthread_nxt;
+	pthread_t	pthread_prv;
+	struct timespec	abstime;
+	void		*p_stack;
+
+	/* Set a debug flag based on an environment variable. */
+	f_debug = (getenv("LIBC_R_DEBUG") == NULL);
+
+	/* Set the name of this thread. */
+	pthread_set_name_np(_thread_run,"GC");
+
+	while (!f_done) {
+		/* Check if debugging this application. */
+		if (f_debug)
+			/* Dump thread info to file. */
+			_thread_dump_info();
+
+		/* Lock the thread list: */
+		_lock_thread_list();
+
+		/* Check if this is the last running thread: */
+		if (_thread_link_list == _thread_run &&
+		    _thread_link_list->nxt == NULL)
+			/*
+			 * This is the last thread, so it can exit
+			 * now.
+			 */
+			f_done = 1;
+
+		/* Unlock the thread list: */
+		_unlock_thread_list();
+
+		/*
+		 * Lock the garbage collector mutex which ensures that
+		 * this thread sees another thread exit:
+		 */
+		if (pthread_mutex_lock(&_gc_mutex) != 0)
+			PANIC("Cannot lock gc mutex");
+
+		/* No stack of thread structure to free yet: */
+		p_stack = NULL;
+		pthread_cln = NULL;
+
+		/* Point to the first dead thread (if there are any): */
+		pthread = _thread_dead;
+
+		/* There is no previous dead thread: */
+		pthread_prv = NULL;
+
+		/*
+		 * Enter a loop to search for the first dead thread that
+		 * has memory to free.
+		 */
+		while (p_stack == NULL && pthread_cln == NULL &&
+		    pthread != NULL) {
+			/* Save a pointer to the next thread: */
+			pthread_nxt = pthread->nxt_dead;
+
+			/* Check if the initial thread: */
+			if (pthread == _thread_initial)
+				/* Don't destroy the initial thread. */
+				pthread_prv = pthread;
+
+			/*
+			 * Check if this thread has detached:
+			 */
+			else if ((pthread->attr.flags &
+			    PTHREAD_DETACHED) != 0) {
+				/*
+				 * Check if there is no previous dead
+				 * thread:
+				 */
+				if (pthread_prv == NULL)
+					/*
+					 * The dead thread is at the head
+					 * of the list: 
+					 */
+					_thread_dead = pthread_nxt;
+				else
+					/*
+					 * The dead thread is not at the
+					 * head of the list: 
+					 */
+					pthread_prv->nxt_dead =
+					    pthread->nxt_dead;
+
+				/*
+				 * Check if the stack was not specified by
+				 * the caller to pthread_create and has not
+				 * been destroyed yet: 
+				 */
+				if (pthread->attr.stackaddr_attr == NULL &&
+				    pthread->stack != NULL) {
+					/*
+					 * Point to the stack that must
+					 * be freed outside the locks:
+					 */
+					p_stack = pthread->stack;
+				}
+
+				/*
+				 * Point to the thread structure that must
+				 * be freed outside the locks:
+				 */
+				pthread_cln = pthread;
+			} else {
+				/*
+				 * This thread has not detached, so do
+				 * not destroy it: 
+				 */
+				pthread_prv = pthread;
+
+				/*
+				 * Check if the stack was not specified by
+				 * the caller to pthread_create and has not
+				 * been destroyed yet: 
+				 */
+				if (pthread->attr.stackaddr_attr == NULL &&
+				    pthread->stack != NULL) {
+					/*
+					 * Point to the stack that must
+					 * be freed outside the locks:
+					 */
+					p_stack = pthread->stack;
+
+					/*
+					 * NULL the stack pointer now
+					 * that the memory has been freed: 
+					 */
+					pthread->stack = NULL;
+				}
+			}
+
+			/* Point to the next thread: */
+			pthread = pthread_nxt;
+		}
+
+		/*
+		 * Check if this is not the last thread and there is no
+		 * memory to free this time around.
+		 */
+		if (!f_done && p_stack == NULL && pthread_cln == NULL) {
+			/* Get the current time. */
+			if (clock_gettime(CLOCK_REALTIME,&abstime) != 0)
+				PANIC("gc cannot get time");
+
+			/*
+			 * Do a backup poll in 10 seconds if no threads
+			 * die before then.
+			 */
+			abstime.tv_sec += 10;
+
+			/*
+			 * Wait for a signal from a dying thread or a
+			 * timeout (for a backup poll).
+			 */
+			if ((ret = pthread_cond_timedwait(&_gc_cond,
+			    &_gc_mutex, &abstime)) != 0 && ret != ETIMEDOUT)
+				PANIC("gc cannot wait for a signal");
+		}
+
+		/* Unlock the garbage collector mutex: */
+		if (pthread_mutex_unlock(&_gc_mutex) != 0)
+			PANIC("Cannot unlock gc mutex");
+
+		/*
+		 * If there is memory to free, do it now. The call to
+		 * free() might block, so this must be done outside the
+		 * locks.
+		 */
+		if (p_stack != NULL)
+			free(p_stack);
+		if (pthread_cln != NULL) {
+			/* Lock the thread list: */
+			_lock_thread_list();
+
+			/*
+			 * Check if the thread is at the head of the
+			 * linked list.
+			 */
+			if (_thread_link_list == pthread_cln)
+				/* There is no previous thread: */
+				_thread_link_list = pthread_cln->nxt;
+			else {
+				/* Point to the first thread in the list: */
+				pthread = _thread_link_list;
+
+				/*
+				 * Enter a loop to find the thread in the
+				 * linked list before the thread that is
+				 * about to be freed.
+				 */
+				while (pthread != NULL &&
+				    pthread->nxt != pthread_cln)
+					/* Point to the next thread: */
+					pthread = pthread->nxt;
+
+				/* Check that a previous thread was found: */
+				if (pthread != NULL) {
+					/*
+					 * Point the previous thread to
+					 * the one after the thread being
+					 * freed: 
+					 */
+					pthread->nxt = pthread_cln->nxt;
+				}
+			}
+
+			/* Unlock the thread list: */
+			_unlock_thread_list();
+
+			/*
+			 * Free the memory allocated for the thread
+			 * structure.
+			 */
+			free(pthread_cln);
+		}
+		
+	}
+	return (NULL);
+}
diff --git a/lib/libpthread/thread/thr_init.c b/lib/libpthread/thread/thr_init.c
index 69b0fef..50f3bef 100644
--- a/lib/libpthread/thread/thr_init.c
+++ b/lib/libpthread/thread/thr_init.c
@@ -251,6 +251,11 @@ _thread_init(void)
 	__set_dynamic_handler_allocator( dynamic_allocator_handler_fn );
 #endif /* GCC_2_8_MADE_THREAD_AWARE */
 
+	/* Initialise the garbage collector mutex and condition variable. */
+	if (pthread_mutex_init(&_gc_mutex,NULL) != 0 ||
+	    pthread_cond_init(&_gc_cond,NULL) != 0)
+		PANIC("Failed to initialise garbage collector mutex or condvar");
+
 	return;
 }
 
diff --git a/lib/libpthread/thread/thr_kern.c b/lib/libpthread/thread/thr_kern.c
index ce17cf8..da125cd 100644
--- a/lib/libpthread/thread/thr_kern.c
+++ b/lib/libpthread/thread/thr_kern.c
@@ -29,7 +29,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $Id: uthread_kern.c,v 1.11 1998/04/30 21:50:29 jb Exp $
+ * $Id: uthread_kern.c,v 1.12 1998/09/07 21:55:01 alex Exp $
  *
  */
 #include <errno.h>
@@ -62,8 +62,6 @@ _thread_kern_sched(struct sigcontext * scp)
 	int             prio = -1;
 	pthread_t       pthread;
 	pthread_t       pthread_h = NULL;
-	pthread_t       pthread_nxt = NULL;
-	pthread_t       pthread_prv = NULL;
 	pthread_t       pthread_s = NULL;
 	struct itimerval itimer;
 	struct timespec ts;
@@ -113,85 +111,9 @@ __asm__("fnsave %0": :"m"(*fdata));
 		 */
 		_dispatch_signals();
 		return;
-	} else {
+	} else
 		/* Flag the jump buffer was the last state saved: */
 		_thread_run->sig_saved = 0;
-	}
-
-	/* Point to the first dead thread (if there are any): */
-	pthread = _thread_dead;
-
-	/* There is no previous dead thread: */
-	pthread_prv = NULL;
-
-	/* Enter a loop to cleanup after dead threads: */
-	while (pthread != NULL) {
-		/* Save a pointer to the next thread: */
-		pthread_nxt = pthread->nxt;
-
-		/* Check if this thread is one which is running: */
-		if (pthread == _thread_run || pthread == _thread_initial) {
-			/*
-			 * Don't destroy the running thread or the initial
-			 * thread. 
-			 */
-			pthread_prv = pthread;
-		}
-		/*
-		 * Check if this thread has detached:
-		 */
-		else if ((pthread->attr.flags & PTHREAD_DETACHED) != 0) {
-			/* Check if there is no previous dead thread: */
-			if (pthread_prv == NULL) {
-				/*
-				 * The dead thread is at the head of the
-				 * list: 
-				 */
-				_thread_dead = pthread_nxt;
-			} else {
-				/*
-				 * The dead thread is not at the head of the
-				 * list: 
-				 */
-				pthread_prv->nxt = pthread->nxt;
-			}
-
-			/*
-			 * Check if the stack was not specified by the caller
-			 * to pthread_create and has not been destroyed yet: 
-			 */
-			if (pthread->attr.stackaddr_attr == NULL && pthread->stack != NULL) {
-				/* Free the stack of the dead thread: */
-				free(pthread->stack);
-			}
-			/* Free the memory allocated to the thread structure: */
-			free(pthread);
-		} else {
-			/*
-			 * This thread has not detached, so do not destroy
-			 * it: 
-			 */
-			pthread_prv = pthread;
-
-			/*
-			 * Check if the stack was not specified by the caller
-			 * to pthread_create and has not been destroyed yet: 
-			 */
-			if (pthread->attr.stackaddr_attr == NULL && pthread->stack != NULL) {
-				/* Free the stack of the dead thread: */
-				free(pthread->stack);
-
-				/*
-				 * NULL the stack pointer now that the memory
-				 * has been freed: 
-				 */
-				pthread->stack = NULL;
-			}
-		}
-
-		/* Point to the next thread: */
-		pthread = pthread_nxt;
-	}
 
 	/*
 	 * Enter a the scheduling loop that finds the next thread that is