7 files changed, 516 insertions, 0 deletions

diff --git a/lib/libc/gen/_spinlock_stub.c b/lib/libc/gen/_spinlock_stub.c
new file mode 100644
index 000000000000..a189eef7f2e1
--- /dev/null
+++ b/lib/libc/gen/_spinlock_stub.c
@@ -0,0 +1,64 @@
+/*
+ * 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: _spinlock_stub.c,v 1.2 1998/04/29 09:02:16 jb Exp $
+ *
+ */
+
+#include <stdio.h>
+
+/* Don't build these stubs into libc_r: */
+#ifndef	_THREAD_SAFE
+#include "spinlock.h"
+
+/*
+ * Declare weak references in case the application is not linked
+ * with libpthread.
+ */
+#pragma weak _spinlock=_spinlock_stub
+#pragma weak _spinlock_debug=_spinlock_debug_stub
+
+/*
+ * This function is a stub for the spinlock function in libpthread.
+ */
+void
+_spinlock_stub(spinlock_t *lck)
+{
+}
+
+/*
+ * This function is a stub for the debug spinlock function in libpthread.
+ */
+void
+_spinlock_debug_stub(spinlock_t *lck, char *fname, int lineno)
+{
+}
+#endif
diff --git a/lib/libc/gen/ftok.3 b/lib/libc/gen/ftok.3
new file mode 100644
index 000000000000..b0a8a2324c20
--- /dev/null
+++ b/lib/libc/gen/ftok.3
@@ -0,0 +1,83 @@
+.\" Copyright (c) 1994 SigmaSoft, Th. Lockert <tholo@sigmasoft.com>
+.\" 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. The name of the author may not be used to endorse or promote products
+.\"    derived from this software without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+.\" PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+.\" OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+.\" WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+.\" OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+.\" ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+.\"
+.\"	$Id: ftok.3,v 1.9 1998/03/19 07:33:54 charnier Exp $
+.Dd June 24, 1994
+.Os
+.Dt ftok 3
+.Sh NAME
+.Nm ftok
+.Nd create IPC identifier from path name
+.Sh SYNOPSIS
+.Fd #include <sys/types.h>
+.Fd #include <sys/ipc.h>
+.Ft key_t
+.Fn ftok "const char *path" "int id"
+.Sh DESCRIPTION
+.Bf -symbolic
+This function is available from the compatibility library, libcompat.
+.Ef
+The
+.Fn ftok
+function attempts to create a unique key suitable for use with the
+.Xr msgget 3 ,
+.Xr semget 2
+and
+.Xr shmget 2
+functions given the
+.Fa path
+of an existing file and a user-selectable
+.Fa id .
+.Pp
+The specified
+.Fa path
+must specify an existing file that is accessible to the calling process
+or the call will fail.  Also, note that links to files will return the
+same key, given the same
+.Fa id .
+.Sh RETURN VALUES
+The
+.Fn ftok
+function will return -1 if
+.Fa path
+does not exist or if it cannot be accessed by the calling process.
+.Sh SEE ALSO
+.Xr semget 2 ,
+.Xr shmget 2 ,
+.Xr msgget 3
+.Sh HISTORY
+The
+.Fn ftok
+function originates with System V and is typically used by programs
+that use the System V IPC routines.
+.Sh AUTHORS
+.An Thorsten Lockert Aq tholo@sigmasoft.com
+.Sh BUGS
+The returned key is computed based on the device minor number and inode of the
+specified
+.Fa path
+in combination with the lower 8 bits of the given
+.Fa id .
+Thus it is quite possible for the routine to return duplicate keys.
diff --git a/lib/libc/gen/ftok.c b/lib/libc/gen/ftok.c
new file mode 100644
index 000000000000..7942f82d5495
--- /dev/null
+++ b/lib/libc/gen/ftok.c
@@ -0,0 +1,47 @@
+/*
+ * Copyright (c) 1994 SigmaSoft, Th. Lockert <tholo@sigmasoft.com>
+ * 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. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char *rcsid = "$Id: ftok.c,v 1.3 1997/02/22 15:06:10 peter Exp $";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ipc.h>
+
+key_t
+ftok(path, id)
+	const char *path;
+	char id;
+{
+	struct stat st;
+
+	if (stat(path, &st) < 0)
+		return (key_t)-1;
+
+	return (key_t) (id << 24 | (st.st_dev & 0xff) << 16 | (st.st_ino & 0xffff));
+}
diff --git a/lib/libc/include/spinlock.h b/lib/libc/include/spinlock.h
new file mode 100644
index 000000000000..e3136846afab
--- /dev/null
+++ b/lib/libc/include/spinlock.h
@@ -0,0 +1,71 @@
+/*
+ * 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: spinlock.h,v 1.2 1998/05/05 21:46:30 jb Exp $
+ *
+ * Lock definitions used in both libc and libpthread.
+ *
+ */
+
+#ifndef _SPINLOCK_H_
+#define _SPINLOCK_H_
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+/*
+ * Lock structure with room for debugging information.
+ */
+typedef struct {
+	volatile long	access_lock;
+	volatile long	lock_owner;
+	volatile char	*fname;
+	volatile int	lineno;
+} spinlock_t;
+
+#define	_SPINLOCK_INITIALIZER	{ 0, 0, 0, 0 }
+
+#define _SPINUNLOCK(_lck)	(_lck)->access_lock = 0
+#ifdef	_LOCK_DEBUG
+#define	_SPINLOCK(_lck)		_spinlock_debug(_lck, __FILE__, __LINE__)
+#else
+#define	_SPINLOCK(_lck)		_spinlock(_lck)
+#endif
+
+/*
+ * Thread function prototype definitions:
+ */
+__BEGIN_DECLS
+long	_atomic_lock __P((volatile long *));
+void	_spinlock __P((spinlock_t *));
+void	_spinlock_debug __P((spinlock_t *, char *, int));
+__END_DECLS
+
+#endif /* _SPINLOCK_H_ */
diff --git a/lib/libc_r/uthread/uthread_recvmsg.c b/lib/libc_r/uthread/uthread_recvmsg.c
new file mode 100644
index 000000000000..44a4a6552cc7
--- /dev/null
+++ b/lib/libc_r/uthread/uthread_recvmsg.c
@@ -0,0 +1,72 @@
+/*
+ * 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.
+ *
+ */
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <fcntl.h>
+#ifdef _THREAD_SAFE
+#include <pthread.h>
+#include "pthread_private.h"
+
+ssize_t
+recvmsg(int fd, struct msghdr *msg, int flags)
+{
+	int             ret;
+
+	if ((ret = _FD_LOCK(fd, FD_READ, NULL)) == 0) {
+		while ((ret = _thread_sys_recvmsg(fd, msg, flags)) < 0) {
+			if (!(_thread_fd_table[fd]->flags & O_NONBLOCK) && ((errno == EWOULDBLOCK) || (errno == EAGAIN))) {
+				_thread_run->data.fd.fd = fd;
+
+				/* Set the timeout: */
+				_thread_kern_set_timeout(NULL);
+				_thread_run->interrupted = 0;
+				_thread_kern_sched_state(PS_FDR_WAIT, __FILE__, __LINE__);
+
+				/* Check if the wait was interrupted: */
+				if (_thread_run->interrupted) {
+					/* Return an error status: */
+					errno = EINTR;
+					ret = -1;
+					break;
+				}
+			} else {
+				ret = -1;
+				break;
+			}
+		}
+		_FD_UNLOCK(fd, FD_READ);
+	}
+	return (ret);
+}
+#endif
diff --git a/lib/libc_r/uthread/uthread_sendmsg.c b/lib/libc_r/uthread/uthread_sendmsg.c
new file mode 100644
index 000000000000..9d97c121dcff
--- /dev/null
+++ b/lib/libc_r/uthread/uthread_sendmsg.c
@@ -0,0 +1,71 @@
+/*
+ * 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.
+ *
+ */
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <fcntl.h>
+#ifdef _THREAD_SAFE
+#include <pthread.h>
+#include "pthread_private.h"
+
+ssize_t
+sendmsg(int fd, const struct msghdr *msg, int flags)
+{
+	int             ret;
+
+	if ((ret = _FD_LOCK(fd, FD_WRITE, NULL)) == 0) {
+		while ((ret = _thread_sys_sendmsg(fd, msg, flags)) < 0) {
+			if (!(_thread_fd_table[fd]->flags & O_NONBLOCK) && ((errno == EWOULDBLOCK) || (errno == EAGAIN))) {
+				_thread_run->data.fd.fd = fd;
+
+				/* Set the timeout: */
+				_thread_kern_set_timeout(NULL);
+				_thread_run->interrupted = 0;
+				_thread_kern_sched_state(PS_FDW_WAIT, __FILE__, __LINE__);
+
+				/* Check if the operation was interrupted: */
+				if (_thread_run->interrupted) {
+					errno = EINTR;
+					ret = -1;
+					break;
+				}
+			} else {
+				ret = -1;
+				break;
+			}
+		}
+		_FD_UNLOCK(fd, FD_WRITE);
+	}
+	return (ret);
+}
+#endif
diff --git a/lib/libc_r/uthread/uthread_spinlock.c b/lib/libc_r/uthread/uthread_spinlock.c
new file mode 100644
index 000000000000..9da115e5eedb
--- /dev/null
+++ b/lib/libc_r/uthread/uthread_spinlock.c
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 1997 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: uthread_spinlock.c,v 1.3 1998/06/06 07:27:06 jb Exp $
+ *
+ */
+
+#include <stdio.h>
+#include <sched.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <string.h>
+#include "pthread_private.h"
+
+extern char *__progname;
+
+/*
+ * Lock a location for the running thread. Yield to allow other
+ * threads to run if this thread is blocked because the lock is
+ * not available. Note that this function does not sleep. It
+ * assumes that the lock will be available very soon.
+ */
+void
+_spinlock(spinlock_t *lck)
+{
+	/*
+	 * Try to grab the lock and loop if another thread grabs
+	 * it before we do.
+	 */
+	while(_atomic_lock(&lck->access_lock)) {
+		/* Give up the time slice: */
+		sched_yield();
+
+		/* Check if already locked by the running thread: */
+		if (lck->lock_owner == (long) _thread_run)
+			return;
+	}
+
+	/* The running thread now owns the lock: */
+	lck->lock_owner = (long) _thread_run;
+}
+
+/*
+ * Lock a location for the running thread. Yield to allow other
+ * threads to run if this thread is blocked because the lock is
+ * not available. Note that this function does not sleep. It
+ * assumes that the lock will be available very soon.
+ *
+ * This function checks if the running thread has already locked the
+ * location, warns if this occurs and creates a thread dump before
+ * returning.
+ */
+void
+_spinlock_debug(spinlock_t *lck, char *fname, int lineno)
+{
+	/*
+	 * Try to grab the lock and loop if another thread grabs
+	 * it before we do.
+	 */
+	while(_atomic_lock(&lck->access_lock)) {
+		/* Give up the time slice: */
+		sched_yield();
+
+		/* Check if already locked by the running thread: */
+		if (lck->lock_owner == (long) _thread_run) {
+			char str[256];
+			snprintf(str, sizeof(str), "%s - Warning: Thread %p attempted to lock %p from %s (%d) which it had already locked in %s (%d)\n", __progname, _thread_run, lck, fname, lineno, lck->fname, lck->lineno);
+			_thread_sys_write(2,str,strlen(str));
+
+			/* Create a thread dump to help debug this problem: */
+			_thread_dump_info();
+			return;
+		}
+	}
+
+	/* The running thread now owns the lock: */
+	lck->lock_owner = (long) _thread_run;
+	lck->fname = fname;
+	lck->lineno = lineno;
+}