Implement pthread read/write locks as defined by Version 2 of the Single

UNIX Specification.

As with our standard mutexes, process shared locks are not supported at
this time.

42 files changed, 3729 insertions, 5 deletions

diff --git a/include/pthread.h b/include/pthread.h
index 701328b..0c38271 100644
--- a/include/pthread.h
+++ b/include/pthread.h
@@ -80,6 +80,12 @@
 #define PTHREAD_EXPLICIT_SCHED      0
 
 /*
+ * Flags for read/write lock attributes
+ */
+#define PTHREAD_PROCESS_PRIVATE     0
+#define PTHREAD_PROCESS_SHARED      1	
+
+/*
  * Forward structure definitions.
  *
  * These are mostly opaque to the user.
@@ -91,6 +97,8 @@ struct pthread_cond_attr;
 struct pthread_mutex;
 struct pthread_mutex_attr;
 struct pthread_once;
+struct pthread_rwlock;
+struct pthread_rwlockattr;
 struct sched_param;
 
 /*
@@ -108,6 +116,8 @@ typedef struct	pthread_cond		*pthread_cond_t;
 typedef struct	pthread_cond_attr	*pthread_condattr_t;
 typedef int     			pthread_key_t;
 typedef struct	pthread_once		pthread_once_t;
+typedef struct	pthread_rwlock		*pthread_rwlock_t;
+typedef struct	pthread_rwlockattr	*pthread_rwlockattr_t;
 
 /*
  * Additional type definitions:
@@ -142,6 +152,7 @@ struct pthread_once {
  */
 #define PTHREAD_MUTEX_INITIALIZER	NULL
 #define PTHREAD_COND_INITIALIZER	NULL
+#define PTHREAD_RWLOCK_INITIALIZER	NULL
 
 /*
  * Default attribute arguments (draft 4, deprecated).
@@ -232,6 +243,20 @@ int		pthread_mutex_trylock __P((pthread_mutex_t *));
 int		pthread_mutex_unlock __P((pthread_mutex_t *));
 int		pthread_once __P((pthread_once_t *,
 			void (*init_routine) (void)));
+int		pthread_rwlock_destroy __P((pthread_rwlock_t *));
+int		pthread_rwlock_init __P((pthread_rwlock_t *,
+			const pthread_rwlockattr_t *));
+int		pthread_rwlock_rdlock __P((pthread_rwlock_t *));
+int		pthread_rwlock_tryrdlock __P((pthread_rwlock_t *));
+int		pthread_rwlock_trywrlock __P((pthread_rwlock_t *));
+int		pthread_rwlock_unlock __P((pthread_rwlock_t *));
+int		pthread_rwlock_wrlock __P((pthread_rwlock_t *));
+int		pthread_rwlockattr_init __P((pthread_rwlockattr_t *));
+int		pthread_rwlockattr_getpshared __P((const pthread_rwlockattr_t *,
+			int *));
+int		pthread_rwlockattr_setpshared __P((pthread_rwlockattr_t *,
+			int *));
+int		pthread_rwlockattr_destroy __P((pthread_rwlockattr_t *));
 pthread_t	pthread_self __P((void));
 int		pthread_setcancelstate __P((int, int *));
 int		pthread_setcanceltype __P((int, int *));
diff --git a/lib/libc_r/man/Makefile.inc b/lib/libc_r/man/Makefile.inc
index e6bb8a5..f92f3df 100644
--- a/lib/libc_r/man/Makefile.inc
+++ b/lib/libc_r/man/Makefile.inc
@@ -1,4 +1,4 @@
-# $Id: Makefile.inc,v 1.3 1997/02/22 15:05:23 peter Exp $
+# $Id: Makefile.inc,v 1.4 1998/07/31 09:09:19 phk Exp $
 
 # POSIX thread man files
 
@@ -26,5 +26,14 @@ MAN3+=	pthread_cleanup_pop.3 \
 	pthread_mutex_trylock.3 \
 	pthread_mutex_unlock.3 \
 	pthread_once.3 \
+	pthread_rwlock_destroy.3 \
+	pthread_rwlock_init.3 \
+	pthread_rwlock_rdlock.3 \
+	pthread_rwlock_unlock.3 \
+	pthread_rwlock_wrlock.3 \
+	pthread_rwlockattr_destroy.3 \
+	pthread_rwlockattr_getpshared.3 \
+	pthread_rwlockattr_init.3 \
+	pthread_rwlockattr_setpshared.3 \
 	pthread_self.3 \
 	pthread_setspecific.3
diff --git a/lib/libc_r/man/pthread_rwlock_destroy.3 b/lib/libc_r/man/pthread_rwlock_destroy.3
new file mode 100644
index 0000000..7453274
--- /dev/null
+++ b/lib/libc_r/man/pthread_rwlock_destroy.3
@@ -0,0 +1,80 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCK_DESTROY 3
+.Os
+.Sh NAME
+.Nm pthread_rwlock_destroy
+.Nd destroy a read/write lock
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlock_destroy "pthread_rwlock_t *lock"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlock_destroy
+function is used to destroy a read/write lock previously created with 
+.Fn pthread_rwlock_init .
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlock_destroy
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_init 3 ,
+.Sh STANDARDS
+The
+.Fn pthread_rwlock_destroy
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+The
+.Fn pthread_rwlock_destroy
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EPERM
+The caller does not have the privilege to perform the operation.
+.El
+.Pp
+The
+.Fn pthread_rwlock_destroy
+function may fail if:
+.Bl -tag -width Er
+.It Bq Er EBUSY
+The system has detected an attempt to destroy the object referenced by
+.Fa lock
+while it is locked.
+.It Bq Er EINVAL
+The value specified by
+.Fa lock
+is invalid.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlock_destroy
+function first appeared in
+.Fx 3.0 .
diff --git a/lib/libc_r/man/pthread_rwlock_init.3 b/lib/libc_r/man/pthread_rwlock_init.3
new file mode 100644
index 0000000..a561695
--- /dev/null
+++ b/lib/libc_r/man/pthread_rwlock_init.3
@@ -0,0 +1,99 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCK_INIT 3
+.Os
+.Sh NAME
+.Nm pthread_rwlock_init
+.Nd initialize a read/write lock
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlock_init "pthread_rwlock_t *lock" "const pthread_rwlockattr_t *attr"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlock_init
+function is used to initialize a read/write lock, with attributes
+specified by
+.Fa attr .
+If
+.Fa attr
+is NULL, the default read/write lock attributes are used.
+.Pp
+The results of calling
+.Fn pthread_rwlock_init
+with an already initialized lock are undefined.
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlock_init
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_destroy 3 ,
+.Xr pthread_rwlockattr_init 3 ,
+.Xr pthread_rwlockattr_setpshared 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlock_init
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+The
+.Fn pthread_rwlock_init
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EAGAIN
+The system lacked the necessary resources (other than memory) to
+initialize the lock.
+.It Bq Er ENOMEM
+Insufficient memory exists to initialize the lock.
+.It Bq Er EPERM
+The caller does not have sufficient privilege to perform the
+operation.
+.El
+.Pp
+The
+.Fn pthread_rwlock_init
+function may fail if:
+.Bl -tag -width Er
+.It Bq Er EBUSY
+The system has detected an attempt to re-initialize the object
+referenced by
+.Fa lock ,
+a previously initialized but not yet destroyed read/write lock.
+.It Bq Er EINVAL
+The value specified by
+.Fa attr
+is invalid.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlock_init
+function first appeared in
+.Fx 3.0 .
+.Sh BUGS
+The PTHREAD_PROCESS_SHARED attribute is not supported.
diff --git a/lib/libc_r/man/pthread_rwlock_rdlock.3 b/lib/libc_r/man/pthread_rwlock_rdlock.3
new file mode 100644
index 0000000..9181be9
--- /dev/null
+++ b/lib/libc_r/man/pthread_rwlock_rdlock.3
@@ -0,0 +1,122 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCK_RDLOCK 3
+.Os
+.Sh NAME
+.Nm pthread_rwlock_rdlock ,
+.Nm pthread_rwlock_tryrdlock
+.Nd acquire a read/write lock for reading
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlock_rdlock "pthread_rwlock_t *lock"
+.Ft int
+.Fn pthread_rwlock_tryrdlock "pthread_rwlock_t *lock"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlock_rdlock
+function acquires a read lock on
+.Fa lock
+provided that
+.Fa lock
+is not presently held for writing and no writer threads are
+presently blocked on the lock.  If the read lock cannot be
+immediately acquired, the calling thread blocks until it can
+acquire the lock.
+.Pp
+The
+.Fn pthread_rwlock_tryrdlock
+function performs the same action, but does not block if the lock
+cannot be immediately obtained (i.e. the lock is held for writing
+or there are waiting writers).
+.Pp
+A thread may hold multiple concurrent read locks.  If so,
+.Fn pthread_rwlock_unlock
+must be called once for each lock obtained.
+.Pp
+The results of acquiring a read lock while the calling thread holds
+a write lock are undefined.
+.Sh IMPLEMENTATION NOTES
+To prevent writer starvation, writers are favored over readers.
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlock_rdlock
+and
+.Fn pthread_rwlock_tryrdlock
+functions will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_init 3 ,
+.Xr pthread_rwlock_trywrlock 3 ,
+.Xr pthread_rwlock_unlock 3 ,
+.Xr pthread_rwlock_wrlock 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlock_rdlock
+and
+.Fn pthread_rwlock_tryrdlock
+functions are expected to conform to
+.St -susv2 .
+.Sh ERRORS
+The
+.Fn pthread_rwlock_tryrdlock
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EBUSY
+The lock could not be acquired because a writer holds the lock or
+was blocked on it.
+.El
+.Pp
+The
+.Fn pthread_rwlock_rdlock
+and
+.Fn pthread_rwlock_tryrdlock
+functions may fail if:
+.Bl -tag -width Er
+.It Bq Er EAGAIN
+The lock could not be acquired because the maximum number of read locks
+against
+.Fa lock
+has been exceeded.
+.It Bq Er EDEADLK
+The current thread already owns
+.Fa lock
+for writing.
+.It Bq Er EINVAL
+The value specified by
+.Fa lock
+is invalid.
+.It Bq Er ENOMEM
+Insufficient memory exists to initialize the lock (applies to
+statically initialized locks only).
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlock_rdlock
+function first appeared in
+.Fx 3.0 .
diff --git a/lib/libc_r/man/pthread_rwlock_unlock.3 b/lib/libc_r/man/pthread_rwlock_unlock.3
new file mode 100644
index 0000000..1c9fd05
--- /dev/null
+++ b/lib/libc_r/man/pthread_rwlock_unlock.3
@@ -0,0 +1,79 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCK_UNLOCK 3
+.Os
+.Sh NAME
+.Nm pthread_rwlock_unlock
+.Nd release a read/write lock
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlock_unlock "pthread_rwlock_t *lock"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlock_unlock
+function is used to release the read/write lock previously obtained by
+.Fn pthread_rwlock_rdlock ,
+.Fn pthread_rwlock_wrlock ,
+.Fn pthread_rwlock_tryrdlock ,
+or
+.Fn pthread_rwlock_trywrlock .
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlock_unlock
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Pp
+The results are undefined if
+.Fa lock
+is not held by the calling thread.
+.Sh SEE ALSO
+.Xr pthread_rwlock_rdlock 3 ,
+.Xr pthread_rwlock_wrlock 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlock_unlock
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+The
+.Fn pthread_rwlock_unlock
+function may fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The value specified by
+.Fa lock
+is invalid.
+.It Bq Er EPERM
+The current thread does not own the read/write lock.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlock_unlock
+function first appeared in
+.Fx 3.0 .
diff --git a/lib/libc_r/man/pthread_rwlock_wrlock.3 b/lib/libc_r/man/pthread_rwlock_wrlock.3
new file mode 100644
index 0000000..a5a3674
--- /dev/null
+++ b/lib/libc_r/man/pthread_rwlock_wrlock.3
@@ -0,0 +1,102 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCK_WRLOCK 3
+.Os
+.Sh NAME
+.Nm pthread_rwlock_wrlock ,
+.Nm pthread_rwlock_trywrlock
+.Nd acquire a read/write lock for writing
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlock_wrlock "pthread_rwlock_t *lock"
+.Ft int
+.Fn pthread_rwlock_trywrlock "pthread_rwlock_t *lock"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlock_wrlock
+function blocks until a write lock can be acquired against
+.Fa lock .
+The
+.Fn pthread_rwlock_trywrlock
+function performs the same action, but does not block if the lock
+cannot be immediately obtained.
+.Pp
+The results are undefined if the calling thread already holds the
+lock at the time the call is made.
+.Sh IMPLEMENTATION NOTES
+To prevent writer starvation, writers are favored over readers.
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlock_wrlock
+and
+.Fn pthread_rwlock_trywrlock
+functions will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_trywrlock 3 ,
+.Xr pthread_rwlock_unlock 3 ,
+.Xr pthread_rwlock_wrlock 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlock_wrlock
+and
+.Fn pthread_rwlock_trywrlock
+functions are expected to conform to
+.St -susv2 .
+.Sh ERRORS
+The
+.Fn pthread_rwlock_trywrlock
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EBUSY
+The calling thread is not able to acquire the lock without blocking.
+.El
+.Pp
+The
+.Fn pthread_rwlock_wrlock
+and
+.Fn pthread_rwlock_trywrlock
+functions may fail if:
+.Bl -tag -width Er
+.It Bq Er EDEADLK
+The calling thread already owns the read/write lock (for reading
+or writing).
+.It Bq Er EINVAL
+The value specified by
+.Fa lock
+is invalid.
+.It Bq Er ENOMEM
+Insufficient memory exists to initialize the lock (applies to
+statically initialized locks only).
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlock_wrlock
+function first appeared in
+.Fx 3.0 .
diff --git a/lib/libc_r/man/pthread_rwlockattr_destroy.3 b/lib/libc_r/man/pthread_rwlockattr_destroy.3
new file mode 100644
index 0000000..ee3c405
--- /dev/null
+++ b/lib/libc_r/man/pthread_rwlockattr_destroy.3
@@ -0,0 +1,68 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCKATTR_DESTROY 3
+.Os
+.Sh NAME
+.Nm pthread_rwlockattr_destroy
+.Nd destroy a read/write lock
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlockattr_destroy "pthread_rwlockattr_t *attr"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlockattr_destroy
+function is used to destroy a read/write lock attribute object
+previously created with 
+.Fn pthread_rwlockattr_init .
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlockattr_destroy
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlockattr_init 3 ,
+.Sh STANDARDS
+The
+.Fn pthread_rwlockattr_destroy
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+.Fn pthread_rwlockattr_destroy
+may fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The value specified by
+.Fa attr
+is invalid.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlockattr_destroy
+function first appeared in
+.Fx 3.0 .
diff --git a/lib/libc_r/man/pthread_rwlockattr_getpshared.3 b/lib/libc_r/man/pthread_rwlockattr_getpshared.3
new file mode 100644
index 0000000..8e8160b
--- /dev/null
+++ b/lib/libc_r/man/pthread_rwlockattr_getpshared.3
@@ -0,0 +1,80 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCKATTR_GETPSHARED 3
+.Os
+.Sh NAME
+.Nm pthread_rwlockattr_getpshared
+.Nd set the process shared attribute
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlockattr_getpshared "pthread_rwlockattr_t *attr" "int *pshared"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlockattr_getpshared
+function is used to get the process shared setting of a read/write
+lock attribute object.  The setting is returned via
+.Fa pshared ,
+and may be one of two values:
+.Bl -hang -offset flag -width 123456789012345678901234
+.It Ar PTHREAD_PROCESS_SHARED
+Any thread of any process that has access to the memory where the
+read/write lock resides can manipulate the lock.
+.It Ar PTHREAD_PROCESS_PRIVATE
+Only threads created within the same process as the thread that
+initialized the read/write lock can manipulate the lock.  This is
+the default value.
+.El
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlockattr_getpshared
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_init 3 ,
+.Xr pthread_rwlockattr_init 3 ,
+.Xr pthread_rwlockattr_setpshared 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlockattr_getpshared
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+.Fn pthread_rwlockattr_getpshared
+may fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The value specified by
+.Fa attr
+is invalid.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlockattr_getpshared
+function first appeared in
+.Fx 3.0 .
diff --git a/lib/libc_r/man/pthread_rwlockattr_init.3 b/lib/libc_r/man/pthread_rwlockattr_init.3
new file mode 100644
index 0000000..8827121
--- /dev/null
+++ b/lib/libc_r/man/pthread_rwlockattr_init.3
@@ -0,0 +1,67 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCKATTR_INIT 3
+.Os
+.Sh NAME
+.Nm pthread_rwlockattr_init
+.Nd initialize a read/write lock
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlockattr_init "pthread_rwlockattr_t *attr"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlockattr_init
+function is used to initialize a read/write lock attributes object.
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlockattr_init
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_init 3 ,
+.Xr pthread_rwlockattr_destroy 3 ,
+.Xr pthread_rwlockattr_getpshared 3
+.Xr pthread_rwlockattr_setpshared 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlockattr_init
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+.Fn pthread_rwlockattr_init
+will fail if:
+.Bl -tag -width Er
+.It Bq Er ENOMEM
+Insufficient memory exists to initialize the attribute object.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlockattr_init
+function first appeared in
+.Fx 3.0 .
diff --git a/lib/libc_r/man/pthread_rwlockattr_setpshared.3 b/lib/libc_r/man/pthread_rwlockattr_setpshared.3
new file mode 100644
index 0000000..e63debf
--- /dev/null
+++ b/lib/libc_r/man/pthread_rwlockattr_setpshared.3
@@ -0,0 +1,86 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCKATTR_SETPSHARED 3
+.Os
+.Sh NAME
+.Nm pthread_rwlockattr_setpshared
+.Nd set the process shared attribute
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlockattr_setpshared "pthread_rwlockattr_t *attr" "int *pshared"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlockattr_setpshared
+function sets the process shared attribute of
+.Fa attr
+to the value referenced by
+.Fa pshared .
+.Fa pshared
+may be one of two values:
+.Bl -hang -offset flag -width 123456789012345678901234
+.It Ar PTHREAD_PROCESS_SHARED
+Any thread of any process that has access to the memory where the
+read/write lock resides can manipulate the lock.
+.It Ar PTHREAD_PROCESS_PRIVATE
+Only threads created within the same process as the thread that
+initialized the read/write lock can manipulate the lock.  This is
+the default value.
+.El
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlockattr_setpshared
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_init 3 ,
+.Xr pthread_rwlockattr_init 3 ,
+.Xr pthread_rwlockattr_setpshared 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlockattr_setpshared
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+.Fn pthread_rwlockattr_setpshared
+will fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The value specified by
+.Fa attr
+or
+.Fa pshared
+is invalid.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlockattr_setpshared
+function first appeared in
+.Fx 3.0 .
+.Sh BUGS
+The PTHREAD_PROCESS_SHARED attribute is not supported.
diff --git a/lib/libc_r/uthread/Makefile.inc b/lib/libc_r/uthread/Makefile.inc
index dc46af9..4fd3034 100644
--- a/lib/libc_r/uthread/Makefile.inc
+++ b/lib/libc_r/uthread/Makefile.inc
@@ -1,4 +1,4 @@
-#	$Id: Makefile.inc,v 1.12 1998/05/31 23:48:26 jb Exp $
+#	$Id: Makefile.inc,v 1.13 1998/06/01 02:14:34 jb Exp $
 
 # uthread sources
 .PATH: ${.CURDIR}/uthread
@@ -67,6 +67,8 @@ SRCS+= \
 	uthread_recvfrom.c \
 	uthread_recvmsg.c \
 	uthread_resume_np.c \
+	uthread_rwlock.c \
+	uthread_rwlockattr.c \
 	uthread_select.c \
 	uthread_self.c \
 	uthread_sendmsg.c \
diff --git a/lib/libc_r/uthread/pthread_private.h b/lib/libc_r/uthread/pthread_private.h
index 39ce14d..5b76a86 100644
--- a/lib/libc_r/uthread/pthread_private.h
+++ b/lib/libc_r/uthread/pthread_private.h
@@ -224,6 +224,18 @@ struct pthread_key {
 	void            (*destructor) ();
 };
 
+struct pthread_rwlockattr {
+	int		pshared;
+};
+
+struct pthread_rwlock {
+	pthread_mutex_t	lock;	/* monitor lock */
+	int		state;	/* 0 = idle  >0 = # of readers  -1 = writer */
+	pthread_cond_t	read_signal;
+	pthread_cond_t	write_signal;
+	int		blocked_writers;
+};
+
 /*
  * Thread states.
  */
diff --git a/lib/libc_r/uthread/uthread_rwlock.c b/lib/libc_r/uthread/uthread_rwlock.c
new file mode 100644
index 0000000..356eb29
--- /dev/null
+++ b/lib/libc_r/uthread/uthread_rwlock.c
@@ -0,0 +1,333 @@
+/*-
+ * Copyright (c) 1998 Alex Nash
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ *	$Id$
+ */
+
+#ifdef _THREAD_SAFE
+#include <errno.h>
+#include <limits.h>
+#include <stdlib.h>
+
+#include <pthread.h>
+#include "pthread_private.h"
+
+/* maximum number of times a read lock may be obtained */
+#define	MAX_READ_LOCKS		(INT_MAX - 1)
+
+static int init_static (pthread_rwlock_t *rwlock);
+
+static spinlock_t static_init_lock = _SPINLOCK_INITIALIZER;
+
+static int
+init_static (pthread_rwlock_t *rwlock)
+{
+	int ret;
+
+	_SPINLOCK(&static_init_lock);
+
+	if (*rwlock == NULL)
+		ret = pthread_rwlock_init(rwlock, NULL);
+	else
+		ret = 0;
+
+	_SPINUNLOCK(&static_init_lock);
+
+	return(ret);
+}
+
+int
+pthread_rwlock_destroy (pthread_rwlock_t *rwlock)
+{
+	int ret;
+
+	if (rwlock == NULL)
+		ret = EINVAL;
+	else {
+		pthread_rwlock_t prwlock;
+
+		prwlock = *rwlock;
+
+		pthread_mutex_destroy(&prwlock->lock);
+		pthread_cond_destroy(&prwlock->read_signal);
+		pthread_cond_destroy(&prwlock->write_signal);
+		free(prwlock);
+
+		*rwlock = NULL;
+	}
+
+	return(ret);
+}
+
+int
+pthread_rwlock_init (pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *attr)
+{
+	pthread_rwlock_t	prwlock;
+	int			ret;
+
+	/* allocate rwlock object */
+	prwlock = (pthread_rwlock_t)malloc(sizeof(struct pthread_rwlock));
+
+	if (prwlock == NULL)
+		return(ENOMEM);
+
+	/* initialize the lock */
+	if ((ret = pthread_mutex_init(&prwlock->lock, NULL)) != 0)
+		free(prwlock);
+	else {
+		/* initialize the read condition signal */
+		ret = pthread_cond_init(&prwlock->read_signal, NULL);
+
+		if (ret != 0) {
+			pthread_mutex_destroy(&prwlock->lock);
+			free(prwlock);
+		} else {
+			/* initialize the write condition signal */
+			ret = pthread_cond_init(&prwlock->write_signal, NULL);
+
+			if (ret != 0) {
+				pthread_cond_destroy(&prwlock->read_signal);
+				pthread_mutex_destroy(&prwlock->lock);
+				free(prwlock);
+			} else {
+				/* success */
+				prwlock->state		 = 0;
+				prwlock->blocked_writers = 0;
+
+				*rwlock = prwlock;
+			}
+		}
+	}
+
+	return(ret);
+}
+
+int
+pthread_rwlock_rdlock (pthread_rwlock_t *rwlock)
+{
+	pthread_rwlock_t 	prwlock;
+	int			ret = 0;
+
+	if (rwlock == NULL)
+		return(EINVAL);
+
+	prwlock = *rwlock;
+
+	/* check for static initialization */
+	if (prwlock == NULL) {
+		if ((ret = init_static(rwlock)) != 0)
+			return(ret);
+
+		prwlock = *rwlock;
+	}
+
+	/* grab the monitor lock */
+	if ((ret = pthread_mutex_lock(&prwlock->lock)) != 0)
+		return(ret);
+
+	/* give writers priority over readers */
+	while (prwlock->blocked_writers || prwlock->state < 0) {
+		ret = pthread_cond_wait(&prwlock->read_signal, &prwlock->lock);
+
+		if (ret != 0) {
+			/* can't do a whole lot if this fails */
+			pthread_mutex_unlock(&prwlock->lock);
+			return(ret);
+		}
+	}
+
+	/* check lock count */
+	if (prwlock->state == MAX_READ_LOCKS)
+		ret = EAGAIN;
+	else
+		++prwlock->state; /* indicate we are locked for reading */
+
+	/*
+	 * Something is really wrong if this call fails.  Returning
+	 * error won't do because we've already obtained the read
+	 * lock.  Decrementing 'state' is no good because we probably
+	 * don't have the monitor lock.
+	 */
+	pthread_mutex_unlock(&prwlock->lock);
+
+	return(ret);
+}
+
+int
+pthread_rwlock_tryrdlock (pthread_rwlock_t *rwlock)
+{
+	pthread_rwlock_t 	prwlock;
+	int			ret = 0;
+
+	if (rwlock == NULL)
+		return(EINVAL);
+
+	prwlock = *rwlock;
+
+	/* check for static initialization */
+	if (prwlock == NULL) {
+		if ((ret = init_static(rwlock)) != 0)
+			return(ret);
+
+		prwlock = *rwlock;
+	}
+
+	/* grab the monitor lock */
+	if ((ret = pthread_mutex_lock(&prwlock->lock)) != 0)
+		return(ret);
+
+	/* give writers priority over readers */
+	if (prwlock->blocked_writers || prwlock->state < 0)
+		ret = EWOULDBLOCK;
+	else if (prwlock->state == MAX_READ_LOCKS)
+		ret = EAGAIN; /* too many read locks acquired */
+	else
+		++prwlock->state; /* indicate we are locked for reading */
+
+	/* see the comment on this in pthread_rwlock_rdlock */
+	pthread_mutex_unlock(&prwlock->lock);
+
+	return(ret);
+}
+
+int
+pthread_rwlock_trywrlock (pthread_rwlock_t *rwlock)
+{
+	pthread_rwlock_t 	prwlock;
+	int			ret = 0;
+
+	if (rwlock == NULL)
+		return(EINVAL);
+
+	prwlock = *rwlock;
+
+	/* check for static initialization */
+	if (prwlock == NULL) {
+		if ((ret = init_static(rwlock)) != 0)
+			return(ret);
+
+		prwlock = *rwlock;
+	}
+
+	/* grab the monitor lock */
+	if ((ret = pthread_mutex_lock(&prwlock->lock)) != 0)
+		return(ret);
+
+	if (prwlock->state != 0)
+		ret = EWOULDBLOCK;
+	else
+		/* indicate we are locked for writing */
+		prwlock->state = -1;
+
+	/* see the comment on this in pthread_rwlock_rdlock */
+	pthread_mutex_unlock(&prwlock->lock);
+
+	return(ret);
+}
+
+int
+pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
+{
+	pthread_rwlock_t 	prwlock;
+	int			ret = 0;
+
+	if (rwlock == NULL)
+		return(EINVAL);
+
+	prwlock = *rwlock;
+
+	if (prwlock == NULL)
+		return(EINVAL);
+
+	/* grab the monitor lock */
+	if ((ret = pthread_mutex_lock(&prwlock->lock)) != 0)
+		return(ret);
+
+	if (prwlock->state > 0) {
+		if (--prwlock->state == 0 && prwlock->blocked_writers)
+			ret = pthread_cond_signal(&prwlock->write_signal);
+	} else if (prwlock->state < 0) {
+		prwlock->state = 0;
+
+		if (prwlock->blocked_writers)
+			ret = pthread_cond_signal(&prwlock->write_signal);
+		else
+			ret = pthread_cond_broadcast(&prwlock->read_signal);
+	} else
+		ret = EINVAL;
+
+	/* see the comment on this in pthread_rwlock_rdlock */
+	pthread_mutex_unlock(&prwlock->lock);
+
+	return(ret);
+}
+
+int
+pthread_rwlock_wrlock (pthread_rwlock_t *rwlock)
+{
+	pthread_rwlock_t 	prwlock;
+	int			ret = 0;
+
+	if (rwlock == NULL)
+		return(EINVAL);
+
+	prwlock = *rwlock;
+
+	/* check for static initialization */
+	if (prwlock == NULL) {
+		if ((ret = init_static(rwlock)) != 0)
+			return(ret);
+
+		prwlock = *rwlock;
+	}
+
+	/* grab the monitor lock */
+	if ((ret = pthread_mutex_lock(&prwlock->lock)) != 0)
+		return(ret);
+
+	while (prwlock->state != 0) {
+		++prwlock->blocked_writers;
+
+		ret = pthread_cond_wait(&prwlock->write_signal, &prwlock->lock);
+
+		if (ret != 0) {
+			--prwlock->blocked_writers;
+			pthread_mutex_unlock(&prwlock->lock);
+			return(ret);
+		}
+
+		--prwlock->blocked_writers;
+	}
+
+	/* indicate we are locked for writing */
+	prwlock->state = -1;
+
+	/* see the comment on this in pthread_rwlock_rdlock */
+	pthread_mutex_unlock(&prwlock->lock);
+
+	return(ret);
+}
+
+#endif /* _THREAD_SAFE */
diff --git a/lib/libc_r/uthread/uthread_rwlockattr.c b/lib/libc_r/uthread/uthread_rwlockattr.c
new file mode 100644
index 0000000..a3683bc
--- /dev/null
+++ b/lib/libc_r/uthread/uthread_rwlockattr.c
@@ -0,0 +1,97 @@
+/*-
+ * Copyright (c) 1998 Alex Nash
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ *	$Id$
+ */
+
+#ifdef _THREAD_SAFE
+#include <errno.h>
+
+#include <pthread.h>
+#include "pthread_private.h"
+
+int
+pthread_rwlockattr_destroy (pthread_rwlockattr_t *rwlockattr)
+{
+	pthread_rwlockattr_t prwlockattr;
+
+	if (rwlockattr == NULL)
+		return(EINVAL);
+
+	prwlockattr = *rwlockattr;
+
+	if (prwlockattr == NULL)
+		return(EINVAL);
+
+	free(prwlockattr);
+
+	return(0);
+}
+
+int
+pthread_rwlockattr_getpshared (const pthread_rwlockattr_t *rwlockattr,
+	int *pshared)
+{
+	*pshared = (*rwlockattr)->pshared;
+
+	return(0);
+}
+
+int
+pthread_rwlockattr_init (pthread_rwlockattr_t *rwlockattr)
+{
+	pthread_rwlockattr_t prwlockattr;
+
+	if (rwlockattr == NULL)
+		return(EINVAL);
+
+	prwlockattr = (pthread_rwlockattr_t)
+		malloc(sizeof(struct pthread_rwlockattr));
+
+	if (prwlockattr == NULL)
+		return(ENOMEM);
+
+	prwlockattr->pshared 	= PTHREAD_PROCESS_PRIVATE;
+	*rwlockattr		= prwlockattr;
+
+	return(0);
+}
+
+int
+pthread_rwlockattr_setpshared (pthread_rwlockattr_t *rwlockattr,
+	int *pshared)
+{
+	int ps = *pshared;
+
+	/* only PTHREAD_PROCESS_PRIVATE is supported */
+	if (ps != PTHREAD_PROCESS_PRIVATE)
+		return(EINVAL);
+
+	(*rwlockattr)->pshared = ps;
+
+	return(0);
+}
+
+#endif /* _THREAD_SAFE */
diff --git a/lib/libkse/thread/Makefile.inc b/lib/libkse/thread/Makefile.inc
index dc46af9..4fd3034 100644
--- a/lib/libkse/thread/Makefile.inc
+++ b/lib/libkse/thread/Makefile.inc
@@ -1,4 +1,4 @@
-#	$Id: Makefile.inc,v 1.12 1998/05/31 23:48:26 jb Exp $
+#	$Id: Makefile.inc,v 1.13 1998/06/01 02:14:34 jb Exp $
 
 # uthread sources
 .PATH: ${.CURDIR}/uthread
@@ -67,6 +67,8 @@ SRCS+= \
 	uthread_recvfrom.c \
 	uthread_recvmsg.c \
 	uthread_resume_np.c \
+	uthread_rwlock.c \
+	uthread_rwlockattr.c \
 	uthread_select.c \
 	uthread_self.c \
 	uthread_sendmsg.c \
diff --git a/lib/libkse/thread/thr_private.h b/lib/libkse/thread/thr_private.h
index 39ce14d..5b76a86 100644
--- a/lib/libkse/thread/thr_private.h
+++ b/lib/libkse/thread/thr_private.h
@@ -224,6 +224,18 @@ struct pthread_key {
 	void            (*destructor) ();
 };
 
+struct pthread_rwlockattr {
+	int		pshared;
+};
+
+struct pthread_rwlock {
+	pthread_mutex_t	lock;	/* monitor lock */
+	int		state;	/* 0 = idle  >0 = # of readers  -1 = writer */
+	pthread_cond_t	read_signal;
+	pthread_cond_t	write_signal;
+	int		blocked_writers;
+};
+
 /*
  * Thread states.
  */
diff --git a/lib/libkse/thread/thr_rwlock.c b/lib/libkse/thread/thr_rwlock.c
new file mode 100644
index 0000000..356eb29
--- /dev/null
+++ b/lib/libkse/thread/thr_rwlock.c
@@ -0,0 +1,333 @@
+/*-
+ * Copyright (c) 1998 Alex Nash
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ *	$Id$
+ */
+
+#ifdef _THREAD_SAFE
+#include <errno.h>
+#include <limits.h>
+#include <stdlib.h>
+
+#include <pthread.h>
+#include "pthread_private.h"
+
+/* maximum number of times a read lock may be obtained */
+#define	MAX_READ_LOCKS		(INT_MAX - 1)
+
+static int init_static (pthread_rwlock_t *rwlock);
+
+static spinlock_t static_init_lock = _SPINLOCK_INITIALIZER;
+
+static int
+init_static (pthread_rwlock_t *rwlock)
+{
+	int ret;
+
+	_SPINLOCK(&static_init_lock);
+
+	if (*rwlock == NULL)
+		ret = pthread_rwlock_init(rwlock, NULL);
+	else
+		ret = 0;
+
+	_SPINUNLOCK(&static_init_lock);
+
+	return(ret);
+}
+
+int
+pthread_rwlock_destroy (pthread_rwlock_t *rwlock)
+{
+	int ret;
+
+	if (rwlock == NULL)
+		ret = EINVAL;
+	else {
+		pthread_rwlock_t prwlock;
+
+		prwlock = *rwlock;
+
+		pthread_mutex_destroy(&prwlock->lock);
+		pthread_cond_destroy(&prwlock->read_signal);
+		pthread_cond_destroy(&prwlock->write_signal);
+		free(prwlock);
+
+		*rwlock = NULL;
+	}
+
+	return(ret);
+}
+
+int
+pthread_rwlock_init (pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *attr)
+{
+	pthread_rwlock_t	prwlock;
+	int			ret;
+
+	/* allocate rwlock object */
+	prwlock = (pthread_rwlock_t)malloc(sizeof(struct pthread_rwlock));
+
+	if (prwlock == NULL)
+		return(ENOMEM);
+
+	/* initialize the lock */
+	if ((ret = pthread_mutex_init(&prwlock->lock, NULL)) != 0)
+		free(prwlock);
+	else {
+		/* initialize the read condition signal */
+		ret = pthread_cond_init(&prwlock->read_signal, NULL);
+
+		if (ret != 0) {
+			pthread_mutex_destroy(&prwlock->lock);
+			free(prwlock);
+		} else {
+			/* initialize the write condition signal */
+			ret = pthread_cond_init(&prwlock->write_signal, NULL);
+
+			if (ret != 0) {
+				pthread_cond_destroy(&prwlock->read_signal);
+				pthread_mutex_destroy(&prwlock->lock);
+				free(prwlock);
+			} else {
+				/* success */
+				prwlock->state		 = 0;
+				prwlock->blocked_writers = 0;
+
+				*rwlock = prwlock;
+			}
+		}
+	}
+
+	return(ret);
+}
+
+int
+pthread_rwlock_rdlock (pthread_rwlock_t *rwlock)
+{
+	pthread_rwlock_t 	prwlock;
+	int			ret = 0;
+
+	if (rwlock == NULL)
+		return(EINVAL);
+
+	prwlock = *rwlock;
+
+	/* check for static initialization */
+	if (prwlock == NULL) {
+		if ((ret = init_static(rwlock)) != 0)
+			return(ret);
+
+		prwlock = *rwlock;
+	}
+
+	/* grab the monitor lock */
+	if ((ret = pthread_mutex_lock(&prwlock->lock)) != 0)
+		return(ret);
+
+	/* give writers priority over readers */
+	while (prwlock->blocked_writers || prwlock->state < 0) {
+		ret = pthread_cond_wait(&prwlock->read_signal, &prwlock->lock);
+
+		if (ret != 0) {
+			/* can't do a whole lot if this fails */
+			pthread_mutex_unlock(&prwlock->lock);
+			return(ret);
+		}
+	}
+
+	/* check lock count */
+	if (prwlock->state == MAX_READ_LOCKS)
+		ret = EAGAIN;
+	else
+		++prwlock->state; /* indicate we are locked for reading */
+
+	/*
+	 * Something is really wrong if this call fails.  Returning
+	 * error won't do because we've already obtained the read
+	 * lock.  Decrementing 'state' is no good because we probably
+	 * don't have the monitor lock.
+	 */
+	pthread_mutex_unlock(&prwlock->lock);
+
+	return(ret);
+}
+
+int
+pthread_rwlock_tryrdlock (pthread_rwlock_t *rwlock)
+{
+	pthread_rwlock_t 	prwlock;
+	int			ret = 0;
+
+	if (rwlock == NULL)
+		return(EINVAL);
+
+	prwlock = *rwlock;
+
+	/* check for static initialization */
+	if (prwlock == NULL) {
+		if ((ret = init_static(rwlock)) != 0)
+			return(ret);
+
+		prwlock = *rwlock;
+	}
+
+	/* grab the monitor lock */
+	if ((ret = pthread_mutex_lock(&prwlock->lock)) != 0)
+		return(ret);
+
+	/* give writers priority over readers */
+	if (prwlock->blocked_writers || prwlock->state < 0)
+		ret = EWOULDBLOCK;
+	else if (prwlock->state == MAX_READ_LOCKS)
+		ret = EAGAIN; /* too many read locks acquired */
+	else
+		++prwlock->state; /* indicate we are locked for reading */
+
+	/* see the comment on this in pthread_rwlock_rdlock */
+	pthread_mutex_unlock(&prwlock->lock);
+
+	return(ret);
+}
+
+int
+pthread_rwlock_trywrlock (pthread_rwlock_t *rwlock)
+{
+	pthread_rwlock_t 	prwlock;
+	int			ret = 0;
+
+	if (rwlock == NULL)
+		return(EINVAL);
+
+	prwlock = *rwlock;
+
+	/* check for static initialization */
+	if (prwlock == NULL) {
+		if ((ret = init_static(rwlock)) != 0)
+			return(ret);
+
+		prwlock = *rwlock;
+	}
+
+	/* grab the monitor lock */
+	if ((ret = pthread_mutex_lock(&prwlock->lock)) != 0)
+		return(ret);
+
+	if (prwlock->state != 0)
+		ret = EWOULDBLOCK;
+	else
+		/* indicate we are locked for writing */
+		prwlock->state = -1;
+
+	/* see the comment on this in pthread_rwlock_rdlock */
+	pthread_mutex_unlock(&prwlock->lock);
+
+	return(ret);
+}
+
+int
+pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
+{
+	pthread_rwlock_t 	prwlock;
+	int			ret = 0;
+
+	if (rwlock == NULL)
+		return(EINVAL);
+
+	prwlock = *rwlock;
+
+	if (prwlock == NULL)
+		return(EINVAL);
+
+	/* grab the monitor lock */
+	if ((ret = pthread_mutex_lock(&prwlock->lock)) != 0)
+		return(ret);
+
+	if (prwlock->state > 0) {
+		if (--prwlock->state == 0 && prwlock->blocked_writers)
+			ret = pthread_cond_signal(&prwlock->write_signal);
+	} else if (prwlock->state < 0) {
+		prwlock->state = 0;
+
+		if (prwlock->blocked_writers)
+			ret = pthread_cond_signal(&prwlock->write_signal);
+		else
+			ret = pthread_cond_broadcast(&prwlock->read_signal);
+	} else
+		ret = EINVAL;
+
+	/* see the comment on this in pthread_rwlock_rdlock */
+	pthread_mutex_unlock(&prwlock->lock);
+
+	return(ret);
+}
+
+int
+pthread_rwlock_wrlock (pthread_rwlock_t *rwlock)
+{
+	pthread_rwlock_t 	prwlock;
+	int			ret = 0;
+
+	if (rwlock == NULL)
+		return(EINVAL);
+
+	prwlock = *rwlock;
+
+	/* check for static initialization */
+	if (prwlock == NULL) {
+		if ((ret = init_static(rwlock)) != 0)
+			return(ret);
+
+		prwlock = *rwlock;
+	}
+
+	/* grab the monitor lock */
+	if ((ret = pthread_mutex_lock(&prwlock->lock)) != 0)
+		return(ret);
+
+	while (prwlock->state != 0) {
+		++prwlock->blocked_writers;
+
+		ret = pthread_cond_wait(&prwlock->write_signal, &prwlock->lock);
+
+		if (ret != 0) {
+			--prwlock->blocked_writers;
+			pthread_mutex_unlock(&prwlock->lock);
+			return(ret);
+		}
+
+		--prwlock->blocked_writers;
+	}
+
+	/* indicate we are locked for writing */
+	prwlock->state = -1;
+
+	/* see the comment on this in pthread_rwlock_rdlock */
+	pthread_mutex_unlock(&prwlock->lock);
+
+	return(ret);
+}
+
+#endif /* _THREAD_SAFE */
diff --git a/lib/libkse/thread/thr_rwlockattr.c b/lib/libkse/thread/thr_rwlockattr.c
new file mode 100644
index 0000000..a3683bc
--- /dev/null
+++ b/lib/libkse/thread/thr_rwlockattr.c
@@ -0,0 +1,97 @@
+/*-
+ * Copyright (c) 1998 Alex Nash
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ *	$Id$
+ */
+
+#ifdef _THREAD_SAFE
+#include <errno.h>
+
+#include <pthread.h>
+#include "pthread_private.h"
+
+int
+pthread_rwlockattr_destroy (pthread_rwlockattr_t *rwlockattr)
+{
+	pthread_rwlockattr_t prwlockattr;
+
+	if (rwlockattr == NULL)
+		return(EINVAL);
+
+	prwlockattr = *rwlockattr;
+
+	if (prwlockattr == NULL)
+		return(EINVAL);
+
+	free(prwlockattr);
+
+	return(0);
+}
+
+int
+pthread_rwlockattr_getpshared (const pthread_rwlockattr_t *rwlockattr,
+	int *pshared)
+{
+	*pshared = (*rwlockattr)->pshared;
+
+	return(0);
+}
+
+int
+pthread_rwlockattr_init (pthread_rwlockattr_t *rwlockattr)
+{
+	pthread_rwlockattr_t prwlockattr;
+
+	if (rwlockattr == NULL)
+		return(EINVAL);
+
+	prwlockattr = (pthread_rwlockattr_t)
+		malloc(sizeof(struct pthread_rwlockattr));
+
+	if (prwlockattr == NULL)
+		return(ENOMEM);
+
+	prwlockattr->pshared 	= PTHREAD_PROCESS_PRIVATE;
+	*rwlockattr		= prwlockattr;
+
+	return(0);
+}
+
+int
+pthread_rwlockattr_setpshared (pthread_rwlockattr_t *rwlockattr,
+	int *pshared)
+{
+	int ps = *pshared;
+
+	/* only PTHREAD_PROCESS_PRIVATE is supported */
+	if (ps != PTHREAD_PROCESS_PRIVATE)
+		return(EINVAL);
+
+	(*rwlockattr)->pshared = ps;
+
+	return(0);
+}
+
+#endif /* _THREAD_SAFE */
diff --git a/lib/libpthread/man/Makefile.inc b/lib/libpthread/man/Makefile.inc
index e6bb8a5..f92f3df 100644
--- a/lib/libpthread/man/Makefile.inc
+++ b/lib/libpthread/man/Makefile.inc
@@ -1,4 +1,4 @@
-# $Id: Makefile.inc,v 1.3 1997/02/22 15:05:23 peter Exp $
+# $Id: Makefile.inc,v 1.4 1998/07/31 09:09:19 phk Exp $
 
 # POSIX thread man files
 
@@ -26,5 +26,14 @@ MAN3+=	pthread_cleanup_pop.3 \
 	pthread_mutex_trylock.3 \
 	pthread_mutex_unlock.3 \
 	pthread_once.3 \
+	pthread_rwlock_destroy.3 \
+	pthread_rwlock_init.3 \
+	pthread_rwlock_rdlock.3 \
+	pthread_rwlock_unlock.3 \
+	pthread_rwlock_wrlock.3 \
+	pthread_rwlockattr_destroy.3 \
+	pthread_rwlockattr_getpshared.3 \
+	pthread_rwlockattr_init.3 \
+	pthread_rwlockattr_setpshared.3 \
 	pthread_self.3 \
 	pthread_setspecific.3
diff --git a/lib/libpthread/man/pthread_rwlock_destroy.3 b/lib/libpthread/man/pthread_rwlock_destroy.3
new file mode 100644
index 0000000..7453274
--- /dev/null
+++ b/lib/libpthread/man/pthread_rwlock_destroy.3
@@ -0,0 +1,80 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCK_DESTROY 3
+.Os
+.Sh NAME
+.Nm pthread_rwlock_destroy
+.Nd destroy a read/write lock
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlock_destroy "pthread_rwlock_t *lock"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlock_destroy
+function is used to destroy a read/write lock previously created with 
+.Fn pthread_rwlock_init .
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlock_destroy
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_init 3 ,
+.Sh STANDARDS
+The
+.Fn pthread_rwlock_destroy
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+The
+.Fn pthread_rwlock_destroy
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EPERM
+The caller does not have the privilege to perform the operation.
+.El
+.Pp
+The
+.Fn pthread_rwlock_destroy
+function may fail if:
+.Bl -tag -width Er
+.It Bq Er EBUSY
+The system has detected an attempt to destroy the object referenced by
+.Fa lock
+while it is locked.
+.It Bq Er EINVAL
+The value specified by
+.Fa lock
+is invalid.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlock_destroy
+function first appeared in
+.Fx 3.0 .
diff --git a/lib/libpthread/man/pthread_rwlock_init.3 b/lib/libpthread/man/pthread_rwlock_init.3
new file mode 100644
index 0000000..a561695
--- /dev/null
+++ b/lib/libpthread/man/pthread_rwlock_init.3
@@ -0,0 +1,99 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCK_INIT 3
+.Os
+.Sh NAME
+.Nm pthread_rwlock_init
+.Nd initialize a read/write lock
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlock_init "pthread_rwlock_t *lock" "const pthread_rwlockattr_t *attr"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlock_init
+function is used to initialize a read/write lock, with attributes
+specified by
+.Fa attr .
+If
+.Fa attr
+is NULL, the default read/write lock attributes are used.
+.Pp
+The results of calling
+.Fn pthread_rwlock_init
+with an already initialized lock are undefined.
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlock_init
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_destroy 3 ,
+.Xr pthread_rwlockattr_init 3 ,
+.Xr pthread_rwlockattr_setpshared 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlock_init
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+The
+.Fn pthread_rwlock_init
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EAGAIN
+The system lacked the necessary resources (other than memory) to
+initialize the lock.
+.It Bq Er ENOMEM
+Insufficient memory exists to initialize the lock.
+.It Bq Er EPERM
+The caller does not have sufficient privilege to perform the
+operation.
+.El
+.Pp
+The
+.Fn pthread_rwlock_init
+function may fail if:
+.Bl -tag -width Er
+.It Bq Er EBUSY
+The system has detected an attempt to re-initialize the object
+referenced by
+.Fa lock ,
+a previously initialized but not yet destroyed read/write lock.
+.It Bq Er EINVAL
+The value specified by
+.Fa attr
+is invalid.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlock_init
+function first appeared in
+.Fx 3.0 .
+.Sh BUGS
+The PTHREAD_PROCESS_SHARED attribute is not supported.
diff --git a/lib/libpthread/man/pthread_rwlock_rdlock.3 b/lib/libpthread/man/pthread_rwlock_rdlock.3
new file mode 100644
index 0000000..9181be9
--- /dev/null
+++ b/lib/libpthread/man/pthread_rwlock_rdlock.3
@@ -0,0 +1,122 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCK_RDLOCK 3
+.Os
+.Sh NAME
+.Nm pthread_rwlock_rdlock ,
+.Nm pthread_rwlock_tryrdlock
+.Nd acquire a read/write lock for reading
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlock_rdlock "pthread_rwlock_t *lock"
+.Ft int
+.Fn pthread_rwlock_tryrdlock "pthread_rwlock_t *lock"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlock_rdlock
+function acquires a read lock on
+.Fa lock
+provided that
+.Fa lock
+is not presently held for writing and no writer threads are
+presently blocked on the lock.  If the read lock cannot be
+immediately acquired, the calling thread blocks until it can
+acquire the lock.
+.Pp
+The
+.Fn pthread_rwlock_tryrdlock
+function performs the same action, but does not block if the lock
+cannot be immediately obtained (i.e. the lock is held for writing
+or there are waiting writers).
+.Pp
+A thread may hold multiple concurrent read locks.  If so,
+.Fn pthread_rwlock_unlock
+must be called once for each lock obtained.
+.Pp
+The results of acquiring a read lock while the calling thread holds
+a write lock are undefined.
+.Sh IMPLEMENTATION NOTES
+To prevent writer starvation, writers are favored over readers.
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlock_rdlock
+and
+.Fn pthread_rwlock_tryrdlock
+functions will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_init 3 ,
+.Xr pthread_rwlock_trywrlock 3 ,
+.Xr pthread_rwlock_unlock 3 ,
+.Xr pthread_rwlock_wrlock 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlock_rdlock
+and
+.Fn pthread_rwlock_tryrdlock
+functions are expected to conform to
+.St -susv2 .
+.Sh ERRORS
+The
+.Fn pthread_rwlock_tryrdlock
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EBUSY
+The lock could not be acquired because a writer holds the lock or
+was blocked on it.
+.El
+.Pp
+The
+.Fn pthread_rwlock_rdlock
+and
+.Fn pthread_rwlock_tryrdlock
+functions may fail if:
+.Bl -tag -width Er
+.It Bq Er EAGAIN
+The lock could not be acquired because the maximum number of read locks
+against
+.Fa lock
+has been exceeded.
+.It Bq Er EDEADLK
+The current thread already owns
+.Fa lock
+for writing.
+.It Bq Er EINVAL
+The value specified by
+.Fa lock
+is invalid.
+.It Bq Er ENOMEM
+Insufficient memory exists to initialize the lock (applies to
+statically initialized locks only).
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlock_rdlock
+function first appeared in
+.Fx 3.0 .
diff --git a/lib/libpthread/man/pthread_rwlock_unlock.3 b/lib/libpthread/man/pthread_rwlock_unlock.3
new file mode 100644
index 0000000..1c9fd05
--- /dev/null
+++ b/lib/libpthread/man/pthread_rwlock_unlock.3
@@ -0,0 +1,79 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCK_UNLOCK 3
+.Os
+.Sh NAME
+.Nm pthread_rwlock_unlock
+.Nd release a read/write lock
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlock_unlock "pthread_rwlock_t *lock"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlock_unlock
+function is used to release the read/write lock previously obtained by
+.Fn pthread_rwlock_rdlock ,
+.Fn pthread_rwlock_wrlock ,
+.Fn pthread_rwlock_tryrdlock ,
+or
+.Fn pthread_rwlock_trywrlock .
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlock_unlock
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Pp
+The results are undefined if
+.Fa lock
+is not held by the calling thread.
+.Sh SEE ALSO
+.Xr pthread_rwlock_rdlock 3 ,
+.Xr pthread_rwlock_wrlock 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlock_unlock
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+The
+.Fn pthread_rwlock_unlock
+function may fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The value specified by
+.Fa lock
+is invalid.
+.It Bq Er EPERM
+The current thread does not own the read/write lock.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlock_unlock
+function first appeared in
+.Fx 3.0 .
diff --git a/lib/libpthread/man/pthread_rwlock_wrlock.3 b/lib/libpthread/man/pthread_rwlock_wrlock.3
new file mode 100644
index 0000000..a5a3674
--- /dev/null
+++ b/lib/libpthread/man/pthread_rwlock_wrlock.3
@@ -0,0 +1,102 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCK_WRLOCK 3
+.Os
+.Sh NAME
+.Nm pthread_rwlock_wrlock ,
+.Nm pthread_rwlock_trywrlock
+.Nd acquire a read/write lock for writing
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlock_wrlock "pthread_rwlock_t *lock"
+.Ft int
+.Fn pthread_rwlock_trywrlock "pthread_rwlock_t *lock"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlock_wrlock
+function blocks until a write lock can be acquired against
+.Fa lock .
+The
+.Fn pthread_rwlock_trywrlock
+function performs the same action, but does not block if the lock
+cannot be immediately obtained.
+.Pp
+The results are undefined if the calling thread already holds the
+lock at the time the call is made.
+.Sh IMPLEMENTATION NOTES
+To prevent writer starvation, writers are favored over readers.
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlock_wrlock
+and
+.Fn pthread_rwlock_trywrlock
+functions will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_trywrlock 3 ,
+.Xr pthread_rwlock_unlock 3 ,
+.Xr pthread_rwlock_wrlock 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlock_wrlock
+and
+.Fn pthread_rwlock_trywrlock
+functions are expected to conform to
+.St -susv2 .
+.Sh ERRORS
+The
+.Fn pthread_rwlock_trywrlock
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EBUSY
+The calling thread is not able to acquire the lock without blocking.
+.El
+.Pp
+The
+.Fn pthread_rwlock_wrlock
+and
+.Fn pthread_rwlock_trywrlock
+functions may fail if:
+.Bl -tag -width Er
+.It Bq Er EDEADLK
+The calling thread already owns the read/write lock (for reading
+or writing).
+.It Bq Er EINVAL
+The value specified by
+.Fa lock
+is invalid.
+.It Bq Er ENOMEM
+Insufficient memory exists to initialize the lock (applies to
+statically initialized locks only).
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlock_wrlock
+function first appeared in
+.Fx 3.0 .
diff --git a/lib/libpthread/man/pthread_rwlockattr_destroy.3 b/lib/libpthread/man/pthread_rwlockattr_destroy.3
new file mode 100644
index 0000000..ee3c405
--- /dev/null
+++ b/lib/libpthread/man/pthread_rwlockattr_destroy.3
@@ -0,0 +1,68 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCKATTR_DESTROY 3
+.Os
+.Sh NAME
+.Nm pthread_rwlockattr_destroy
+.Nd destroy a read/write lock
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlockattr_destroy "pthread_rwlockattr_t *attr"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlockattr_destroy
+function is used to destroy a read/write lock attribute object
+previously created with 
+.Fn pthread_rwlockattr_init .
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlockattr_destroy
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlockattr_init 3 ,
+.Sh STANDARDS
+The
+.Fn pthread_rwlockattr_destroy
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+.Fn pthread_rwlockattr_destroy
+may fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The value specified by
+.Fa attr
+is invalid.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlockattr_destroy
+function first appeared in
+.Fx 3.0 .
diff --git a/lib/libpthread/man/pthread_rwlockattr_getpshared.3 b/lib/libpthread/man/pthread_rwlockattr_getpshared.3
new file mode 100644
index 0000000..8e8160b
--- /dev/null
+++ b/lib/libpthread/man/pthread_rwlockattr_getpshared.3
@@ -0,0 +1,80 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCKATTR_GETPSHARED 3
+.Os
+.Sh NAME
+.Nm pthread_rwlockattr_getpshared
+.Nd set the process shared attribute
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlockattr_getpshared "pthread_rwlockattr_t *attr" "int *pshared"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlockattr_getpshared
+function is used to get the process shared setting of a read/write
+lock attribute object.  The setting is returned via
+.Fa pshared ,
+and may be one of two values:
+.Bl -hang -offset flag -width 123456789012345678901234
+.It Ar PTHREAD_PROCESS_SHARED
+Any thread of any process that has access to the memory where the
+read/write lock resides can manipulate the lock.
+.It Ar PTHREAD_PROCESS_PRIVATE
+Only threads created within the same process as the thread that
+initialized the read/write lock can manipulate the lock.  This is
+the default value.
+.El
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlockattr_getpshared
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_init 3 ,
+.Xr pthread_rwlockattr_init 3 ,
+.Xr pthread_rwlockattr_setpshared 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlockattr_getpshared
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+.Fn pthread_rwlockattr_getpshared
+may fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The value specified by
+.Fa attr
+is invalid.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlockattr_getpshared
+function first appeared in
+.Fx 3.0 .
diff --git a/lib/libpthread/man/pthread_rwlockattr_init.3 b/lib/libpthread/man/pthread_rwlockattr_init.3
new file mode 100644
index 0000000..8827121
--- /dev/null
+++ b/lib/libpthread/man/pthread_rwlockattr_init.3
@@ -0,0 +1,67 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCKATTR_INIT 3
+.Os
+.Sh NAME
+.Nm pthread_rwlockattr_init
+.Nd initialize a read/write lock
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlockattr_init "pthread_rwlockattr_t *attr"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlockattr_init
+function is used to initialize a read/write lock attributes object.
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlockattr_init
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_init 3 ,
+.Xr pthread_rwlockattr_destroy 3 ,
+.Xr pthread_rwlockattr_getpshared 3
+.Xr pthread_rwlockattr_setpshared 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlockattr_init
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+.Fn pthread_rwlockattr_init
+will fail if:
+.Bl -tag -width Er
+.It Bq Er ENOMEM
+Insufficient memory exists to initialize the attribute object.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlockattr_init
+function first appeared in
+.Fx 3.0 .
diff --git a/lib/libpthread/man/pthread_rwlockattr_setpshared.3 b/lib/libpthread/man/pthread_rwlockattr_setpshared.3
new file mode 100644
index 0000000..e63debf
--- /dev/null
+++ b/lib/libpthread/man/pthread_rwlockattr_setpshared.3
@@ -0,0 +1,86 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCKATTR_SETPSHARED 3
+.Os
+.Sh NAME
+.Nm pthread_rwlockattr_setpshared
+.Nd set the process shared attribute
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlockattr_setpshared "pthread_rwlockattr_t *attr" "int *pshared"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlockattr_setpshared
+function sets the process shared attribute of
+.Fa attr
+to the value referenced by
+.Fa pshared .
+.Fa pshared
+may be one of two values:
+.Bl -hang -offset flag -width 123456789012345678901234
+.It Ar PTHREAD_PROCESS_SHARED
+Any thread of any process that has access to the memory where the
+read/write lock resides can manipulate the lock.
+.It Ar PTHREAD_PROCESS_PRIVATE
+Only threads created within the same process as the thread that
+initialized the read/write lock can manipulate the lock.  This is
+the default value.
+.El
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlockattr_setpshared
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_init 3 ,
+.Xr pthread_rwlockattr_init 3 ,
+.Xr pthread_rwlockattr_setpshared 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlockattr_setpshared
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+.Fn pthread_rwlockattr_setpshared
+will fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The value specified by
+.Fa attr
+or
+.Fa pshared
+is invalid.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlockattr_setpshared
+function first appeared in
+.Fx 3.0 .
+.Sh BUGS
+The PTHREAD_PROCESS_SHARED attribute is not supported.
diff --git a/lib/libpthread/thread/Makefile.inc b/lib/libpthread/thread/Makefile.inc
index dc46af9..4fd3034 100644
--- a/lib/libpthread/thread/Makefile.inc
+++ b/lib/libpthread/thread/Makefile.inc
@@ -1,4 +1,4 @@
-#	$Id: Makefile.inc,v 1.12 1998/05/31 23:48:26 jb Exp $
+#	$Id: Makefile.inc,v 1.13 1998/06/01 02:14:34 jb Exp $
 
 # uthread sources
 .PATH: ${.CURDIR}/uthread
@@ -67,6 +67,8 @@ SRCS+= \
 	uthread_recvfrom.c \
 	uthread_recvmsg.c \
 	uthread_resume_np.c \
+	uthread_rwlock.c \
+	uthread_rwlockattr.c \
 	uthread_select.c \
 	uthread_self.c \
 	uthread_sendmsg.c \
diff --git a/lib/libpthread/thread/thr_private.h b/lib/libpthread/thread/thr_private.h
index 39ce14d..5b76a86 100644
--- a/lib/libpthread/thread/thr_private.h
+++ b/lib/libpthread/thread/thr_private.h
@@ -224,6 +224,18 @@ struct pthread_key {
 	void            (*destructor) ();
 };
 
+struct pthread_rwlockattr {
+	int		pshared;
+};
+
+struct pthread_rwlock {
+	pthread_mutex_t	lock;	/* monitor lock */
+	int		state;	/* 0 = idle  >0 = # of readers  -1 = writer */
+	pthread_cond_t	read_signal;
+	pthread_cond_t	write_signal;
+	int		blocked_writers;
+};
+
 /*
  * Thread states.
  */
diff --git a/lib/libpthread/thread/thr_rwlock.c b/lib/libpthread/thread/thr_rwlock.c
new file mode 100644
index 0000000..356eb29
--- /dev/null
+++ b/lib/libpthread/thread/thr_rwlock.c
@@ -0,0 +1,333 @@
+/*-
+ * Copyright (c) 1998 Alex Nash
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ *	$Id$
+ */
+
+#ifdef _THREAD_SAFE
+#include <errno.h>
+#include <limits.h>
+#include <stdlib.h>
+
+#include <pthread.h>
+#include "pthread_private.h"
+
+/* maximum number of times a read lock may be obtained */
+#define	MAX_READ_LOCKS		(INT_MAX - 1)
+
+static int init_static (pthread_rwlock_t *rwlock);
+
+static spinlock_t static_init_lock = _SPINLOCK_INITIALIZER;
+
+static int
+init_static (pthread_rwlock_t *rwlock)
+{
+	int ret;
+
+	_SPINLOCK(&static_init_lock);
+
+	if (*rwlock == NULL)
+		ret = pthread_rwlock_init(rwlock, NULL);
+	else
+		ret = 0;
+
+	_SPINUNLOCK(&static_init_lock);
+
+	return(ret);
+}
+
+int
+pthread_rwlock_destroy (pthread_rwlock_t *rwlock)
+{
+	int ret;
+
+	if (rwlock == NULL)
+		ret = EINVAL;
+	else {
+		pthread_rwlock_t prwlock;
+
+		prwlock = *rwlock;
+
+		pthread_mutex_destroy(&prwlock->lock);
+		pthread_cond_destroy(&prwlock->read_signal);
+		pthread_cond_destroy(&prwlock->write_signal);
+		free(prwlock);
+
+		*rwlock = NULL;
+	}
+
+	return(ret);
+}
+
+int
+pthread_rwlock_init (pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *attr)
+{
+	pthread_rwlock_t	prwlock;
+	int			ret;
+
+	/* allocate rwlock object */
+	prwlock = (pthread_rwlock_t)malloc(sizeof(struct pthread_rwlock));
+
+	if (prwlock == NULL)
+		return(ENOMEM);
+
+	/* initialize the lock */
+	if ((ret = pthread_mutex_init(&prwlock->lock, NULL)) != 0)
+		free(prwlock);
+	else {
+		/* initialize the read condition signal */
+		ret = pthread_cond_init(&prwlock->read_signal, NULL);
+
+		if (ret != 0) {
+			pthread_mutex_destroy(&prwlock->lock);
+			free(prwlock);
+		} else {
+			/* initialize the write condition signal */
+			ret = pthread_cond_init(&prwlock->write_signal, NULL);
+
+			if (ret != 0) {
+				pthread_cond_destroy(&prwlock->read_signal);
+				pthread_mutex_destroy(&prwlock->lock);
+				free(prwlock);
+			} else {
+				/* success */
+				prwlock->state		 = 0;
+				prwlock->blocked_writers = 0;
+
+				*rwlock = prwlock;
+			}
+		}
+	}
+
+	return(ret);
+}
+
+int
+pthread_rwlock_rdlock (pthread_rwlock_t *rwlock)
+{
+	pthread_rwlock_t 	prwlock;
+	int			ret = 0;
+
+	if (rwlock == NULL)
+		return(EINVAL);
+
+	prwlock = *rwlock;
+
+	/* check for static initialization */
+	if (prwlock == NULL) {
+		if ((ret = init_static(rwlock)) != 0)
+			return(ret);
+
+		prwlock = *rwlock;
+	}
+
+	/* grab the monitor lock */
+	if ((ret = pthread_mutex_lock(&prwlock->lock)) != 0)
+		return(ret);
+
+	/* give writers priority over readers */
+	while (prwlock->blocked_writers || prwlock->state < 0) {
+		ret = pthread_cond_wait(&prwlock->read_signal, &prwlock->lock);
+
+		if (ret != 0) {
+			/* can't do a whole lot if this fails */
+			pthread_mutex_unlock(&prwlock->lock);
+			return(ret);
+		}
+	}
+
+	/* check lock count */
+	if (prwlock->state == MAX_READ_LOCKS)
+		ret = EAGAIN;
+	else
+		++prwlock->state; /* indicate we are locked for reading */
+
+	/*
+	 * Something is really wrong if this call fails.  Returning
+	 * error won't do because we've already obtained the read
+	 * lock.  Decrementing 'state' is no good because we probably
+	 * don't have the monitor lock.
+	 */
+	pthread_mutex_unlock(&prwlock->lock);
+
+	return(ret);
+}
+
+int
+pthread_rwlock_tryrdlock (pthread_rwlock_t *rwlock)
+{
+	pthread_rwlock_t 	prwlock;
+	int			ret = 0;
+
+	if (rwlock == NULL)
+		return(EINVAL);
+
+	prwlock = *rwlock;
+
+	/* check for static initialization */
+	if (prwlock == NULL) {
+		if ((ret = init_static(rwlock)) != 0)
+			return(ret);
+
+		prwlock = *rwlock;
+	}
+
+	/* grab the monitor lock */
+	if ((ret = pthread_mutex_lock(&prwlock->lock)) != 0)
+		return(ret);
+
+	/* give writers priority over readers */
+	if (prwlock->blocked_writers || prwlock->state < 0)
+		ret = EWOULDBLOCK;
+	else if (prwlock->state == MAX_READ_LOCKS)
+		ret = EAGAIN; /* too many read locks acquired */
+	else
+		++prwlock->state; /* indicate we are locked for reading */
+
+	/* see the comment on this in pthread_rwlock_rdlock */
+	pthread_mutex_unlock(&prwlock->lock);
+
+	return(ret);
+}
+
+int
+pthread_rwlock_trywrlock (pthread_rwlock_t *rwlock)
+{
+	pthread_rwlock_t 	prwlock;
+	int			ret = 0;
+
+	if (rwlock == NULL)
+		return(EINVAL);
+
+	prwlock = *rwlock;
+
+	/* check for static initialization */
+	if (prwlock == NULL) {
+		if ((ret = init_static(rwlock)) != 0)
+			return(ret);
+
+		prwlock = *rwlock;
+	}
+
+	/* grab the monitor lock */
+	if ((ret = pthread_mutex_lock(&prwlock->lock)) != 0)
+		return(ret);
+
+	if (prwlock->state != 0)
+		ret = EWOULDBLOCK;
+	else
+		/* indicate we are locked for writing */
+		prwlock->state = -1;
+
+	/* see the comment on this in pthread_rwlock_rdlock */
+	pthread_mutex_unlock(&prwlock->lock);
+
+	return(ret);
+}
+
+int
+pthread_rwlock_unlock (pthread_rwlock_t *rwlock)
+{
+	pthread_rwlock_t 	prwlock;
+	int			ret = 0;
+
+	if (rwlock == NULL)
+		return(EINVAL);
+
+	prwlock = *rwlock;
+
+	if (prwlock == NULL)
+		return(EINVAL);
+
+	/* grab the monitor lock */
+	if ((ret = pthread_mutex_lock(&prwlock->lock)) != 0)
+		return(ret);
+
+	if (prwlock->state > 0) {
+		if (--prwlock->state == 0 && prwlock->blocked_writers)
+			ret = pthread_cond_signal(&prwlock->write_signal);
+	} else if (prwlock->state < 0) {
+		prwlock->state = 0;
+
+		if (prwlock->blocked_writers)
+			ret = pthread_cond_signal(&prwlock->write_signal);
+		else
+			ret = pthread_cond_broadcast(&prwlock->read_signal);
+	} else
+		ret = EINVAL;
+
+	/* see the comment on this in pthread_rwlock_rdlock */
+	pthread_mutex_unlock(&prwlock->lock);
+
+	return(ret);
+}
+
+int
+pthread_rwlock_wrlock (pthread_rwlock_t *rwlock)
+{
+	pthread_rwlock_t 	prwlock;
+	int			ret = 0;
+
+	if (rwlock == NULL)
+		return(EINVAL);
+
+	prwlock = *rwlock;
+
+	/* check for static initialization */
+	if (prwlock == NULL) {
+		if ((ret = init_static(rwlock)) != 0)
+			return(ret);
+
+		prwlock = *rwlock;
+	}
+
+	/* grab the monitor lock */
+	if ((ret = pthread_mutex_lock(&prwlock->lock)) != 0)
+		return(ret);
+
+	while (prwlock->state != 0) {
+		++prwlock->blocked_writers;
+
+		ret = pthread_cond_wait(&prwlock->write_signal, &prwlock->lock);
+
+		if (ret != 0) {
+			--prwlock->blocked_writers;
+			pthread_mutex_unlock(&prwlock->lock);
+			return(ret);
+		}
+
+		--prwlock->blocked_writers;
+	}
+
+	/* indicate we are locked for writing */
+	prwlock->state = -1;
+
+	/* see the comment on this in pthread_rwlock_rdlock */
+	pthread_mutex_unlock(&prwlock->lock);
+
+	return(ret);
+}
+
+#endif /* _THREAD_SAFE */
diff --git a/lib/libpthread/thread/thr_rwlockattr.c b/lib/libpthread/thread/thr_rwlockattr.c
new file mode 100644
index 0000000..a3683bc
--- /dev/null
+++ b/lib/libpthread/thread/thr_rwlockattr.c
@@ -0,0 +1,97 @@
+/*-
+ * Copyright (c) 1998 Alex Nash
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ *	$Id$
+ */
+
+#ifdef _THREAD_SAFE
+#include <errno.h>
+
+#include <pthread.h>
+#include "pthread_private.h"
+
+int
+pthread_rwlockattr_destroy (pthread_rwlockattr_t *rwlockattr)
+{
+	pthread_rwlockattr_t prwlockattr;
+
+	if (rwlockattr == NULL)
+		return(EINVAL);
+
+	prwlockattr = *rwlockattr;
+
+	if (prwlockattr == NULL)
+		return(EINVAL);
+
+	free(prwlockattr);
+
+	return(0);
+}
+
+int
+pthread_rwlockattr_getpshared (const pthread_rwlockattr_t *rwlockattr,
+	int *pshared)
+{
+	*pshared = (*rwlockattr)->pshared;
+
+	return(0);
+}
+
+int
+pthread_rwlockattr_init (pthread_rwlockattr_t *rwlockattr)
+{
+	pthread_rwlockattr_t prwlockattr;
+
+	if (rwlockattr == NULL)
+		return(EINVAL);
+
+	prwlockattr = (pthread_rwlockattr_t)
+		malloc(sizeof(struct pthread_rwlockattr));
+
+	if (prwlockattr == NULL)
+		return(ENOMEM);
+
+	prwlockattr->pshared 	= PTHREAD_PROCESS_PRIVATE;
+	*rwlockattr		= prwlockattr;
+
+	return(0);
+}
+
+int
+pthread_rwlockattr_setpshared (pthread_rwlockattr_t *rwlockattr,
+	int *pshared)
+{
+	int ps = *pshared;
+
+	/* only PTHREAD_PROCESS_PRIVATE is supported */
+	if (ps != PTHREAD_PROCESS_PRIVATE)
+		return(EINVAL);
+
+	(*rwlockattr)->pshared = ps;
+
+	return(0);
+}
+
+#endif /* _THREAD_SAFE */
diff --git a/share/man/man3/pthread_rwlock_destroy.3 b/share/man/man3/pthread_rwlock_destroy.3
new file mode 100644
index 0000000..7453274
--- /dev/null
+++ b/share/man/man3/pthread_rwlock_destroy.3
@@ -0,0 +1,80 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCK_DESTROY 3
+.Os
+.Sh NAME
+.Nm pthread_rwlock_destroy
+.Nd destroy a read/write lock
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlock_destroy "pthread_rwlock_t *lock"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlock_destroy
+function is used to destroy a read/write lock previously created with 
+.Fn pthread_rwlock_init .
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlock_destroy
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_init 3 ,
+.Sh STANDARDS
+The
+.Fn pthread_rwlock_destroy
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+The
+.Fn pthread_rwlock_destroy
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EPERM
+The caller does not have the privilege to perform the operation.
+.El
+.Pp
+The
+.Fn pthread_rwlock_destroy
+function may fail if:
+.Bl -tag -width Er
+.It Bq Er EBUSY
+The system has detected an attempt to destroy the object referenced by
+.Fa lock
+while it is locked.
+.It Bq Er EINVAL
+The value specified by
+.Fa lock
+is invalid.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlock_destroy
+function first appeared in
+.Fx 3.0 .
diff --git a/share/man/man3/pthread_rwlock_init.3 b/share/man/man3/pthread_rwlock_init.3
new file mode 100644
index 0000000..a561695
--- /dev/null
+++ b/share/man/man3/pthread_rwlock_init.3
@@ -0,0 +1,99 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCK_INIT 3
+.Os
+.Sh NAME
+.Nm pthread_rwlock_init
+.Nd initialize a read/write lock
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlock_init "pthread_rwlock_t *lock" "const pthread_rwlockattr_t *attr"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlock_init
+function is used to initialize a read/write lock, with attributes
+specified by
+.Fa attr .
+If
+.Fa attr
+is NULL, the default read/write lock attributes are used.
+.Pp
+The results of calling
+.Fn pthread_rwlock_init
+with an already initialized lock are undefined.
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlock_init
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_destroy 3 ,
+.Xr pthread_rwlockattr_init 3 ,
+.Xr pthread_rwlockattr_setpshared 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlock_init
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+The
+.Fn pthread_rwlock_init
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EAGAIN
+The system lacked the necessary resources (other than memory) to
+initialize the lock.
+.It Bq Er ENOMEM
+Insufficient memory exists to initialize the lock.
+.It Bq Er EPERM
+The caller does not have sufficient privilege to perform the
+operation.
+.El
+.Pp
+The
+.Fn pthread_rwlock_init
+function may fail if:
+.Bl -tag -width Er
+.It Bq Er EBUSY
+The system has detected an attempt to re-initialize the object
+referenced by
+.Fa lock ,
+a previously initialized but not yet destroyed read/write lock.
+.It Bq Er EINVAL
+The value specified by
+.Fa attr
+is invalid.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlock_init
+function first appeared in
+.Fx 3.0 .
+.Sh BUGS
+The PTHREAD_PROCESS_SHARED attribute is not supported.
diff --git a/share/man/man3/pthread_rwlock_rdlock.3 b/share/man/man3/pthread_rwlock_rdlock.3
new file mode 100644
index 0000000..9181be9
--- /dev/null
+++ b/share/man/man3/pthread_rwlock_rdlock.3
@@ -0,0 +1,122 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCK_RDLOCK 3
+.Os
+.Sh NAME
+.Nm pthread_rwlock_rdlock ,
+.Nm pthread_rwlock_tryrdlock
+.Nd acquire a read/write lock for reading
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlock_rdlock "pthread_rwlock_t *lock"
+.Ft int
+.Fn pthread_rwlock_tryrdlock "pthread_rwlock_t *lock"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlock_rdlock
+function acquires a read lock on
+.Fa lock
+provided that
+.Fa lock
+is not presently held for writing and no writer threads are
+presently blocked on the lock.  If the read lock cannot be
+immediately acquired, the calling thread blocks until it can
+acquire the lock.
+.Pp
+The
+.Fn pthread_rwlock_tryrdlock
+function performs the same action, but does not block if the lock
+cannot be immediately obtained (i.e. the lock is held for writing
+or there are waiting writers).
+.Pp
+A thread may hold multiple concurrent read locks.  If so,
+.Fn pthread_rwlock_unlock
+must be called once for each lock obtained.
+.Pp
+The results of acquiring a read lock while the calling thread holds
+a write lock are undefined.
+.Sh IMPLEMENTATION NOTES
+To prevent writer starvation, writers are favored over readers.
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlock_rdlock
+and
+.Fn pthread_rwlock_tryrdlock
+functions will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_init 3 ,
+.Xr pthread_rwlock_trywrlock 3 ,
+.Xr pthread_rwlock_unlock 3 ,
+.Xr pthread_rwlock_wrlock 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlock_rdlock
+and
+.Fn pthread_rwlock_tryrdlock
+functions are expected to conform to
+.St -susv2 .
+.Sh ERRORS
+The
+.Fn pthread_rwlock_tryrdlock
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EBUSY
+The lock could not be acquired because a writer holds the lock or
+was blocked on it.
+.El
+.Pp
+The
+.Fn pthread_rwlock_rdlock
+and
+.Fn pthread_rwlock_tryrdlock
+functions may fail if:
+.Bl -tag -width Er
+.It Bq Er EAGAIN
+The lock could not be acquired because the maximum number of read locks
+against
+.Fa lock
+has been exceeded.
+.It Bq Er EDEADLK
+The current thread already owns
+.Fa lock
+for writing.
+.It Bq Er EINVAL
+The value specified by
+.Fa lock
+is invalid.
+.It Bq Er ENOMEM
+Insufficient memory exists to initialize the lock (applies to
+statically initialized locks only).
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlock_rdlock
+function first appeared in
+.Fx 3.0 .
diff --git a/share/man/man3/pthread_rwlock_unlock.3 b/share/man/man3/pthread_rwlock_unlock.3
new file mode 100644
index 0000000..1c9fd05
--- /dev/null
+++ b/share/man/man3/pthread_rwlock_unlock.3
@@ -0,0 +1,79 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCK_UNLOCK 3
+.Os
+.Sh NAME
+.Nm pthread_rwlock_unlock
+.Nd release a read/write lock
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlock_unlock "pthread_rwlock_t *lock"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlock_unlock
+function is used to release the read/write lock previously obtained by
+.Fn pthread_rwlock_rdlock ,
+.Fn pthread_rwlock_wrlock ,
+.Fn pthread_rwlock_tryrdlock ,
+or
+.Fn pthread_rwlock_trywrlock .
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlock_unlock
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Pp
+The results are undefined if
+.Fa lock
+is not held by the calling thread.
+.Sh SEE ALSO
+.Xr pthread_rwlock_rdlock 3 ,
+.Xr pthread_rwlock_wrlock 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlock_unlock
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+The
+.Fn pthread_rwlock_unlock
+function may fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The value specified by
+.Fa lock
+is invalid.
+.It Bq Er EPERM
+The current thread does not own the read/write lock.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlock_unlock
+function first appeared in
+.Fx 3.0 .
diff --git a/share/man/man3/pthread_rwlock_wrlock.3 b/share/man/man3/pthread_rwlock_wrlock.3
new file mode 100644
index 0000000..a5a3674
--- /dev/null
+++ b/share/man/man3/pthread_rwlock_wrlock.3
@@ -0,0 +1,102 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCK_WRLOCK 3
+.Os
+.Sh NAME
+.Nm pthread_rwlock_wrlock ,
+.Nm pthread_rwlock_trywrlock
+.Nd acquire a read/write lock for writing
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlock_wrlock "pthread_rwlock_t *lock"
+.Ft int
+.Fn pthread_rwlock_trywrlock "pthread_rwlock_t *lock"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlock_wrlock
+function blocks until a write lock can be acquired against
+.Fa lock .
+The
+.Fn pthread_rwlock_trywrlock
+function performs the same action, but does not block if the lock
+cannot be immediately obtained.
+.Pp
+The results are undefined if the calling thread already holds the
+lock at the time the call is made.
+.Sh IMPLEMENTATION NOTES
+To prevent writer starvation, writers are favored over readers.
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlock_wrlock
+and
+.Fn pthread_rwlock_trywrlock
+functions will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_trywrlock 3 ,
+.Xr pthread_rwlock_unlock 3 ,
+.Xr pthread_rwlock_wrlock 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlock_wrlock
+and
+.Fn pthread_rwlock_trywrlock
+functions are expected to conform to
+.St -susv2 .
+.Sh ERRORS
+The
+.Fn pthread_rwlock_trywrlock
+function will fail if:
+.Bl -tag -width Er
+.It Bq Er EBUSY
+The calling thread is not able to acquire the lock without blocking.
+.El
+.Pp
+The
+.Fn pthread_rwlock_wrlock
+and
+.Fn pthread_rwlock_trywrlock
+functions may fail if:
+.Bl -tag -width Er
+.It Bq Er EDEADLK
+The calling thread already owns the read/write lock (for reading
+or writing).
+.It Bq Er EINVAL
+The value specified by
+.Fa lock
+is invalid.
+.It Bq Er ENOMEM
+Insufficient memory exists to initialize the lock (applies to
+statically initialized locks only).
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlock_wrlock
+function first appeared in
+.Fx 3.0 .
diff --git a/share/man/man3/pthread_rwlockattr_destroy.3 b/share/man/man3/pthread_rwlockattr_destroy.3
new file mode 100644
index 0000000..ee3c405
--- /dev/null
+++ b/share/man/man3/pthread_rwlockattr_destroy.3
@@ -0,0 +1,68 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCKATTR_DESTROY 3
+.Os
+.Sh NAME
+.Nm pthread_rwlockattr_destroy
+.Nd destroy a read/write lock
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlockattr_destroy "pthread_rwlockattr_t *attr"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlockattr_destroy
+function is used to destroy a read/write lock attribute object
+previously created with 
+.Fn pthread_rwlockattr_init .
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlockattr_destroy
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlockattr_init 3 ,
+.Sh STANDARDS
+The
+.Fn pthread_rwlockattr_destroy
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+.Fn pthread_rwlockattr_destroy
+may fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The value specified by
+.Fa attr
+is invalid.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlockattr_destroy
+function first appeared in
+.Fx 3.0 .
diff --git a/share/man/man3/pthread_rwlockattr_getpshared.3 b/share/man/man3/pthread_rwlockattr_getpshared.3
new file mode 100644
index 0000000..8e8160b
--- /dev/null
+++ b/share/man/man3/pthread_rwlockattr_getpshared.3
@@ -0,0 +1,80 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCKATTR_GETPSHARED 3
+.Os
+.Sh NAME
+.Nm pthread_rwlockattr_getpshared
+.Nd set the process shared attribute
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlockattr_getpshared "pthread_rwlockattr_t *attr" "int *pshared"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlockattr_getpshared
+function is used to get the process shared setting of a read/write
+lock attribute object.  The setting is returned via
+.Fa pshared ,
+and may be one of two values:
+.Bl -hang -offset flag -width 123456789012345678901234
+.It Ar PTHREAD_PROCESS_SHARED
+Any thread of any process that has access to the memory where the
+read/write lock resides can manipulate the lock.
+.It Ar PTHREAD_PROCESS_PRIVATE
+Only threads created within the same process as the thread that
+initialized the read/write lock can manipulate the lock.  This is
+the default value.
+.El
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlockattr_getpshared
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_init 3 ,
+.Xr pthread_rwlockattr_init 3 ,
+.Xr pthread_rwlockattr_setpshared 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlockattr_getpshared
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+.Fn pthread_rwlockattr_getpshared
+may fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The value specified by
+.Fa attr
+is invalid.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlockattr_getpshared
+function first appeared in
+.Fx 3.0 .
diff --git a/share/man/man3/pthread_rwlockattr_init.3 b/share/man/man3/pthread_rwlockattr_init.3
new file mode 100644
index 0000000..8827121
--- /dev/null
+++ b/share/man/man3/pthread_rwlockattr_init.3
@@ -0,0 +1,67 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCKATTR_INIT 3
+.Os
+.Sh NAME
+.Nm pthread_rwlockattr_init
+.Nd initialize a read/write lock
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlockattr_init "pthread_rwlockattr_t *attr"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlockattr_init
+function is used to initialize a read/write lock attributes object.
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlockattr_init
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_init 3 ,
+.Xr pthread_rwlockattr_destroy 3 ,
+.Xr pthread_rwlockattr_getpshared 3
+.Xr pthread_rwlockattr_setpshared 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlockattr_init
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+.Fn pthread_rwlockattr_init
+will fail if:
+.Bl -tag -width Er
+.It Bq Er ENOMEM
+Insufficient memory exists to initialize the attribute object.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlockattr_init
+function first appeared in
+.Fx 3.0 .
diff --git a/share/man/man3/pthread_rwlockattr_setpshared.3 b/share/man/man3/pthread_rwlockattr_setpshared.3
new file mode 100644
index 0000000..e63debf
--- /dev/null
+++ b/share/man/man3/pthread_rwlockattr_setpshared.3
@@ -0,0 +1,86 @@
+.\" Copyright (c) 1998 Alex Nash
+.\" 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.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+.\"
+.\"	$Id$
+.\"
+.Dd August 4, 1998
+.Dt PTHREAD_RWLOCKATTR_SETPSHARED 3
+.Os
+.Sh NAME
+.Nm pthread_rwlockattr_setpshared
+.Nd set the process shared attribute
+.Sh SYNOPSIS
+.Fd #include <pthread.h>
+.Ft int
+.Fn pthread_rwlockattr_setpshared "pthread_rwlockattr_t *attr" "int *pshared"
+.Sh DESCRIPTION
+The
+.Fn pthread_rwlockattr_setpshared
+function sets the process shared attribute of
+.Fa attr
+to the value referenced by
+.Fa pshared .
+.Fa pshared
+may be one of two values:
+.Bl -hang -offset flag -width 123456789012345678901234
+.It Ar PTHREAD_PROCESS_SHARED
+Any thread of any process that has access to the memory where the
+read/write lock resides can manipulate the lock.
+.It Ar PTHREAD_PROCESS_PRIVATE
+Only threads created within the same process as the thread that
+initialized the read/write lock can manipulate the lock.  This is
+the default value.
+.El
+.Sh RETURN VALUES
+If successful, the
+.Fn pthread_rwlockattr_setpshared
+function will return zero.  Otherwise an error number will be returned
+to indicate the error.
+.Sh SEE ALSO
+.Xr pthread_rwlock_init 3 ,
+.Xr pthread_rwlockattr_init 3 ,
+.Xr pthread_rwlockattr_setpshared 3
+.Sh STANDARDS
+The
+.Fn pthread_rwlockattr_setpshared
+function is expected to conform to
+.St -susv2 .
+.Sh ERRORS
+.Fn pthread_rwlockattr_setpshared
+will fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+The value specified by
+.Fa attr
+or
+.Fa pshared
+is invalid.
+.El
+.Sh HISTORY
+The
+.Fn pthread_rwlockattr_setpshared
+function first appeared in
+.Fx 3.0 .
+.Sh BUGS
+The PTHREAD_PROCESS_SHARED attribute is not supported.