Merge remote-tracking branch 'upstream/master'HEADmaster

26 files changed, 153 insertions, 1978 deletions

diff --git a/src/libthread/386-ucontext.c b/src/libthread/386-ucontext.c
deleted file mode 100644
index 3afa9513..00000000
--- a/src/libthread/386-ucontext.c
+++ /dev/null
@@ -1,22 +0,0 @@
-#include "threadimpl.h"
-
-void
-makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...)
-{
-	int *sp;
-
-	sp = USPALIGN(ucp, 4);
-	sp -= argc;
-	memmove(sp, &argc+1, argc*sizeof(int));
-	*--sp = 0;		/* return address */
-	ucp->uc_mcontext.mc_eip = (long)func;
-	ucp->uc_mcontext.mc_esp = (int)sp;
-}
-
-int
-swapcontext(ucontext_t *oucp, ucontext_t *ucp)
-{
-	if(getcontext(oucp) == 0)
-		setcontext(ucp);
-	return 0;
-}
diff --git a/src/libthread/386-ucontext.h b/src/libthread/386-ucontext.h
deleted file mode 100644
index b1ee81b3..00000000
--- a/src/libthread/386-ucontext.h
+++ /dev/null
@@ -1,119 +0,0 @@
-#define	setcontext(u)	setmcontext(&(u)->uc_mcontext)
-#define	getcontext(u)	getmcontext(&(u)->uc_mcontext)
-typedef struct mcontext mcontext_t;
-typedef struct ucontext ucontext_t;
-
-extern	int		swapcontext(ucontext_t*, ucontext_t*);
-extern	void		makecontext(ucontext_t*, void(*)(), int, ...);
-extern	int		getmcontext(mcontext_t*);
-extern	void		setmcontext(mcontext_t*);
-
-/*-
- * Copyright (c) 1999 Marcel Moolenaar
- * 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
- *    in this position and unchanged.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. The name of the author may not be used to endorse or promote products
- *    derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * $FreeBSD: src/sys/sys/ucontext.h,v 1.4 1999/10/11 20:33:17 luoqi Exp $
- */
-
-/* #include <machine/ucontext.h> */
-
-/*-
- * Copyright (c) 1999 Marcel Moolenaar
- * 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
- *    in this position and unchanged.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- * 3. The name of the author may not be used to endorse or promote products
- *    derived from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * $FreeBSD: src/sys/i386/include/ucontext.h,v 1.4 1999/10/11 20:33:09 luoqi Exp $
- */
-
-struct mcontext {
-	/*
-	 * The first 20 fields must match the definition of
-	 * sigcontext. So that we can support sigcontext
-	 * and ucontext_t at the same time.
-	 */
-	int	mc_onstack;		/* XXX - sigcontext compat. */
-	int	mc_gs;
-	int	mc_fs;
-	int	mc_es;
-	int	mc_ds;
-	int	mc_edi;
-	int	mc_esi;
-	int	mc_ebp;
-	int	mc_isp;
-	int	mc_ebx;
-	int	mc_edx;
-	int	mc_ecx;
-	int	mc_eax;
-	int	mc_trapno;
-	int	mc_err;
-	int	mc_eip;
-	int	mc_cs;
-	int	mc_eflags;
-	int	mc_esp;			/* machine state */
-	int	mc_ss;
-
-	int	mc_fpregs[28];		/* env87 + fpacc87 + u_long */
-	int	__spare__[17];
-};
-
-struct ucontext {
-	/*
-	 * Keep the order of the first two fields. Also,
-	 * keep them the first two fields in the structure.
-	 * This way we can have a union with struct
-	 * sigcontext and ucontext_t. This allows us to
-	 * support them both at the same time.
-	 * note: the union is not defined, though.
-	 */
-	sigset_t	uc_sigmask;
-	mcontext_t	uc_mcontext;
-
-	struct __ucontext *uc_link;
-	stack_t		uc_stack;
-	int		__spare__[8];
-};
diff --git a/src/libthread/COPYING.SPARC64-CONTEXT b/src/libthread/COPYING.SPARC64-CONTEXT
deleted file mode 100644
index 3b204400..00000000
--- a/src/libthread/COPYING.SPARC64-CONTEXT
+++ /dev/null
@@ -1,458 +0,0 @@
-		  GNU LESSER GENERAL PUBLIC LICENSE
-		       Version 2.1, February 1999
-
- Copyright (C) 1991, 1999 Free Software Foundation, Inc.
-     59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
- Everyone is permitted to copy and distribute verbatim copies
- of this license document, but changing it is not allowed.
-
-[This is the first released version of the Lesser GPL.  It also counts
- as the successor of the GNU Library Public License, version 2, hence
- the version number 2.1.]
-
-			    Preamble
-
-  The licenses for most software are designed to take away your
-freedom to share and change it.  By contrast, the GNU General Public
-Licenses are intended to guarantee your freedom to share and change
-free software--to make sure the software is free for all its users.
-
-  This license, the Lesser General Public License, applies to some
-specially designated software packages--typically libraries--of the
-Free Software Foundation and other authors who decide to use it.  You
-can use it too, but we suggest you first think carefully about whether
-this license or the ordinary General Public License is the better
-strategy to use in any particular case, based on the explanations below.
-
-  When we speak of free software, we are referring to freedom of use,
-not price.  Our General Public Licenses are designed to make sure that
-you have the freedom to distribute copies of free software (and charge
-for this service if you wish); that you receive source code or can get
-it if you want it; that you can change the software and use pieces of
-it in new free programs; and that you are informed that you can do
-these things.
-
-  To protect your rights, we need to make restrictions that forbid
-distributors to deny you these rights or to ask you to surrender these
-rights.  These restrictions translate to certain responsibilities for
-you if you distribute copies of the library or if you modify it.
-
-  For example, if you distribute copies of the library, whether gratis
-or for a fee, you must give the recipients all the rights that we gave
-you.  You must make sure that they, too, receive or can get the source
-code.  If you link other code with the library, you must provide
-complete object files to the recipients, so that they can relink them
-with the library after making changes to the library and recompiling
-it.  And you must show them these terms so they know their rights.
-
-  We protect your rights with a two-step method: (1) we copyright the
-library, and (2) we offer you this license, which gives you legal
-permission to copy, distribute and/or modify the library.
-
-  To protect each distributor, we want to make it very clear that
-there is no warranty for the free library.  Also, if the library is
-modified by someone else and passed on, the recipients should know
-that what they have is not the original version, so that the original
-author's reputation will not be affected by problems that might be
-introduced by others.
-
-  Finally, software patents pose a constant threat to the existence of
-any free program.  We wish to make sure that a company cannot
-effectively restrict the users of a free program by obtaining a
-restrictive license from a patent holder.  Therefore, we insist that
-any patent license obtained for a version of the library must be
-consistent with the full freedom of use specified in this license.
-
-  Most GNU software, including some libraries, is covered by the
-ordinary GNU General Public License.  This license, the GNU Lesser
-General Public License, applies to certain designated libraries, and
-is quite different from the ordinary General Public License.  We use
-this license for certain libraries in order to permit linking those
-libraries into non-free programs.
-
-  When a program is linked with a library, whether statically or using
-a shared library, the combination of the two is legally speaking a
-combined work, a derivative of the original library.  The ordinary
-General Public License therefore permits such linking only if the
-entire combination fits its criteria of freedom.  The Lesser General
-Public License permits more lax criteria for linking other code with
-the library.
-
-  We call this license the "Lesser" General Public License because it
-does Less to protect the user's freedom than the ordinary General
-Public License.  It also provides other free software developers Less
-of an advantage over competing non-free programs.  These disadvantages
-are the reason we use the ordinary General Public License for many
-libraries.  However, the Lesser license provides advantages in certain
-special circumstances.
-
-  For example, on rare occasions, there may be a special need to
-encourage the widest possible use of a certain library, so that it becomes
-a de-facto standard.  To achieve this, non-free programs must be
-allowed to use the library.  A more frequent case is that a free
-library does the same job as widely used non-free libraries.  In this
-case, there is little to gain by limiting the free library to free
-software only, so we use the Lesser General Public License.
-
-  In other cases, permission to use a particular library in non-free
-programs enables a greater number of people to use a large body of
-free software.  For example, permission to use the GNU C Library in
-non-free programs enables many more people to use the whole GNU
-operating system, as well as its variant, the GNU/Linux operating
-system.
-
-  Although the Lesser General Public License is Less protective of the
-users' freedom, it does ensure that the user of a program that is
-linked with the Library has the freedom and the wherewithal to run
-that program using a modified version of the Library.
-
-  The precise terms and conditions for copying, distribution and
-modification follow.  Pay close attention to the difference between a
-"work based on the library" and a "work that uses the library".  The
-former contains code derived from the library, whereas the latter must
-be combined with the library in order to run.
-
-		  GNU LESSER GENERAL PUBLIC LICENSE
-   TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
-
-  0. This License Agreement applies to any software library or other
-program which contains a notice placed by the copyright holder or
-other authorized party saying it may be distributed under the terms of
-this Lesser General Public License (also called "this License").
-Each licensee is addressed as "you".
-
-  A "library" means a collection of software functions and/or data
-prepared so as to be conveniently linked with application programs
-(which use some of those functions and data) to form executables.
-
-  The "Library", below, refers to any such software library or work
-which has been distributed under these terms.  A "work based on the
-Library" means either the Library or any derivative work under
-copyright law: that is to say, a work containing the Library or a
-portion of it, either verbatim or with modifications and/or translated
-straightforwardly into another language.  (Hereinafter, translation is
-included without limitation in the term "modification".)
-
-  "Source code" for a work means the preferred form of the work for
-making modifications to it.  For a library, complete source code means
-all the source code for all modules it contains, plus any associated
-interface definition files, plus the scripts used to control compilation
-and installation of the library.
-
-  Activities other than copying, distribution and modification are not
-covered by this License; they are outside its scope.  The act of
-running a program using the Library is not restricted, and output from
-such a program is covered only if its contents constitute a work based
-on the Library (independent of the use of the Library in a tool for
-writing it).  Whether that is true depends on what the Library does
-and what the program that uses the Library does.
-  
-  1. You may copy and distribute verbatim copies of the Library's
-complete source code as you receive it, in any medium, provided that
-you conspicuously and appropriately publish on each copy an
-appropriate copyright notice and disclaimer of warranty; keep intact
-all the notices that refer to this License and to the absence of any
-warranty; and distribute a copy of this License along with the
-Library.
-
-  You may charge a fee for the physical act of transferring a copy,
-and you may at your option offer warranty protection in exchange for a
-fee.
-
-  2. You may modify your copy or copies of the Library or any portion
-of it, thus forming a work based on the Library, and copy and
-distribute such modifications or work under the terms of Section 1
-above, provided that you also meet all of these conditions:
-
-    a) The modified work must itself be a software library.
-
-    b) You must cause the files modified to carry prominent notices
-    stating that you changed the files and the date of any change.
-
-    c) You must cause the whole of the work to be licensed at no
-    charge to all third parties under the terms of this License.
-
-    d) If a facility in the modified Library refers to a function or a
-    table of data to be supplied by an application program that uses
-    the facility, other than as an argument passed when the facility
-    is invoked, then you must make a good faith effort to ensure that,
-    in the event an application does not supply such function or
-    table, the facility still operates, and performs whatever part of
-    its purpose remains meaningful.
-
-    (For example, a function in a library to compute square roots has
-    a purpose that is entirely well-defined independent of the
-    application.  Therefore, Subsection 2d requires that any
-    application-supplied function or table used by this function must
-    be optional: if the application does not supply it, the square
-    root function must still compute square roots.)
-
-These requirements apply to the modified work as a whole.  If
-identifiable sections of that work are not derived from the Library,
-and can be reasonably considered independent and separate works in
-themselves, then this License, and its terms, do not apply to those
-sections when you distribute them as separate works.  But when you
-distribute the same sections as part of a whole which is a work based
-on the Library, the distribution of the whole must be on the terms of
-this License, whose permissions for other licensees extend to the
-entire whole, and thus to each and every part regardless of who wrote
-it.
-
-Thus, it is not the intent of this section to claim rights or contest
-your rights to work written entirely by you; rather, the intent is to
-exercise the right to control the distribution of derivative or
-collective works based on the Library.
-
-In addition, mere aggregation of another work not based on the Library
-with the Library (or with a work based on the Library) on a volume of
-a storage or distribution medium does not bring the other work under
-the scope of this License.
-
-  3. You may opt to apply the terms of the ordinary GNU General Public
-License instead of this License to a given copy of the Library.  To do
-this, you must alter all the notices that refer to this License, so
-that they refer to the ordinary GNU General Public License, version 2,
-instead of to this License.  (If a newer version than version 2 of the
-ordinary GNU General Public License has appeared, then you can specify
-that version instead if you wish.)  Do not make any other change in
-these notices.
-
-  Once this change is made in a given copy, it is irreversible for
-that copy, so the ordinary GNU General Public License applies to all
-subsequent copies and derivative works made from that copy.
-
-  This option is useful when you wish to copy part of the code of
-the Library into a program that is not a library.
-
-  4. You may copy and distribute the Library (or a portion or
-derivative of it, under Section 2) in object code or executable form
-under the terms of Sections 1 and 2 above provided that you accompany
-it with the complete corresponding machine-readable source code, which
-must be distributed under the terms of Sections 1 and 2 above on a
-medium customarily used for software interchange.
-
-  If distribution of object code is made by offering access to copy
-from a designated place, then offering equivalent access to copy the
-source code from the same place satisfies the requirement to
-distribute the source code, even though third parties are not
-compelled to copy the source along with the object code.
-
-  5. A program that contains no derivative of any portion of the
-Library, but is designed to work with the Library by being compiled or
-linked with it, is called a "work that uses the Library".  Such a
-work, in isolation, is not a derivative work of the Library, and
-therefore falls outside the scope of this License.
-
-  However, linking a "work that uses the Library" with the Library
-creates an executable that is a derivative of the Library (because it
-contains portions of the Library), rather than a "work that uses the
-library".  The executable is therefore covered by this License.
-Section 6 states terms for distribution of such executables.
-
-  When a "work that uses the Library" uses material from a header file
-that is part of the Library, the object code for the work may be a
-derivative work of the Library even though the source code is not.
-Whether this is true is especially significant if the work can be
-linked without the Library, or if the work is itself a library.  The
-threshold for this to be true is not precisely defined by law.
-
-  If such an object file uses only numerical parameters, data
-structure layouts and accessors, and small macros and small inline
-functions (ten lines or less in length), then the use of the object
-file is unrestricted, regardless of whether it is legally a derivative
-work.  (Executables containing this object code plus portions of the
-Library will still fall under Section 6.)
-
-  Otherwise, if the work is a derivative of the Library, you may
-distribute the object code for the work under the terms of Section 6.
-Any executables containing that work also fall under Section 6,
-whether or not they are linked directly with the Library itself.
-
-  6. As an exception to the Sections above, you may also combine or
-link a "work that uses the Library" with the Library to produce a
-work containing portions of the Library, and distribute that work
-under terms of your choice, provided that the terms permit
-modification of the work for the customer's own use and reverse
-engineering for debugging such modifications.
-
-  You must give prominent notice with each copy of the work that the
-Library is used in it and that the Library and its use are covered by
-this License.  You must supply a copy of this License.  If the work
-during execution displays copyright notices, you must include the
-copyright notice for the Library among them, as well as a reference
-directing the user to the copy of this License.  Also, you must do one
-of these things:
-
-    a) Accompany the work with the complete corresponding
-    machine-readable source code for the Library including whatever
-    changes were used in the work (which must be distributed under
-    Sections 1 and 2 above); and, if the work is an executable linked
-    with the Library, with the complete machine-readable "work that
-    uses the Library", as object code and/or source code, so that the
-    user can modify the Library and then relink to produce a modified
-    executable containing the modified Library.  (It is understood
-    that the user who changes the contents of definitions files in the
-    Library will not necessarily be able to recompile the application
-    to use the modified definitions.)
-
-    b) Use a suitable shared library mechanism for linking with the
-    Library.  A suitable mechanism is one that (1) uses at run time a
-    copy of the library already present on the user's computer system,
-    rather than copying library functions into the executable, and (2)
-    will operate properly with a modified version of the library, if
-    the user installs one, as long as the modified version is
-    interface-compatible with the version that the work was made with.
-
-    c) Accompany the work with a written offer, valid for at
-    least three years, to give the same user the materials
-    specified in Subsection 6a, above, for a charge no more
-    than the cost of performing this distribution.
-
-    d) If distribution of the work is made by offering access to copy
-    from a designated place, offer equivalent access to copy the above
-    specified materials from the same place.
-
-    e) Verify that the user has already received a copy of these
-    materials or that you have already sent this user a copy.
-
-  For an executable, the required form of the "work that uses the
-Library" must include any data and utility programs needed for
-reproducing the executable from it.  However, as a special exception,
-the materials to be distributed need not include anything that is
-normally distributed (in either source or binary form) with the major
-components (compiler, kernel, and so on) of the operating system on
-which the executable runs, unless that component itself accompanies
-the executable.
-
-  It may happen that this requirement contradicts the license
-restrictions of other proprietary libraries that do not normally
-accompany the operating system.  Such a contradiction means you cannot
-use both them and the Library together in an executable that you
-distribute.
-
-  7. You may place library facilities that are a work based on the
-Library side-by-side in a single library together with other library
-facilities not covered by this License, and distribute such a combined
-library, provided that the separate distribution of the work based on
-the Library and of the other library facilities is otherwise
-permitted, and provided that you do these two things:
-
-    a) Accompany the combined library with a copy of the same work
-    based on the Library, uncombined with any other library
-    facilities.  This must be distributed under the terms of the
-    Sections above.
-
-    b) Give prominent notice with the combined library of the fact
-    that part of it is a work based on the Library, and explaining
-    where to find the accompanying uncombined form of the same work.
-
-  8. You may not copy, modify, sublicense, link with, or distribute
-the Library except as expressly provided under this License.  Any
-attempt otherwise to copy, modify, sublicense, link with, or
-distribute the Library is void, and will automatically terminate your
-rights under this License.  However, parties who have received copies,
-or rights, from you under this License will not have their licenses
-terminated so long as such parties remain in full compliance.
-
-  9. You are not required to accept this License, since you have not
-signed it.  However, nothing else grants you permission to modify or
-distribute the Library or its derivative works.  These actions are
-prohibited by law if you do not accept this License.  Therefore, by
-modifying or distributing the Library (or any work based on the
-Library), you indicate your acceptance of this License to do so, and
-all its terms and conditions for copying, distributing or modifying
-the Library or works based on it.
-
-  10. Each time you redistribute the Library (or any work based on the
-Library), the recipient automatically receives a license from the
-original licensor to copy, distribute, link with or modify the Library
-subject to these terms and conditions.  You may not impose any further
-restrictions on the recipients' exercise of the rights granted herein.
-You are not responsible for enforcing compliance by third parties with
-this License.
-
-  11. If, as a consequence of a court judgment or allegation of patent
-infringement or for any other reason (not limited to patent issues),
-conditions are imposed on you (whether by court order, agreement or
-otherwise) that contradict the conditions of this License, they do not
-excuse you from the conditions of this License.  If you cannot
-distribute so as to satisfy simultaneously your obligations under this
-License and any other pertinent obligations, then as a consequence you
-may not distribute the Library at all.  For example, if a patent
-license would not permit royalty-free redistribution of the Library by
-all those who receive copies directly or indirectly through you, then
-the only way you could satisfy both it and this License would be to
-refrain entirely from distribution of the Library.
-
-If any portion of this section is held invalid or unenforceable under any
-particular circumstance, the balance of the section is intended to apply,
-and the section as a whole is intended to apply in other circumstances.
-
-It is not the purpose of this section to induce you to infringe any
-patents or other property right claims or to contest validity of any
-such claims; this section has the sole purpose of protecting the
-integrity of the free software distribution system which is
-implemented by public license practices.  Many people have made
-generous contributions to the wide range of software distributed
-through that system in reliance on consistent application of that
-system; it is up to the author/donor to decide if he or she is willing
-to distribute software through any other system and a licensee cannot
-impose that choice.
-
-This section is intended to make thoroughly clear what is believed to
-be a consequence of the rest of this License.
-
-  12. If the distribution and/or use of the Library is restricted in
-certain countries either by patents or by copyrighted interfaces, the
-original copyright holder who places the Library under this License may add
-an explicit geographical distribution limitation excluding those countries,
-so that distribution is permitted only in or among countries not thus
-excluded.  In such case, this License incorporates the limitation as if
-written in the body of this License.
-
-  13. The Free Software Foundation may publish revised and/or new
-versions of the Lesser General Public License from time to time.
-Such new versions will be similar in spirit to the present version,
-but may differ in detail to address new problems or concerns.
-
-Each version is given a distinguishing version number.  If the Library
-specifies a version number of this License which applies to it and
-"any later version", you have the option of following the terms and
-conditions either of that version or of any later version published by
-the Free Software Foundation.  If the Library does not specify a
-license version number, you may choose any version ever published by
-the Free Software Foundation.
-
-  14. If you wish to incorporate parts of the Library into other free
-programs whose distribution conditions are incompatible with these,
-write to the author to ask for permission.  For software which is
-copyrighted by the Free Software Foundation, write to the Free
-Software Foundation; we sometimes make exceptions for this.  Our
-decision will be guided by the two goals of preserving the free status
-of all derivatives of our free software and of promoting the sharing
-and reuse of software generally.
-
-			    NO WARRANTY
-
-  15. BECAUSE THE LIBRARY IS LICENSED FREE OF CHARGE, THERE IS NO
-WARRANTY FOR THE LIBRARY, TO THE EXTENT PERMITTED BY APPLICABLE LAW.
-EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR
-OTHER PARTIES PROVIDE THE LIBRARY "AS IS" WITHOUT WARRANTY OF ANY
-KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE
-IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
-PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE
-LIBRARY IS WITH YOU.  SHOULD THE LIBRARY PROVE DEFECTIVE, YOU ASSUME
-THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
-
-  16. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
-WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY
-AND/OR REDISTRIBUTE THE LIBRARY AS PERMITTED ABOVE, BE LIABLE TO YOU
-FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR
-CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE
-LIBRARY (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
-RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
-FAILURE OF THE LIBRARY TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
-SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
-DAMAGES.
-
-		     END OF TERMS AND CONDITIONS
diff --git a/src/libthread/COPYRIGHT b/src/libthread/COPYRIGHT
index d0820965..212b96bc 100644
--- a/src/libthread/COPYRIGHT
+++ b/src/libthread/COPYRIGHT
@@ -42,12 +42,3 @@ Contains parts of an earlier library that has:
  * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
  * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
 */
-
-===
-
-The above notices do *NOT* apply to Linux-sparc64-context.S
-or to sparc64-ucontext.c.  Those are functions from
-the GNU C library and are provided for systems that use the GNU C
-library but somehow are missing those functions.  They are
-distributed under the Lesser GPL; see COPYING.SPARC64-CONTEXT.
-
diff --git a/src/libthread/Linux-arm-asm.s b/src/libthread/Linux-arm-asm.s
deleted file mode 100644
index 9bd54f8a..00000000
--- a/src/libthread/Linux-arm-asm.s
+++ /dev/null
@@ -1,41 +0,0 @@
-.globl mygetmcontext
-mygetmcontext:
-	str	r1, [r0,#4]
-	str	r2, [r0,#8]
-	str	r3, [r0,#12]
-	str	r4, [r0,#16]
-	str	r5, [r0,#20]
-	str	r6, [r0,#24]
-	str	r7, [r0,#28]
-	str	r8, [r0,#32]
-	str	r9, [r0,#36]
-	str	r10, [r0,#40]
-	str	r11, [r0,#44]
-	str	r12, [r0,#48]
-	str	r13, [r0,#52]
-	str	r14, [r0,#56]
-	/* store 1 as r0-to-restore */
-	mov	r1, #1
-	str	r1, [r0]
-	/* return 0 */
-	mov	r0, #0
-	mov	pc, lr
-
-.globl mysetmcontext
-mysetmcontext:
-	ldr	r1, [r0,#4]
-	ldr	r2, [r0,#8]
-	ldr	r3, [r0,#12]
-	ldr	r4, [r0,#16]
-	ldr	r5, [r0,#20]
-	ldr	r6, [r0,#24]
-	ldr	r7, [r0,#28]
-	ldr	r8, [r0,#32]
-	ldr	r9, [r0,#36]
-	ldr	r10, [r0,#40]
-	ldr	r11, [r0,#44]
-	ldr	r12, [r0,#48]
-	ldr	r13, [r0,#52]
-	ldr	r14, [r0,#56]
-	ldr	r0, [r0]
-	mov	pc, lr
diff --git a/src/libthread/Linux-sparc64-context.S b/src/libthread/Linux-sparc64-context.S
deleted file mode 100644
index 1cc38391..00000000
--- a/src/libthread/Linux-sparc64-context.S
+++ /dev/null
@@ -1,135 +0,0 @@
-/* Copyright (C) 2001 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-     Contributed by Jakub Jelinek <jakub@redhat.com>.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, write to the Free
-   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
-   02111-1307 USA.  */
-
-/* Constants shared between setcontext() and getcontext().  Don't
-   install this header file.  */
-
-
-#define UC_LINK		0
-#define __UC_SIGMASK	16
-#define UC_M_PC		40
-#define UC_M_NPC	48
-#define UC_SIGMASK	536
-#define SIGMASK_WORDS	16
-
-/* Copyright (C) 1997, 2001 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Richard Henderson (rth@tamu.edu).
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, write to the Free
-   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
-   02111-1307 USA.  */
-
-#define ENTRY(x) x:
-#define END(x)
-
-/*#include "ucontext_i.h" (up above) */
-
-/* int getcontext(ucontext_t *); */
-
-ENTRY(getcontext)
-
-	ldx	[%o0 + UC_LINK], %o1	/* Preserve uc_link field, the
-					   trap clears it.  */
-	ta	0x6e
-1:
-	ldx	[%o0 + UC_M_PC], %o2
-	ldx	[%o0 + UC_M_NPC], %o3
-	ldx	[%o0 + __UC_SIGMASK], %o4
-	stx	%o1, [%o0 + UC_LINK]
-	add	%o2, 2f - 1b, %o2
-	stx	%o2, [%o0 + UC_M_PC]
-	add	%o3, 2f - 1b, %o3
-	stx	%o3, [%o0 + UC_M_NPC]
-#if SIGMASK_WORDS == 16
-	stx	%o4, [%o0 + UC_SIGMASK]
-	stx	%g0, [%o0 + UC_SIGMASK + 8]
-	stx	%g0, [%o0 + UC_SIGMASK + 16]
-	stx	%g0, [%o0 + UC_SIGMASK + 24]
-	stx	%g0, [%o0 + UC_SIGMASK + 32]
-	stx	%g0, [%o0 + UC_SIGMASK + 40]
-	stx	%g0, [%o0 + UC_SIGMASK + 48]
-	stx	%g0, [%o0 + UC_SIGMASK + 56]
-	stx	%g0, [%o0 + UC_SIGMASK + 64]
-	stx	%g0, [%o0 + UC_SIGMASK + 72]
-	stx	%g0, [%o0 + UC_SIGMASK + 80]
-	stx	%g0, [%o0 + UC_SIGMASK + 88]
-	stx	%g0, [%o0 + UC_SIGMASK + 96]
-	stx	%g0, [%o0 + UC_SIGMASK + 104]
-	stx	%g0, [%o0 + UC_SIGMASK + 112]
-	stx	%g0, [%o0 + UC_SIGMASK + 120]
-#else
-# error Adjust getcontext
-#endif
-2:
-	retl
-	 clr	%o0
-
-END(getcontext)
-
-/* Copyright (C) 1997, 2001 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Richard Henderson (rth@tamu.edu).
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, write to the Free
-   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
-   02111-1307 USA.  */
-
-/*
-#include <sysdep.h>
-#include "ucontext_i.h"
-*/
-
-/* int setcontext(ucontext_t *ctx); */
-.weak setcontext
-ENTRY(setcontext)
-
-	mov	1, %o1
-
-/* int __setcontext(ucontext_t *ctx, int restoremask); */
-ENTRY(__setcontext)
-
-	ldx	[%o0 + UC_SIGMASK], %o2
-	stx	%o2, [%o0 + __UC_SIGMASK]
-	ta	0x6f
-
-END(__setcontext)
-
diff --git a/src/libthread/NetBSD-386-asm.s b/src/libthread/NetBSD-386-asm.s
deleted file mode 100644
index 197f12b5..00000000
--- a/src/libthread/NetBSD-386-asm.s
+++ /dev/null
@@ -1,7 +0,0 @@
-.globl _tas
-_tas:
-	movl $0xCAFEBABE, %eax
-	movl 4(%esp), %ecx
-	xchgl %eax, 0(%ecx)
-	ret
-
diff --git a/src/libthread/NetBSD-power-asm.s b/src/libthread/NetBSD-power-asm.s
deleted file mode 100644
index d6e21c15..00000000
--- a/src/libthread/NetBSD-power-asm.s
+++ /dev/null
@@ -1,16 +0,0 @@
-	.globl	_tas
-_tas:
-	li	%r0, 0
-	mr	%r4, %r3
-	lis	%r5, 0xcafe
-	ori	%r5, %r5, 0xbabe
-1:
-	lwarx	%r3, %r0, %r4
-	cmpwi	%r3, 0
-	bne	2f
-	stwcx.	%r5, %r0, %r4
-	bne-	1b
-2:
-	sync
-	blr
-
diff --git a/src/libthread/NetBSD.c b/src/libthread/NetBSD.c
deleted file mode 100644
index 2b14146b..00000000
--- a/src/libthread/NetBSD.c
+++ /dev/null
@@ -1,437 +0,0 @@
-#include "threadimpl.h"
-
-#undef exits
-#undef _exits
-
-static int
-timefmt(Fmt *fmt)
-{
-	static char *mon[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun",
-		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
-	vlong ns;
-	Tm tm;
-	ns = nsec();
-	tm = *localtime(time(0));
-	return fmtprint(fmt, "%s %2d %02d:%02d:%02d.%03d",
-		mon[tm.mon], tm.mday, tm.hour, tm.min, tm.sec,
-		(int)(ns%1000000000)/1000000);
-}
-
-/*
- * spin locks
- */
-extern int _tas(int*);
-
-void
-_threadunlock(Lock *l, ulong pc)
-{
-	USED(pc);
-
-	l->held = 0;
-}
-
-int
-_threadlock(Lock *l, int block, ulong pc)
-{
-	int i;
-static int first=1;
-if(first) {first=0; fmtinstall('\001', timefmt);}
-
-	USED(pc);
-
-	/* once fast */
-	if(!_tas(&l->held))
-		return 1;
-	if(!block)
-		return 0;
-
-	/* a thousand times pretty fast */
-	for(i=0; i<1000; i++){
-		if(!_tas(&l->held))
-			return 1;
-		sched_yield();
-	}
-	/* now increasingly slow */
-	for(i=0; i<10; i++){
-		if(!_tas(&l->held))
-			return 1;
-		usleep(1);
-	}
-fprint(2, "%\001 %s: lock loop1 %p from %lux\n", argv0, l, pc);
-	for(i=0; i<10; i++){
-		if(!_tas(&l->held))
-			return 1;
-		usleep(10);
-	}
-fprint(2, "%\001 %s: lock loop2 %p from %lux\n", argv0, l, pc);
-	for(i=0; i<10; i++){
-		if(!_tas(&l->held))
-			return 1;
-		usleep(100);
-	}
-fprint(2, "%\001 %s: lock loop3 %p from %lux\n", argv0, l, pc);
-	for(i=0; i<10; i++){
-		if(!_tas(&l->held))
-			return 1;
-		usleep(1000);
-	}
-fprint(2, "%\001 %s: lock loop4 %p from %lux\n", argv0, l, pc);
-	for(i=0; i<10; i++){
-		if(!_tas(&l->held))
-			return 1;
-		usleep(10*1000);
-	}
-fprint(2, "%\001 %s: lock loop5 %p from %lux\n", argv0, l, pc);
-	for(i=0; i<1000; i++){
-		if(!_tas(&l->held))
-			return 1;
-		usleep(100*1000);
-	}
-fprint(2, "%\001 %s: lock loop6 %p from %lux\n", argv0, l, pc);
-	/* take your time */
-	while(_tas(&l->held))
-		usleep(1000*1000);
-	return 1;
-}
-
-/*
- * sleep and wakeup
- */
-static void
-ign(int x)
-{
-	USED(x);
-}
-
-static void /*__attribute__((constructor))*/
-ignusr1(int restart)
-{
-	struct sigaction sa;
-
-	memset(&sa, 0, sizeof sa);
-	sa.sa_handler = ign;
-	sigemptyset(&sa.sa_mask);
-	sigaddset(&sa.sa_mask, SIGUSR1);
-	if(restart)
-		sa.sa_flags = SA_RESTART;
-	sigaction(SIGUSR1, &sa, nil);
-}
-
-void
-_procsleep(_Procrendez *r)
-{
-	sigset_t mask;
-
-	/*
-	 * Go to sleep.
-	 *
-	 * Block USR1, set the handler to interrupt system calls,
-	 * unlock the vouslock so our waker can wake us,
-	 * and then suspend.
-	 */
-again:
-	r->asleep = 1;
-	r->pid = getpid();
-
-	sigprocmask(SIG_SETMASK, nil, &mask);
-	sigaddset(&mask, SIGUSR1);
-	sigprocmask(SIG_SETMASK, &mask, nil);
-	ignusr1(0);
-	unlock(r->l);
-	sigdelset(&mask, SIGUSR1);
-	sigsuspend(&mask);
-
-	/*
-	 * We're awake.  Make USR1 not interrupt system calls.
-	 */
-	lock(r->l);
-	ignusr1(1);
-	if(r->asleep && r->pid == getpid()){
-		/* Didn't really wake up - signal from something else */
-		goto again;
-	}
-}
-
-void
-_procwakeupandunlock(_Procrendez *r)
-{
-	int pid;
-
-	pid = 0;
-	if(r->asleep){
-		r->asleep = 0;
-		assert(r->pid >= 1);
-		pid = r->pid;
-	}
-	assert(r->l);
-	unlock(r->l);
-	if(pid)
-		kill(pid, SIGUSR1);
-}
-
-/*
- * process creation and exit
- */
-typedef struct Stackfree Stackfree;
-struct Stackfree
-{
-	Stackfree	*next;
-	int	pid;
-	int	pid1;
-};
-static Lock stacklock;
-static Stackfree *stackfree;
-
-static void
-delayfreestack(uchar *stk, int pid, int pid1)
-{
-	Stackfree *sf;
-
-	sf = (Stackfree*)stk;
-	sf->pid = pid;
-	sf->pid1 = pid1;
-	lock(&stacklock);
-	sf->next = stackfree;
-	stackfree = sf;
-	unlock(&stacklock);
-}
-
-static void
-dofreestacks(void)
-{
-	Stackfree *sf, *last, *next;
-
-	if(stackfree==nil || !canlock(&stacklock))
-		return;
-
-	for(last=nil,sf=stackfree; sf; last=sf,sf=next){
-		next = sf->next;
-		if(sf->pid >= 1 && kill(sf->pid, 0) < 0 && errno == ESRCH)
-		if(sf->pid1 >= 1 && kill(sf->pid1, 0) < 0 && errno == ESRCH){
-			free(sf);
-			if(last)
-				last->next = next;
-			else
-				stackfree = next;
-			sf = last;
-		}
-	}
-	unlock(&stacklock);
-}
-
-static int
-startprocfn(void *v)
-{
-	void **a;
-	uchar *stk;
-	void (*fn)(void*);
-	Proc *p;
-	int pid0, pid1;
-
-	a = (void**)v;
-	fn = a[0];
-	p = a[1];
-	stk = a[2];
-	pid0 = (int)a[4];
-	pid1 = getpid();
-	free(a);
-	p->osprocid = pid1;
-
-	(*fn)(p);
-
-	delayfreestack(stk, pid0, pid1);
-	_exit(0);
-	return 0;
-}
-
-/*
- * indirect through here so that parent need not wait for child zombie
- *
- * slight race - if child exits and then another process starts before we
- * manage to exit, we'll be running on a freed stack.
- */
-static int
-trampnowait(void *v)
-{
-	void **a;
-	int *kidpid;
-
-	a = (void*)v;
-	kidpid = a[3];
-	a[4] = (void*)getpid();
-	*kidpid = clone(startprocfn, a[2]+65536-512, CLONE_VM|CLONE_FILES, a);
-	_exit(0);
-	return 0;
-}
-
-void
-_procstart(Proc *p, void (*fn)(Proc*))
-{
-	void **a;
-	uchar *stk;
-	int pid, kidpid, status;
-
-	dofreestacks();
-	a = malloc(5*sizeof a[0]);
-	if(a == nil)
-		sysfatal("_procstart malloc: %r");
-	stk = malloc(65536);
-	if(stk == nil)
-		sysfatal("_procstart malloc stack: %r");
-
-	a[0] = fn;
-	a[1] = p;
-	a[2] = stk;
-	a[3] = &kidpid;
-	kidpid = -1;
-
-	pid = clone(trampnowait, stk+65536-16, CLONE_VM|CLONE_FILES, a);
-	if(pid > 0)
-		if(wait4(pid, &status, __WALL, 0) < 0)
-			fprint(2, "ffork wait4: %r\n");
-	if(pid < 0 || kidpid < 0){
-		fprint(2, "_procstart clone: %r\n");
-		abort();
-	}
-}
-
-static char *threadexitsmsg;
-void
-sigusr2handler(int s)
-{
-/*	fprint(2, "%d usr2 %d\n", time(0), getpid()); */
-	if(threadexitsmsg)
-		_exits(threadexitsmsg);
-}
-
-void
-threadexitsall(char *msg)
-{
-	static int pid[1024];
-	int i, npid, mypid;
-	Proc *p;
-
-	if(msg == nil)
-		msg = "";
-
-	/*
-	 * Only one guy, ever, gets to run this.
-	 * If two guys do it, inevitably they end up
-	 * tripping over each other in the underlying
-	 * C library exit() implementation, which is
-	 * trying to run the atexit handlers and apparently
-	 * not thread safe.  This has been observed on
-	 * both Linux and OpenBSD.  Sigh.
-	 */
-	{
-		static Lock onelock;
-		if(!canlock(&onelock))
-			_exits(threadexitsmsg);
-		threadexitsmsg = msg;
-	}
-
-	mypid = getpid();
-	lock(&_threadprocslock);
-	npid = 0;
-	for(p=_threadprocs; p; p=p->next)
-		if(p->osprocid != mypid && p->osprocid >= 1)
-			pid[npid++] = p->osprocid;
-	for(i=0; i<npid; i++)
-		kill(pid[i], SIGUSR2);
-	unlock(&_threadprocslock);
-	exits(msg);
-}
-
-/*
- * per-process data, indexed by pid
- *
- * could use modify_ldt and a segment register
- * to avoid the many calls to getpid(), but i don't
- * care -- this is compatibility code.  linux 2.6 with
- * nptl is a good enough pthreads to avoid this whole file.
- */
-typedef struct Perproc Perproc;
-struct Perproc
-{
-	int		pid;
-	Proc	*proc;
-};
-
-static Lock perlock;
-static Perproc perproc[1024];
-#define P ((Proc*)-1)
-
-static Perproc*
-myperproc(void)
-{
-	int i, pid, h;
-	Perproc *p;
-
-	pid = getpid();
-	h = pid%nelem(perproc);
-	for(i=0; i<nelem(perproc); i++){
-		p = &perproc[(i+h)%nelem(perproc)];
-		if(p->pid == pid)
-			return p;
-		if(p->pid == 0){
-			print("found 0 at %d (h=%d)\n", (i+h)%nelem(perproc), h);
-			break;
-		}
-	}
-	fprint(2, "myperproc %d (%s): cannot find self\n", pid, argv0);
-	abort();
-	return nil;
-}
-
-static Perproc*
-newperproc(void)
-{
-	int i, pid, h;
-	Perproc *p;
-
-	lock(&perlock);
-	pid = getpid();
-	h = pid%nelem(perproc);
-	for(i=0; i<nelem(perproc); i++){
-		p = &perproc[(i+h)%nelem(perproc)];
-		if(p->pid == pid || p->pid == -1 || p->pid == 0){
-			p->pid = pid;
-			unlock(&perlock);
-			return p;
-		}
-	}
-	fprint(2, "newperproc %d: out of procs\n", pid);
-	abort();
-	return nil;
-}
-
-Proc*
-_threadproc(void)
-{
-	return myperproc()->proc;
-}
-
-void
-_threadsetproc(Proc *p)
-{
-	Perproc *pp;
-
-	if(p)
-		p->osprocid = getpid();
-	pp = newperproc();
-	pp->proc = p;
-	if(p == nil)
-		pp->pid = -1;
-}
-
-void
-_pthreadinit(void)
-{
-	signal(SIGUSR2, sigusr2handler);
-}
-
-void
-_threadpexit(void)
-{
-	_exit(0);
-}
diff --git a/src/libthread/OpenBSD-386-asm.s b/src/libthread/OpenBSD-386-asm.s
deleted file mode 100644
index ed18d2f0..00000000
--- a/src/libthread/OpenBSD-386-asm.s
+++ /dev/null
@@ -1,45 +0,0 @@
-.globl getmcontext
-getmcontext:
-	movl	4(%esp), %eax
-
-	movl	%fs, 8(%eax)
-	movl	%es, 12(%eax)
-	movl	%ds, 16(%eax)
-	movl	%ss, 76(%eax)
-	movl	%edi, 20(%eax)
-	movl	%esi, 24(%eax)
-	movl	%ebp, 28(%eax)
-	movl	%ebx, 36(%eax)
-	movl	%edx, 40(%eax)
-	movl	%ecx, 44(%eax)
-
-	movl	$1, 48(%eax)	/* %eax */
-	movl	(%esp), %ecx	/* %eip */
-	movl	%ecx, 60(%eax)
-	leal	4(%esp), %ecx	/* %esp */
-	movl	%ecx, 72(%eax)
-
-	movl	44(%eax), %ecx	/* restore %ecx */
-	movl	$0, %eax
-	ret
-
-.globl setmcontext
-setmcontext:
-	movl	4(%esp), %eax
-
-	movl	8(%eax), %fs
-	movl	12(%eax), %es
-	movl	16(%eax), %ds
-	movl	76(%eax), %ss
-	movl	20(%eax), %edi
-	movl	24(%eax), %esi
-	movl	28(%eax), %ebp
-	movl	36(%eax), %ebx
-	movl	40(%eax), %edx
-	movl	44(%eax), %ecx
-
-	movl	72(%eax), %esp
-	pushl	60(%eax)	/* new %eip */
-	movl	48(%eax), %eax
-	ret
-
diff --git a/src/libthread/OpenBSD-power-asm.S b/src/libthread/OpenBSD-power-asm.S
deleted file mode 100644
index 36035eb5..00000000
--- a/src/libthread/OpenBSD-power-asm.S
+++ /dev/null
@@ -1,73 +0,0 @@
-ENTRY(_getmcontext)				/* xxx: instruction scheduling */
-	mflr	%r0
-	mfcr	%r5
-	mfctr	%r6
-	mfxer	%r7
-	stw	%r0, 0*4(%r3)
-	stw	%r5, 1*4(%r3)
-	stw	%r6, 2*4(%r3)
-	stw	%r7, 3*4(%r3)
-
-	stw	%r1, 4*4(%r3)
-	stw	%r2, 5*4(%r3)
-	li	%r5, 1			/* return value for setmcontext */
-	stw	%r5, 6*4(%r3)
-
-	stw	%r13, (0+7)*4(%r3)	/* callee-save GPRs */
-	stw	%r14, (1+7)*4(%r3)	/* xxx: block move */
-	stw	%r15, (2+7)*4(%r3)
-	stw	%r16, (3+7)*4(%r3)
-	stw	%r17, (4+7)*4(%r3)
-	stw	%r18, (5+7)*4(%r3)
-	stw	%r19, (6+7)*4(%r3)
-	stw	%r20, (7+7)*4(%r3)
-	stw	%r21, (8+7)*4(%r3)
-	stw	%r22, (9+7)*4(%r3)
-	stw	%r23, (10+7)*4(%r3)
-	stw	%r24, (11+7)*4(%r3)
-	stw	%r25, (12+7)*4(%r3)
-	stw	%r26, (13+7)*4(%r3)
-	stw	%r27, (14+7)*4(%r3)
-	stw	%r28, (15+7)*4(%r3)
-	stw	%r29, (16+7)*4(%r3)
-	stw	%r30, (17+7)*4(%r3)
-	stw	%r31, (18+7)*4(%r3)
-
-	li	%r3, 0			/* return */
-	blr
-
-ENTRY(_setmcontext)
-	lwz	%r13, (0+7)*4(%r3)	/* callee-save GPRs */
-	lwz	%r14, (1+7)*4(%r3)	/* xxx: block move */
-	lwz	%r15, (2+7)*4(%r3)
-	lwz	%r16, (3+7)*4(%r3)
-	lwz	%r17, (4+7)*4(%r3)
-	lwz	%r18, (5+7)*4(%r3)
-	lwz	%r19, (6+7)*4(%r3)
-	lwz	%r20, (7+7)*4(%r3)
-	lwz	%r21, (8+7)*4(%r3)
-	lwz	%r22, (9+7)*4(%r3)
-	lwz	%r23, (10+7)*4(%r3)
-	lwz	%r24, (11+7)*4(%r3)
-	lwz	%r25, (12+7)*4(%r3)
-	lwz	%r26, (13+7)*4(%r3)
-	lwz	%r27, (14+7)*4(%r3)
-	lwz	%r28, (15+7)*4(%r3)
-	lwz	%r29, (16+7)*4(%r3)
-	lwz	%r30, (17+7)*4(%r3)
-	lwz	%r31, (18+7)*4(%r3)
-
-	lwz	%r1, 4*4(%r3)
-	lwz	%r2, 5*4(%r3)
-
-	lwz	%r0, 0*4(%r3)
-	mtlr	%r0
-	lwz	%r0, 1*4(%r3)
-	mtcr	%r0			/* mtcrf 0xFF, %r0 */
-	lwz	%r0, 2*4(%r3)
-	mtctr	%r0
-	lwz	%r0, 3*4(%r3)
-	mtxer	%r0
-
-	lwz	%r3,	6*4(%r3)
-	blr
diff --git a/src/libthread/OpenBSD-x86_64-asm.S b/src/libthread/OpenBSD-x86_64-asm.S
deleted file mode 100644
index e982cdef..00000000
--- a/src/libthread/OpenBSD-x86_64-asm.S
+++ /dev/null
@@ -1,44 +0,0 @@
-.text
-.align 8
-
-.globl libthread_getmcontext
-libthread_getmcontext:
-	movq	$1, 0*8(%rdi)  // rax
-	movq	%rbx, 1*8(%rdi)
-	movq	%rcx, 2*8(%rdi)
-	movq	%rdx, 3*8(%rdi)
-	movq	%rsi, 4*8(%rdi)
-	movq	%rdi, 5*8(%rdi)
-	movq	%rbp, 6*8(%rdi)
-	movq	%rsp, 7*8(%rdi)
-	movq	%r8, 8*8(%rdi)
-	movq	%r9, 9*8(%rdi)
-	movq	%r10, 10*8(%rdi)
-	movq	%r11, 11*8(%rdi)
-	movq	%r12, 12*8(%rdi)
-	movq	%r13, 13*8(%rdi)
-	movq	%r14, 14*8(%rdi)
-	movq	%r15, 15*8(%rdi)
-	movq	$0, %rax
-	ret
-
-.globl libthread_setmcontext
-libthread_setmcontext:
-	movq	0*8(%rdi), %rax
-	movq	1*8(%rdi), %rbx
-	movq	2*8(%rdi), %rcx
-	movq	3*8(%rdi), %rdx
-	movq	4*8(%rdi), %rsi
-	// %rdi later
-	movq	6*8(%rdi), %rbp
-	movq	7*8(%rdi), %rsp
-	movq	8*8(%rdi), %r8
-	movq	9*8(%rdi), %r9
-	movq	10*8(%rdi), %r10
-	movq	11*8(%rdi), %r11
-	movq	12*8(%rdi), %r12
-	movq	13*8(%rdi), %r13
-	movq	14*8(%rdi), %r14
-	movq	15*8(%rdi), %r15
-	movq	5*8(%rdi), %rdi
-	ret
diff --git a/src/libthread/arm-ucontext.c b/src/libthread/arm-ucontext.c
deleted file mode 100644
index 512ca973..00000000
--- a/src/libthread/arm-ucontext.c
+++ /dev/null
@@ -1,24 +0,0 @@
-#include "threadimpl.h"
-
-void
-makecontext(ucontext_t *uc, void (*fn)(void), int argc, ...)
-{
-	int i, *sp;
-	va_list arg;
-
-	sp = USPALIGN(uc, 4);
-	va_start(arg, argc);
-	for(i=0; i<4 && i<argc; i++)
-		(&uc->uc_mcontext.arm_r0)[i] = va_arg(arg, uint);
-	va_end(arg);
-	uc->uc_mcontext.arm_sp = (uint)sp;
-	uc->uc_mcontext.arm_lr = (uint)fn;
-}
-
-int
-swapcontext(ucontext_t *oucp, const ucontext_t *ucp)
-{
-	if(getcontext(oucp) == 0)
-		setcontext(ucp);
-	return 0;
-}
diff --git a/src/libthread/bg.c b/src/libthread/bg.c
new file mode 100644
index 00000000..2edbc0e4
--- /dev/null
+++ b/src/libthread/bg.c
@@ -0,0 +1,7 @@
+#include "threadimpl.h"
+
+int
+threadmaybackground(void)
+{
+	return 0;
+}
diff --git a/src/libthread/daemonize.c b/src/libthread/daemonize.c
index 387d1527..29929068 100644
--- a/src/libthread/daemonize.c
+++ b/src/libthread/daemonize.c
@@ -8,7 +8,7 @@
 #undef wait
 
 static int sigpid;
-static int threadpassfd;
+static int threadpassfd = -1;
 static int gotsigchld;
 
 static void
@@ -101,6 +101,13 @@ _threadsetupdaemonize(void)
 
 	sigpid = 1;
 
+	/*
+	 * We've been told this program is likely to background itself.
+	 * Put it in its own process group so that we don't get a SIGHUP
+	 * when the parent exits.
+	 */
+	setpgrp();
+
 	if(pipe(p) < 0)
 		sysfatal("passer pipe: %r");
 
@@ -163,9 +170,9 @@ _threadsetupdaemonize(void)
 void
 _threaddaemonize(void)
 {
-	if(threadpassfd >= 0){
-		write(threadpassfd, "0", 1);
-		close(threadpassfd);
-		threadpassfd = -1;
-	}
+	if(threadpassfd < 0)
+		sysfatal("threads in main proc exited w/o threadmaybackground");
+	write(threadpassfd, "0", 1);
+	close(threadpassfd);
+	threadpassfd = -1;
 }
diff --git a/src/libthread/mkfile b/src/libthread/mkfile
index 8a77a316..40941f43 100644
--- a/src/libthread/mkfile
+++ b/src/libthread/mkfile
@@ -1,14 +1,14 @@
 <$PLAN9/src/mkhdr
 
-SYSOFILES=`{sh ./sysofiles.sh}
 LIB=libthread.a
 OFILES=\
-	$SYSOFILES\
+	bg.$O\
 	channel.$O\
 	daemonize.$O\
 	exec.$O\
 	ioproc.$O\
 	iorw.$O\
+	pthread.$O\
 	ref.$O\
 	thread.$O\
 	wait.$O\
diff --git a/src/libthread/power-ucontext.c b/src/libthread/power-ucontext.c
deleted file mode 100644
index 32a8e931..00000000
--- a/src/libthread/power-ucontext.c
+++ /dev/null
@@ -1,26 +0,0 @@
-#include "threadimpl.h"
-
-void
-makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...)
-{
-	ulong *sp, *tos;
-	va_list arg;
-
-	if(argc != 2)
-		sysfatal("libthread: makecontext misused");
-	sp = USPALIGN(ucp, 16);
-	ucp->mc.pc = (long)func;
-	ucp->mc.sp = (long)sp;
-	va_start(arg, argc);
-	ucp->mc.r3 = va_arg(arg, long);
-	ucp->mc.r4 = va_arg(arg, long);
-	va_end(arg);
-}
-
-int
-swapcontext(ucontext_t *oucp, ucontext_t *ucp)
-{
-	if(getcontext(oucp) == 0)
-		setcontext(ucp);
-	return 0;
-}
diff --git a/src/libthread/power-ucontext.h b/src/libthread/power-ucontext.h
deleted file mode 100644
index 1985d98d..00000000
--- a/src/libthread/power-ucontext.h
+++ /dev/null
@@ -1,36 +0,0 @@
-#define	setcontext(u)	_setmcontext(&(u)->mc)
-#define	getcontext(u)	_getmcontext(&(u)->mc)
-typedef struct mcontext mcontext_t;
-typedef struct ucontext ucontext_t;
-struct mcontext
-{
-	ulong	pc;		/* lr */
-	ulong	cr;		/* mfcr */
-	ulong	ctr;		/* mfcr */
-	ulong	xer;		/* mfcr */
-	ulong	sp;		/* callee saved: r1 */
-	ulong	toc;		/* callee saved: r2 */
-	ulong	r3;		/* first arg to function, return register: r3 */
-	ulong	gpr[19];	/* callee saved: r13-r31 */
-/*
-// XXX: currently do not save vector registers or floating-point state
-//	ulong	pad;
-//	uvlong	fpr[18];	/ * callee saved: f14-f31 * /
-//	ulong	vr[4*12];	/ * callee saved: v20-v31, 256-bits each * /
-*/
-};
-
-struct ucontext
-{
-	struct {
-		void *ss_sp;
-		uint ss_size;
-	} uc_stack;
-	sigset_t uc_sigmask;
-	mcontext_t mc;
-};
-
-void makecontext(ucontext_t*, void(*)(void), int, ...);
-int swapcontext(ucontext_t*, ucontext_t*);
-int _getmcontext(mcontext_t*);
-void _setmcontext(mcontext_t*);
diff --git a/src/libthread/sparc64-ucontext.c b/src/libthread/sparc64-ucontext.c
deleted file mode 100644
index e4800c19..00000000
--- a/src/libthread/sparc64-ucontext.c
+++ /dev/null
@@ -1,49 +0,0 @@
-/* Copyright (C) 2001 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-   Contributed by Jakub Jelinek <jakub@redhat.com>.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library; if not, write to the Free
-   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
-   02111-1307 USA.  */
-
-#include <ucontext.h>
-
-#define UC_M_PC 40
-#define UC_M_NPC 48
-
-extern int __getcontext (ucontext_t *ucp);
-extern int __setcontext (const ucontext_t *ucp, int restoremask);
-
-int
-swapcontext (ucontext_t *oucp, const ucontext_t *ucp)
-{
-  extern void __swapcontext_ret (void);
-  /* Save the current machine context to oucp.  */
-  __getcontext (oucp);
-  /* Modify oucp to skip the __setcontext call on reactivation.  */
-  *(long*)((char*)oucp+UC_M_PC) = (long)__swapcontext_ret;
-  *(long*)((char*)oucp+UC_M_NPC) = (long)__swapcontext_ret + 4;
-  /* Restore the machine context in ucp.  */
-  __setcontext (ucp, 1);
-  return 0;
-}
-
-asm ("							\n\
-	.text						\n\
-	.type	__swapcontext_ret, #function		\n\
-__swapcontext_ret:					\n\
-	return	%i7 + 8					\n\
-	 clr	%o0					\n\
-	.size	__swapcontext_ret, .-__swapcontext_ret	\n\
-     ");
diff --git a/src/libthread/stkmalloc.c b/src/libthread/stkmalloc.c
deleted file mode 100644
index 083aea1b..00000000
--- a/src/libthread/stkmalloc.c
+++ /dev/null
@@ -1,13 +0,0 @@
-#include "threadimpl.h"
-
-void*
-_threadstkalloc(int n)
-{
-	return malloc(n);
-}
-
-void
-_threadstkfree(void *v, int n)
-{
-	free(v);
-}
diff --git a/src/libthread/stkmmap.c b/src/libthread/stkmmap.c
deleted file mode 100644
index f4a24630..00000000
--- a/src/libthread/stkmmap.c
+++ /dev/null
@@ -1,25 +0,0 @@
-#include <u.h>
-#include <sys/mman.h>
-#include "threadimpl.h"
-
-#ifndef MAP_STACK
-#define MAP_STACK 0
-#endif
-
-void*
-_threadstkalloc(int n)
-{
-	void *p;
-
-	p = mmap(nil, n, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON|MAP_STACK, -1, 0);
-	if(p == (void*)-1)
-		return nil;
-	return p;
-}
-
-void
-_threadstkfree(void *v, int n)
-{
-	if(n > 0)
-		munmap(v, n);
-}
diff --git a/src/libthread/sysofiles.sh b/src/libthread/sysofiles.sh
deleted file mode 100644
index 833afbe0..00000000
--- a/src/libthread/sysofiles.sh
+++ /dev/null
@@ -1,28 +0,0 @@
-#!/bin/sh
-
-test -f $PLAN9/config && . $PLAN9/config
-
-case "$SYSNAME" in
-NetBSD)
-	echo ${SYSNAME}-${OBJTYPE}-asm.o $SYSNAME.o stkmalloc.o
-	;;
-OpenBSD)
-	echo pthread.o stkmmap.o
-	;;
-*)
-	echo pthread.o stkmalloc.o
-esac
-
-# Various libc don't supply swapcontext, makecontext, so we do.
-case "$SYSNAME-$OBJTYPE" in
-Linux-arm | Linux-sparc64 | NetBSD-arm | OpenBSD-386 | OpenBSD-power | OpenBSD-x86_64)
-	echo $OBJTYPE-ucontext.o
-	;;
-esac
-
-# A few libc don't supply setcontext, getcontext, so we do.
-case "$SYSNAME-$OBJTYPE" in
-Linux-arm | Linux-sparc64 | OpenBSD-386 | OpenBSD-power | OpenBSD-x86_64)
-	echo $SYSNAME-$OBJTYPE-asm.o
-	;;
-esac
diff --git a/src/libthread/thread.c b/src/libthread/thread.c
index 65e65194..79e0ec71 100644
--- a/src/libthread/thread.c
+++ b/src/libthread/thread.c
@@ -1,13 +1,12 @@
 #include "threadimpl.h"
 
-int	_threaddebuglevel;
+int	_threaddebuglevel = 0;
 
 static	uint		threadnproc;
 static	uint		threadnsysproc;
 static	Lock		threadnproclock;
 static	Ref		threadidref;
 static	Proc		*threadmainproc;
-static	int		pthreadperthread;
 
 static	void		addproc(Proc*);
 static	void		delproc(Proc*);
@@ -16,17 +15,18 @@ static	void		delthread(_Threadlist*, _Thread*);
 static	int		onlist(_Threadlist*, _Thread*);
 static	void		addthreadinproc(Proc*, _Thread*);
 static	void		delthreadinproc(Proc*, _Thread*);
-static	void		contextswitch(Context *from, Context *to);
 static	void		procmain(Proc*);
-static	void		procscheduler(Proc*);
 static	int		threadinfo(void*, char*);
+static 	void		pthreadscheduler(Proc *p);
+static	void		pthreadsleepschedlocked(Proc *p, _Thread *t);
+static	void		pthreadwakeupschedlocked(Proc *p, _Thread *self, _Thread *t);
+static	_Thread*	procnext(Proc*, _Thread*);
 
 static void
-_threaddebug(char *fmt, ...)
+_threaddebug(_Thread *t, char *fmt, ...)
 {
 	va_list arg;
 	char buf[128];
-	_Thread *t;
 	char *p;
 	static int fd = -1;
 
@@ -52,7 +52,8 @@ _threaddebug(char *fmt, ...)
 	va_start(arg, fmt);
 	vsnprint(buf, sizeof buf, fmt, arg);
 	va_end(arg);
-	t = proc()->thread;
+	if(t == nil)
+		t = proc()->thread;
 	if(t)
 		fprint(fd, "%p %d.%d: %s\n", proc(), getpid(), t->id, buf);
 	else
@@ -82,109 +83,24 @@ procalloc(void)
 	return p;
 }
 
-static void
-threadstart(uint y, uint x)
-{
-	_Thread *t;
-	ulong z;
-
-//print("threadstart\n");
-	z = (ulong)x << 16;	/* hide undefined 32-bit shift from 32-bit compilers */
-	z <<= 16;
-	z |= y;
-	t = (_Thread*)z;
-
-//print("threadstart sp=%p arg=%p startfn=%p t=%p\n", &t, t, t->startfn, t->startarg);
-	t->startfn(t->startarg);
-/*print("threadexits %p\n", v); */
-	threadexits(nil);
-/*print("not reacehd\n"); */
-}
-
-static _Thread*
-threadalloc(void (*fn)(void*), void *arg, uint stack)
+_Thread*
+_threadcreate(Proc *p, void (*fn)(void*), void *arg, uint stack)
 {
 	_Thread *t;
-	sigset_t zero;
-	uint x, y;
-	ulong z;
 
-	/* allocate the task and stack together */
+	USED(stack);
 	t = malloc(sizeof *t);
 	if(t == nil)
-		sysfatal("threadalloc malloc: %r");
+		sysfatal("threadcreate malloc: %r");
 	memset(t, 0, sizeof *t);
 	t->id = incref(&threadidref);
-//print("fn=%p arg=%p\n", fn, arg);
 	t->startfn = fn;
 	t->startarg = arg;
-//print("makecontext sp=%p t=%p startfn=%p\n", (char*)t->stk+t->stksize, t, t->startfn);
-
-	/* do a reasonable initialization */
-	if(stack == 0)
-		return t;
-	t->stk = _threadstkalloc(stack);
-	if(t->stk == nil)
-		sysfatal("threadalloc malloc stack: %r");
-	t->stksize = stack;
-	memset(&t->context.uc, 0, sizeof t->context.uc);
-	sigemptyset(&zero);
-	sigprocmask(SIG_BLOCK, &zero, &t->context.uc.uc_sigmask);
-//print("makecontext sp=%p t=%p startfn=%p\n", (char*)t->stk+t->stksize, t, t->startfn);
-
-	/* must initialize with current context */
-	if(getcontext(&t->context.uc) < 0)
-		sysfatal("threadalloc getcontext: %r");
-//print("makecontext sp=%p t=%p startfn=%p\n", (char*)t->stk+t->stksize, t, t->startfn);
-
-	/*
-	 * Call makecontext to do the real work.
-	 * To avoid various mistakes on other system software,
-	 * debuggers, and so on, don't get too close to both
-	 * ends of the stack. Just staying away is much easier
-	 * than debugging everything (outside our control)
-	 * that has off-by-one errors.
-	 */
-	t->context.uc.uc_stack.ss_sp = (void*)(t->stk+64);
-	t->context.uc.uc_stack.ss_size = t->stksize-2*64;
-#if defined(__sun__) && !defined(__MAKECONTEXT_V2_SOURCE)		/* sigh */
-	/* can avoid this with __MAKECONTEXT_V2_SOURCE but only on SunOS 5.9 */
-	t->context.uc.uc_stack.ss_sp =
-		(char*)t->context.uc.uc_stack.ss_sp
-		+t->context.uc.uc_stack.ss_size;
-#endif
-	/*
-	 * All this magic is because you have to pass makecontext a
-	 * function that takes some number of word-sized variables,
-	 * and on 64-bit machines pointers are bigger than words.
-	 */
-//print("makecontext sp=%p t=%p startfn=%p\n", (char*)t->stk+t->stksize, t, t->startfn);
-	z = (ulong)t;
-	y = z;
-	z >>= 16;	/* hide undefined 32-bit shift from 32-bit compilers */
-	x = z>>16;
-	makecontext(&t->context.uc, (void(*)(void))threadstart, 2, y, x);
-
-	return t;
-}
-
-_Thread*
-_threadcreate(Proc *p, void (*fn)(void*), void *arg, uint stack)
-{
-	_Thread *t;
-
-	/* defend against bad C libraries */
-	if(stack < (256<<10))
-		stack = 256<<10;
-
-	if(p->nthread == 0 || pthreadperthread)
-		stack = 0; // not using it
-	t = threadalloc(fn, arg, stack);
 	t->proc = p;
-	if(p->nthread == 0)
-		p->thread0 = t;
-	else if(pthreadperthread)
+	if(p->nthread != 0)
 		_threadpthreadstart(p, t);
+	else
+		t->mainthread = 1;
 	p->nthread++;
 	addthreadinproc(p, t);
 	_threadready(t);
@@ -197,6 +113,7 @@ threadcreate(void (*fn)(void*), void *arg, uint stack)
 	_Thread *t;
 
 	t = _threadcreate(proc(), fn, arg, stack);
+	_threaddebug(nil, "threadcreate %d", t->id);
 	return t->id;
 }
 
@@ -210,41 +127,11 @@ proccreate(void (*fn)(void*), void *arg, uint stack)
 	p = procalloc();
 	t = _threadcreate(p, fn, arg, stack);
 	id = t->id;	/* t might be freed after _procstart */
+	_threaddebug(t, "proccreate %p", p);
 	_procstart(p, procmain);
 	return id;
 }
 
-// For pthreadperthread mode, procswitch flips
-// between the threads.
-static void
-procswitch(Proc *p, _Thread *from, _Thread *to)
-{
-	_threaddebug("procswitch %p %d %d", p, from?from->id:-1, to?to->id:-1);
-	lock(&p->schedlock);
-	from->schedrend.l = &p->schedlock;
-	if(to) {
-		p->schedthread = to;
-		to->schedrend.l = &p->schedlock;
-		_threaddebug("procswitch wakeup %p %d", p, to->id);
-		_procwakeup(&to->schedrend);
-	}
-	if(p->schedthread != from) {
-		if(from->exiting) {
-			unlock(&p->schedlock);
-			_threadpexit();
-			_threaddebug("procswitch exit wakeup!!!\n");
-		}
-		while(p->schedthread != from) {
-			_threaddebug("procswitch sleep %p %d", p, from->id);
-			_procsleep(&from->schedrend);
-			_threaddebug("procswitch awake %p %d", p, from->id);
-		}
-		if(p->schedthread != from)
-			sysfatal("_procswitch %p %p oops", p->schedthread, from);
-	}
-	unlock(&p->schedlock);
-}
-
 void
 _threadswitch(void)
 {
@@ -252,15 +139,8 @@ _threadswitch(void)
 
 	needstack(0);
 	p = proc();
-
 /*print("threadswtch %p\n", p); */
-
-	if(p->thread == p->thread0)
-		procscheduler(p);
-	else if(pthreadperthread)
-		procswitch(p, p->thread, p->thread0);
-	else
-		contextswitch(&p->thread->context, &p->schedcontext);
+	pthreadscheduler(p);
 }
 
 void
@@ -359,15 +239,6 @@ threadsysfatal(char *fmt, va_list arg)
 }
 
 static void
-contextswitch(Context *from, Context *to)
-{
-	if(swapcontext(&from->uc, &to->uc) < 0){
-		fprint(2, "swapcontext failed: %r\n");
-		assert(0);
-	}
-}
-
-static void
 procmain(Proc *p)
 {
 	_Thread *t;
@@ -377,7 +248,6 @@ procmain(Proc *p)
 	/* take out first thread to run on system stack */
 	t = p->runqueue.head;
 	delthread(&p->runqueue, t);
-	memset(&t->context.uc, 0, sizeof t->context.uc);
 
 	/* run it */
 	p->thread = t;
@@ -390,118 +260,133 @@ void
 _threadpthreadmain(Proc *p, _Thread *t)
 {
 	_threadsetproc(p);
-	procswitch(p, t, nil);
+	lock(&p->lock);
+	pthreadsleepschedlocked(p, t);
+	unlock(&p->lock);
+	_threaddebug(nil, "startfn");
 	t->startfn(t->startarg);
 	threadexits(nil);
 }
 
 static void
-procscheduler(Proc *p)
+pthreadsleepschedlocked(Proc *p, _Thread *t)
 {
-	_Thread *t;
+	_threaddebug(t, "pthreadsleepsched %p %d", p, t->id);;
+	t->schedrend.l = &p->lock;
+	while(p->schedthread != t)
+		_procsleep(&t->schedrend);
+}
+
+static void
+pthreadwakeupschedlocked(Proc *p, _Thread *self, _Thread *t)
+{
+	_threaddebug(self, "pthreadwakeupschedlocked %p %d", p, t->id);;
+	t->schedrend.l = &p->lock;
+	p->schedthread = t;
+	_procwakeup(&t->schedrend);
+}
+
+static void
+pthreadscheduler(Proc *p)
+{
+	_Thread *self, *t;
 
-	_threaddebug("scheduler enter");
-//print("s %p\n", p);
-Top:
+	_threaddebug(nil, "scheduler");
 	lock(&p->lock);
-	t = p->thread;
+	self = p->thread;
 	p->thread = nil;
-	if(t->exiting){
-		delthreadinproc(p, t);
+	_threaddebug(self, "pausing");
+
+	if(self->exiting) {
+		_threaddebug(self, "exiting");
+		delthreadinproc(p, self);
 		p->nthread--;
-/*print("nthread %d\n", p->nthread); */
-		_threadstkfree(t->stk, t->stksize);
-		/*
-		 * Cannot free p->thread0 yet: it is used for the
-		 * context switches back to the scheduler.
-		 * Instead, we will free it at the end of this function.
-		 * But all the other threads can be freed now.
-		 */
-		if(t != p->thread0)
-			free(t);
 	}
 
-	for(;;){
-		if((t = p->pinthread) != nil){
-			while(!onlist(&p->runqueue, t)){
-				p->runrend.l = &p->lock;
-				_threaddebug("scheduler sleep (pin)");
-				_procsleep(&p->runrend);
-				_threaddebug("scheduler wake (pin)");
-			}
-		}else
-		while((t = p->runqueue.head) == nil){
-			if(p->nthread == 0)
-				goto Out;
-			if((t = p->idlequeue.head) != nil){
-				/*
-				 * Run all the idling threads once.
-				 */
-				while((t = p->idlequeue.head) != nil){
-					delthread(&p->idlequeue, t);
-					addthread(&p->runqueue, t);
-				}
-				continue;
-			}
-			p->runrend.l = &p->lock;
-			_threaddebug("scheduler sleep");
-			_procsleep(&p->runrend);
-			_threaddebug("scheduler wake");
-		}
-		if(p->pinthread && p->pinthread != t)
-			fprint(2, "p->pinthread %p t %p\n", p->pinthread, t);
-		assert(p->pinthread == nil || p->pinthread == t);
-		delthread(&p->runqueue, t);
-		unlock(&p->lock);
-		p->thread = t;
-		p->nswitch++;
-		_threaddebug("run %d (%s)", t->id, t->name);
-//print("run %p %p %p %p\n", t, *(uintptr*)(t->context.uc.mc.sp), t->context.uc.mc.di, t->context.uc.mc.si);
-		if(t == p->thread0)
+	t = procnext(p, self);
+	if(t != nil) {
+		pthreadwakeupschedlocked(p, self, t);
+		if(!self->exiting) {
+			pthreadsleepschedlocked(p, self);
+			_threaddebug(nil, "resume %d", self->id);
+			unlock(&p->lock);
 			return;
-		if(pthreadperthread)
-			procswitch(p, p->thread0, t);
-		else
-			contextswitch(&p->schedcontext, &t->context);
-		_threaddebug("back in scheduler");
-/*print("back in scheduler\n"); */
-		goto Top;
+		}
 	}
 
-Out:
-	_threaddebug("scheduler exit");
-	if(p->mainproc){
-		/*
-		 * Stupid bug - on Linux 2.6 and maybe elsewhere,
-		 * if the main thread exits then the others keep running
-		 * but the process shows up as a zombie in ps and is not
-		 * attachable with ptrace.  We'll just sit around pretending
-		 * to be a system proc instead of exiting.
-		 */
-		_threaddaemonize();
+	if(t == nil) {
+		/* Tear down proc bookkeeping. Wait to free p. */
+		delproc(p);
 		lock(&threadnproclock);
-		if(++threadnsysproc == threadnproc)
+		if(p->sysproc)
+			--threadnsysproc;
+		if(--threadnproc == threadnsysproc)
 			threadexitsall(p->msg);
-		p->sysproc = 1;
 		unlock(&threadnproclock);
-		for(;;)
-		 	sleep(1000);
 	}
 
-	delproc(p);
-	lock(&threadnproclock);
-	if(p->sysproc)
-		--threadnsysproc;
-	if(--threadnproc == threadnsysproc)
-		threadexitsall(p->msg);
-	unlock(&threadnproclock);
-	unlock(&p->lock);
+	/* Tear down pthread. */
+	if(self->mainthread && p->mainproc) {
+		_threaddaemonize();
+		_threaddebug(self, "sleeper");
+		unlock(&p->lock);
+		/*
+		 * Avoid bugs with main pthread exiting.
+		 * When all procs are gone, threadexitsall above will happen.
+		 */
+		for(;;)
+			sleep(60*60*1000);
+	}
 	_threadsetproc(nil);
-	free(p->thread0);
-	free(p);
+	free(self);
+	unlock(&p->lock);
+	if(t == nil)
+		free(p);
 	_threadpexit();
 }
 
+static _Thread*
+procnext(Proc *p, _Thread *self)
+{
+	_Thread *t;
+
+	if((t = p->pinthread) != nil){
+		while(!onlist(&p->runqueue, t)){
+			p->runrend.l = &p->lock;
+			_threaddebug(self, "scheduler sleep (pin)");
+			_procsleep(&p->runrend);
+			_threaddebug(self, "scheduler wake (pin)");
+		}
+	} else
+	while((t = p->runqueue.head) == nil){
+		if(p->nthread == 0)
+			return nil;
+		if((t = p->idlequeue.head) != nil){
+			/*
+			 * Run all the idling threads once.
+			 */
+			while((t = p->idlequeue.head) != nil){
+				delthread(&p->idlequeue, t);
+				addthread(&p->runqueue, t);
+			}
+			continue;
+		}
+		p->runrend.l = &p->lock;
+		_threaddebug(self, "scheduler sleep");
+		_procsleep(&p->runrend);
+		_threaddebug(self, "scheduler wake");
+	}
+
+	if(p->pinthread && p->pinthread != t)
+		fprint(2, "p->pinthread %p t %p\n", p->pinthread, t);
+	assert(p->pinthread == nil || p->pinthread == t);
+	delthread(&p->runqueue, t);
+
+	p->thread = t;
+	p->nswitch++;
+	return t;
+}
+
 void
 _threadsetsysproc(void)
 {
@@ -784,14 +669,18 @@ threadrwakeup(Rendez *r, int all, ulong pc)
 	int i;
 	_Thread *t;
 
+	_threaddebug(nil, "rwakeup %p %d", r, all);
 	for(i=0;; i++){
 		if(i==1 && !all)
 			break;
 		if((t = r->waiting.head) == nil)
 			break;
+		_threaddebug(nil, "rwakeup %p %d -> wake %d", r, all, t->id);
 		delthread(&r->waiting, t);
 		_threadready(t);
+		_threaddebug(nil, "rwakeup %p %d -> loop", r, all);
 	}
+	_threaddebug(nil, "rwakeup %p %d -> total %d", r, all, i);
 	return i;
 }
 
@@ -827,6 +716,7 @@ int
 main(int argc, char **argv)
 {
 	Proc *p;
+	_Thread *t;
 	char *opts;
 
 	argv0 = argv[0];
@@ -835,16 +725,7 @@ main(int argc, char **argv)
 	if(opts == nil)
 		opts = "";
 
-	pthreadperthread = (strstr(opts, "pthreadperthread") != nil);
-#ifdef PLAN9PORT_ASAN
-	// ASAN can't deal with the coroutine stack switches.
-	// In theory it has support for informing it about stack switches,
-	// but even with those calls added it can't deal with things
-	// like fork or exit from a coroutine stack.
-	// Easier to just run in pthread-per-thread mode.
-	pthreadperthread = 1;
-#endif
-	if(strstr(opts, "nodaemon") == nil && getenv("NOLIBTHREADDAEMONIZE") == nil)
+	if(threadmaybackground() && strstr(opts, "nodaemon") == nil && getenv("NOLIBTHREADDAEMONIZE") == nil)
 		_threadsetupdaemonize();
 
 	threadargc = argc;
@@ -875,9 +756,10 @@ main(int argc, char **argv)
 	if(mainstacksize == 0)
 		mainstacksize = 256*1024;
 	atnotify(threadinfo, 1);
-	_threadcreate(p, threadmainstart, nil, mainstacksize);
+	t = _threadcreate(p, threadmainstart, nil, mainstacksize);
+	t->mainthread = 1;
 	procmain(p);
-	sysfatal("procscheduler returned in threadmain!");
+	sysfatal("procmain returned in libthread");
 	/* does not return */
 	return 0;
 }
diff --git a/src/libthread/threadimpl.h b/src/libthread/threadimpl.h
index 8d22a161..fd40f252 100644
--- a/src/libthread/threadimpl.h
+++ b/src/libthread/threadimpl.h
@@ -9,36 +9,11 @@
 #	if defined(__APPLE__)
 #		define _XOPEN_SOURCE    /* for Snow Leopard */
 #	endif
-#	include <ucontext.h>
 #endif
 #include <sys/utsname.h>
 #include "libc.h"
 #include "thread.h"
 
-#if defined(__OpenBSD__)
-#	define mcontext libthread_mcontext
-#	define mcontext_t libthread_mcontext_t
-#	define ucontext libthread_ucontext
-#	define ucontext_t libthread_ucontext_t
-#	if defined __i386__
-#		include "386-ucontext.h"
-#	elif defined __amd64__
-#		include "x86_64-ucontext.h"
-#	else
-#		include "power-ucontext.h"
-#	endif
-extern pid_t rfork_thread(int, void*, int(*)(void*), void*);
-#endif
-
-#if defined(__arm__)
-int mygetmcontext(ulong*);
-void mysetmcontext(const ulong*);
-#define	setcontext(u)	mysetmcontext(&(u)->uc_mcontext.arm_r0)
-#define	getcontext(u)	mygetmcontext(&(u)->uc_mcontext.arm_r0)
-#endif
-
-
-typedef struct Context Context;
 typedef struct Execjob Execjob;
 typedef struct Proc Proc;
 typedef struct _Procrendez _Procrendez;
@@ -54,11 +29,6 @@ enum
 	STACK = 8192
 };
 
-struct Context
-{
-	ucontext_t	uc;
-};
-
 struct Execjob
 {
 	int *fd;
@@ -72,11 +42,7 @@ struct _Procrendez
 {
 	Lock		*l;
 	int		asleep;
-#ifdef PLAN9PORT_USING_PTHREADS
 	pthread_cond_t	cond;
-#else
-	int		pid;
-#endif
 };
 
 struct _Thread
@@ -85,18 +51,14 @@ struct _Thread
 	_Thread	*prev;
 	_Thread	*allnext;
 	_Thread	*allprev;
-	Context	context;
 	void	(*startfn)(void*);
 	void	*startarg;
 	uint	id;
-#ifdef PLAN9PORT_USING_PTHREADS
 	pthread_t	osprocid;
-#else
-	int		osprocid;
-#endif
 	uchar	*stk;
 	uint	stksize;
 	int		exiting;
+	int		mainthread;
 	Proc	*proc;
 	char	name[256];
 	char	state[256];
@@ -114,11 +76,7 @@ struct Proc
 	Proc		*next;
 	Proc		*prev;
 	char		msg[128];
-#ifdef PLAN9PORT_USING_PTHREADS
 	pthread_t	osprocid;
-#else
-	int		osprocid;
-#endif
 	Lock		lock;
 	int			nswitch;
 	_Thread		*thread0;
@@ -130,9 +88,7 @@ struct Proc
 	uint		nthread;
 	uint		sysproc;
 	_Procrendez	runrend;
-	Lock		schedlock;
 	_Thread	*schedthread;
-	Context	schedcontext;
 	void		*udata;
 	Jmp		sigjmp;
 	int		mainproc;
diff --git a/src/libthread/x86_64-ucontext.c b/src/libthread/x86_64-ucontext.c
deleted file mode 100644
index 5d1aaefc..00000000
--- a/src/libthread/x86_64-ucontext.c
+++ /dev/null
@@ -1,28 +0,0 @@
-#include "threadimpl.h"
-
-void
-makecontext(ucontext_t *uc, void (*fn)(void), int argc, ...)
-{
-	uintptr *sp;
-	va_list arg;
-
-	if(argc != 2)
-		sysfatal("libthread: makecontext misused");
-	va_start(arg, argc);
-	uc->mc.di = va_arg(arg, uint);
-	uc->mc.si = va_arg(arg, uint);
-	va_end(arg);
-
-	sp = USPALIGN(uc, 16);
-	*--sp = 0;  // fn's return address
-	*--sp = (uintptr)fn;  // return address of setcontext
-	uc->mc.sp = (uintptr)sp;
-}
-
-int
-swapcontext(ucontext_t *oucp, ucontext_t *ucp)
-{
-	if(getcontext(oucp) == 0)
-		setcontext(ucp);
-	return 0;
-}
diff --git a/src/libthread/x86_64-ucontext.h b/src/libthread/x86_64-ucontext.h
deleted file mode 100644
index e0640761..00000000
--- a/src/libthread/x86_64-ucontext.h
+++ /dev/null
@@ -1,42 +0,0 @@
-#define	setcontext(u)	libthread_setmcontext(&(u)->mc)
-#define	getcontext(u)	libthread_getmcontext(&(u)->mc)
-typedef struct mcontext mcontext_t;
-typedef struct ucontext ucontext_t;
-
-struct mcontext
-{
-	uintptr	ax;
-	uintptr	bx;
-	uintptr cx;
-	uintptr dx;
-	uintptr si;
-	uintptr di;
-	uintptr	bp;
-	uintptr sp;
-	uintptr r8;
-	uintptr r9;
-	uintptr r10;
-	uintptr r11;
-	uintptr r12;
-	uintptr r13;
-	uintptr r14;
-	uintptr r15;
-/*
-// XXX: currently do not save vector registers or floating-point state
-*/
-};
-
-struct ucontext
-{
-	struct {
-		void *ss_sp;
-		uint ss_size;
-	} uc_stack;
-	sigset_t uc_sigmask;
-	mcontext_t mc;
-};
-
-void makecontext(ucontext_t*, void(*)(void), int, ...);
-int swapcontext(ucontext_t*, ucontext_t*);
-int libthread_getmcontext(mcontext_t*);
-void libthread_setmcontext(mcontext_t*);