libthread: rm OpenBSD tas implementations OpenBSD is using pthreads now, so no need for tas.

libthread: use consistent stack calculation code in makecontext Also reduce duplication: makecontext is per-arch not per-os-arch. May fix #353.

libthread: rm NetBSD pthread reference in sysofiles.sh It may be that pthreads on NetBSD is now good enough, but the build as written (introduced in 23a2368 at my suggestion) is certainly broken, since both NetBSD.c and pthread.c define the same functions. If NetBSD does support pthreads now, then a few things should happen together: - libthread/sysofiles.sh should drop its top NetBSD case entirely - libthread/NetBSD.c should be deleted - libthread/NetBSD-*-asm.s should be deleted - include/u.h's NetBSD case should define PLAN9PORT_USING_PTHREADS and #include <pthread.h> For now, restore to less clearly broken build.

all: remove Linux 2.4 vs 2.6 detection Linux 2.4 is dead. (The libthread code hasn't worked for Linux 2.4 for a long time.)

libthread: remove Linux 2.4 code Linux.c was for Linux 2.4 and is no longer used directly, only indirectly because NetBSD.c was a 1-line file #including Linux.c. So mv Linux.c NetBSD.c. Also rm Linux-*-asm.s which was for Linux 2.4 as well.

libthread: rm unused sparc-ucontext.h More dead code.

libthread: rm Darwin pre-11.0.0 support Darwin 11.0.0 was Mac OS X 10.7.0 aka Lion. The previous version was Snow Leopard, which has been unsupported by Apple since February 2014.

libthread: rm FreeBSD 4 code Pretty sure FreeBSD 4 is gone now. :-)

libthread: rm OpenBSD.c This should have been deleted in 20f5692b (2012-07-14), which removed the mkfile and sysofiles.sh references to it.

libthread: rm unused ARM (get|set)mcontext (#354) They were just a duplicate of my(get|set)mcontext from the other assembly file, and unused from threadimpl.h. Change-Id: Id8003e5177ed9d37a7f0210037acbe55bbf7f708

9fs: remove tip (dead?), redirect sources to 9p.io Fixes #195. Signed-off-by: Dan Cross <cross@gajendra.net>

devdraw: abort alt sequence on window change on macOS Fixes #3.

libthread: NetBSD supports pthreads, remove ancient systems in sysofiles.sh Signed-off-by: Dan Cross <cross@gajendra.net>

malloc: remove locking The issue manifests in fork: POSIX fork mandates that a fork'd process is created with a single thread. If a multithreaded program forks, and some thread was in malloc() when the fork() happened, then in the child the lock will be held but there will be no thread to release it. We assume the system malloc() must already know how to deal with this and is thread-safe, but it won't know about our custom spinlock. Judging that this is no longer necessary (the lock code was added 15 years ago) we remove it. Signed-off-by: Dan Cross <cross@gajendra.net>

lib9: putenv wraps POSIX setenv, not legacy putenv POSIX setenv does everything that p9putenv's body, so just delegate to that. Signed-off-by: Dan Cross <cross@gajendra.net>