MFC r289172,r290254:

r289172:

Refactor the test/ Makefiles after recent changes to bsd.test.mk (r289158) and
netbsd-tests.test.mk (r289151)

- Eliminate explicit OBJTOP/SRCTOP setting
- Convert all ad hoc NetBSD test integration over to netbsd-tests.test.mk
- Remove unnecessary TESTSDIR setting
- Use SRCTOP where possible for clarity

r290254:

Remove unused variable (SRCDIR)

MFC r282057,r282092,r282106:

r282057:

Build/install libc, librt, libthr, and msun NetBSD test suites on all
architectures

r282092 (by andrew):

Correct the spelling of MACHINE_CPUARCH, MACHINE_CPU is not set on arm64.

r282106:

Remove per-architecture checks for enabling HAVE_FENV_H

The conditional came from NetBSD, where only select architectures have this
header/support

All architectures on FreeBSD have the necessary support though, so the
conditional's completely unnecessary

make tinderbox done on all architectures (including arm64, where the issue
occurred before) this time

MFC r274578,r274580:

r274578:

Add reachover Makefiles for contrib/netbsd-tests/lib/libpthread as
lib/libthr/tests

A variant of this code has been tested on amd64/i386 for some time by
EMC/Isilon on 10-STABLE/11-CURRENT. It builds on other architectures, but the
code will remain off until it's proven it works on virtual hardware or real
hardware on other architectures

Original work by: pho
Sponsored by: EMC / Isilon Storage Division

r274580:

Add reachover Makefiles for contrib/netbsd-tests/lib/librt

A variant of this code has been tested on amd64/i386 for some time by
EMC/Isilon on 10-STABLE/11-CURRENT. It builds on other architectures, but the
code will remain off until it's proven it works on virtual hardware or real
hardware on other architectures

Sponsored by: EMC / Isilon Storage Division

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Convert this piece of code to use C11 atomics.

As mentioned before, we should at least aim to have one piece of code in
both user space and kernel space that uses C11 atomics, to get some
coverage. This piece of code can be migrated trivially, so it's a good
candidate.

Register signal 33 explicitly as reserved by real-time library, and
use it by its new name (SIGLIBRT) rather than internal definition
in librt (SIGSERVICE).

Approved by: davidxu, arch

Free unused allocation on error.

Reported by: slonoman2011 yandex ru
MFC after: 1 week

Fix the 32-bit build stage on amd64 when WITH_CTF is enabled. It seems
ctfconvert will corrupt object files that are compiled with -g, if it is
not run with -g itself.

To fix it, remove -g from CFLAGS in lib/librt/Makefile. If you need to
compile this library with debug info, use DEBUG_FLAGS=-g instead, which
will work correctly, even when using WITH_CTF.

To support stack unwinding for cancellation points, add -fexceptions flag
for them, two functions _pthread_cancel_enter and _pthread_cancel_leave
are added to let thread enter and leave a cancellation point, it also
makes it possible that other functions can be cancellation points in
libraries without having to be rewritten in libthr.

Fixed dependencies (make checkdpadd).

Build lib/ with WARNS=6 by default.

Similar to libexec/, do the same with lib/. Make WARNS=6 the norm and
lower it when needed.

I'm setting WARNS?=0 for secure/. It seems secure/ includes the
Makefile.inc provided by lib/. I'm not going to touch that directory.
Most of the code there is contributed anyway.

Make following functions be cancellation points:
mq_receive
mq_send
mq_timereceive
mq_timedsend

link libpthread because the librt really needs it to fully function.

Fix compiler warnings.

atomic_fetchadd_int works on unsigned quantities - change
sigev_generation to be unsigned

MFC after: 1 month

Enable symbol versioning by default. Use WITHOUT_SYMVER to disable it.
Warning, after symbol versioning is enabled, going back is not easy
(use WITHOUT_SYMVER at your own risk).

Change the default thread library to libthr.

There most likely still needs to be a version bump for at least the
thread libraries. If necessary, this will happen later.

Don't enable symbol versioning for librt by default just yet.

Symbol version librt.

Account for recent changes in namespace.h. Use _pthread_create
instead of pthread_create.

Implement SIGEV_THREAD notification for aio_fsync.

No need to define NO_MAN here.

Block all signals in helper threads except those should not be blocked.

Set SNF_SYNC flag for timer, as the timer notification should be
serialized.

Remove stale comments.

1. Always call user callback function in newly created thread, it seems
POSIX implies that the user callback function must be executed in clean
environment.
2. Use newly introduced pthread stubs in libc.

Use a thread pool to process notification if sigev_notify_attributes
is default and caller does not require dedicated thread. timer needs
a dedicated thread to maintain overrun count correctly in notification
context. mqueue and aio can use thread pool to do notification
concurrently, the thread pool has lifecycle control, some threads will
exit if they have idled for a while.

save sigev_node pointer.

1. Fix a race in aio_return.
2. Save and restore syscall errno correctly.
3. Style fix.

Style fix.

Fix a mutex lock/unlock mismatch.

Forgot to revert to use weak symbols when I was debugging, fix it!

Add missing parameter mq_attr * for mq_open.

Bring in my initial version of POSIX realtime extension library.
Current the library implements mqueue, timer and aio with SIGEV_THREAD
notification supported.

Earlier version reviewed by: deischen