pthread: Nix trailing whitespace.

Use __pthread_volatile for ptc_waiters (Greg A. Woods)

- Make pthread_condvar and pthread_mutex work on the stack rather than in
pthread_t, so there's less chance of bad things happening if someone calls
(for example) pthread_cond_broadcast() from a signal handler.

- Remove all the deferred waiter handling except for the one case that really
matters which is transferring waiters from condvar -> mutex on wakeup, and
do that by splicing the condvar's waiters onto the mutex.

- Remove the mutex waiters bit as it's another complication that's not
strictly needed.

In the interests of reliability simplify waiter handling more and redo
condvars to manage the list of waiters with atomic ops.

Support <pthread_typs.h> on C89 compilers

Clang 5.0.0(svn) reports warnings on <pthread_types.h> for C99 constructs
when used with strict -std=c89.

Restrict designated initializers usage to C99 or newer code.
C89 and C++ will share the same code without extension of designated
initializers.

PR 52285

unnamed unions need special treatment since they need braced initializers
for old style initializations.

cplusplus does not like complex named initializers...

use named initializers

Use anonymous union for ptm_ceiling and old __pthread_spin_t field to
maintain backward compatibility and fix hppa build. hppa has an non-
integer type __pthread_spin_t

branches: 1.18.2;
GSoC 2016 Charles Cui: Implement thread priority protection based on work
by Andy Doran. Also document the get/set pshared thread calls as not
implemented, and add a skeleton implementation that is disabled.
XXX: document _sched_protect(2).

Fix PTHREAD_FOO_INITIALIZER for C++ by not using volatile in the relevant
pthread types in C++ builds, attempt 2.

The problem with attempt 1 was making assumptions of what the MD
__cpu_simple_lock_t (declared volatile) looks like. To get a same type
except non-volatile, we change the MD type to __cpu_simple_lock_nv_t
and typedef __cpu_simple_lock_t as a volatile __cpu_simple_lock_nv_t.
IMO, __cpu_simple_lock_t should not be volatile at all, but changing it
now is too risky.

Fixes at least Rumprun w/ gcc 5.1/5.2. Furthermore, the mpd application
(and possibly others) will no longer require NetBSD-specific patches.

Tested: build.sh for i386, Rumprun for x86_64 w/ gcc 5.2.

Based on the patch from Christos in lib/49989.

Rev 1.14 was nice except it didn't work with _INITIALIZER, which
sort of negates the whole point ... so revert everything while in
drawing board mode.

Don't depend on __CPU_SIMPLE_LOCK_PAD to determine the type of
__cpu_simple_lock_t (because it doesn't). Instead, use sizeof/alignof
with a struct { uchar[] }.

Fixes problem in previous commit, caught by Nick Hudson.

C++ (namely libc++) expects to be using PTHREAD_FOO_INITIALIZER as a
member initializer. This does not work for volatile types. Since C++
does not touch the guts of those types, redefine them as non-volatile.

Fixes libc++ compilation with g++ 5.1, as reported in PR lib/49989.

branches: 1.13.6;
Change pthread_mutex_t to use the amount of space as and be congruent to
the version used in the SA version of pthreads. This preserves binary
compatibility between both versions of the library.

Back out previous because it breaks the build.

glibc compatibile PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP, requested by
rafal@.

branches: 1.10.2;
Remove clause 3 and 4 from TNF licenses

branches: 1.9.4;
Adjust mutex/rwlock definitions to match reality now that there is only
one implementation of each. PR lib/38030.

- Don't take the mutex's spinlock (ptr_interlock) in pthread_cond_wait().
Instead, make the deferred wakeup list a per-thread array and pass down
the lwpid_t's that way.

- In pthread_cond_wait(), take the mutex before dealing with early wakeup.
In this way there should never be contention on the CV's spinlock if
the app follows POSIX rules (there should only be contention on the
user-provided mutex).

- Add a port of the kernel's rwlocks. The rwlock's spinlock is only taken if
there is contention. This is enabled where atomic ops are available. Right
now that is only i386 and amd64 because I don't have other hardware to
test with. It's trivial to add stubs for other architectures as long as
they have compare-and-swap. When we have proper atomic ops the old rwlock
code can be removed.

- Add a new mutex implementation that's similar to the kernel's mutexes, but
uses compare-and-swap to maintain the waiters list, so no spinlocks are
involved. Same caveats apply as for the rwlocks.

branches: 1.7.2; 1.7.4;
Some significant performance improvements, and a fix for a race with pthread
detach/join.

- Make mutex acquire spin for a short time, as done with spinlocks.
- Make the number of spins controllable with the env var PTHREAD_NSPINS.
- Reduce the amount of time that libpthread internal spinlocks are held.
- Rely more on the barrier effects of park/unpark to avoid taking spinlocks.
- Simplify the locking around pthreads and the global queues.
- Align per-thread sync data on a 128 byte boundary.
- Offset thread stacks by a small amount to try and reduce cache thrash.

branches: 1.6.2;
Remove obsolete comment.

Don't include <machine/lock.h> anymore; instead, we now get
__cpu_simple_lock_t and __SIMPLELOCK_{UN,}LOCKED from <sys/types.h>.
Should prevent the massive namespace pollution by way of dragging in
many MD headers that has been observed to break stuff.

Prepare for inclusion in sys/types.h by ensuring that all the symbols
defined end with _t or start with _[A-Z_].

Make pthread_barrier_wait() handle spurious wakeups from pthread__block()
by adding a generation number to the barrier structure and incrementing it
when the barrier fires.

XXX this is an ABI change for anything using barriers, but the library is
new enough and nothing in the tree uses barriers so I'm going to let it
slide. Using the private data pointer for a field that will always be present
would be excessive.

Merge the nathanw_sa branch.

branches: 1.1.2;
file pthread_types.h was initially added on branch nathanw_sa.

Use __pthread_volatile for ptc_waiters (Greg A. Woods)

- Make pthread_condvar and pthread_mutex work on the stack rather than in
pthread_t, so there's less chance of bad things happening if someone calls
(for example) pthread_cond_broadcast() from a signal handler.

- Remove all the deferred waiter handling except for the one case that really
matters which is transferring waiters from condvar -> mutex on wakeup, and
do that by splicing the condvar's waiters onto the mutex.

- Remove the mutex waiters bit as it's another complication that's not
strictly needed.

In the interests of reliability simplify waiter handling more and redo
condvars to manage the list of waiters with atomic ops.

Support <pthread_typs.h> on C89 compilers

Clang 5.0.0(svn) reports warnings on <pthread_types.h> for C99 constructs
when used with strict -std=c89.

Restrict designated initializers usage to C99 or newer code.
C89 and C++ will share the same code without extension of designated
initializers.

PR 52285

unnamed unions need special treatment since they need braced initializers
for old style initializations.

cplusplus does not like complex named initializers...

use named initializers

Use anonymous union for ptm_ceiling and old __pthread_spin_t field to
maintain backward compatibility and fix hppa build. hppa has an non-
integer type __pthread_spin_t

branches: 1.18.2;
GSoC 2016 Charles Cui: Implement thread priority protection based on work
by Andy Doran. Also document the get/set pshared thread calls as not
implemented, and add a skeleton implementation that is disabled.
XXX: document _sched_protect(2).

Fix PTHREAD_FOO_INITIALIZER for C++ by not using volatile in the relevant
pthread types in C++ builds, attempt 2.

The problem with attempt 1 was making assumptions of what the MD
__cpu_simple_lock_t (declared volatile) looks like. To get a same type
except non-volatile, we change the MD type to __cpu_simple_lock_nv_t
and typedef __cpu_simple_lock_t as a volatile __cpu_simple_lock_nv_t.
IMO, __cpu_simple_lock_t should not be volatile at all, but changing it
now is too risky.

Fixes at least Rumprun w/ gcc 5.1/5.2. Furthermore, the mpd application
(and possibly others) will no longer require NetBSD-specific patches.

Tested: build.sh for i386, Rumprun for x86_64 w/ gcc 5.2.

Based on the patch from Christos in lib/49989.

Rev 1.14 was nice except it didn't work with _INITIALIZER, which
sort of negates the whole point ... so revert everything while in
drawing board mode.

Don't depend on __CPU_SIMPLE_LOCK_PAD to determine the type of
__cpu_simple_lock_t (because it doesn't). Instead, use sizeof/alignof
with a struct { uchar[] }.

Fixes problem in previous commit, caught by Nick Hudson.

C++ (namely libc++) expects to be using PTHREAD_FOO_INITIALIZER as a
member initializer. This does not work for volatile types. Since C++
does not touch the guts of those types, redefine them as non-volatile.

Fixes libc++ compilation with g++ 5.1, as reported in PR lib/49989.

branches: 1.13.6;
Change pthread_mutex_t to use the amount of space as and be congruent to
the version used in the SA version of pthreads. This preserves binary
compatibility between both versions of the library.

Back out previous because it breaks the build.

glibc compatibile PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP, requested by
rafal@.

branches: 1.10.2;
Remove clause 3 and 4 from TNF licenses

branches: 1.9.4;
Adjust mutex/rwlock definitions to match reality now that there is only
one implementation of each. PR lib/38030.

- Don't take the mutex's spinlock (ptr_interlock) in pthread_cond_wait().
Instead, make the deferred wakeup list a per-thread array and pass down
the lwpid_t's that way.

- In pthread_cond_wait(), take the mutex before dealing with early wakeup.
In this way there should never be contention on the CV's spinlock if
the app follows POSIX rules (there should only be contention on the
user-provided mutex).

- Add a port of the kernel's rwlocks. The rwlock's spinlock is only taken if
there is contention. This is enabled where atomic ops are available. Right
now that is only i386 and amd64 because I don't have other hardware to
test with. It's trivial to add stubs for other architectures as long as
they have compare-and-swap. When we have proper atomic ops the old rwlock
code can be removed.

- Add a new mutex implementation that's similar to the kernel's mutexes, but
uses compare-and-swap to maintain the waiters list, so no spinlocks are
involved. Same caveats apply as for the rwlocks.

branches: 1.7.2; 1.7.4;
Some significant performance improvements, and a fix for a race with pthread
detach/join.

- Make mutex acquire spin for a short time, as done with spinlocks.
- Make the number of spins controllable with the env var PTHREAD_NSPINS.
- Reduce the amount of time that libpthread internal spinlocks are held.
- Rely more on the barrier effects of park/unpark to avoid taking spinlocks.
- Simplify the locking around pthreads and the global queues.
- Align per-thread sync data on a 128 byte boundary.
- Offset thread stacks by a small amount to try and reduce cache thrash.

branches: 1.6.2;
Remove obsolete comment.

Don't include <machine/lock.h> anymore; instead, we now get
__cpu_simple_lock_t and __SIMPLELOCK_{UN,}LOCKED from <sys/types.h>.
Should prevent the massive namespace pollution by way of dragging in
many MD headers that has been observed to break stuff.

Prepare for inclusion in sys/types.h by ensuring that all the symbols
defined end with _t or start with _[A-Z_].

Make pthread_barrier_wait() handle spurious wakeups from pthread__block()
by adding a generation number to the barrier structure and incrementing it
when the barrier fires.

XXX this is an ABI change for anything using barriers, but the library is
new enough and nothing in the tree uses barriers so I'm going to let it
slide. Using the private data pointer for a field that will always be present
would be excessive.

Merge the nathanw_sa branch.

branches: 1.1.2;
file pthread_types.h was initially added on branch nathanw_sa.

- Make pthread_condvar and pthread_mutex work on the stack rather than in
pthread_t, so there's less chance of bad things happening if someone calls
(for example) pthread_cond_broadcast() from a signal handler.

- Remove all the deferred waiter handling except for the one case that really
matters which is transferring waiters from condvar -> mutex on wakeup, and
do that by splicing the condvar's waiters onto the mutex.

- Remove the mutex waiters bit as it's another complication that's not
strictly needed.

In the interests of reliability simplify waiter handling more and redo
condvars to manage the list of waiters with atomic ops.

Support <pthread_typs.h> on C89 compilers

Clang 5.0.0(svn) reports warnings on <pthread_types.h> for C99 constructs
when used with strict -std=c89.

Restrict designated initializers usage to C99 or newer code.
C89 and C++ will share the same code without extension of designated
initializers.

PR 52285

unnamed unions need special treatment since they need braced initializers
for old style initializations.

cplusplus does not like complex named initializers...

use named initializers

Use anonymous union for ptm_ceiling and old __pthread_spin_t field to
maintain backward compatibility and fix hppa build. hppa has an non-
integer type __pthread_spin_t

branches: 1.18.2;
GSoC 2016 Charles Cui: Implement thread priority protection based on work
by Andy Doran. Also document the get/set pshared thread calls as not
implemented, and add a skeleton implementation that is disabled.
XXX: document _sched_protect(2).

Fix PTHREAD_FOO_INITIALIZER for C++ by not using volatile in the relevant
pthread types in C++ builds, attempt 2.

The problem with attempt 1 was making assumptions of what the MD
__cpu_simple_lock_t (declared volatile) looks like. To get a same type
except non-volatile, we change the MD type to __cpu_simple_lock_nv_t
and typedef __cpu_simple_lock_t as a volatile __cpu_simple_lock_nv_t.
IMO, __cpu_simple_lock_t should not be volatile at all, but changing it
now is too risky.

Fixes at least Rumprun w/ gcc 5.1/5.2. Furthermore, the mpd application
(and possibly others) will no longer require NetBSD-specific patches.

Tested: build.sh for i386, Rumprun for x86_64 w/ gcc 5.2.

Based on the patch from Christos in lib/49989.

Rev 1.14 was nice except it didn't work with _INITIALIZER, which
sort of negates the whole point ... so revert everything while in
drawing board mode.

Don't depend on __CPU_SIMPLE_LOCK_PAD to determine the type of
__cpu_simple_lock_t (because it doesn't). Instead, use sizeof/alignof
with a struct { uchar[] }.

Fixes problem in previous commit, caught by Nick Hudson.

C++ (namely libc++) expects to be using PTHREAD_FOO_INITIALIZER as a
member initializer. This does not work for volatile types. Since C++
does not touch the guts of those types, redefine them as non-volatile.

Fixes libc++ compilation with g++ 5.1, as reported in PR lib/49989.

branches: 1.13.6;
Change pthread_mutex_t to use the amount of space as and be congruent to
the version used in the SA version of pthreads. This preserves binary
compatibility between both versions of the library.

Back out previous because it breaks the build.

glibc compatibile PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP, requested by
rafal@.

branches: 1.10.2;
Remove clause 3 and 4 from TNF licenses

branches: 1.9.4;
Adjust mutex/rwlock definitions to match reality now that there is only
one implementation of each. PR lib/38030.

- Don't take the mutex's spinlock (ptr_interlock) in pthread_cond_wait().
Instead, make the deferred wakeup list a per-thread array and pass down
the lwpid_t's that way.

- In pthread_cond_wait(), take the mutex before dealing with early wakeup.
In this way there should never be contention on the CV's spinlock if
the app follows POSIX rules (there should only be contention on the
user-provided mutex).

- Add a port of the kernel's rwlocks. The rwlock's spinlock is only taken if
there is contention. This is enabled where atomic ops are available. Right
now that is only i386 and amd64 because I don't have other hardware to
test with. It's trivial to add stubs for other architectures as long as
they have compare-and-swap. When we have proper atomic ops the old rwlock
code can be removed.

- Add a new mutex implementation that's similar to the kernel's mutexes, but
uses compare-and-swap to maintain the waiters list, so no spinlocks are
involved. Same caveats apply as for the rwlocks.

branches: 1.7.2; 1.7.4;
Some significant performance improvements, and a fix for a race with pthread
detach/join.

- Make mutex acquire spin for a short time, as done with spinlocks.
- Make the number of spins controllable with the env var PTHREAD_NSPINS.
- Reduce the amount of time that libpthread internal spinlocks are held.
- Rely more on the barrier effects of park/unpark to avoid taking spinlocks.
- Simplify the locking around pthreads and the global queues.
- Align per-thread sync data on a 128 byte boundary.
- Offset thread stacks by a small amount to try and reduce cache thrash.

branches: 1.6.2;
Remove obsolete comment.

Don't include <machine/lock.h> anymore; instead, we now get
__cpu_simple_lock_t and __SIMPLELOCK_{UN,}LOCKED from <sys/types.h>.
Should prevent the massive namespace pollution by way of dragging in
many MD headers that has been observed to break stuff.

Prepare for inclusion in sys/types.h by ensuring that all the symbols
defined end with _t or start with _[A-Z_].

Make pthread_barrier_wait() handle spurious wakeups from pthread__block()
by adding a generation number to the barrier structure and incrementing it
when the barrier fires.

XXX this is an ABI change for anything using barriers, but the library is
new enough and nothing in the tree uses barriers so I'm going to let it
slide. Using the private data pointer for a field that will always be present
would be excessive.

Merge the nathanw_sa branch.

branches: 1.1.2;
file pthread_types.h was initially added on branch nathanw_sa.

In the interests of reliability simplify waiter handling more and redo
condvars to manage the list of waiters with atomic ops.

Support <pthread_typs.h> on C89 compilers

Clang 5.0.0(svn) reports warnings on <pthread_types.h> for C99 constructs
when used with strict -std=c89.

Restrict designated initializers usage to C99 or newer code.
C89 and C++ will share the same code without extension of designated
initializers.

PR 52285

unnamed unions need special treatment since they need braced initializers
for old style initializations.

cplusplus does not like complex named initializers...

use named initializers

Use anonymous union for ptm_ceiling and old __pthread_spin_t field to
maintain backward compatibility and fix hppa build. hppa has an non-
integer type __pthread_spin_t

branches: 1.18.2;
GSoC 2016 Charles Cui: Implement thread priority protection based on work
by Andy Doran. Also document the get/set pshared thread calls as not
implemented, and add a skeleton implementation that is disabled.
XXX: document _sched_protect(2).

Fix PTHREAD_FOO_INITIALIZER for C++ by not using volatile in the relevant
pthread types in C++ builds, attempt 2.

The problem with attempt 1 was making assumptions of what the MD
__cpu_simple_lock_t (declared volatile) looks like. To get a same type
except non-volatile, we change the MD type to __cpu_simple_lock_nv_t
and typedef __cpu_simple_lock_t as a volatile __cpu_simple_lock_nv_t.
IMO, __cpu_simple_lock_t should not be volatile at all, but changing it
now is too risky.

Fixes at least Rumprun w/ gcc 5.1/5.2. Furthermore, the mpd application
(and possibly others) will no longer require NetBSD-specific patches.

Tested: build.sh for i386, Rumprun for x86_64 w/ gcc 5.2.

Based on the patch from Christos in lib/49989.

Rev 1.14 was nice except it didn't work with _INITIALIZER, which
sort of negates the whole point ... so revert everything while in
drawing board mode.

Don't depend on __CPU_SIMPLE_LOCK_PAD to determine the type of
__cpu_simple_lock_t (because it doesn't). Instead, use sizeof/alignof
with a struct { uchar[] }.

Fixes problem in previous commit, caught by Nick Hudson.

C++ (namely libc++) expects to be using PTHREAD_FOO_INITIALIZER as a
member initializer. This does not work for volatile types. Since C++
does not touch the guts of those types, redefine them as non-volatile.

Fixes libc++ compilation with g++ 5.1, as reported in PR lib/49989.

branches: 1.13.6;
Change pthread_mutex_t to use the amount of space as and be congruent to
the version used in the SA version of pthreads. This preserves binary
compatibility between both versions of the library.

Back out previous because it breaks the build.

glibc compatibile PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP, requested by
rafal@.

branches: 1.10.2;
Remove clause 3 and 4 from TNF licenses

branches: 1.9.4;
Adjust mutex/rwlock definitions to match reality now that there is only
one implementation of each. PR lib/38030.

- Don't take the mutex's spinlock (ptr_interlock) in pthread_cond_wait().
Instead, make the deferred wakeup list a per-thread array and pass down
the lwpid_t's that way.

- In pthread_cond_wait(), take the mutex before dealing with early wakeup.
In this way there should never be contention on the CV's spinlock if
the app follows POSIX rules (there should only be contention on the
user-provided mutex).

- Add a port of the kernel's rwlocks. The rwlock's spinlock is only taken if
there is contention. This is enabled where atomic ops are available. Right
now that is only i386 and amd64 because I don't have other hardware to
test with. It's trivial to add stubs for other architectures as long as
they have compare-and-swap. When we have proper atomic ops the old rwlock
code can be removed.

- Add a new mutex implementation that's similar to the kernel's mutexes, but
uses compare-and-swap to maintain the waiters list, so no spinlocks are
involved. Same caveats apply as for the rwlocks.

branches: 1.7.2; 1.7.4;
Some significant performance improvements, and a fix for a race with pthread
detach/join.

- Make mutex acquire spin for a short time, as done with spinlocks.
- Make the number of spins controllable with the env var PTHREAD_NSPINS.
- Reduce the amount of time that libpthread internal spinlocks are held.
- Rely more on the barrier effects of park/unpark to avoid taking spinlocks.
- Simplify the locking around pthreads and the global queues.
- Align per-thread sync data on a 128 byte boundary.
- Offset thread stacks by a small amount to try and reduce cache thrash.

branches: 1.6.2;
Remove obsolete comment.

Don't include <machine/lock.h> anymore; instead, we now get
__cpu_simple_lock_t and __SIMPLELOCK_{UN,}LOCKED from <sys/types.h>.
Should prevent the massive namespace pollution by way of dragging in
many MD headers that has been observed to break stuff.

Prepare for inclusion in sys/types.h by ensuring that all the symbols
defined end with _t or start with _[A-Z_].

Make pthread_barrier_wait() handle spurious wakeups from pthread__block()
by adding a generation number to the barrier structure and incrementing it
when the barrier fires.

XXX this is an ABI change for anything using barriers, but the library is
new enough and nothing in the tree uses barriers so I'm going to let it
slide. Using the private data pointer for a field that will always be present
would be excessive.

Merge the nathanw_sa branch.

branches: 1.1.2;
file pthread_types.h was initially added on branch nathanw_sa.

Support <pthread_typs.h> on C89 compilers

Clang 5.0.0(svn) reports warnings on <pthread_types.h> for C99 constructs
when used with strict -std=c89.

Restrict designated initializers usage to C99 or newer code.
C89 and C++ will share the same code without extension of designated
initializers.

PR 52285

unnamed unions need special treatment since they need braced initializers
for old style initializations.

cplusplus does not like complex named initializers...

use named initializers

Use anonymous union for ptm_ceiling and old __pthread_spin_t field to
maintain backward compatibility and fix hppa build. hppa has an non-
integer type __pthread_spin_t

branches: 1.18.2;
GSoC 2016 Charles Cui: Implement thread priority protection based on work
by Andy Doran. Also document the get/set pshared thread calls as not
implemented, and add a skeleton implementation that is disabled.
XXX: document _sched_protect(2).

Fix PTHREAD_FOO_INITIALIZER for C++ by not using volatile in the relevant
pthread types in C++ builds, attempt 2.

The problem with attempt 1 was making assumptions of what the MD
__cpu_simple_lock_t (declared volatile) looks like. To get a same type
except non-volatile, we change the MD type to __cpu_simple_lock_nv_t
and typedef __cpu_simple_lock_t as a volatile __cpu_simple_lock_nv_t.
IMO, __cpu_simple_lock_t should not be volatile at all, but changing it
now is too risky.

Fixes at least Rumprun w/ gcc 5.1/5.2. Furthermore, the mpd application
(and possibly others) will no longer require NetBSD-specific patches.

Tested: build.sh for i386, Rumprun for x86_64 w/ gcc 5.2.

Based on the patch from Christos in lib/49989.

Rev 1.14 was nice except it didn't work with _INITIALIZER, which
sort of negates the whole point ... so revert everything while in
drawing board mode.

Don't depend on __CPU_SIMPLE_LOCK_PAD to determine the type of
__cpu_simple_lock_t (because it doesn't). Instead, use sizeof/alignof
with a struct { uchar[] }.

Fixes problem in previous commit, caught by Nick Hudson.

C++ (namely libc++) expects to be using PTHREAD_FOO_INITIALIZER as a
member initializer. This does not work for volatile types. Since C++
does not touch the guts of those types, redefine them as non-volatile.

Fixes libc++ compilation with g++ 5.1, as reported in PR lib/49989.

branches: 1.13.6;
Change pthread_mutex_t to use the amount of space as and be congruent to
the version used in the SA version of pthreads. This preserves binary
compatibility between both versions of the library.

Back out previous because it breaks the build.

glibc compatibile PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP, requested by
rafal@.

branches: 1.10.2;
Remove clause 3 and 4 from TNF licenses

branches: 1.9.4;
Adjust mutex/rwlock definitions to match reality now that there is only
one implementation of each. PR lib/38030.

- Don't take the mutex's spinlock (ptr_interlock) in pthread_cond_wait().
Instead, make the deferred wakeup list a per-thread array and pass down
the lwpid_t's that way.

- In pthread_cond_wait(), take the mutex before dealing with early wakeup.
In this way there should never be contention on the CV's spinlock if
the app follows POSIX rules (there should only be contention on the
user-provided mutex).

- Add a port of the kernel's rwlocks. The rwlock's spinlock is only taken if
there is contention. This is enabled where atomic ops are available. Right
now that is only i386 and amd64 because I don't have other hardware to
test with. It's trivial to add stubs for other architectures as long as
they have compare-and-swap. When we have proper atomic ops the old rwlock
code can be removed.

- Add a new mutex implementation that's similar to the kernel's mutexes, but
uses compare-and-swap to maintain the waiters list, so no spinlocks are
involved. Same caveats apply as for the rwlocks.

branches: 1.7.2; 1.7.4;
Some significant performance improvements, and a fix for a race with pthread
detach/join.

- Make mutex acquire spin for a short time, as done with spinlocks.
- Make the number of spins controllable with the env var PTHREAD_NSPINS.
- Reduce the amount of time that libpthread internal spinlocks are held.
- Rely more on the barrier effects of park/unpark to avoid taking spinlocks.
- Simplify the locking around pthreads and the global queues.
- Align per-thread sync data on a 128 byte boundary.
- Offset thread stacks by a small amount to try and reduce cache thrash.

branches: 1.6.2;
Remove obsolete comment.

Don't include <machine/lock.h> anymore; instead, we now get
__cpu_simple_lock_t and __SIMPLELOCK_{UN,}LOCKED from <sys/types.h>.
Should prevent the massive namespace pollution by way of dragging in
many MD headers that has been observed to break stuff.

Prepare for inclusion in sys/types.h by ensuring that all the symbols
defined end with _t or start with _[A-Z_].

Make pthread_barrier_wait() handle spurious wakeups from pthread__block()
by adding a generation number to the barrier structure and incrementing it
when the barrier fires.

XXX this is an ABI change for anything using barriers, but the library is
new enough and nothing in the tree uses barriers so I'm going to let it
slide. Using the private data pointer for a field that will always be present
would be excessive.

Merge the nathanw_sa branch.

branches: 1.1.2;
file pthread_types.h was initially added on branch nathanw_sa.

unnamed unions need special treatment since they need braced initializers
for old style initializations.

cplusplus does not like complex named initializers...

use named initializers

Use anonymous union for ptm_ceiling and old __pthread_spin_t field to
maintain backward compatibility and fix hppa build. hppa has an non-
integer type __pthread_spin_t

branches: 1.18.2;
GSoC 2016 Charles Cui: Implement thread priority protection based on work
by Andy Doran. Also document the get/set pshared thread calls as not
implemented, and add a skeleton implementation that is disabled.
XXX: document _sched_protect(2).

Fix PTHREAD_FOO_INITIALIZER for C++ by not using volatile in the relevant
pthread types in C++ builds, attempt 2.

The problem with attempt 1 was making assumptions of what the MD
__cpu_simple_lock_t (declared volatile) looks like. To get a same type
except non-volatile, we change the MD type to __cpu_simple_lock_nv_t
and typedef __cpu_simple_lock_t as a volatile __cpu_simple_lock_nv_t.
IMO, __cpu_simple_lock_t should not be volatile at all, but changing it
now is too risky.

Fixes at least Rumprun w/ gcc 5.1/5.2. Furthermore, the mpd application
(and possibly others) will no longer require NetBSD-specific patches.

Tested: build.sh for i386, Rumprun for x86_64 w/ gcc 5.2.

Based on the patch from Christos in lib/49989.

Rev 1.14 was nice except it didn't work with _INITIALIZER, which
sort of negates the whole point ... so revert everything while in
drawing board mode.

Don't depend on __CPU_SIMPLE_LOCK_PAD to determine the type of
__cpu_simple_lock_t (because it doesn't). Instead, use sizeof/alignof
with a struct { uchar[] }.

Fixes problem in previous commit, caught by Nick Hudson.

C++ (namely libc++) expects to be using PTHREAD_FOO_INITIALIZER as a
member initializer. This does not work for volatile types. Since C++
does not touch the guts of those types, redefine them as non-volatile.

Fixes libc++ compilation with g++ 5.1, as reported in PR lib/49989.

branches: 1.13.6;
Change pthread_mutex_t to use the amount of space as and be congruent to
the version used in the SA version of pthreads. This preserves binary
compatibility between both versions of the library.

Back out previous because it breaks the build.

glibc compatibile PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP, requested by
rafal@.

branches: 1.10.2;
Remove clause 3 and 4 from TNF licenses

branches: 1.9.4;
Adjust mutex/rwlock definitions to match reality now that there is only
one implementation of each. PR lib/38030.

- Don't take the mutex's spinlock (ptr_interlock) in pthread_cond_wait().
Instead, make the deferred wakeup list a per-thread array and pass down
the lwpid_t's that way.

- In pthread_cond_wait(), take the mutex before dealing with early wakeup.
In this way there should never be contention on the CV's spinlock if
the app follows POSIX rules (there should only be contention on the
user-provided mutex).

- Add a port of the kernel's rwlocks. The rwlock's spinlock is only taken if
there is contention. This is enabled where atomic ops are available. Right
now that is only i386 and amd64 because I don't have other hardware to
test with. It's trivial to add stubs for other architectures as long as
they have compare-and-swap. When we have proper atomic ops the old rwlock
code can be removed.

- Add a new mutex implementation that's similar to the kernel's mutexes, but
uses compare-and-swap to maintain the waiters list, so no spinlocks are
involved. Same caveats apply as for the rwlocks.

branches: 1.7.2; 1.7.4;
Some significant performance improvements, and a fix for a race with pthread
detach/join.

- Make mutex acquire spin for a short time, as done with spinlocks.
- Make the number of spins controllable with the env var PTHREAD_NSPINS.
- Reduce the amount of time that libpthread internal spinlocks are held.
- Rely more on the barrier effects of park/unpark to avoid taking spinlocks.
- Simplify the locking around pthreads and the global queues.
- Align per-thread sync data on a 128 byte boundary.
- Offset thread stacks by a small amount to try and reduce cache thrash.

branches: 1.6.2;
Remove obsolete comment.

Don't include <machine/lock.h> anymore; instead, we now get
__cpu_simple_lock_t and __SIMPLELOCK_{UN,}LOCKED from <sys/types.h>.
Should prevent the massive namespace pollution by way of dragging in
many MD headers that has been observed to break stuff.

Prepare for inclusion in sys/types.h by ensuring that all the symbols
defined end with _t or start with _[A-Z_].

Make pthread_barrier_wait() handle spurious wakeups from pthread__block()
by adding a generation number to the barrier structure and incrementing it
when the barrier fires.

XXX this is an ABI change for anything using barriers, but the library is
new enough and nothing in the tree uses barriers so I'm going to let it
slide. Using the private data pointer for a field that will always be present
would be excessive.

Merge the nathanw_sa branch.

branches: 1.1.2;
file pthread_types.h was initially added on branch nathanw_sa.