Commit Graph

10 Commits

Author SHA1 Message Date
Joseph Myers
688903eb3e Update copyright dates with scripts/update-copyrights.
* All files with FSF copyright notices: Update copyright dates
	using scripts/update-copyrights.
	* locale/programs/charmap-kw.h: Regenerated.
	* locale/programs/locfile-kw.h: Likewise.
2018-01-01 00:32:25 +00:00
Adhemerval Zanella
06be6368da nptl: Define __PTHREAD_MUTEX_{NUSERS_AFTER_KIND,USE_UNION}
This patch adds two new internal defines to set the internal
pthread_mutex_t layout required by the supported ABIS:

  1. __PTHREAD_MUTEX_NUSERS_AFTER_KIND which control whether to define
     __nusers fields before or after __kind.  The preferred value for
     is 0 for new ports and it sets __nusers before __kind.

  2. __PTHREAD_MUTEX_USE_UNION which control whether internal __spins and
     __list members will be place inside an union for linuxthreads
     compatibility.  The preferred value is 0 for ports and it sets
     to not use an union to define both fields.

It fixes the wrong offsets value for __kind value on x86_64-linux-gnu-x32.
Checked with a make check run-built-tests=no on all afected ABIs.

	[BZ #22298]
	* nptl/allocatestack.c (allocate_stack): Check if
	__PTHREAD_MUTEX_HAVE_PREV is non-zero, instead if
	__PTHREAD_MUTEX_HAVE_PREV is defined.
	* nptl/descr.h (pthread): Likewise.
	* nptl/nptl-init.c (__pthread_initialize_minimal_internal):
	Likewise.
	* nptl/pthread_create.c (START_THREAD_DEFN): Likewise.
	* sysdeps/nptl/fork.c (__libc_fork): Likewise.
	* sysdeps/nptl/pthread.h (PTHREAD_MUTEX_INITIALIZER): Likewise.
	* sysdeps/nptl/bits/thread-shared-types.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): New
	defines.
	(__pthread_internal_list): Check __PTHREAD_MUTEX_USE_UNION instead
	of __WORDSIZE for internal layout.
	(__pthread_mutex_s): Check __PTHREAD_MUTEX_NUSERS_AFTER_KIND instead
	of __WORDSIZE for internal __nusers layout and __PTHREAD_MUTEX_USE_UNION
	instead of __WORDSIZE whether to use an union for __spins and __list
	fields.
	(__PTHREAD_MUTEX_HAVE_PREV): Define also for __PTHREAD_MUTEX_USE_UNION
	case.
	* sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION): New
	defines.
	* sysdeps/alpha/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/arm/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/hppa/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/ia64/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/m68k/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/mips/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/nios2/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/powerpc/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/s390/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/sh/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/sparc/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/tile/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.
	* sysdeps/x86/nptl/bits/pthreadtypes-arch.h
	(__PTHREAD_MUTEX_NUSERS_AFTER_KIND, __PTHREAD_MUTEX_USE_UNION):
	Likewise.

Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2017-11-07 09:48:41 -02:00
Adhemerval Zanella
eab380d8ec Move shared pthread definitions to common headers
This patch removes all the replicated pthread definition accross the
architectures and consolidates it on shared headers.  The new
organization is as follow:

  * Architecture specific definition (such as pthread types sizes) are
    place in the new pthreadtypes-arch.h header in arch specific path.

  * All shared structure definition are moved to a common NPTL header
    at sysdeps/nptl/bits/pthreadtypes.h (with now includes the arch
    specific one for internal definitions).

  * Also, for C11 future thread support, both mutex and condition
    definition are placed in a common header at
    sysdeps/nptl/bits/thread-shared-types.h.

It is also a refactor patch without expected functional changes.
Checked with a build for all major ABI (aarch64-linux-gnu, alpha-linux-gnu,
arm-linux-gnueabi, i386-linux-gnu, ia64-linux-gnu,
m68k-linux-gnu, microblaze-linux-gnu, mips{64}-linux-gnu, nios2-linux-gnu,
powerpc{64le}-linux-gnu, s390{x}-linux-gnu, sparc{64}-linux-gnu,
tile{pro,gx}-linux-gnu, and x86_64-linux-gnu).

	* posix/Makefile (headers): Add pthreadtypes-arch.h and
	thread-shared-types.h.
	* sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h: New file: arch
	specific thread definition.
	* sysdeps/alpha/nptl/bits/pthreadtypes-arch.h: Likewise.
	* sysdeps/arm/nptl/bits/pthreadtypes-arch.h: Likewise.
	* sysdeps/hppa/nptl/bits/pthreadtypes-arch.h: Likewise.
	* sysdeps/ia64/nptl/bits/pthreadtypes-arch.h: Likewise.
	* sysdeps/m68k/nptl/bits/pthreadtypes-arch.h: Likewise.
	* sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h: Likewise.
	* sysdeps/mips/nptl/bits/pthreadtypes-arch.h: Likewise.
	* sysdeps/nios2/nptl/bits/pthreadtypes-arch.h: Likewise.
	* sysdeps/powerpc/nptl/bits/pthreadtypes-arch.h: Likewise.
	* sysdeps/s390/nptl/bits/pthreadtypes-arch.h: Likewise.
	* sysdeps/sh/nptl/bits/pthreadtypes-arch.h: Likewise.
	* sysdeps/sparc/nptl/bits/pthreadtypes-arch.h: Likewise.
	* sysdeps/tile/nptl/bits/pthreadtypes-arch.h: Likewise.
	* sysdeps/x86/nptl/bits/pthreadtypes-arch.h: Likewise.
	* sysdeps/nptl/bits/thread-shared-types.h: New file: shared
	thread definition between POSIX and C11.
	* sysdeps/aarch64/nptl/bits/pthreadtypes.h.: Remove file.
	* sysdeps/alpha/nptl/bits/pthreadtypes.h: Likewise.
	* sysdeps/arm/nptl/bits/pthreadtypes.h: Likewise.
	* sysdeps/hppa/nptl/bits/pthreadtypes.h: Likewise.
	* sysdeps/m68k/nptl/bits/pthreadtypes.h: Likewise.
	* sysdeps/microblaze/nptl/bits/pthreadtypes.h: Likewise.
	* sysdeps/mips/nptl/bits/pthreadtypes.h: Likewise.
	* sysdeps/nios2/nptl/bits/pthreadtypes.h: Likewise.
	* sysdeps/ia64/nptl/bits/pthreadtypes.h: Likewise.
	* sysdeps/powerpc/nptl/bits/pthreadtypes.h: Likewise.
	* sysdeps/s390/nptl/bits/pthreadtypes.h: Likewise.
	* sysdeps/sh/nptl/bits/pthreadtypes.h: Likewise.
	* sysdeps/sparc/nptl/bits/pthreadtypes.h: Likewise.
	* sysdeps/tile/nptl/bits/pthreadtypes.h: Likewise.
	* sysdeps/x86/nptl/bits/pthreadtypes.h: Likewise.
	* sysdeps/nptl/bits/pthreadtypes.h: New file: common thread
	definitions shared across all architectures.
2017-05-09 17:49:17 -03:00
Torvald Riegel
cc25c8b4c1 New pthread rwlock that is more scalable.
This replaces the pthread rwlock with a new implementation that uses a
more scalable algorithm (primarily through not using a critical section
anymore to make state changes).  The fast path for rdlock acquisition and
release is now basically a single atomic read-modify write or CAS and a few
branches.  See nptl/pthread_rwlock_common.c for details.

	* nptl/DESIGN-rwlock.txt: Remove.
	* nptl/lowlevelrwlock.sym: Remove.
	* nptl/Makefile: Add new tests.
	* nptl/pthread_rwlock_common.c: New file.  Contains the new rwlock.
	* nptl/pthreadP.h (PTHREAD_RWLOCK_PREFER_READER_P): Remove.
	(PTHREAD_RWLOCK_WRPHASE, PTHREAD_RWLOCK_WRLOCKED,
	PTHREAD_RWLOCK_RWAITING, PTHREAD_RWLOCK_READER_SHIFT,
	PTHREAD_RWLOCK_READER_OVERFLOW, PTHREAD_RWLOCK_WRHANDOVER,
	PTHREAD_RWLOCK_FUTEX_USED): New.
	* nptl/pthread_rwlock_init.c (__pthread_rwlock_init): Adapt to new
	implementation.
	* nptl/pthread_rwlock_rdlock.c (__pthread_rwlock_rdlock_slow): Remove.
	(__pthread_rwlock_rdlock): Adapt.
	* nptl/pthread_rwlock_timedrdlock.c
	(pthread_rwlock_timedrdlock): Adapt.
	* nptl/pthread_rwlock_timedwrlock.c
	(pthread_rwlock_timedwrlock): Adapt.
	* nptl/pthread_rwlock_trywrlock.c (pthread_rwlock_trywrlock): Adapt.
	* nptl/pthread_rwlock_tryrdlock.c (pthread_rwlock_tryrdlock): Adapt.
	* nptl/pthread_rwlock_unlock.c (pthread_rwlock_unlock): Adapt.
	* nptl/pthread_rwlock_wrlock.c (__pthread_rwlock_wrlock_slow): Remove.
	(__pthread_rwlock_wrlock): Adapt.
	* nptl/tst-rwlock10.c: Adapt.
	* nptl/tst-rwlock11.c: Adapt.
	* nptl/tst-rwlock17.c: New file.
	* nptl/tst-rwlock18.c: New file.
	* nptl/tst-rwlock19.c: New file.
	* nptl/tst-rwlock2b.c: New file.
	* nptl/tst-rwlock8.c: Adapt.
	* nptl/tst-rwlock9.c: Adapt.
	* sysdeps/aarch64/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/arm/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/hppa/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/ia64/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/m68k/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/microblaze/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/mips/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/nios2/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/s390/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/sh/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/sparc/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/tile/nptl/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h
	(pthread_rwlock_t): Adapt.
	* sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h
	(pthread_rwlock_t): Adapt.
	* sysdeps/x86/bits/pthreadtypes.h (pthread_rwlock_t): Adapt.
	* nptl/nptl-printers.py (): Adapt.
	* nptl/nptl_lock_constants.pysym: Adapt.
	* nptl/test-rwlock-printers.py: Adapt.
	* nptl/test-rwlockattr-printers.c: Adapt.
	* nptl/test-rwlockattr-printers.py: Adapt.
2017-01-10 11:50:17 +01:00
Joseph Myers
bfff8b1bec Update copyright dates with scripts/update-copyrights. 2017-01-01 00:14:16 +00:00
Torvald Riegel
ed19993b5b New condvar implementation that provides stronger ordering guarantees.
This is a new implementation for condition variables, required
after http://austingroupbugs.net/view.php?id=609 to fix bug 13165.  In
essence, we need to be stricter in which waiters a signal or broadcast
is required to wake up; this couldn't be solved using the old algorithm.
ISO C++ made a similar clarification, so this also fixes a bug in
current libstdc++, for example.

We can't use the old algorithm anymore because futexes do not guarantee
to wake in FIFO order.  Thus, when we wake, we can't simply let any
waiter grab a signal, but we need to ensure that one of the waiters
happening before the signal is woken up.  This is something the previous
algorithm violated (see bug 13165).

There's another issue specific to condvars: ABA issues on the underlying
futexes.  Unlike mutexes that have just three states, or semaphores that
have no tokens or a limited number of them, the state of a condvar is
the *order* of the waiters.  A waiter on a semaphore can grab a token
whenever one is available; a condvar waiter must only consume a signal
if it is eligible to do so as determined by the relative order of the
waiter and the signal.
Therefore, this new algorithm maintains two groups of waiters: Those
eligible to consume signals (G1), and those that have to wait until
previous waiters have consumed signals (G2).  Once G1 is empty, G2
becomes the new G1.  64b counters are used to avoid ABA issues.

This condvar doesn't yet use a requeue optimization (ie, on a broadcast,
waking just one thread and requeueing all others on the futex of the
mutex supplied by the program).  I don't think doing the requeue is
necessarily the right approach (but I haven't done real measurements
yet):
* If a program expects to wake many threads at the same time and make
that scalable, a condvar isn't great anyway because of how it requires
waiters to operate mutually exclusive (due to the mutex usage).  Thus, a
thundering herd problem is a scalability problem with or without the
optimization.  Using something like a semaphore might be more
appropriate in such a case.
* The scalability problem is actually at the mutex side; the condvar
could help (and it tries to with the requeue optimization), but it
should be the mutex who decides how that is done, and whether it is done
at all.
* Forcing all but one waiter into the kernel-side wait queue of the
mutex prevents/avoids the use of lock elision on the mutex.  Thus, it
prevents the only cure against the underlying scalability problem
inherent to condvars.
* If condvars use short critical sections (ie, hold the mutex just to
check a binary flag or such), which they should do ideally, then forcing
all those waiter to proceed serially with kernel-based hand-off (ie,
futex ops in the mutex' contended state, via the futex wait queues) will
be less efficient than just letting a scalable mutex implementation take
care of it.  Our current mutex impl doesn't employ spinning at all, but
if critical sections are short, spinning can be much better.
* Doing the requeue stuff requires all waiters to always drive the mutex
into the contended state.  This leads to each waiter having to call
futex_wake after lock release, even if this wouldn't be necessary.

	[BZ #13165]
	* nptl/pthread_cond_broadcast.c (__pthread_cond_broadcast): Rewrite to
	use new algorithm.
	* nptl/pthread_cond_destroy.c (__pthread_cond_destroy): Likewise.
	* nptl/pthread_cond_init.c (__pthread_cond_init): Likewise.
	* nptl/pthread_cond_signal.c (__pthread_cond_signal): Likewise.
	* nptl/pthread_cond_wait.c (__pthread_cond_wait): Likewise.
	(__pthread_cond_timedwait): Move here from pthread_cond_timedwait.c.
	(__condvar_confirm_wakeup, __condvar_cancel_waiting,
	__condvar_cleanup_waiting, __condvar_dec_grefs,
	__pthread_cond_wait_common): New.
	(__condvar_cleanup): Remove.
	* npt/pthread_condattr_getclock.c (pthread_condattr_getclock): Adapt.
	* npt/pthread_condattr_setclock.c (pthread_condattr_setclock):
	Likewise.
	* npt/pthread_condattr_getpshared.c (pthread_condattr_getpshared):
	Likewise.
	* npt/pthread_condattr_init.c (pthread_condattr_init): Likewise.
	* nptl/tst-cond1.c: Add comment.
	* nptl/tst-cond20.c (do_test): Adapt.
	* nptl/tst-cond22.c (do_test): Likewise.
	* sysdeps/aarch64/nptl/bits/pthreadtypes.h (pthread_cond_t): Adapt
	structure.
	* sysdeps/arm/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/ia64/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/m68k/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/microblaze/nptl/bits/pthreadtypes.h (pthread_cond_t):
	Likewise.
	* sysdeps/mips/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/nios2/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/s390/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/sh/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/tile/nptl/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/unix/sysv/linux/alpha/bits/pthreadtypes.h (pthread_cond_t):
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h (pthread_cond_t):
	Likewise.
	* sysdeps/x86/bits/pthreadtypes.h (pthread_cond_t): Likewise.
	* sysdeps/nptl/internaltypes.h (COND_NWAITERS_SHIFT): Remove.
	(COND_CLOCK_BITS): Adapt.
	* sysdeps/nptl/pthread.h (PTHREAD_COND_INITIALIZER): Adapt.
	* nptl/pthreadP.h (__PTHREAD_COND_CLOCK_MONOTONIC_MASK,
	__PTHREAD_COND_SHARED_MASK): New.
	* nptl/nptl-printers.py (CLOCK_IDS): Remove.
	(ConditionVariablePrinter, ConditionVariableAttributesPrinter): Adapt.
	* nptl/nptl_lock_constants.pysym: Adapt.
	* nptl/test-cond-printers.py: Adapt.
	* sysdeps/unix/sysv/linux/hppa/internaltypes.h (cond_compat_clear,
	cond_compat_check_and_clear): Adapt.
	* sysdeps/unix/sysv/linux/hppa/pthread_cond_timedwait.c: Remove file ...
	* sysdeps/unix/sysv/linux/hppa/pthread_cond_wait.c
	(__pthread_cond_timedwait): ... and move here.
	* nptl/DESIGN-condvar.txt: Remove file.
	* nptl/lowlevelcond.sym: Likewise.
	* nptl/pthread_cond_timedwait.c: Likewise.
	* sysdeps/unix/sysv/linux/i386/i486/pthread_cond_broadcast.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i486/pthread_cond_signal.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i486/pthread_cond_timedwait.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i486/pthread_cond_wait.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i586/pthread_cond_broadcast.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i586/pthread_cond_signal.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i586/pthread_cond_timedwait.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i586/pthread_cond_wait.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i686/pthread_cond_broadcast.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i686/pthread_cond_signal.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i686/pthread_cond_timedwait.S: Likewise.
	* sysdeps/unix/sysv/linux/i386/i686/pthread_cond_wait.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/pthread_cond_broadcast.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/pthread_cond_signal.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S: Likewise.
2016-12-31 14:56:47 +01:00
Florian Weimer
c74940f2a7 nptl: Document the reason why __kind in pthread_mutex_t is part of the ABI 2016-11-07 20:24:32 +01:00
Joseph Myers
f7a9f785e5 Update copyright dates with scripts/update-copyrights. 2016-01-04 16:05:18 +00:00
Joseph Myers
b168057aaa Update copyright dates with scripts/update-copyrights. 2015-01-02 16:29:47 +00:00
Roland McGrath
15bed4728f m68k: Consolidate nptl/ subdirectories under linux/... 2014-06-23 09:24:18 -07:00