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0377a7fde6
15 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Adhemerval Zanella
|
0377a7fde6 |
nptl: Remove rwlock elision definitions
The new rwlock implementation added by
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Alistair Francis
|
aa706e13f4 |
Split up endian.h to minimize exposure of BYTE_ORDER.
With only two exceptions (sys/types.h and sys/param.h, both of which historically might have defined BYTE_ORDER) the public headers that include <endian.h> only want to be able to test __BYTE_ORDER against __*_ENDIAN. This patch creates a new bits/endian.h that can be included by any header that wants to be able to test __BYTE_ORDER and/or __FLOAT_WORD_ORDER against the __*_ENDIAN constants, or needs __LONG_LONG_PAIR. It only defines macros in the implementation namespace. The existing bits/endian.h (which could not be included independently of endian.h, and only defines __BYTE_ORDER and maybe __FLOAT_WORD_ORDER) is renamed to bits/endianness.h. I also took the opportunity to canonicalize the form of this header, which we are stuck with having one copy of per architecture. Since they are so short, this means git doesn’t understand that they were renamed from existing headers, sigh. endian.h itself is a nonstandard header and its only remaining use from a standard header is guarded by __USE_MISC, so I dropped the __USE_MISC conditionals from around all of the public-namespace things it defines. (This means, an application that requests strict library conformance but includes endian.h will still see the definition of BYTE_ORDER.) A few changes to specific bits/endian(ness).h variants deserve mention: - sysdeps/unix/sysv/linux/ia64/bits/endian.h is moved to sysdeps/ia64/bits/endianness.h. If I remember correctly, ia64 did have selectable endianness, but we have assembly code in sysdeps/ia64 that assumes it’s little-endian, so there is no reason to treat the ia64 endianness.h as linux-specific. - The C-SKY port does not fully support big-endian mode, the compile will error out if __CSKYBE__ is defined. - The PowerPC port had extra logic in its bits/endian.h to detect a broken compiler, which strikes me as unnecessary, so I removed it. - The only files that defined __FLOAT_WORD_ORDER always defined it to the same value as __BYTE_ORDER, so I removed those definitions. The SH bits/endian(ness).h had comments inconsistent with the actual setting of __FLOAT_WORD_ORDER, which I also removed. - I *removed* copyright boilerplate from the few bits/endian(ness).h headers that had it; these files record a single fact in a fashion dictated by an external spec, so I do not think they are copyrightable. As long as I was changing every copy of ieee754.h in the tree, I noticed that only the MIPS variant includes float.h, because it uses LDBL_MANT_DIG to decide among three different versions of ieee854_long_double. This patch makes it not include float.h when GCC’s intrinsic __LDBL_MANT_DIG__ is available. * string/endian.h: Unconditionally define LITTLE_ENDIAN, BIG_ENDIAN, PDP_ENDIAN, and BYTE_ORDER. Condition byteswapping macros only on !__ASSEMBLER__. Move the definitions of __BIG_ENDIAN, __LITTLE_ENDIAN, __PDP_ENDIAN, __FLOAT_WORD_ORDER, and __LONG_LONG_PAIR to... * string/bits/endian.h: ...this new file, which includes the renamed header bits/endianness.h for the definition of __BYTE_ORDER and possibly __FLOAT_WORD_ORDER. * string/Makefile: Install bits/endianness.h. * include/bits/endian.h: New wrapper. * bits/endian.h: Rename to bits/endianness.h. Add multiple-include guard. Rewrite the comment explaining what the machine-specific variants of this file should do. * sysdeps/unix/sysv/linux/ia64/bits/endian.h: Move to sysdeps/ia64. * sysdeps/aarch64/bits/endian.h * sysdeps/alpha/bits/endian.h * sysdeps/arm/bits/endian.h * sysdeps/csky/bits/endian.h * sysdeps/hppa/bits/endian.h * sysdeps/ia64/bits/endian.h * sysdeps/m68k/bits/endian.h * sysdeps/microblaze/bits/endian.h * sysdeps/mips/bits/endian.h * sysdeps/nios2/bits/endian.h * sysdeps/powerpc/bits/endian.h * sysdeps/riscv/bits/endian.h * sysdeps/s390/bits/endian.h * sysdeps/sh/bits/endian.h * sysdeps/sparc/bits/endian.h * sysdeps/x86/bits/endian.h: Rename to endianness.h; canonicalize form of file; remove redundant definitions of __FLOAT_WORD_ORDER. * sysdeps/powerpc/bits/endianness.h: Remove logic to check for broken compilers. * ctype/ctype.h * sysdeps/aarch64/nptl/bits/pthreadtypes-arch.h * sysdeps/arm/nptl/bits/pthreadtypes-arch.h * sysdeps/csky/nptl/bits/pthreadtypes-arch.h * sysdeps/ia64/ieee754.h * sysdeps/ieee754/ieee754.h * sysdeps/ieee754/ldbl-128/ieee754.h * sysdeps/ieee754/ldbl-128ibm/ieee754.h * sysdeps/m68k/nptl/bits/pthreadtypes-arch.h * sysdeps/microblaze/nptl/bits/pthreadtypes-arch.h * sysdeps/mips/ieee754/ieee754.h * sysdeps/mips/nptl/bits/pthreadtypes-arch.h * sysdeps/nios2/nptl/bits/pthreadtypes-arch.h * sysdeps/nptl/pthread.h * sysdeps/riscv/nptl/bits/pthreadtypes-arch.h * sysdeps/sh/nptl/bits/pthreadtypes-arch.h * sysdeps/sparc/sparc32/ieee754.h * sysdeps/unix/sysv/linux/generic/bits/stat.h * sysdeps/unix/sysv/linux/generic/bits/statfs.h * sysdeps/unix/sysv/linux/sys/acct.h * wctype/bits/wctype-wchar.h: Include bits/endian.h, not endian.h. * sysdeps/unix/sysv/linux/hppa/pthread.h: Don’t include endian.h. * sysdeps/mips/ieee754/ieee754.h: Use __LDBL_MANT_DIG__ in ifdefs, instead of LDBL_MANT_DIG. Only include float.h when __LDBL_MANT_DIG__ is not predefined, in which case define __LDBL_MANT_DIG__ to equal LDBL_MANT_DIG. |
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Paul Eggert
|
5a82c74822 |
Prefer https to http for gnu.org and fsf.org URLs
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:
sed -ri '
s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
$(find $(git ls-files) -prune -type f \
! -name '*.po' \
! -name 'ChangeLog*' \
! -path COPYING ! -path COPYING.LIB \
! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
! -path manual/texinfo.tex ! -path scripts/config.guess \
! -path scripts/config.sub ! -path scripts/install-sh \
! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
! -path INSTALL ! -path locale/programs/charmap-kw.h \
! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
! '(' -name configure \
-execdir test -f configure.ac -o -f configure.in ';' ')' \
! '(' -name preconfigure \
-execdir test -f preconfigure.ac ';' ')' \
-print)
and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:
chmod a+x sysdeps/unix/sysv/linux/riscv/configure
# Omit irrelevant whitespace and comment-only changes,
# perhaps from a slightly-different Autoconf version.
git checkout -f \
sysdeps/csky/configure \
sysdeps/hppa/configure \
sysdeps/riscv/configure \
sysdeps/unix/sysv/linux/csky/configure
# Omit changes that caused a pre-commit check to fail like this:
# remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
git checkout -f \
sysdeps/powerpc/powerpc64/ppc-mcount.S \
sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
# Omit change that caused a pre-commit check to fail like this:
# remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
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Joseph Myers
|
04277e02d7 |
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. |
||
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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. |
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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>
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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.
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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. |
||
|
Joseph Myers
|
bfff8b1bec | Update copyright dates with scripts/update-copyrights. | ||
|
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. |
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Florian Weimer
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c74940f2a7 | nptl: Document the reason why __kind in pthread_mutex_t is part of the ABI | ||
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Joseph Myers
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f7a9f785e5 | Update copyright dates with scripts/update-copyrights. | ||
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Joseph Myers
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b168057aaa | Update copyright dates with scripts/update-copyrights. | ||
Andi Kleen
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8491ed6d70 |
Add adaptive elision to rwlocks
This patch relies on the C version of the rwlocks posted earlier. With C rwlocks it is very straight forward to do adaptive elision using TSX. It is based on the infrastructure added earlier for mutexes, but uses its own elision macros. The macros are fairly general purpose and could be used for other elision purposes too. This version is much cleaner than the earlier assembler based version, and in particular implements adaptation which makes it safer. I changed the behavior slightly to not require any changes in the test suite and fully conform to all expected behaviors (generally at the cost of not eliding in various situations). In particular this means the timedlock variants are not elided. Nested trylock aborts. |
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Roland McGrath
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68e6b6b1bf | Move NPTL public ABI headers for SH to sysdeps/sh/nptl/. |