Commit Graph

432 Commits

Author SHA1 Message Date
Konstantin Belousov
b144e48b2a Use _SIG_VALID instead of expanded form of the macro.
Submitted by:	Garrett Cooper <yanegomi gmail com>
MFC after:	1 week
2010-07-12 10:15:33 +00:00
Nathan Whitehorn
944792aa12 Fix SVN mismerge. We somehow ended up with the 32-bit powerpc version
in arch/powerpc64 instead of the 64-bit one.
2010-07-11 05:13:38 +00:00
Nathan Whitehorn
65801ce52d Powerpc64 thread libraries support. 2010-07-10 15:13:49 +00:00
Daniel Eischen
1cfc8fc759 Coalesce one more broken line. 2010-05-24 13:44:39 +00:00
Daniel Eischen
9ed8360e53 Coalesce a couple of broken lines since they can fit within 80
characters.  Little nit found while looking at a bug report.
2010-05-24 13:43:11 +00:00
Ulrich Spörlein
aa12cea2cc mdoc: order prologue macros consistently by Dd/Dt/Os
Although groff_mdoc(7) gives another impression, this is the ordering
most widely used and also required by mdocml/mandoc.

Reviewed by:	ru
Approved by:	philip, ed (mentors)
2010-04-14 19:08:06 +00:00
Warner Losh
b543d9ad75 Merge r195129 from project/mips to head by hand:
r195129 | gonzo | 2009-06-27 17:28:56 -0600 (Sat, 27 Jun 2009) | 2 lines
- Use sysarch(2) in MIPS version of _tcb_set/_tcb_get
2010-01-09 00:07:47 +00:00
David Xu
60e9cdf158 remove file thr_sem_new.c. 2010-01-05 07:50:31 +00:00
David Xu
791f7a99e2 Remove extra new semaphore stubs, because libc already has them, and
ld can find the newest version which is default.

Poked by: kan@
2010-01-05 06:21:29 +00:00
David Xu
9b0f1823b5 Use umtx to implement process sharable semaphore, to make this work,
now type sema_t is a structure which can be put in a shared memory area,
and multiple processes can operate it concurrently.
User can either use mmap(MAP_SHARED) + sem_init(pshared=1) or use sem_open()
to initialize a shared semaphore.
Named semaphore uses file system and is located in /tmp directory, and its
file name is prefixed with 'SEMD', so now it is chroot or jail friendly.
In simplist cases, both for named and un-named semaphore, userland code
does not have to enter kernel to reduce/increase semaphore's count.
The semaphore is designed to be crash-safe, it means even if an application
is crashed in the middle of operating semaphore, the semaphore state is
still safely recovered by later use, there is no waiter counter maintained
by userland code.
The main semaphore code is in libc and libthr only has some necessary stubs,
this makes it possible that a non-threaded application can use semaphore
without linking to thread library.
Old semaphore implementation is kept libc to maintain binary compatibility.
The kernel ksem API is no longer used in the new implemenation.

Discussed on: threads@
2010-01-05 02:37:59 +00:00
Marcel Moolenaar
e4f141b546 Work-around a race condition on ia64 while unlocking a contested lock.
The race condition is believed to be in UMTX_OP_MUTEX_WAKE. On ia64,
we simply go to the kernel to unlock.
The big question is why this is only a race condition on ia64...

MFC after:	3 days
2009-12-14 01:26:01 +00:00
Konstantin Belousov
6d772c3b9e Revert r199830 for now. Too many ports dlopen() libraries linked with
libthr, but forgot to link main binary with it.
2009-11-28 14:34:28 +00:00
Konstantin Belousov
86665365a8 Libthr cannot be dynamically loaded into the running process.
Mark it with -z nodlopen for now.

Discussed with:	jhb, kan
MFC after:	3 weeks
2009-11-26 14:01:14 +00:00
Konstantin Belousov
066d836b02 Current pselect(3) is implemented in usermode and thus vulnerable to
well-known race condition, which elimination was the reason for the
function appearance in first place. If sigmask supplied as argument to
pselect() enables a signal, the signal might be delivered before thread
called select(2), causing lost wakeup. Reimplement pselect() in kernel,
making change of sigmask and sleep atomic.

Since signal shall be delivered to the usermode, but sigmask restored,
set TDP_OLDMASK and save old mask in td_oldsigmask. The TDP_OLDMASK
should be cleared by ast() in case signal was not gelivered during
syscall execution.

Reviewed by:	davidxu
Tested by:	pho
MFC after:	1 month
2009-10-27 10:55:34 +00:00
Marcel Moolenaar
3b43a26b50 Implement _umtx_op_err() for ia64. 2009-10-24 20:07:17 +00:00
Jilles Tjoelker
29670497af Make openat(2) a cancellation point.
This is required by POSIX and matches open(2).

Reviewed by:	kib, jhb
MFC after:	1 month
2009-10-11 20:19:45 +00:00
David Xu
daf3ced72b don't report error if key was deleted.
PR:	threads/135462
2009-09-25 00:15:30 +00:00
Attilio Rao
b13c5f2883 rwlock implemented from libthr need to fall through the 'hard path' and
query umtx also if the shared waiters bit is set on a shared lock.
The writer starvation avoidance technique, infact, can lead to shared
waiters on a shared lock which can bring to a missed wakeup and thus
to a deadlock if the right bit is not checked (a notable case is the
writers counterpart to be handled through expired timeouts).

Fix that by checking for the shared waiters bit also when unlocking the
shared locks.

That bug was causing a reported MySQL deadlock.
Many thanks go to Nick Esborn and his employer DesertNet which provided
time and machines to identify and fix this issue.

PR:		thread/135673
Reported by:	Nick Esborn <nick at desert dot net>
Tested by:	Nick Esborn <nick at desert dot net>
Reviewed by:	jeff
2009-09-23 21:38:57 +00:00
Attilio Rao
137ae5d291 In the current code, rdlock_count is not correctly handled for some cases.
The most notable is that it is not bumped in rwlock_rdlock_common() when
the hard path (__thr_rwlock_rdlock()) returns successfully.
This can lead to deadlocks in libthr when rwlocks recursion in read mode
happens.
Fix the interested parts by correctly handling rdlock_count.

PR:		threads/136345
Reported by:	rink
Tested by:	rink
Reviewed by:	jeff
Approved by:	re (kib)
MFC:		2 weeks
2009-07-06 09:31:04 +00:00
Brian Feldman
43af51a2b5 These are some cosmetic changes to improve the clarity of libthr's fork implementation. 2009-05-11 16:45:53 +00:00
Robert Watson
d1f2f1c3f3 Now that the kernel defines CACHE_LINE_SIZE in machine/param.h, use
that definition in the custom locking code for the run-time linker
rather than local definitions.

Pointed out by:	tinderbox
MFC after:	2 weeks
2009-04-19 23:02:50 +00:00
David Xu
35c608253d Turn on nodelete linker flag because libthr can not be unloaded safely,
it does hook on to libc.
2009-03-31 02:50:18 +00:00
Konstantin Belousov
29986e1bac Forcibly unlock the malloc() locks in the child process after fork(),
by temporary pretending that the process is still multithreaded.
Current malloc lock primitives do nothing for singlethreaded process.

Reviewed by:	davidxu, deischen
2009-03-19 10:32:25 +00:00
David Xu
5b71b82e70 Don't ignore other fcntl functions, directly call __sys_fcntl if
WITHOUT_SYSCALL_COMPAT is not defined.

Reviewed by:	deischen
2009-03-09 05:54:43 +00:00
David Xu
c30c187d60 Don't reference non-existent __fcntl_compat if WITHOUT_SYSCALL_COMPAT is defined.
Submitted by:	Pawel Worach "pawel dot worach at gmail dot com"
2009-03-09 02:34:02 +00:00
Ruslan Ermilov
241715e78f With only one threading library, simplify the logic of setting SHLIBDIR. 2009-02-24 16:23:34 +00:00
Ruslan Ermilov
d9ca85fca7 Fix build when WITH_SSP is set explicitly.
Submitted by:	Jeremie Le Hen
2009-02-21 15:04:31 +00:00
Jung-uk Kim
455cc6ec70 Honor WITHOUT_INSTALLLIB in some places. 2009-02-13 16:51:36 +00:00
Peter Wemm
70ba1e8fc1 When libthr and rtld start up, there are a number of magic spells cast
in order to get the symbol binding state "just so".  This is to allow
locking to be activated and not run into recursion problems later.

However, one of the magic bits involves an explicit call to _umtx_op()
to force symbol resolution.  It does a wakeup operation on a fake,
uninitialized (ie: random contents) umtx.  Since libthr isn't active, this
is harmless.  Nothing can match the random wakeup.

However, valgrind finds this and is not amused.  Normally I'd just
write a suppression record for it, but the idea of passing random
args to syscalls (on purpose) just doesn't feel right.
2008-12-07 02:32:49 +00:00
Konstantin Belousov
10b4034657 Provide custom simple allocator for rtld locks in libthr. The allocator
does not use any external symbols, thus avoiding possible recursion into
rtld to resolve symbols, when called.

Reviewed by:	kan, davidxu
Tested by:	rink
MFC after:	1 month
2008-12-02 11:58:31 +00:00
Alexander Kabaev
97df383415 Invoke _rtld_atfork_post earlier, before we reinitialize rtld locks
by switching into single-thread mode.

libthr ignores broken use of lock bitmaps used by default rtld locking
implementation, this in turn turns lock handoff in _rtld_thread_init
into NOP. This in turn makes child processes of forked multi-threaded
programs to run with _thr_signal_block still in effect, with most
signals blocked.

Reported by: phk, kib
2008-12-01 21:00:25 +00:00
Konstantin Belousov
e711c6f0d1 Unlock the malloc() locks in the child process after fork(). This gives
us working malloc in the fork child of the multithreaded process.

Although POSIX requires that only async-signal safe functions shall be
operable after fork in multithreaded process, not having malloc lower
the quality of our implementation.

Tested by:	rink
Discussed with:	kan, davidxu
Reviewed by:	kan
MFC after:	1 month
2008-11-29 21:46:28 +00:00
Konstantin Belousov
cb5c4b10ba Add two rtld exported symbols, _rtld_atfork_pre and _rtld_atfork_post.
Threading library calls _pre before the fork, allowing the rtld to
lock itself to ensure that other threads of the process are out of
dynamic linker. _post releases the locks.

This allows the rtld to have consistent state in the child. Although
child may legitimately call only async-safe functions, the call may
need plt relocation resolution, and this requires working rtld.

Reported and debugging help by:	rink
Reviewed by:	kan, davidxu
MFC after:	1 month (anyway, not before 7.1 is out)
2008-11-27 11:27:59 +00:00
Marcel Moolenaar
03fad2ad5f Allow psaddr_t to be widened by using thr_pread_{int,long,ptr},
where critical. Some places still use ps_pread/ps_pwrite directly,
but only need changed when byte-order comes into the picture.
Also, change th_p in td_event_msg_t from a pointer type to
psaddr_t, so that events also work when psaddr_t is widened.
2008-09-14 16:07:21 +00:00
Jason Evans
5b3842aefa Move call to _malloc_thread_cleanup() so that if this is the last thread,
the call never happens.  This is necessary because malloc may be used
during exit handler processing.

Submitted by:	davidxu
2008-09-09 17:14:32 +00:00
Jason Evans
d6742bfbd3 Add thread-specific caching for small size classes, based on magazines.
This caching allows for completely lock-free allocation/deallocation in the
steady state, at the expense of likely increased memory use and
fragmentation.

Reduce the default number of arenas to 2*ncpus, since thread-specific
caching typically reduces arena contention.

Modify size class spacing to include ranges of 2^n-spaced, quantum-spaced,
cacheline-spaced, and subpage-spaced size classes.  The advantages are:
fewer size classes, reduced false cacheline sharing, and reduced internal
fragmentation for allocations that are slightly over 512, 1024, etc.

Increase RUN_MAX_SMALL, in order to limit fragmentation for the
subpage-spaced size classes.

Add a size-->bin lookup table for small sizes to simplify translating sizes
to size classes.  Include a hard-coded constant table that is used unless
custom size class spacing is specified at run time.

Add the ability to disable tiny size classes at compile time via
MALLOC_TINY.
2008-08-27 02:00:53 +00:00
David Xu
fc45432be6 In function pthread_condattr_getpshared, store result correctly.
PR:		kern/126128
2008-08-01 01:21:49 +00:00
Ruslan Ermilov
042df2e2da Enable GCC stack protection (aka Propolice) for userland:
- It is opt-out for now so as to give it maximum testing, but it may be
  turned opt-in for stable branches depending on the consensus.  You
  can turn it off with WITHOUT_SSP.
- WITHOUT_SSP was previously used to disable the build of GNU libssp.
  It is harmless to steal the knob as SSP symbols have been provided
  by libc for a long time, GNU libssp should not have been much used.
- SSP is disabled in a few corners such as system bootstrap programs
  (sys/boot), process bootstrap code (rtld, csu) and SSP symbols themselves.
- It should be safe to use -fstack-protector-all to build world, however
  libc will be automatically downgraded to -fstack-protector because it
  breaks rtld otherwise.
- This option is unavailable on ia64.

Enable GCC stack protection (aka Propolice) for kernel:
- It is opt-out for now so as to give it maximum testing.
- Do not compile your kernel with -fstack-protector-all, it won't work.

Submitted by:	Jeremie Le Hen <jeremie@le-hen.org>
2008-06-25 21:33:28 +00:00
David Xu
7de1ecef2d Add two commands to _umtx_op system call to allow a simple mutex to be
locked and unlocked completely in userland. by locking and unlocking mutex
in userland, it reduces the total time a mutex is locked by a thread,
in some application code, a mutex only protects a small piece of code, the
code's execution time is less than a simple system call, if a lock contention
happens, however in current implemenation, the lock holder has to extend its
locking time and enter kernel to unlock it, the change avoids this disadvantage,
it first sets mutex to free state and then enters kernel and wake one waiter
up. This improves performance dramatically in some sysbench mutex tests.

Tested by: kris
Sounds great: jeff
2008-06-24 07:32:12 +00:00
David Xu
83a0758789 Make pthread_cleanup_push() and pthread_cleanup_pop() as a pair of macros,
use stack space to keep cleanup information, this eliminates overhead of
calling malloc() and free() in thread library.

Discussed on: thread@
2008-06-09 01:14:10 +00:00
Doug Rabson
cd7d66a21f Call the fcntl compatiblity wrapper from the thread library fcntl wrappers
so that they get the benefit of the (limited) forward ABI compatibility.

MFC after: 1 week
2008-05-30 14:47:42 +00:00
David Xu
1b3418b2dc Eliminate global mutex by using pthread_once's state field as
a semaphore.
2008-05-30 00:02:59 +00:00
David Xu
850f4d66cb - Reduce function call overhead for uncontended case.
- Remove unused flags MUTEX_FLAGS_* and their code.
- Check validity of the timeout parameter in mutex_self_lock().
2008-05-29 07:57:33 +00:00
Warner Losh
13d2e92b70 Commit missing mips libthr support that I thought I'd committed earlier 2008-05-11 05:54:52 +00:00
David Xu
cf181aee60 Remove libc_r's remnant code. 2008-05-06 07:27:11 +00:00
David Xu
8d6a11a070 Use UMTX_OP_WAIT_UINT_PRIVATE and UMTX_OP_WAKE_PRIVATE to save
time in kernel(avoid VM lookup).
2008-04-29 03:58:18 +00:00
Kris Kennaway
dd77f9f7f2 Increase the default MUTEX_ADAPTIVE_SPINS to 2000, after further
testing it turns out 200 was too short to give good adaptive
performance.

Reviewed by:   jeff
MFC after:     1 week
2008-04-26 13:19:07 +00:00
Warner Losh
416e6cfbf0 Bring in mips threads support from perforce mips2-jnpr branch. 2008-04-26 12:17:57 +00:00
Xin LI
d0aa4fd3ca Avoid various shadowed variables. libthr is now almost WARNS=4 clean except
for some const dequalifiers that needs more careful investigation.

Ok'ed by:	davidxu
2008-04-23 21:06:51 +00:00
David Xu
fb2641d9b1 Use native rwlock. 2008-04-22 06:44:11 +00:00