Commit Graph

57 Commits

Author SHA1 Message Date
Pedro F. Giffuni
4eecef9062 Small inclusion guard comment fix. 2017-02-16 20:28:30 +00:00
Pedro F. Giffuni
649702c5a3 Make use of clang nullability attributes.
Replace uses of the GCC __nonnull__ attribute with the clang nullability
qualifiers. The replacement should be transparent for clang developers as
the new qualifiers will produce the same warnings and will be useful for
static checkers but will not cause aggressive optimizations.

GCC will not produce such warnings and developers will have to use
upgraded GCC ports built with the system headers from r312538.

Hinted by:	Apple's Libc-1158.20.4, Bionic libc
MFC after:	11.1 Release

Differential Revision:	https://reviews.freebsd.org/D9004
2017-01-28 20:54:43 +00:00
Pedro F. Giffuni
f1b298ad46 Remove some uses of the GCC __nonnull() attribute.
While the checks are considered useful, the attribute does dangerous
optimizations, removing NULL checks where they can be needed. Remove the
uses of this attribute introduced in r281130: the changes were inspired on
Google's bionic where this attribute is not used anymore.

The __nonnull() attribute will be deprecrated from our headers and
replaced with the Clang _Nonnull qualifier in the future.

MFC after:	3 days
2017-01-01 17:16:47 +00:00
Konstantin Belousov
2a339d9e3d Add implementation of robust mutexes, hopefully close enough to the
intention of the POSIX IEEE Std 1003.1TM-2008/Cor 1-2013.

A robust mutex is guaranteed to be cleared by the system upon either
thread or process owner termination while the mutex is held.  The next
mutex locker is then notified about inconsistent mutex state and can
execute (or abandon) corrective actions.

The patch mostly consists of small changes here and there, adding
neccessary checks for the inconsistent and abandoned conditions into
existing paths.  Additionally, the thread exit handler was extended to
iterate over the userspace-maintained list of owned robust mutexes,
unlocking and marking as terminated each of them.

The list of owned robust mutexes cannot be maintained atomically
synchronous with the mutex lock state (it is possible in kernel, but
is too expensive).  Instead, for the duration of lock or unlock
operation, the current mutex is remembered in a special slot that is
also checked by the kernel at thread termination.

Kernel must be aware about the per-thread location of the heads of
robust mutex lists and the current active mutex slot.  When a thread
touches a robust mutex for the first time, a new umtx op syscall is
issued which informs about location of lists heads.

The umtx sleep queues for PP and PI mutexes are split between
non-robust and robust.

Somewhat unrelated changes in the patch:
1. Style.
2. The fix for proper tdfind() call use in umtxq_sleep_pi() for shared
   pi mutexes.
3. Removal of the userspace struct pthread_mutex m_owner field.
4. The sysctl kern.ipc.umtx_vnode_persistent is added, which controls
   the lifetime of the shared mutex associated with a vnode' page.

Reviewed by:	jilles (previous version, supposedly the objection was fixed)
Discussed with:	brooks, Martin Simmons <martin@lispworks.com> (some aspects)
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
2016-05-17 09:56:22 +00:00
Konstantin Belousov
1bdbd70599 Implement process-shared locks support for libthr.so.3, without
breaking the ABI.  Special value is stored in the lock pointer to
indicate shared lock, and offline page in the shared memory is
allocated to store the actual lock.

Reviewed by:	vangyzen (previous version)
Discussed with:	deischen, emaste, jhb, rwatson,
	Martin Simmons <martin@lispworks.com>
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
2016-02-28 17:52:33 +00:00
Pedro F. Giffuni
153cbcd657 Make use of gcc attributes in some standard include headers.
The `nonnull' attribute specifies that some function parameters should be
non-null pointers.  This is very useful as it helps the compiler generate
warnings on suspicious code and can also enable some small optimizations.

Also start using 'alloc_size' attribute in the allocator functions.

This is an initial step to better integrate our libc with the compiler:
these attributes are fully supported by clang and they are also useful
for the static analyzer.

Note that due to some bogus internal procedure in the way gcc ports
are built they may require updating if they were built before r280801.

Relnotes:		yes
Hinted by:		Android's bionic libc
Differential Revision:	https://reviews.freebsd.org/D2107
2015-04-06 01:39:16 +00:00
Pedro F. Giffuni
4b069c8287 Clean some spaces vs tabs.
No, this file doesn't conform with KNF at all.
2015-03-29 20:20:45 +00:00
Pedro F. Giffuni
28cdb3ee15 Temporarily revert 280458.
GCC is still carries an old version of cdefs.h which doesn't
accept multiple parameters for the nonnull attribute.

Since this issue probably affects many ports in the tree
we will revert it for now until gcc gets fixed.
2015-03-25 21:53:17 +00:00
Pedro F. Giffuni
512cd1357a Introduce nonnull attributes in the signal and pthread headers.
The `nonnull' attribute specifies that some function parameters should be
non-null pointers.  This is very useful as it helps the compiler generate
warnings on suspicious code and can also enable some small optimizations.
In clang this is also useful for the static analyzer.

While we could go on defining this all over the tree, it only
makes sense to annotate a subset of critical functions.

Hinted by:		Android's bionic libc
Differential Revision:	https://reviews.freebsd.org/D2101
2015-03-24 20:33:24 +00:00
Ed Schouten
49891e45d2 Add lock annotations to the header files of our threading libraries.
This change extends all of the functions present in the <pthread.h> and
<threads.h> headers to have lock annotations. This will allow Clang to
warn about the following:

- Locking a function twice,
- Unlocking a function without a mutex being locked,
- Forgetting to unlock a mutex before returning,
- Destroying or reinitializing a mutex that is currenty locked,
- Using an unlocked mutex in combination with a condition variable.

Enabling these annotations already allowed me to catch a bug in one of
our userspace tools (r270749).
2014-09-01 18:34:30 +00:00
Tijl Coosemans
23bbf7fa70 Add a dummy statement to the beginning of the pthread_cleanup_pop() macro
to allow a call of the macro to be labelled as in:

label:
  pthread_cleanup_pop();

Reviewed by:	imp
MFC after:	3 days
2013-10-22 19:53:52 +00:00
David Xu
f66ffe64ce Remove leftover for r214093. 2011-01-06 03:30:16 +00:00
David Xu
a6b9b59e04 Add pthread_rwlockattr_setkind_np and pthread_rwlockattr_getkind_np, the
functions set or get pthread_rwlock type, current supported types are:
   PTHREAD_RWLOCK_PREFER_READER_NP,
   PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP,
   PTHREAD_RWLOCK_PREFER_WRITER_NP,
default is PTHREAD_RWLOCK_PREFER_WRITER_NONCECURSIVE_NP, this maintains
binary compatible with old code.
2010-10-18 05:09:22 +00:00
David Xu
bbb64c2143 In current code, statically initialized and destroyed object have
same null value, the code can not distinguish between them, to
fix the problem, now a destroyed object is assigned to a non-null
value, and it will be rejected by some pthread functions.
PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP is changed to number 1, so that
adaptive mutex can be statically initialized correctly.
2010-09-28 04:57:56 +00:00
David Schultz
48a3f7d9ae Fix the visibility of several prototypes. Also move pthread_kill() and
pthread_sigmask() to signal.h. In principle, this shouldn't break anything,
since they're already in signal.h on other systems, and the FreeBSD
manpage says that both pthread.h and signal.h need to be included to
get these functions.

Add a hack to declare pthread_t in the P1003.1-2008 namespace
in signal.h.
2009-03-14 20:10:14 +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
David Xu
9939a13667 Add POSIX pthread API pthread_getcpuclockid() to get a thread's cpu
time clock id.
2008-03-22 09:59:20 +00:00
Kris Kennaway
2017a7cdfe Add a new "non-portable" mutex type, PTHREAD_MUTEX_ADAPTIVE_NP. This
is also implemented in glibc and is used by a number of existing
applications (mysql, firefox, etc).

This mutex type is a default mutex with the additional property that
it spins briefly when attempting to acquire a contested lock, doing
trylock operations in userland before entering the kernel to block if
eventually unsuccessful.

The expectation is that applications requesting this mutex type know
that the mutex is likely to be only held for very brief periods, so it
is faster to spin in userland and probably succeed in acquiring the
mutex, than to enter the kernel and sleep, only to be woken up almost
immediately.  This can help significantly in certain cases when
pthread mutexes are heavily contended and held for brief durations
(such as mysql).

Spin up to 200 times before entering the kernel, which represents only
a few us on modern CPUs.  No performance degradation was observed with
this value and it is sufficient to avoid a large performance drop in
mysql performance in the heavily contended pthread mutex case.

The libkse implementation is a NOP.

Reviewed by:      jeff
MFC after:        3 days
2007-10-29 21:01:47 +00:00
David Xu
02ea638732 Add prototype for following functions, plus tab fixes.
pthread_condattr_getpshared
	pthread_condattr_setpshared
	pthread_mutexattr_getpshared
	pthread_mutexattr_setpshared
2005-10-24 05:53:54 +00:00
Stefan Farfeleder
323abbb7ce Improve POSIX conformance:
- Don't pollute the namespace by including <sys/types.h>, <sys/time.h>,
  <sys/signal.h> and <limits.h>.  Use __MINSIGSTKSZ and __ULONG_MAX from
  <machine/_limits.h>, __sigset_t from <sys/_sigset.h> instead.
- Include <time.h> because POSIX says we have to.

PTHREAD_{DESTRUCTOR_ITERATIONS,KEYS_MAX,STACK_MIN,THREADS_MAX} should
eventually move to <limits.h> but are left here for now.

Discussed on:	standards@, threads@
2005-09-01 15:33:22 +00:00
Stefan Farfeleder
ad7c49168f - Prefix MUTEX_TYPE_MAX with PTHREAD_ to avoid namespace pollution.
- Remove the macros MUTEX_TYPE_FAST and MUTEX_TYPE_COUNTING_FAST.

OK'ed by:	deischen
2005-08-19 21:31:42 +00:00
Stefan Farfeleder
6ee81d6ffb Remove parameter names, the identifiers were in the user namespace. 2005-08-19 08:37:16 +00:00
Craig Rodrigues
4d62f529a3 According to:
http://www.opengroup.org/onlinepubs/009695399/basedefs/sys/types.h.html

#include <sys/types.h>
should include the definitions of pthread types.

PR:		standards/78907
Reported by:	Brooks Davis
Approved by:	das (mentor)
2005-05-31 15:18:17 +00:00
David Xu
213a268eec Increase PTHREAD_STACK_MIN to MINSIGSTKSZ because thread libraries now use
makecontext which enforces a minimum stack size to be MINSIGSTKSZ.

Bug report: Bill Middleton <flashdict at gmail dot com>, BSD-sharp project.
2005-04-11 03:47:42 +00:00
David Xu
fc5684ec15 Add pthread_condattr_getclock, pthread_condattr_setclock. 2005-04-03 23:55:02 +00:00
David Xu
792d9d0376 Fix typo, function name pthread_rwlock_timedrwlock should be
pthread_rwlock_timedwrlock.
2005-01-08 11:07:13 +00:00
Daniel Eischen
8b813ec31c Add the pthread_atfork() prototype.
Reviewed by:	davidxu
2003-11-04 20:10:15 +00:00
David Xu
c095b4a999 Add code to support pthread spin lock.
Reviewed by: deischen
2003-09-09 06:57:51 +00:00
David Xu
407c3de522 Add small piece of code to support pthread_rwlock_timedrdlock and
pthread_rwlock_timedrwlock.
2003-09-06 00:07:52 +00:00
David Xu
2ab83179b5 Add code to support barrier synchronous object and implement
pthread_mutex_timedlock().

Reviewed by: deischen
2003-09-04 14:06:43 +00:00
John Polstra
8c0d4b5f92 Add stub implementations of pthread_[gs]etconcurrency to libc_r and
libthr.  No changes were made to libpthread by request of deischen,
who will soon commit a real implementation for that library.

PR:		standards/50848
Submitted by:	Sergey A. Osokin <osa@freebsd.org.ru>
MFC after:	1 week
2003-04-20 01:53:13 +00:00
Alfred Perlstein
4e44912c6c Add pthread_attr_getstack() and pthread_attr_setstack().
Submitted by: Craig Rodrigues <rodrigc@attbi.com>
2003-02-10 08:48:04 +00:00
Garrett Wollman
cd7b801ba0 In the absence of consensus as to implement stubs for these TSH-shaded
routines, remove their declarations.  Even though rwlocks have the same
functions, XBDft does not shade those declarations so I am leaving them in.
(This is probably a bug in the Standard.)
2003-01-23 01:09:43 +00:00
Warner Losh
bb28f3c29b Breath deep and take __P out of the system include files.
# This appears to not break X11, but I'm having problems compiling the
# glide part of the server with or without this patch, so I can't tell
# for sure.
2002-03-23 17:24:55 +00:00
Jason Evans
aa33517e94 Implement pthread_attr_[gs]etguardsize(). Non-default-size stacks used to
be malloc()ed, but they are now allocated using mmap(), just as the
default-size stacks are.  A separate cache of stacks is kept for
non-default-size stacks.

Collaboration with:	deischen
2001-07-20 04:23:11 +00:00
Alfred Perlstein
86e03b89bb mark pthread_exit() as non-returning.
Requested by: Farooq Mela <fmela0@sm.socccd.cc.ca.us>
2001-03-04 22:17:52 +00:00
Jason Evans
d57caa9b95 Remove prototypes for pthread_attr_[gs]etfloatstate(), which we don't
implement.
2000-12-28 18:46:21 +00:00
Bruce Evans
80a07932e7 Fixed missing consts for function parameters, so that the code matches
the man page and POSIX.1.  Fixed nearby misformatting.  Fixed a missing
prototype.
2000-05-11 15:57:17 +00:00
Jason Evans
60ad8853e0 Do not conditionalize function prototype definition for functions we
implement.

Noticed by:	Thimble Smith <tim@mysql.com>
Approved by:	jkh
2000-02-20 07:40:25 +00:00
Daniel Eischen
3eadb69d1f Make sched_param parameter a const to comply with POSIX and SUSv2 specs.
This doesn't need to be applied to stable, because somehow -stable seems
to have gotten it right.

Reviewed by:	jasone
2000-01-10 04:14:08 +00:00
Jason Evans
386812d440 Fix some minor POSIX/SUSv2 compliance nits.
PR:		kern/11982
1999-12-18 01:00:42 +00:00
Jason Evans
346b6c5db8 Move POSIX feature constants from pthread.h to unistd.h, as required by
1003.1c-1995.

Undefine _POSIX_THREAD_SAFE_FUNCTIONS, since we do not implement all of the
necessary interfaces.  At least getgrgid_r(), getrnam_r(), getpwuid_r(),
getpwnam_r(), getc_unlocked(), getchar_unlocked(), putc_unlocked(),
and putchar_unlocked() are missing.  Due to a likely typo in 1003.1c-1995,
we are not technically allowed to define _POSIX_THREADS without defining
_POSIX_THREAD_SAFE_FUNCTIONS, but either way we're non-compliant, so I'm
leaving _POSIX_THREADS defined.

PR:		bin/8281
1999-12-16 21:53:39 +00:00
Alfred Perlstein
7285bccf1a add pthread_cancel, obtained from OpenBSD.
eischen (Daniel Eischen) added wrappers to protect against cancled
threads orphaning internal resources.

the cancelability code is still a bit fuzzy but works for test
programs of my own, OpenBSD's and some examples from ORA's books.

add readdir_r to both libc and libc_r

add some 'const' attributes to function parameters

Reviewed by: eischen, jasone
1999-11-28 05:38:13 +00:00
Peter Wemm
a4add9a9b1 $Id$ -> $FreeBSD$ 1999-08-27 23:45:13 +00:00
Ralf S. Engelschall
026cb3a62c Cleanups to the pthread header files.
Submitted by:   Ralf S. Engelschall <rse@engelschall.com>
Reviewed by:    John Birrell <jb@cimlogic.com.au>
1999-07-31 08:36:07 +00:00
Daniel Eischen
5b90d09f8a Hide pthread cancellation routines behind #ifdef NOT_YET. They are
not currently supported.  Also corrected the declaration for
pthread_testcancel which incorrectly returned int when POSIX and
SUSv2 both say it should be void.

Submitted by:	Ralf S. Engelschall <rse@engelschall.com>
Reviewed by:	John Birrell <jb@freebsd.org>
1999-07-27 03:29:01 +00:00
John Birrell
b847980f15 o Runnable threads are now maintained in priority queues. The
implementation requires two things:

      1.) The priority queues must be protected during insertion
          and removal of threads.  Since the kernel scheduler
          must modify the priority queues, a spinlock for
          protection cannot be used.   The functions
          _thread_kern_sched_defer() and _thread_kern_sched_undefer()
          were added to {un}defer kernel scheduler activation.

      2.) A thread (active) priority change can be performed only
          when the thread is removed from the priority queue.  The
          implementation uses a threads active priority when
          inserting it into the queue.

    A by-product is that thread switches are much faster.  A
    separate queue is used for waiting and/or blocked threads,
    and it is searched at most 2 times in the kernel scheduler
    when there are active threads.  It should be possible to
    reduce this to once by combining polling of threads waiting
    on I/O with the loop that looks for timed out threads and
    the minimum timeout value.

  o Functions to defer kernel scheduler activation were added.  These
    are _thread_kern_sched_defer() and _thread_kern_sched_undefer()
    and may be called recursively.  These routines do not block the
    scheduling signal, but latch its occurrence.  The signal handler
    will not call the kernel scheduler when the running thread has
    deferred scheduling, but it will be called when running thread
    undefers scheduling.

  o Added support for _POSIX_THREAD_PRIORITY_SCHEDULING.  All the
    POSIX routines required by this should now be implemented.
    One note, SCHED_OTHER, SCHED_FIFO, and SCHED_RR are required
    to be defined by including pthread.h.  These defines are currently
    in sched.h.  I modified pthread.h to include sched.h but don't
    know if this is the proper thing to do.

  o Added support for priority protection and inheritence mutexes.
    This allows definition of _POSIX_THREAD_PRIO_PROTECT and
    _POSIX_THREAD_PRIO_INHERIT.

  o Added additional error checks required by POSIX for mutexes and
    condition variables.

  o Provided a wrapper for sigpending which is marked as a hidden
    syscall.

  o Added a non-portable function as a debugging aid to allow an
    application to monitor thread context switches.  An application
    can install a routine that gets called everytime a thread
    (explicitly created by the application) gets context switched.
    The routine gets passed the pthread IDs of the threads that are
    being switched in and out.  I found this useful, but we can
    get rid of it if you want.

Submitted by: Dan Eischen <eischen@vigrid.com>
1999-03-23 05:11:30 +00:00
Eivind Eklund
07bab7c6a4 Add support for pthread_mutexattr_settype(). As a side effect of
testing this, fix MUTEX_TYPE_COUNTING_FAST.  Recursive locks now work.
1998-11-28 23:52:58 +00:00
Alexander Langer
c0e366326f Implement pthread read/write locks as defined by Version 2 of the Single
UNIX Specification.

As with our standard mutexes, process shared locks are not supported at
this time.
1998-09-07 19:01:43 +00:00
John Birrell
edb4b26f50 Add static initializer defines as specified by POSIX. 1998-04-04 10:59:42 +00:00