Commit Graph

484 Commits

Author SHA1 Message Date
David Xu
a05fa0abea Only init _thread_sigact once, needn't init it again after a fork().
Obtained from: deischen
2003-06-04 12:40:21 +00:00
David Xu
cd0a0c267b Despite whether threaded mode is turned on, always save thread's
signal mask.
2003-06-04 12:38:21 +00:00
David Xu
e84a8d0d65 KMF_DONE is now in /sys/sys/kse.h, no longer need to define it here. 2003-06-04 03:22:59 +00:00
David Xu
a4c69f224b Free memory of internal low level lock when mutex and condition variable
are destroyed.

Submitted by: tegge
2003-06-03 02:21:01 +00:00
David Xu
9abece6475 Save THR_FLAGS_IN_TDLIST in signal frame, otherwise if a thread received
a signal will can not be removed from thread list after it exited.

Reviewed by: deischen
Approved by: re (jhb)
2003-05-30 14:50:16 +00:00
Alexander Kabaev
84d55c7fad Attempt to eliminate PLT relocations from rwlock aquire/release
path, making them suitable for direct use by the dynamic loader.

Register libpthread-specific locking API with rtld on startup.

This still has some rough edges with signals which should be
addresses later.

Approved by:	re (scottl)
2003-05-30 00:21:52 +00:00
Daniel Eischen
43dd76d242 Call the __sys_sigprocmask(the system call) when sigprocmask()
is called and the application is not threaded.  This works around
a problem when an application that hasn't yet become threaded
tries to jump out of a signal handler.

Reported by:	mbr
Approved by:	re@ (rwatson)
2003-05-30 00:09:22 +00:00
Daniel Eischen
28362a5c80 Don't really spin on a spinlock; silently convert it to the same
low-level lock used by the libpthread implementation.  In the
future, we'll eliminate spinlocks from libc but that will wait
until after 5.1-release.

Don't call an application signal handler if the handler is
the same as the library-installed handler.  This seems to
be possible after a fork and is the cause of konsole hangs.

Approved by:	re@ (jhb)
2003-05-29 17:10:45 +00:00
Daniel Eischen
1cb570c531 Change low-level locking a bit so that we can tell if
a lock is being waitied on.

Fix a races in join and cancellation.

When trying to wait on a CV and the library is not yet
threaded, make it threaded so that waiting actually works.

When trying to nanosleep() and we're not threaded, just
call the system call nanosleep instead of adding the thread
to the wait queue.

Clean up adding/removing new threads to the "all threads queue",
assigning them unique ids, and tracking how many active threads
there are.  Do it all when the thread is added to the scheduling
queue instead of making pthread_create() know how to do it.

Fix a race where a thread could be marked for signal delivery
but it could be exited before we actually add the signal to it.

Other minor cleanups and bug fixes.

Submitted by:	davidxu
Approved by:	re@ (blanket for libpthread)
2003-05-24 02:29:25 +00:00
Daniel Eischen
28f318b941 Eek, staticize a couple of functions that shouldn't
be external (initialize()!).

Remove cancellation points from _pthread_cond_wait and
_pthread_cond_timedwait (single underscore versions are
libc private functions).  Point the weak reference(!) for
these functions to the versions with cancellation points.

Approved by:	re@(blanket till 5/19)
Pointed out by:	kan (cancellation point bug)
2003-05-19 23:04:50 +00:00
Daniel Eischen
fd626336fd Add a method of yielding the current thread with the scheduler
lock held (_thr_sched_switch_unlocked()) and use this to avoid
dropping the scheduler lock and having the scheduler retake the
same lock again.

Add a better way of detecting if a low-level lock is in use.

When switching out a thread due to blocking in the UTS, don't
switch to the KSE's scheduler stack only to switch back to
another thread.  If possible switch to the new thread directly
from the old thread and avoid the overhead of the extra
context switch.

Check for pending signals on a thread when entering the scheduler
and add them to the threads signal frame.  This includes some
other minor signal fixes.

Most of this was a joint effor between davidxu and myself.

Reviewed by:	davidxu
Approved by:	re@ (blanket for libpthread)
2003-05-16 19:58:30 +00:00
Daniel Eischen
07e6b1c7a3 Make pthread_join() async-cancel-safe. David was going to commit
this, but I think he's asleep and want to be sure it gets in before
the freeze.

Submitted by:	davidxu
2003-05-06 00:02:54 +00:00
David Xu
f508d26091 call dump_queues() only when DEBUG_THREAD_KERN is defined, save some
cpu cycles.
2003-05-05 05:01:19 +00:00
Daniel Eischen
40791d9d15 Fix suspend and resume.
Submitted (in part) by:	Kazuaki Oda <kaakun@highway.ne.jp>
2003-05-04 16:17:01 +00:00
David Xu
99c883294c Handle thread canceled case, it is same as signal caused backout,
but will break out of loop.
2003-05-02 11:39:00 +00:00
Daniel Eischen
d143dde438 Move the mailbox to the beginning of the thread and align the
thread so that the context (SSE FPU state) is also aligned.
2003-04-30 15:05:17 +00:00
David Xu
d1021be03f Call kse_wakeup_mutli() after remove current thread from RUNQ to avoid
doing unnecessary idle kse wakeup.
2003-04-30 01:15:21 +00:00
David Xu
30a2952c90 Call kse_wakeup_multi() to wakeup idle KSEs when there are threads ready
to run.
2003-04-30 01:03:58 +00:00
Daniel Eischen
6cc13fa9ad Create the thread signal lock as a KSE lock (as opposed to
a thread lock).

Better protect access to thread state while searching for
threads to handle a signal.

Better protect access to process pending signals while processing
a thread in sigwait().

Submitted by:	davidxu
2003-04-29 21:03:33 +00:00
Daniel Eischen
55613576f5 o Don't add a scope system thread's KSE to the list of available
KSEs when it's thread exits; allow the GC handler to do that.

o Make spinlock/spinlock critical regions.

The following were submitted by davidxu

  o Alow thr_switch() to take a null mailbox argument.

  o Better protect cancellation checks.

  o Don't set KSE specific data when creating new KSEs; rely on the
    first upcall of the KSE to set it.

  o Add the ability to set the maximum concurrency level and do this
    automatically.  We should have a way to enable/disable this with
    some sort of tunable because some applications may not want this
    to be the default.

  o Hold the scheduling lock across thread switch calls.

  o If scheduling of a thread fails, make sure to remove it from the list
    of active threads.

  o Better protect accesses to a joining threads when the target thread is
    exited and detached.

  o Remove some macro definitions that are now provided by <sys/kse.h>.

  o Don't leave the library in threaded mode if creation of the initial
    KSE fails.

  o Wakeup idle KSEs when there are threads ready to run.

  o Maintain the number of threads active in the priority queue.
2003-04-28 23:56:12 +00:00
Daniel Eischen
76f344139c Use the correct link entry for walking the list of threads.
While I'm here, use the TAILQ_FOREACH macro instead of a more
manual method which was inherited from libc_r (so we could
remove elements from the list which isn't needed for libpthread).

Submitted by:	Kazuaki Oda <kaakun@highway.ne.jp>
2003-04-28 21:35:06 +00:00
Daniel Eischen
f1c8192fd4 Protect thread errno from being changed while operating
on behalf of the KSE.

Add a kse_reinit function to reinitialize a reused KSE.

Submitted by:	davidxu
2003-04-23 21:46:50 +00:00
Daniel Eischen
29fde418c1 Set the quantum for scope system threads to 0 (no quantum). 2003-04-22 21:32:32 +00:00
Daniel Eischen
42a5f6248b Add a working pthread_[gs]etconcurrency. Initial null implementation
provided by Sergey A. Osokin <osa@freebsd.org.ru>.

In order to test this on a single CPU machine, you need to:

    sysctl kern.threads.debug=1
    sysctl kern.threads.virtual_cpu=2
2003-04-22 20:29:16 +00:00
Daniel Eischen
6dee371a55 Add a couple asserts to pthread_cond_foo to ensure the (low-level)
lock level is 0.  Thus far, the threads implementation doesn't use
mutexes or condition variables so the lock level should be 0.

Save the return value when trying to schedule a new thread and
use this to return an error from pthread_create().

Change the max sleep time for an idle KSE to 1 minute from 2 minutes.

Maintain a count of the number of KSEs within a KSEG.

With these changes scope system threads seem to work, but heavy
use of them crash the kernel (supposedly VM bugs).
2003-04-22 20:28:33 +00:00
Daniel Eischen
02245e6120 Add an i386-specifc hack to always set %gs. There still seems
to be instances where the kernel doesn't  properly save and/or
restore it.

Use noupcall and nocompleted flags in the KSE mailbox.  These
require kernel changes to work which will be committed sometime
later.  Things still work without the changes.

Remove the general kse entry function and use two different
functions -- one for scope system threads and one for scope
process threads.  The scope system function is not yet enabled
and we use the same function for all threads at the moment.

Keep a copy of the KSE stack for the case that a KSE runs
a scope system thread and uses the same stack as the thread
(no upcalls are generated, so a separate stack isn't needed).
This isn't enabled yet.

Use a separate field for the KSE waiting flag.  It isn't
correct to use the mailbox flags field.

The following fixes were provided by David Xu:

  o Initialize condition variable locks with thread versions
    of the low-level locking functions instead of the kse versions.

  o Enable threading before creating the first thread instead
    of after.

  o Don't enter critical regions when trying to malloc/free
    or call functions that malloc/free.

  o Take the scheduling lock when inheriting thread attributes.

  o Check the attribute's stack pointer instead of the
    attributes stack size for null when allocating a
    thread's stack.

  o Add a kseg reinit function so we don't have to destroy and
    then recreate the same lock.

  o Check the return value of kse_create() and return an
    appropriate error if it fails.

  o Don't forget to destroy a thread's locks when freeing it.

  o Examine the correct flags word for checking to see if
    a thread is in a synchronization queue.

Things should now work on an SMP kernel.
2003-04-21 04:02:56 +00:00
Daniel Eischen
078d4c1b8b Remove duplicate $FreeBSD$ id. 2003-04-18 07:45:03 +00:00
Daniel Eischen
e4c2ac1637 Sorry folks; I accidentally committed a patch from what I was working
on a couple of days ago.  This should be the most recent changes.

Noticed by:	davidxu
2003-04-18 07:09:43 +00:00
Daniel Eischen
a0240e2cb0 Revamp libpthread so that it has a chance of working in an SMP
environment.  This includes support for multiple KSEs and KSEGs.

The ability to create more than 1 KSE via pthread_setconcurrency()
is in the works as well as support for PTHREAD_SCOPE_SYSTEM threads.
Those should come shortly.

There are still some known issues which davidxu and I are working
on, but it'll make it easier for us by committing what we have.

This library now passes all of the ACE tests that libc_r passes
with the exception of one.  It also seems to work OK with KDE
including konqueror, kwrite, etc.  I haven't been able to get
mozilla to run due to lack of java plugin, so I'd be interested
to see how it works with that.

Reviewed by:	davidxu
2003-04-18 05:04:16 +00:00
Jeff Roberson
cc3521d660 - Define a _spinunlock() function so that threading implementations may do
more complicated things than just setting the lock to 0.
 - Implement stubs for this function in libc and the two threading libraries
   that are currently in the tree.
2003-03-26 04:02:24 +00:00
David Xu
5b54b0891a Backout last commit.
Requested by: jhb
2003-03-15 04:45:42 +00:00
David Xu
047a20e644 Fix a bug in rwlock. When a rwlock was locked by reader threads, a
writter thread can block reader threads to get read lock.
2003-03-14 01:02:47 +00:00
Alexey Zelkin
68d8899c03 Fix cut'n'paste error
Noticed by:	julian
2003-03-05 20:50:03 +00:00
Alexey Zelkin
09492be669 MFlibc_r: add and document pthread_attr_get_np() function. 2003-03-03 22:40:20 +00:00
David Xu
96dfe788ad Fix compiling error. 2003-02-26 08:28:28 +00:00
Jonathan Mini
3b63c6c8ea Insert threads interrupted by a signal while running onto the run queue. 2003-02-23 21:15:25 +00:00
Jonathan Mini
f88cb3c627 Add signal logic to the build. 2003-02-23 21:14:08 +00:00
Jonathan Mini
faa8342f9f Deliver signals posted via an upcall to the appropriate thread. 2003-02-17 10:05:18 +00:00
Alfred Perlstein
969e2ea158 Actually link in the attr_{set,get}stack. 2003-02-11 07:28:28 +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
Jonathan Mini
e9d0431f0b Schedule spinlocked threads by moving them through the work queue, instead
of the wait queue.

Approved by: re (blanket)
Stolen from: davidxu
2002-11-24 06:45:45 +00:00
Jonathan Mini
4df51f23bb Get the wall clock time from the KSE mailbox, rather than doing another
syscall.
2002-11-24 06:43:21 +00:00
David Xu
662c0429b9 Fix idle timeout bug, use correct current time of day. 2002-11-20 12:35:59 +00:00
Jonathan Mini
1cb53a1828 Schedule an idle context to block until timeouts expire without blocking
further upcalls.
2002-11-12 00:55:01 +00:00
Jonathan Mini
40e044cbd3 Make pthread_sigmask(3) operate on the thread signal mask, not the process
signal mask.
2002-10-30 07:13:27 +00:00
Jonathan Mini
2d9a293b4e Use KSE to schedule threads. 2002-10-30 06:07:18 +00:00
Robert Drehmel
e31d11c36a Add the 'restrict' type qualifier to the prototypes of `sigaction',
`sigprocmask', `sigaltstack', and `sigwait' as well as to the
prototypes of the apparantly unimplemented functions `sigtimedwait'
and `sigwaitinfo'.  This complies with IEEE Std 1003.1-2001.
2002-10-02 10:53:44 +00:00
Jonathan Mini
255ab70cdf Make libpthread KSE aware.
Reviewed by:	deischen, julian
Approved by:	-arch
2002-09-16 19:52:52 +00:00
Jonathan Mini
cc118d869b Make the changes needed for libpthread to compile in its new home.
The new libpthread will provide POSIX threading support using KSE.
These files were previously repo-copied from src/lib/libc_r.

Reviewed by:	deischen
Approved by:	-arch
2002-09-16 08:45:36 +00:00
Daniel Eischen
d8b5986dd6 Remove much of the dereferencing of the fd table entries to look
at file flags and replace it with functions that will avoid null
pointer checks.

MFC to be done by archie ;-)

PR:		42100
Reviewed by:	archie, robert
MFC after:	3 days
2002-08-29 23:06:07 +00:00
Archie Cobbs
afa4625307 Make the libc_r version of select() set the readable or writable
file descriptor bit if poll() returns POLLERR, POLLHUP, or POLLNVAL.
Othewise, it's possible for select() to return successfully but
with no bits set.

Reviewed by:	deischen
MFC after:	3 days
PR:		bin/42175
2002-08-29 21:39:19 +00:00
Archie Cobbs
ccde72a411 When poll(2)'ing for readability or writability of a file descriptor
on behalf of a thread, we should check the POLLERR, POLLHUP, and
POLLNVAL flags as well to wake up the thread in these cases.

Suggested by:	deischen
MFC after:	3 days
2002-08-29 00:44:11 +00:00
Philippe Charnier
7fed38d0a0 Replace various spelling with FALLTHROUGH which is lint()able 2002-08-25 13:10:45 +00:00
Daniel Eischen
582dfa2dd4 Oops, forgot to set the suspended flag for threads that are created
initially suspended.  This was preventing such threads from getting
resumed.

Reported by:	Bill Huey <billh@gnuppy.monkey.org>
2002-07-09 13:24:52 +00:00
Daniel Eischen
88127f1a62 Make sigpending and sigsuspend account for signals that are pending on
the process as well as pending on the current thread.

Reported by:	Andrew MacIntyre <andymac@bullseye.apana.org.au>
2002-06-28 13:28:41 +00:00
Daniel Eischen
b4e1c937c7 Add a wrapper for pselect() in order to make it a cancellation point.
Prompted by: wollman
2002-06-28 13:26:02 +00:00
Robert Watson
4a85ccbe6d Missed in earlier commit -- I did cvs commit src/lib/libc. Oops. 2002-06-14 04:02:25 +00:00
Daniel Eischen
5eb8d1f0b0 Revamp suspend and resume. While I'm here add pthread_suspend_all_np()
and pthread_resume_all_np().  These suspend and resume all threads except
the current thread, respectively.  The existing functions pthread_single_np()
and pthread_multi_np(), which formerly had no effect, now exhibit the same
behaviour and pthread_suspend_all_np() and pthread_resume_all_np().  These
functions have been added mostly for the native java port.

Don't allow the uthread kernel pipe to use the same descriptors as
stdio.  Mostily submitted by Oswald Buddenhagen <ossi@kde.org>.

Correct some minor style nits.
2002-05-24 04:32:28 +00:00
Alfred Perlstein
2b75bbdb31 Undo namespace pollution by prefixing the globals pthread_guard_default and
pthread_page_size.

Fix a bunch line wrapping.

Pointed out by: deischen
2002-05-15 05:37:48 +00:00
Alfred Perlstein
efe5270b1e Don't use PAGE_SIZE in userland, instead use getpagesize(), this is to
allow running on other arches when the instructions are supported but
the page size granularity is not.

Glanced at by: peter
2002-05-13 07:58:15 +00:00
Alfred Perlstein
e5ba687a2c Use GCC's __attribute__ ((constructor)) mechanism to invoke the pthread
startup code rather than a static C++ object since c++ seems to be broken.

This doesn't seem to work for staticically linked program just yet, I'll
give that some more work when I get a chance.
2002-05-11 08:13:42 +00:00
Archie Cobbs
663fc9cc7c Make these functions cancellation points like they should be:
poll(2), readv(2), select(2), wait4(2), writev(2).

PR:		bin/37658
Reviewed by:	deischen
MFC after:	1 week
2002-05-02 19:58:43 +00:00
Archie Cobbs
ca0989d865 Make sure calls to pthread_cancel() do not take effect if the target
thread is already exiting.

PR:		bin/37614
Reviewed by:	deischen
MFC after:	1 week
2002-05-02 19:57:59 +00:00
David E. O'Brien
07a7a2eba8 The GCC developers have made good on their threats against #pragma for 3.1.
Use __weak_reference in place of the #pragma.

Submitted by:	eischen
2002-04-15 23:11:38 +00:00
Jeroen Ruigrok van der Werven
92d2baa6a2 Return correct number of total bits set in all fd_set's.
Change case of POLLNVAL as an error.
Remove POLLHUP and POLLERR from one case, their place is most likely
amongst read events.

PR:		33723
Submitted by:	Alexander Litvin <archer@whichever.org>
Reviewed by:	deischen [Provided a small change to the PR patch as well]
MFC after:	4 weeks
2002-04-09 05:41:00 +00:00
Mark Murray
4cd0119367 Do not use __progname directly (except in [gs]etprogname(3)).
Also, make an internal _getprogname() that is used only inside
libc. For libc, getprogname(3) is a weak symbol in case a
function of the same name is defined in userland.
2002-03-29 22:43:43 +00:00
Daniel Eischen
3003bdb598 Add the ability to recognize old references to keys, and return NULL
when old keys are referenced (after pthread_key_delete()) via
pthread_getspecific().
2002-03-19 22:58:56 +00:00
Brian S. Dean
b18ae9245d Fix the return code from pthread_rwlock_try[rw|rd]lock() functions;
these should return EBUSY when the calling thread would block.

MFC after: 2 weeks
2002-03-15 18:27:58 +00:00
Daniel Eischen
ca4b2c1a79 Properly clear the status of a join operation if the joining thread is
canceled or the joinee is detached.
2002-03-06 19:28:41 +00:00
Daniel Eischen
9e9c4443f6 Don't rely on <sys/signal.h> to include <sys/ucontext.h> 2002-02-17 17:21:27 +00:00
Maxim Konovalov
0878d2e5e9 Correct a typo pthread_attr_setscope() function fails unconditionally
due to.

PR:		misc/30699
Reviewed by:	jasone, ru
Approved by:	jasone, ru
MFC after:	1 week
2002-02-14 15:20:36 +00:00
Daniel Eischen
69c287d288 This has been sitting in my local tree long enough. Remove the use
of an alternate signal stack for handling signals.  Let the kernel
send signals on the stack of the current thread and teach the threads
signal handler how to deliver signals to the current thread if it
needs to.  Also, always store a threads context as a jmp_buf.  Eventually
this will change to be a ucontext_t or mcontext_t.

Other small nits.  Use struct pthread * instead of pthread_t in internal
library routines.  The threads code wants struct pthread *, and pthread_t
doesn't necessarily have to be the same.

Reviewed by:	jasone
2002-02-09 19:58:41 +00:00
Daniel Eischen
2d170746c7 Use the real function address (instead of function address + 8) for the
return address when modifying a jmp_buf to create a new thread context.
Also set t12 with the return address.

This should fix libc_r on alpha.

With much detective work by: Bernd Walter <ticso@cicely.de>
2001-12-22 06:11:06 +00:00
Daniel Eischen
7512c816c0 Fix the retrieval of USRSTACK via sysctl so that it works for 64-bit
archs.  This should fix libc_r on alpha.

Submitted by:	Bernd Walter <ticso@cicely9.cicely.de>
2001-12-18 02:02:59 +00:00
Daniel Eischen
320bfcf3f1 When cancelling a thread while in a join operation, do not detach
the target thread of the join operation.  This allows the cancelled
thread to detach the target thread in its cancellation handler.
This bug was found by Butenhof's cancel_subcontract test.

Reviewed by:	jasone
2001-12-16 13:26:44 +00:00
Daniel Eischen
35686a943a Pull the target thread of a join operation from the correct place
when cancelling a thread.
2001-12-15 15:52:24 +00:00
Daniel Eischen
ccc7b69205 Fix pthread_join so that it works if the target thread exits while
the joining thread is in a signal handler.

Reported by:	Loren James Rittle <rittle@labs.mot.com>
MFC after:	1 week
2001-11-17 14:28:39 +00:00
Peter Wemm
eb9053b12f Make libc_r check the kern.usrstack sysctl instead of using internal
kernel #defines to figure out where the stack is located.  This stops
libc_r from exploding when the kernel is compiled with a different
KVM size.  IMHO this is all kinda bogus, it would be better to just
check %esp and work from that.
2001-10-26 21:19:22 +00:00
Ruslan Ermilov
98f9b06876 Style: sort __sys_foo() prototypes, tabs -> spaces, etc. 2001-10-26 18:45:02 +00:00
Ruslan Ermilov
53cff25eeb Removed:
- uthread_signal.c; libc_r does not wrap signal() since 1998/04/29.

- uthread_attr_setprio.c; it was never connected to the build, and
  pthread_attr_setprio() does not exist in POSIX.

- uthread_sigblock.c and uthread_sigsetmask.c; these were no-ops
  bloating libc_r's space.

pthread_private.h:

- Removed prototypes of non-syscalls: send().

- Removed prototypes of unused syscalls: sigpending(), sigsuspend(),
  and select().

- Fixed prototype of fork().

- MFS: Fixed prototypes of <sys/socket.h> syscalls.

Reviewed by:	deischen
Approved by:	deischen, jasone
2001-10-26 17:46:36 +00:00
Bruce Evans
6eabd84580 Compensate for "Compensate for header dethreading" by backing it out. 2001-10-10 17:48:44 +00:00
Daniel Eischen
7ae9a22df2 Limit maximum poll interval to 60 seconds. This prevents an overflow
from occurring when converting from a timeval/timespec to a timeout in
milliseconds.

Submitted by:	dwmalone
2001-10-07 02:34:43 +00:00
Jason Evans
204e56e381 Fix logic errors in pthread_cond_wait() and pthread_cond_timedwait() that
could cause deadlock after interruption due to a signal.

Reviewed by:	deischen
2001-08-19 20:05:42 +00:00
Jason Evans
8588aeec8c Fix a bug in canceling joining threads.
Do not detach canceled threads.

Reported by:		Arno Klaassen <arno@heho.snv.jussieu.fr>
Collaboration with:	deischen
2001-08-16 06:31:32 +00:00
Warner Losh
e54b5dd9ff Make the name parameter const char *. 2001-08-11 05:16:00 +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
Daniel Eischen
a9513dc678 Clear the in thread scheduler flag after jumping to the start of
a signal handler from the scheduler.

MFC after:	1 week
2001-06-29 17:09:07 +00:00
Jason Evans
651974ee92 Fix a race condition in pthread_join(). All of the following must occur
atomically:

1) Search _thread_list for the thread to join.
2) Search _dead_list for the thread to join.
3) Set the running thread as the joiner.

While we're at it, fix a race in the case where multiple threads try to
join on the same thread.  POSIX says that the behavior of multiple joiners
is undefined, but the fix is cheap as a result of the other fix.
2001-06-27 11:41:15 +00:00
Jason Evans
6699b0c6fe Instead of using a join queue for each thread, use a single pointer to
keep track of a joiner.  POSIX only supports a single joiner, so this
simplification is acceptable.

At the same time, make sure to mark a joined thread as detached so that
its resources can be freed.

Reviewed by:	deischen
PR:		24345
2001-05-20 23:08:33 +00:00
Jason Evans
ffc19644c0 Condition variable waiters are queued in descending priority order, so
there is no need to wake all waiters to assure that the highest priority
thread is run.  As the semaphore code is written, there was no correctness
problem, but the change improves sem_post() performance.

Pointed out by:	deischen
2001-05-18 00:36:05 +00:00
Jason Evans
1317e200a8 Mark a thread that is suspended while sleeping as interrupted. 2001-05-16 21:58:45 +00:00
Akinori MUSHA
3b26be6ae1 Properly copy the P_ALTSTACK flag in struct proc::p_flag to the child
process on fork(2).

It is the supposed behavior stated in the manpage of sigaction(2), and
Solaris, NetBSD and FreeBSD 3-STABLE correctly do so.

The previous fix against libc_r/uthread/uthread_fork.c fixed the
problem only for the programs linked with libc_r, so back it out and
fix fork(2) itself to help those not linked with libc_r as well.

PR:		kern/26705
Submitted by:	KUROSAWA Takahiro <fwkg7679@mb.infoweb.ne.jp>
Tested by:	knu, GOTOU Yuuzou <gotoyuzo@notwork.org>,
		and some other people
Not objected by:	hackers
MFC in:		3 days
2001-05-07 18:07:29 +00:00
Daniel Eischen
59cc2dcac7 Move the check for a pending signals to after the thread has been
placed in any scheduling queue(s).  The process of dispatching
signals to a thread can change its state which will attempt to add
or remove the thread from any scheduling queue to which it belongs.
This can break some assertions if the thread isn't in the queue(s)
implied by its state.

When adding dispatching a pending signal to a thread, be sure to
remove the signal from the threads set of pending signals.

PR:		27035
Tested by:	brian
MFC in:		1 week
2001-05-04 20:37:07 +00:00
Mark Murray
98d2ef9e72 Compenate for header dethreading. 2001-05-01 09:32:34 +00:00
Daniel Eischen
9391331024 Typo; fix open() so that it is not a cancellation point when called
from libc.
2001-04-18 12:42:11 +00:00
Daniel Eischen
1cf08f3929 Reinstall the alternate signal stack after a fork.
PR:		25110
Tested by:	knu
2001-04-18 12:40:30 +00:00
Daniel Eischen
f9c408bc01 Clean up a bit. Use the correct TAILQ link when walking the thread
lists to free thread resources after a fork (in the child).  Also
remember to free the dead thread list.
2001-04-10 04:25:49 +00:00
Daniel Eischen
437df4859a To be consistent, use the __weak_reference macro from <sys/cdefs.h>
instead of #pragma weak to create weak definitions.

Suggested by:	bde
2001-04-10 04:19:21 +00:00
Thomas Moestl
8b28ef9528 Activate build of posix1e extensions in libc and libc_r that have been
moved in from libposix1e, and deactivate build of the soon-to-be-removed
libposix1e.

Approved by:	rwatson
Obtained from:	TrustedBSD Project
2001-04-04 18:17:28 +00:00
Thomas Moestl
16cb0dd753 Add thread safety wrappers for the posix1e syscalls that deal with file
descriptors.

Approved by:	rwatson
Obtained from:	TrustedBSD Project
2001-04-04 18:10:25 +00:00
Ian Dowse
92f5474235 Add a leading underscore to the pthread_main_np function name, and
a "#pragma weak" directive linking the external symbol. This matches
the other pthread_* definitions, and ensures that users of this
function from within libc get the real version, not the stub.

Suggested by:	deischen
Reviewed by:	deischen, alfred
2001-04-03 22:25:39 +00:00
Alfred Perlstein
8360efbd6c Bring in a hybrid of SunSoft's transport-independent RPC (TI-RPC) and
associated changes that had to happen to make this possible as well as
bugs fixed along the way.

  Bring in required TLI library routines to support this.

  Since we don't support TLI we've essentially copied what NetBSD
  has done, adding a thin layer to emulate direct the TLI calls
  into BSD socket calls.

  This is mostly from Sun's tirpc release that was made in 1994,
  however some fixes were backported from the 1999 release (supposedly
  only made available after this porting effort was underway).

  The submitter has agreed to continue on and bring us up to the
  1999 release.

  Several key features are introduced with this update:
    Client calls are thread safe. (1999 code has server side thread
    safe)
    Updated, a more modern interface.

  Many userland updates were done to bring the code up to par with
  the recent RPC API.

  There is an update to the pthreads library, a function
  pthread_main_np() was added to emulate a function of Sun's threads
  library.

  While we're at it, bring in NetBSD's lockd, it's been far too
  long of a wait.

  New rpcbind(8) replaces portmap(8) (supporting communication over
  an authenticated Unix-domain socket, and by default only allowing
  set and unset requests over that channel). It's much more secure
  than the old portmapper.

  Umount(8), mountd(8), mount_nfs(8), nfsd(8) have also been upgraded
  to support TI-RPC and to support IPV6.

  Umount(8) is also fixed to unmount pathnames longer than 80 chars,
  which are currently truncated by the Kernel statfs structure.

Submitted by: Martin Blapp <mb@imp.ch>
Manpage review: ru
Secure RPC implemented by: wpaul
2001-03-19 12:50:13 +00:00
Daniel Eischen
af4878847e Correct a race condition where it was possible for a signaled
thread to become stranded and not placed in the run queue.

MFC Candidate

Reported by:	tegge
2001-03-09 16:05:43 +00:00
Daniel Eischen
c33f8c177f Really set the flags for a private mutex (used by libc/libc_r). 2001-02-26 01:06:52 +00:00
Daniel Eischen
c6f2aed102 Limit threads clock resolution to no less than 1000usec (1000Hz).
PR:		25300
Submitted by:	Tom Pavel <pavel@alum.mit.edu> (in part)
2001-02-26 01:05:33 +00:00
Daniel Eischen
f434cd45ed Remove (int) file descriptor locking. It should be up to the
application to provide locking for I/O operations.  This doesn't
break any of my tests, but the old behavior can be restored by
compiling with _FDLOCKS_ENABLED.  This will eventually be removed
when it is obvious it does not cause any problems.

Remove most of flockfile implementation, with the exception of
flockfile_debug.

Make error messages more informational (submitted by Mike Heffner
<spock@techfour.net>, who's now known as mikeh@FreeBSD.org).
2001-02-11 22:07:32 +00:00
Daniel Eischen
f8a19b12fb s/_thread_sys_write/__sys_write/
Submitted by:	Mike Heffner <mheffner@vt.edu>
2001-01-31 02:16:57 +00:00
Daniel Eischen
f47892a9f7 Unbreak world by correctly specifying the prototype for __sys_aio_suspend.
A make buildworld was done but not with the committed pthread_private.h.

Reported by:	Manfred Antar <null@pozo.com>
2001-01-29 18:59:53 +00:00
Daniel Eischen
221b1e69c5 _exit in libc is now __sys_exit not __sys__exit.
Add another check for thread library initialization (jdp, we
really need a way to get _thread_init called at program start
before any constructors are run).
2001-01-29 03:24:23 +00:00
Daniel Eischen
e5106342c6 Add weak definitions for wrapped system calls. In general:
_foo - wrapped system call
	foo - weak definition to _foo

and for cancellation points:

	_foo - wrapped system call
	__foo - enter cancellation point, call _foo(), leave
	        cancellation point
	foo - weak definition to __foo

Change use of global _thread_run to call a function to get the
currently running thread.

Make all pthread_foo functions weak definitions to _pthread_foo,
where _pthread_foo is the implementation.  This allows an application
to provide its own pthread functions.

Provide slightly different versions of pthread_mutex_lock and
pthread_mutex_init so that we can tell the difference between
a libc mutex and an application mutex.  Threads holding mutexes
internal to libc should never be allowed to exit, call signal
handlers, or cancel.

Approved by:	-arch
2001-01-24 13:03:38 +00:00
David E. O'Brien
cad1dd7bb4 Force strong references to several pthread_* functions which are weakly
referenced to by libgcc.a.

This is needed when linking statically as SVR4 (ie, ELF) behavior is to only
link in a module if it satisfies an undefined strong reference from somewhere.
(this surprises a lot of people) Things are different when using shared libs,
the entire library and its modules and their symbols are available at run-time
(when the weak reference is seen to still be unsatisfied and is satisfied on
the spot), this is not the case with static libs.

Thus one can have a static binary with unresolved week references, and at
run-time dereference a NULL pointer.

Submitted by:	eischen
2001-01-06 06:07:52 +00:00
Daniel Eischen
9ffc4537c8 When retrieving the time of day in nanosleep(), store it in the
global time of day.  This costs us nothing, but is a bit of a hack
to work around a process blocking and not having the time updated
by an ITIMER_PROF signal.

PR:		23679
2000-12-20 17:04:12 +00:00
Daniel Eischen
d73eb8c8ca Enable check for pending signals after calling a signal handler.
Restoration of a threads signal mask after invocation of a signal
handler may allow pending signals to become deliverable.

PR:		23647
2000-12-20 16:55:57 +00:00
Daniel Eischen
47c1571785 Change a "while {}" loop to a "do {} while" to allow it to be
executed at least once, fixing pthread_mutex_lock() for recursive
mutex lock attempts.

Correctly set a threads signal mask while it is executing a signal
handler.  The mask should be the union of its current mask, the
signal being handled, and the mask from the signal action.

Reported by: Dan Nelson <dnelson@emsphone.com>

MFC Candidate
2000-11-20 13:12:44 +00:00
Daniel Eischen
499c499c61 Fix MD macros to work for alpha. Without this fix, threads under alpha
seem to be totally broke.

MFC Candidate

Submitted by:	gallatin
2000-11-20 01:57:19 +00:00
Daniel Eischen
f17033e38d Fix a bug where a statically initialized condition variable
was not getting properly initialized in pthread_cond_signal()
and pthread_cond_broadcast().  Reportedly, this can cause
an application to die.

MFC candidate

Submitted by:	ade
2000-11-16 22:50:33 +00:00
Daniel Eischen
810888e2f8 Delete 4 lines of misleading/incorrect comments. 2000-11-16 19:15:56 +00:00
Daniel Eischen
eb4463fde6 When entering the scheduler from the signal handler, tell
the kernel to (re)use the alternate signal stack.  In this
case, we don't return normally from the signal handler,
so the kernel still thinks we are using the signal stack.
The fixes a nasty bug where the signal handler can start
fiddling with the stack of a thread while the handler is
actually running on the same stack.

MFC candidate
2000-11-14 20:00:19 +00:00
Daniel Eischen
00e550955e Correct the logic for checking the emptiness of the waiting queue.
This fixes a potential problem where the file descriptors would not
be polled causing waiting threads to stay waiting.  Doh!

MFC candidate.
2000-11-11 22:20:36 +00:00
Daniel Eischen
b5a8a15c2f Don't needlessly poll file descriptors when there are no
file descriptors needing to be polled (Doh!).  Reported
by Dan Nelson <dnelson@emsphone.com>.

Don't install and start the scheduling timer until the
first thread is created.  This prevents the overhead of
having a periodic scheduling signal in a single threaded
program.  Reported by Dan Nelson <dnelson@emsphone.com>.

Allow builtin longjmps out of application installed
signal handlers without the need perform any post-handler
cleanup:

  o Change signal handling to save the threads interrupted
    context on the stack.  The threads current context is
    now always stored in the same place (in the pthread).
    If and when a signal handler returns, the interrupted
    context is copied back to the storage area in the pthread.

  o Before calling invoking a signal handler for a thread,
    back the thread out of any internal waiting queues
    (mutex, CV, join, etc) to which it belongs.

Rework uthread_info.c a bit to make it easier to change
the format of a thread dump.

Use an alternal signal stack for the thread library's
signal handler.  This allows us to fiddle with the main
threads stack without fear of it being in use.

Reviewed by:	jasone
2000-11-09 05:08:26 +00:00
John Polstra
a9bda22cd6 At the beginning of pthread_mutex_lock(), call _thread_init() if
necessary.  This works around a bug in old versions of libgcc_r.a
which are statically linked into old executables.
2000-11-01 20:19:07 +00:00
Daniel Eischen
c418675341 Make pthread_kill() know about temporary signal handlers installed
by sigwait().  This prevents a signal from being sent to the process
when there are no application installed signal handlers.

Correct a typo in sigwait (foo -> foo[i]).
2000-10-25 11:46:07 +00:00
Daniel Eischen
2fbba8b1b8 We use ___setjmp (non-signal saving) to setup a signal frame. When
adding a signal frame to a thread, be sure to label the context
correctly so we don't restore an uninitialized process mask.

Reported by:	kimc@W8HD.ORG and Andrey Rouskol <anry@sovintel.ru>
2000-10-22 18:35:11 +00:00
Peter Wemm
100063a74b Try and get libc_r to compile again on the alpha after deischen's commit 2000-10-17 06:31:40 +00:00
Brian Somers
9c8ec4f794 #include <sys/types.h> 2000-10-15 20:04:09 +00:00
Daniel Eischen
fbeb36e4bf Implement zero system call thread switching. Performance of
thread switches should be on par with that under scheduler
activations.

  o Timing is achieved through the use of a fixed interval
    timer (ITIMER_PROF) to count scheduling ticks instead
    of retrieving the time-of-day upon every thread switch
    and calculating elapsed real time.

  o Polling for I/O readiness is performed once for each
    scheduling tick instead of every thread switch.

  o The non-signal saving/restoring versions of setjmp/longjmp
    are used to save and restore thread contexts.  This may
    allow the removal of _THREAD_SAFE macros from setjmp()
    and longjmp() - needs more investigation.

Change signal handling so that signals are handled in the
context of the thread that is receiving the signal.  When
signals are dispatched to a thread, a special signal handling
frame is created on top of the target threads stack.  The
frame contains the threads saved state information and a new
context in which the thread can run.  The applications signal
handler is invoked through a wrapper routine that knows how
to restore the threads saved state and unwind to previous
frames.

Fix interruption of threads due to signals.  Some states
were being improperly interrupted while other states were
not being interrupted.  This should fix several PRs.

Signal handlers, which are invoked as a result of a process
signal (not by pthread_kill()), are now called with the
code (or siginfo_t if SA_SIGINFO was set in sa_flags) and
sigcontext_t as received from the process signal handler.

Modify the search for a thread to which a signal is delivered.
The search algorithm is now:

  o First thread found in sigwait() with signal in wait mask.
  o First thread found sigsuspend()'d on the signal.
  o Current thread if signal is unmasked.
  o First thread found with signal unmasked.

Collapse machine dependent support into macros defined in
pthread_private.h.  These should probably eventually be moved
into separate MD files.

Change the range of settable priorities to be compliant with
POSIX (0-31).  The threads library uses higher priorities
internally for real-time threads (not yet implemented) and
threads executing signal handlers.  Real-time threads and
threads running signal handlers add 64 and 32, respectively,
to a threads base priority.

Some other small changes and cleanups.

PR:		17757 18559 21943
Reviewed by:	jasone
2000-10-13 22:12:32 +00:00
Maxim Sobolev
24a1dab36f Add thread-safe wrapper for fpathconf(2) syscall.
Reviewed by:	jlemon
2000-09-19 18:01:03 +00:00
Jason Evans
f3ee83c3bf The second call to _thread_kern_sig_defer() in sem_post() should be a call
to _thread_kern_sig_undefer().
2000-08-23 07:59:50 +00:00
Alfred Perlstein
022daa34f2 Fix an off-by-one error in the recursive mutex handling that made it
prematurely release recursive mutexes.

Test case provided by: Bradley T. Hughes <bhughes@trolltech.com>
Reviewed by: deischen
2000-08-13 01:30:36 +00:00
Jonathan Lemon
532c92a865 Add wrapper for kevent() syscall
Noted as missing by: nicolas.leonard@animaths.com
2000-08-07 16:51:56 +00:00
Jason Evans
b167c9a5c1 Make sem_post() safe to call from within a signal handler, as required by
POSIX/SUSv2.
2000-08-01 21:19:09 +00:00
Doug Rabson
678ef1b49e Call _thread_init() from pthread_once() if it has not already been called.
This fixes a segfault in some C++ programs which use exceptions before
main() has been called (i.e. from global constructors).

Reviewed by: deischen
2000-07-21 09:31:13 +00:00
Jason Evans
8e234adf86 Change my email address in the copyright notices for the sake of consistency
(jasone@canonware.com --> jasone@freebsd.org).
2000-07-18 01:38:19 +00:00
Jason Evans
390a1cd5eb Deal correctly with statically initialized condition variables in
pthread_cond_signal(), pthread_cond_broadcast(), and pthread_cond_timedwait().

Do not dump core in pthread_cond_timedwait() (due to a NULL pointer
dereference) if attempting to wait on an uninitialized condition variable.

PR:	bin/18099
2000-07-17 22:55:05 +00:00
Jason Evans
8d107d1210 If multiple threads are blocked in sigwait() for the same signal that does
not have a user-supplied signal handler, when a signal is delivered, one
thread will receive the signal, and then the code reverts to having no
signal handler for the signal.  This can leave the other sigwait()ing
threads stranded permanently if the signal is later ignored, or can result
in process termination when the process should have delivered the signal to
one of the threads in sigwait().

To fix this problem, maintain a count of sigwait()ers for each signal that
has no default signal handler.  Use the count to correctly install/uninstall
dummy signal handlers.

Reviewed by:	deischen
2000-06-27 21:30:16 +00:00
Jason Evans
314be1347b pthread_mutex_lock(), pthread_cond_trywait(), and pthread_cond_wait() are
not allowed to return EINTR, but use of pthread_suspend_np() could cause
EINTR to be returned.  To fix this, restructure pthread_suspend_np() so that
it does not interrupt a thread that is waiting on a mutex or condition, and
keep enough state around that pthread_resume_np() can fix things up
afterwards.

Reviewed by:	deischen
2000-06-14 17:17:41 +00:00
Jake Burkholder
e39756439c Back out the previous change to the queue(3) interface.
It was not discussed and should probably not happen.

Requested by:		msmith and others
2000-05-26 02:09:24 +00:00
Jake Burkholder
740a1973a6 Change the way that the queue(3) structures are declared; don't assume that
the type argument to *_HEAD and *_ENTRY is a struct.

Suggested by:	phk
Reviewed by:	phk
Approved by:	mdodd
2000-05-23 20:41:01 +00:00
Jason Evans
ccb3a748f4 Fix a memory leak. pthread_set_name_np() allocates space for a name, but
was not deallocating space for the previous name, if any.

PR:	misc/18504
2000-05-16 22:08:14 +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
4c089f4dff Add missing man pages. Fix various compliance bugs, mostly having to do with
error return values.  Implement pthread_mutexattr_gettype().

PR:		docs/16537, docs/17538
2000-05-02 06:51:40 +00:00
Jason Evans
98a1f447bb Add a wrapper for the sendfile() system call.
PR:		bin/17366
2000-04-27 00:59:44 +00:00
Jason Evans
7e5e179982 Explicitly include sys/cdefs.h to get the definition of __strong_reference(),
rather than getting lucky due to header dependencies.
2000-03-18 22:36:46 +00:00
Daniel Eischen
1d013a86ed Fix pthread_suspend_np/pthread_resume_np. For the record, suspending a
thread waiting on an event (I/O, condvar, etc) will, when resumed using
pthread_resume_np, return with EINTR.  For example, suspending and resuming
a thread blocked on read() will not requeue the thread for the read, but
will return -1 with errno = EINTR.  If the suspended thread is in a critical
region, the thread is suspended as soon as it leaves the critical region.

Fix a bogon in pthread_kill() where a signal was being delivered twice
to threads waiting in sigwait().

Reported by (suspend/resume bug):	jdp
Reviewed by:	jasone
2000-03-15 13:59:27 +00:00
Jason Evans
8a668b9049 For errors, return -1 and set errno to indicate the error type, rather than
returning the error directly.

For sem_post(), make sure that the correct thread is woken up.  This has
unfortunate performance implications, but is necessary for POSIX compliance.

Approved by:	jkh
2000-02-16 19:34:53 +00:00
Jason Evans
d77639f25f Use __strong_reference() instead of __weak_reference() to assure that the
weak symbols of the same name are not used.
2000-01-29 22:53:55 +00:00
Jason Evans
4ec6f67d10 Use _fcntl() (not fcntl()) inside of fcntl().
Reported by:	green
2000-01-28 22:10:27 +00:00
Jason Evans
9233c4d942 Simplify sytem call renaming. Instead of _foo() <-- _libc_foo <-- foo(),
just use _foo() <-- foo().  In the case of a libpthread that doesn't do
call conversion (such as linuxthreads and our upcoming libpthread), this
is adequate.  In the case of libc_r, we still need three names, which are
now _thread_sys_foo() <-- _foo() <-- foo().

Convert all internal libc usage of: aio_suspend(), close(), fsync(), msync(),
nanosleep(), open(), fcntl(), read(), and write() to _foo() instead of foo().

Remove all internal libc usage of: creat(), pause(), sleep(), system(),
tcdrain(), wait(), and waitpid().

Make thread cancellation fully POSIX-compliant.

Suggested by:	deischen
2000-01-27 23:07:25 +00:00
Jason Evans
0c5d1a3361 Fix millisecond to nanosecond conversion.
PR:		misc/16245
2000-01-22 09:15:15 +00:00
Jason Evans
beab1ec9b5 Minor *jmp() cleanups. 2000-01-20 21:53:59 +00:00
Jason Evans
120bfc9ded Add sem_*() functions. Named semaphores and process-shared semaphores
are not supported by this implementation, and the error return values
from sem_init(), sem_open(), sem_close(), and sem_unlink() reflect this.

Approved by:	jkh
2000-01-20 07:54:49 +00:00
Jason Evans
adbd6ee028 Do signal deferral for pthread_kill() as it was done in the old days.
Submitted by:	deischen
2000-01-20 04:46:52 +00:00
Jason Evans
0a3fa43c7e Implement continuations to correctly handle [sig|_]longjmp() inside of a
signal handler.  Explicitly check for jumps to anywhere other than the
current stack, since such jumps are undefined according to POSIX.

While we're at it, convert thread cancellation to use continuations, since
it's cleaner than the original cancellation code.

Avoid delivering a signal to a thread twice.  This was a pre-existing bug,
but was likely unexposed until these other changes were made.

Defer signals generated by pthread_kill() so that they can be delivered on
the appropriate stack.  deischen claims that this is unnecessary, which is
likely true, but without this change, pthread_kill() can cause undefined
priority queue states and/or PANICs in [sig|_]longjmp(), so I'm leaving
this in for now.  To compile this code out and exercise the bug, define
the _NO_UNDISPATCH cpp macro.  Defining _PTHREADS_INVARIANTS as well will
cause earlier crashes.

PR:			kern/14685
Collaboration with:	deischen
2000-01-19 07:04:50 +00:00
Daniel Eischen
7e416d8e49 Properly initialize the last active time of the initial thread. This fixes
the case that a CPU hungry main thread is prevented from being preempted
due to a negative calculation of its time slice.

Reported by:	Alexander Litvin <archer@lucky.net>
2000-01-18 11:35:25 +00:00
Jason Evans
f560c4e709 Track libc's three-tier symbol naming. libc_r must currently implement
the _libc_*() entry points and add *() weak aliases.  This will all
change for the better when libc_r becomes libpthread.
2000-01-12 09:28:58 +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
91e92a2d3d Don't explicitly mmap() red zones at the bottom of thread stacks (except
the initial thread).  Instead, just leave an unmapped gap between thread
stacks and make sure that the thread stacks won't grow into these gaps,
simply by limiting the size of the stacks with the 'len' argument to
mmap().  This (if I understand correctly) reduces VM overhead
considerably.

Reviewed by:	deischen
1999-12-29 15:44:59 +00:00
Daniel Eischen
1752e66d49 -Wall and minor style(9) cleanups. 1999-12-28 18:13:04 +00:00
Daniel Eischen
69186ed701 Change stack allocation algorithm to make better use of memory
(it was leaving an unused block).  Also protect the global stack
pointer from context changes while fiddling with it.
1999-12-28 18:12:07 +00:00
Daniel Eischen
8d048bba15 Don't wakeup threads when there is a process signal and no installed
handler.  Thread-to-thread signals (pthread_signal) are treated differently
than process signals; a pthread_signal can wakeup a blocked thread if
a signal handler is not installed for that signal.

Found by:	ACE tests
1999-12-28 18:08:09 +00:00
Jason Evans
386812d440 Fix some minor POSIX/SUSv2 compliance nits.
PR:		kern/11982
1999-12-18 01:00:42 +00:00
Daniel Eischen
fc8f3f5bfe Fix problems with cancellation while in critical regions.
o Cancellation flags were not getting properly set/cleared.
  o Loops waiting for internal locks were not being exited
    correctly by a cancelled thread.
  o Minor spelling (cancelation -> cancellation) and formatting
    corrections (missing tab).

Found by:	tg
Reviewed by:	jasone
1999-12-17 00:57:54 +00:00
Daniel Eischen
3dc268f4e7 Fixes for signal handling:
o Don't call signal handlers with the signal handler access lock
    held.
  o Remove pending signals before calling signal handlers.  If
    pending signals were not removed prior to handling them,
    invocation of the handler could cause the handler to be
    called more than once for the same signal.  Found by: JB
  o When SIGCHLD arrives, wake up all threads in PS_WAIT_WAIT
    (wait4).

PR:		bin/15328
Reviewed by:	jasone
1999-12-17 00:56:36 +00:00
Jason Evans
e6a5e33c6b Avoid an infinite loop if the last element of the iov array passed to
writev() has an iov_len of 0.

PR:		bin/8281
1999-12-16 22:35:40 +00:00
Daniel Eischen
4fc937ef8f Change signal handling to conform to POSIX specified semantics.
Before this change, a signal was delivered to each thread that
didn't have the signal masked.  Signals also improperly woke up
threads waiting on I/O.  With this change, signals are now
handled in the following way:

  o If a thread is waiting in a sigwait for the signal,
    then the thread is woken up.

  o If no threads are sigwait'ing on the signal and a
    thread is in a sigsuspend waiting for the signal,
    then the thread is woken up.

  o In the case that no threads are waiting or suspended
    on the signal, then the signal is delivered to the
    first thread we find that has the signal unmasked.

  o If no threads are waiting or suspended on the signal,
    and no threads have the signal unmasked, then the signal
    is added to the process wide pending signal set.  The
    signal will be delivered to the first thread that unmasks
    the signal.

If there is an installed signal handler, it is only invoked
if the chosen thread was not in a sigwait.

In the case that multiple threads are waiting or suspended
on a signal, or multiple threads have the signal unmasked,
we wake up/deliver the signal to the first thread we find.
The above rules still apply.

Reported by:	Scott Hess <scott@avantgo.com>
Reviewed by:	jb, jasone
1999-12-04 22:55:59 +00:00
Doug Rabson
3c085f72bb * Fix the stack allocation code so that it works for alpha. Change it
to use mmap(..., MAP_STACK, ...) on alpha too since that should work
  now.
* Add hooks to allow GDB to access the internals of pthreads without
  having to know the exact layout of struct pthread.

Reviewed by: deischen
1999-11-28 19:47:43 +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
Marcel Moolenaar
74562f1a2a Add the proper headers so that the SIGNOTEMPTY and SIGSETAND
macros are defined.
1999-09-30 14:51:31 +00:00
Marcel Moolenaar
3cf3c5d9dd sigset_t change (part 5 of 5)
-----------------------------

Most of the userland changes are in libc. For both the alpha
and the i386 setjmp has been changed to accomodate for the
new sigset_t. Internally, libc is mostly rewritten to use the
new syscalls. The exception is in compat-43/sigcompat.c

The POSIX thread library has also been rewritten to use the
new sigset_t. Except, that it currently only handles NSIG
signals instead of the maximum _SIG_MAXSIG. This should not
be a problem because current applications don't use any
signals higher than NSIG.

There are version bumps for the following libraries:
  libdialog
  libreadline
  libc
  libc_r
  libedit
  libftpio
  libss

These libraries either a) have one of the modified structures
visible in the interface, or b) use sigset_t internally and
may cause breakage if new binaries are used against libraries
that don't have the sigset_t change. This not an immediate
issue, but will be as soon as applications start using the
new range to its fullest.

NOTE: libncurses already had an version bump and has not been
      given one now.

NOTE: doscmd is a real casualty and has been disconnected for
      the moment. Reconnection will eventually happen after
      doscmd has been fixed. I'm aware that being the last one
      to touch it, I'm automaticly promoted to being maintainer.
      According to good taste this means that I will receive a
      badge which either will be glued or mechanically stapled,
      drilled or otherwise violently forced onto me :-)

NOTE: pcvt/vttest cannot be compiled with -traditional. The
      change cause sys/types to be included along the way which
      contains the const and volatile modifiers. I don't consider
      this a solution, but more a workaround.
1999-09-29 15:18:46 +00:00
Dmitrij Tejblum
ffd73a0043 Fix a memory leak: free the thread-specific poll_data, used in the select()
implementation.

PR:		13368
Submitted by:	Steve Bernacki, Jr. <steve@copacetic.net>
1999-08-30 15:45:42 +00:00
Daniel Eischen
3e12058d25 When checking for valid timevals in the wrapped select() and poll()
routines, don't return EINVAL but set errno to EINVAL and return -1.
Added a check in pthread_cond_timedwait for a null timespec pointer.
1999-08-30 00:02:08 +00:00
Peter Wemm
7f3dea244c $Id$ -> $FreeBSD$ 1999-08-28 00:22:10 +00:00
Alfred Perlstein
89f6acf96a move sanity check of timeval struct so as not to segfault when passed
a null pointer.

Pointed out by: Thomas Gellekum <tg@ihf.rwth-aachen.de>
Reviewed by:    eivind
1999-08-20 21:06:20 +00:00
John Birrell
e4065e8294 When checking if there is a stack to free, observe the fact that it
might have been mmapped, and if so, passing the pointer to free() is
really not a good idea.

[ In the next millenium, when I've taken over the world, I'm going
  to ban 8 character tabs. You've been warned. ]
1999-08-20 12:17:09 +00:00
Alfred Perlstein
4c263f605c time_to_sleep->tv_nsec > 1000000000
-to-
time_to_sleep->tv_nsec >= 1000000000
1999-08-19 23:18:07 +00:00
Alfred Perlstein
91518882e0 Sanity check time structures passed in, return EINVAL like the system
calls do to avoid corrupting the thread library's concept of wakeup
time.

PR:		kern/12141
Reviewed by:	deischen, eivind
1999-08-19 23:06:11 +00:00
Alfred Perlstein
c81c6baf1d handle under/overflow of time values in a more robust manner,
there may be an overflow that need to be adjusted more than once.

Pointed out by: Fabian Thylmann <fthylmann@stats.net>

Reviewed by:	eivind, jb
1999-08-19 16:49:53 +00:00
Daniel Eischen
936aa6b443 Add check for runnable threads before polling file descriptors.
Submitted by:	tegge
1999-08-12 19:34:39 +00:00
Daniel Eischen
fa7c4d5575 Add RCS IDs to those files without them.
Fix copyrights (s/REGENTS/AUTHOR).

Suggested by:	tg
Approved by:	jb
1999-08-05 12:15:30 +00:00
Daniel Eischen
8b5d18ec76 Fix thread initialization to allow for the case where stdio file
descriptors are not opened.

PR:		bin/12853
Reviewed by:	jb
1999-08-05 12:08:10 +00:00
Dmitrij Tejblum
6ff19e189d Use USRSTACK (defined in <machine/vmparam.h>) to get top of the initial stack.
PTHREAD_STACK_TOP was wrong for all supported architectures.
1999-07-12 16:09:30 +00:00
Jason Evans
66da783384 Fix a couple more coding style nits. 1999-07-11 06:06:52 +00:00
Jason Evans
34582929f1 Modify previous changes to conform better to libc_r's coding style.
Always use mmap() for default-size stack allocation.  Use MAP_ANON instead
of MAP_STACK on the alpha architecture.

Reduce the amount of code executed while owning _gc_mutex during stack
allocation.
1999-07-11 05:56:37 +00:00
Jason Evans
876cc3dae0 Always use growable thread stacks on the i386. The VM_STACK kernel option
must be made default for the alpha before growable thread stacks are
enabled for the alpha.
1999-07-06 00:25:38 +00:00
Jason Evans
ecaa6e8c9e Use growable stacks for thread stacks that are the default stack size.
Cache discarded default thread stacks for use in subsequent thread creations.

Create a red zone at the end of each stack (including the initial thread
stack), with the hope of causing a segfault if a stack overflows.

To activate these modifications, add -D_PTHREAD_GSTACK to CFLAGS in
src/lib/libc_r/Makefile.  Since the modifications depend on the VM_STACK
kernel option, I'm not sure how to safely use growable stacks by default.

Testing, as well as algorithmic and stylistic comments are welcome.
1999-07-05 00:35:19 +00:00
Dmitrij Tejblum
db06cf96d5 Defer signals, so we will not wait for SIGCHLD after it was delivered. 1999-06-29 19:57:07 +00:00
Dmitrij Tejblum
2467b7977b Fix few warnings on the alpha. 1999-06-23 15:01:22 +00:00
John Birrell
02292f131a In the words of the author:
o The polling mechanism for I/O readiness was changed from
    select() to poll().  In additon, a wrapped version of poll()
    is now provided.

  o The wrapped select routine now converts each fd_set to a
    poll array so that the thread scheduler doesn't have to
    perform a bitwise search for selected fds each time file
    descriptors are polled for I/O readiness.

  o The thread scheduler was modified to use a new queue (_workq)
    for threads that need work.  Threads waiting for I/O readiness
    and spinblocks are added to the work queue in addition to the
    waiting queue.  This reduces the time spent forming/searching
    the array of file descriptors being polled.

  o The waiting queue (_waitingq) is now maintained in order of
    thread wakeup time.  This allows the thread scheduler to
    find the nearest wakeup time by looking at the first thread
    in the queue instead of searching the entire queue.

  o Removed file descriptor locking for select/poll routines.  An
    application should not rely on the threads library for providing
    this locking; if necessary, the application should use mutexes
    to protect selecting/polling of file descriptors.

  o Retrieve and use the kernel clock rate/resolution at startup
    instead of hardcoding the clock resolution to 10 msec (tested
    with kernel running at 1000 HZ).

  o All queues have been changed to use queue.h macros.  These
    include the queues of all threads, dead threads, and threads
    waiting for file descriptor locks.

  o Added reinitialization of the GC mutex and condition variable
    after a fork.  Also prevented reallocation of the ready queue
    after a fork.

  o Prevented the wrapped close routine from closing the thread
    kernel pipes.

  o Initialized file descriptor table for stdio entries at thread
    init.

  o Provided additional flags to indicate to what queues threads
    belong.

  o Moved TAILQ initialization for statically allocated mutex and
    condition variables to after the spinlock.

  o Added dispatching of signals to pthread_kill.  Removing the
    dispatching of signals from thread activation broke sigsuspend
    when pthread_kill was used to send a signal to a thread.

  o Temporarily set the state of a thread to PS_SUSPENDED when it
    is first created and placed in the list of threads so that it
    will not be accidentally scheduled before becoming a member
    of one of the scheduling queues.

  o Change the signal handler to queue signals to the thread kernel
    pipe if the scheduling queues are protected.  When scheduling
    queues are unprotected, signals are then dequeued and handled.

  o Ensured that all installed signal handlers block the scheduling
    signal and that the scheduling signal handler blocks all
    other signals.  This ensures that the signal handler is only
    interruptible for and by non-scheduling signals.  An atomic
    lock is used to decide which instance of the signal handler
    will handle pending signals.

  o Removed _lock_thread_list and _unlock_thread_list as they are
    no longer used to protect the thread list.

  o Added missing RCS IDs to modified files.

  o Added checks for appropriate queue membership and activity when
    adding, removing, and searching the scheduling queues.  These
    checks add very little overhead and are enabled when compiled
    with _PTHREADS_INVARIANTS defined.  Suggested and implemented
    by Tor Egge with some modification by me.

  o Close a race condition in uthread_close.  (Tor Egge)

  o Protect the scheduling queues while modifying them in
    pthread_cond_signal and _thread_fd_unlock.  (Tor Egge)

  o Ensure that when a thread gets a mutex, the mutex is on that
    threads list of owned mutexes.  (Tor Egge)

  o Set the kernel-in-scheduler flag in _thread_kern_sched_state
    and _thread_kern_sched_state_unlock to prevent a scheduling
    signal from calling the scheduler again.  (Tor Egge)

  o Don't use TAILQ_FOREACH macro while searching the waiting
    queue for threads in a sigwait state, because a change of
    state destroys the TAILQ link.  It is actually safe to do
    so, though, because once a sigwaiting thread is found, the
    loop ends and the function returns.  (Tor Egge)

  o When dispatching signals to threads, make the thread inherit
    the signal deferral flag of the currently running thread.
    (Tor Egge)

Submitted by: Daniel Eischen <eischen@vigrid.com> and
              Tor Egge <Tor.Egge@fast.no>
1999-06-20 08:28:48 +00:00
John Birrell
994d9b67a5 Added a missing comma to the static condition variable initialisation
definition.

Submitted by: David Leonard <David.Leonard@csee.uq.edu.au>, an OpenBSD guy.
1999-05-24 07:22:55 +00:00
John Birrell
eb9dc34d8b Fix a problem with static initialisation of mutexes and condition
variables.

Submitted by: Dan Eischen <eischen@vigrid.com>
1999-05-23 10:55:33 +00:00
John Birrell
65d33b21e6 Ensure that an existing thread gets it's state set to PS_DEAD to
prevent being rescheduled.

Submitted by: Dan Eischen <eischen@vigrid.com>
1999-05-16 05:25:37 +00:00
Nate Williams
283f072c78 - Fixed bug where we NULL'd before we freed the data causing a memory leak.
Submitted by:	 Ralf S. Engelschall
Obtained from:	PR i386/11713
1999-05-14 21:36:16 +00:00
Jason Evans
c578efe575 Back out patch for cond_timedwait() bug from -current, since other changes
have made the patch obsolete, as pointed out by Daniel Eischen
<eischen@vigrid.com>.

PR:		bin/8872
1999-05-08 07:50:05 +00:00
Jason Evans
a1aefaec27 Apply patch included in bin/8872. This fixes a bug that occurs when
pthread_cond_timedwait() times out.

PR:		bin/8872
Submitted by:	Jason Evans <jasone@canonware.com>
Reviewed by:	David Schwartz <davids@webmaster.com>
1999-05-07 07:59:44 +00:00
John Birrell
58a7cc5d1b [ The author's description... ]
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.

Submitted by: Dan Eischen <eischen@vigrid.com>

Changes by me:

  o Added a PS_SPINBLOCK state to deal with the priority inversion
    problem most often (I think) seen by threads calling malloc/free/realloc.

  o Dispatch signals to the running thread directly rather than at a
    context switch to avoid the situation where the switch never occurs.
1999-03-23 05:07:56 +00:00
John Birrell
0883c4c31b Increase the size of private thread flags so that the test for a
thread trying to call pthread_exit() from a cleanup handler actually
works.

Submitted by: David Leonard <david.leonard@csee.uq.edu.au> OpenBSD
1999-01-15 00:21:03 +00:00
Warner Losh
d0c4729014 Fix a minor security problem in libc_r.
Submitted by: Alexandre Snarskii <snar@paranoia.ru>
Approved by: John Birrell
Reminded me that I'd been sitting on this too long: snar@paranoia.ru
1999-01-11 00:02:37 +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
John Birrell
4896148e72 Interrupt threads waiting in select etc.
Submitted by: Alec Wolman <wolman@cs.washington.edu>
1998-11-15 10:01:34 +00:00
John Birrell
e7b7b3f3de Close a window between unlocking a spinlock and changing the thread state. 1998-11-15 09:58:26 +00:00
Dmitrij Tejblum
171a7528a8 Don't call pthread_mutex_lock with _SPINLOCK held.
Made pthread_cond_wait() more similar to pthread_cond_timedwait().

PR:		8375
1998-11-06 21:04:02 +00:00
Dmitrij Tejblum
4b12016bab Fix some bugs in pthread scheduler:
make pthread_yield() more reliable,
  threads always (I hope) preempted at least every 0.1 sec, as intended.

PR:		bin/7744
Submitted by:	"Richard Seaman, Jr." <dick@tar.com>
1998-10-09 19:01:30 +00:00
John Birrell
d3bb66886d Cosmetic cleansing. This code requires extra work to keep the garbage
collector thread running after a fork.
1998-09-30 06:41:16 +00:00
John Birrell
dc3a8b52c0 Move the cleanup code that frees memory allocated for a dead thread from
the thread kernel into a garbage collector thread which is started when
the fisrt thread is created (other than the initial thread). This
removes the window of opportunity where a context switch will cause a
thread that has locked the malloc spinlock, to enter the thread kernel,
find there is a dead thread and try to free memory, therefore trying
to lock the malloc spinlock against itself.

The garbage collector thread acts just like any other thread, so
instead of having a spinlock to control accesses to the dead thread
list, it uses a mutex and a condition variable so that it can happily
wait to be signalled when a thread exists.
1998-09-30 06:36:56 +00:00
John Birrell
05f3e91279 Use snprintf instead of sprintf to avoid long source file paths from
launching an application into space when someone tries to debug it.

The dead thread list now has it's own link pointer, so use that when
reporting the grateful dead.
1998-09-30 06:29:54 +00:00
John Birrell
54059e9f3f Implementation of an additional state called SIGWAIT (with the previous
one renamed to SIGSUSPEND) to fix sigwait().

Submitted by: Daniel M. Eischen <eischen@vigrid.com>
1998-09-30 06:27:31 +00:00
John Birrell
92ce833722 NULL a pointer after it is freed to avoid trying to free it again. 1998-09-30 06:24:57 +00:00
John Birrell
a247f83316 - Fix the debug macros.
-  Add support of a thread being listed in the dead thread list as well
   as the thread list.
-  Add a new thread state to make sigwait work properly. (Submitted by
   Daniel M. Eischen <eischen@vigrid.com>)
-  Add global variable for the garbage collector mutex and condition
   variable.
-  Delete a couple of prototypes that are no longer required.
-  Add a prototype for the garbage collector thread.
1998-09-30 06:22:07 +00:00
Dmitrij Tejblum
deb9688ae1 In libc_r, rename vfork syscall to _thread_sys_vfork and make vfork an alias
to fork. It is difficult to do real vfork in libc_r, since almost every
operation with file descriptsor changes _thread_fd_table and friends.

popen(3) works much better with this change.
1998-09-12 22:03:20 +00:00
Alexander Langer
cecc7b0974 Removed unused variables. 1998-09-07 21:55:01 +00:00
Alexander Langer
e66632a35c Removed some variable initializations which were unnecessary and divergent
from style(9).
1998-09-07 21:07:59 +00:00
Alexander Langer
23424a1f9a -Wall clean. 1998-09-07 19:23:55 +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
5f867deba5 Don't automatically restart syscalls for the signals that the thread
kernel needs.
1998-08-26 20:55:31 +00:00
John Birrell
353a159590 Back out most of the last commit. It created problems with sigpause. 1998-08-26 20:50:42 +00:00
John Birrell
42f37683ee Fix for sigwait problem.
Submitted by: Daniel M. Eischen <eischen@vigrid.com>
PR:           misc/7039
1998-08-25 11:19:14 +00:00
John Birrell
bbf157fac4 Add extra initialisation code that is required for processes that
are started instead of init (pid = 1). This allows an embedded
implementation quite like VxWorks, with (possibly) a single threaded
program running instead of init. The neat thing is that the same threaded
process can run in a multi-user workstation environment too.
1998-08-10 01:24:22 +00:00
Alexander Langer
b4ff1b7295 A style fix for my previous commit. 1998-08-02 23:07:25 +00:00
Alexander Langer
27aa2e8958 Fixed a race condition during the first lock/trylock of a statically
initialized mutex.  Statically initialized mutexes are actually
initialized at first use (pthread_mutex_lock/pthread_mutex_trylock).
To prevent concurrent initialization by multiple threads, all
static initializations are now serialized by a spinlock.

Reviewed by:	jb
1998-08-02 17:04:25 +00:00
Bruce Evans
bcc58f6898 Fixed a printf format error. Didn't fix assumption that sigset_t is
integral.
1998-06-30 18:00:11 +00:00
John Birrell
ff09ba5fbb Add the missing {} that caused the function to return ESRCH if it
had to wait for the thread to exit and if the caller didn't want the
thread exit status.
1998-06-25 00:04:21 +00:00
John Birrell
b9148b8a3e Don't allow a SIGCHLD to wake up a thread if the process has the default
signal handler installed for SIGCHLD. The ACE MT_SOCK_Test was hanging
as the result of being interrupted when it didn't expect to be.
1998-06-17 22:29:12 +00:00
John Birrell
d989fc8faa If a thread is waiting on a child process to complete, the SIGCHLD
signal can arrive before the thread is woken from it's wait4. In this
case, don't return an EINTR, just set the thread state to running and
the wait4 wrapper will loop and get the exit status of the process.
1998-06-17 03:53:16 +00:00
John Birrell
597035b4db If a short write, only loop if no error. 1998-06-14 09:36:14 +00:00
John Birrell
06ca87e9f7 Update the caller's descriptor masks even if there are none ready for
I/O for those applications that don't believe the return value of zero as
meaning that THERE ARE *NO* DESCRIPTORS READY.
1998-06-12 02:17:18 +00:00
John Birrell
8eb25828ad Check the access mode in the flags before waiting on a read or a write
that might never be possible if the file was not opened in the corrent
mode. This prevents a hang for bad programs. Why do people code like that?
1998-06-10 22:28:45 +00:00
John Birrell
aef774b0d5 Remove SA_RESTART from the signal dispatch in user-space since this
seems to be tripping up a lot of applications.
1998-06-10 22:25:18 +00:00
John Birrell
3c165ef7b7 When doing a F_SETFL, read the flags back so that the ones stored
in the file descriptor table are exactly what the kernel knows subject
to the O_NONBLOCK flag being requested by the user.
1998-06-10 22:24:12 +00:00
John Birrell
ddc8afd422 Implement compile time debug support instead of tracking file name and
line number every time a file descriptor is locked.

This looks like a big change but it isn't. It should reduce the size
of libc_r and make it run slightly faster.
1998-06-09 23:21:05 +00:00
John Birrell
3411c10600 Add support for compile time debug. This is enabled if libc_r is built
with -D_LOCK_DEBUG. This adds the file name and line number to each lock
call and these are stored in the spinlock structure. When using debug
mode, the lock function will check if the thread is trying to lock
something it has already locked. This is not supposed to happen because
the lock will be freed too early.

Without lock debug, libc_r should be smaller and slightly faster.
1998-06-09 23:13:10 +00:00
John Birrell
74ebed9424 POSIX says that pthread_exit() is not allowed to be called from a
cleanup destructor, so trap this case to prevent me from being being
burnt again by applications that try to do this. With this change, an
application (like one using a mis-configured ACE) will exit the process
after displaying a message quoting the POSIX section that the application
has violated.
1998-06-09 23:08:41 +00:00
John Birrell
27949f44dc Add compile time thread lock debug support.
Add a thread specific flag to trap the case where pthread_exit() is
called from a destructor in violation of the Posix standard.
1998-06-09 23:02:43 +00:00
John Birrell
2d8a580416 Add a warning message for a thread locking against itself. This is
not supposed to happen, but I have seen bogus g++ code that causes
it.
1998-06-06 07:27:06 +00:00
John Birrell
c6831395f4 Simplify the handling of thread specific data. Only track if a key
is allocated or not, rather than keeping a count and attempting to
know it it is in-use. POSIX says that once a key is deleted, using the
key again results in undefined behaviour.
1998-06-06 07:24:24 +00:00
John Birrell
c359f976b4 Re-design the thread specific key structure. 1998-06-06 07:20:23 +00:00
John Birrell
717d1611f4 I got the last commit back to front. 1998-06-06 07:02:27 +00:00
John Birrell
756534d117 Fix the signal behaviour for internal states which set the thread
state to running despite the SA_RESTART flag which is really just for
syscalls.
1998-06-05 23:31:55 +00:00
John Birrell
fca35cd32f I shouldn't do things early in the morning.
I shouldn't do things early in the morning.
[...]
I shouldn't do things early in the morning.
1998-06-01 02:14:34 +00:00
John Birrell
382306949d Add some missing syscall wrappers. 1998-05-31 23:48:30 +00:00
John Birrell
5d359b97bb Remove some stale code.
Pointed out by: Amancio
1998-05-31 23:47:06 +00:00
John Birrell
d972680a31 Don't restart a syscall when a SIGCHLD is received by a thread waiting
on a child process.
1998-05-31 23:46:01 +00:00
John Birrell
01029f8f17 Make a copy of the caller's iovec array, mallocing if necessary,
and modify that if the writev() syscall does not completely write
all bytes in a single call.
1998-05-27 00:44:58 +00:00
John Birrell
e5a8a007e1 When doing a blocking write, keep looping until all the bytes are
written without returning to the caller. This only occurs on pipes
where either the number of bytes written is greater than the pipe
buffer or if there is insufficient space in the pipe buffer because the
reader is reading slower than the writer is writing.
1998-05-25 21:45:52 +00:00
John Birrell
9839f9695a Treat the lock value as volatile. 1998-05-05 21:47:58 +00:00
John Birrell
b1ad8d9155 Cleanup in the child, not the parent.
Submitted by: Tor Egge <Tor.Egge@idi.ntnu.no>
1998-05-02 03:42:20 +00:00
John Birrell
96efcebdfc Fix the incremental priority increment.
PR: bin/6467 Marino Ladavac <lada@pc8811.gud.siemens.at>
1998-04-30 21:50:29 +00:00
John Birrell
4a027d50c7 Change signal model to match POSIX (i.e. one set of signal handlers
for the process, not a separate set for each thread). By default, the
process now only has signal handlers installed for SIGVTALRM, SIGINFO
and SIGCHLD. The thread kernel signal handler is installed for other
signals on demand. This means that SIG_IGN and SIG_DFL processing is now
left to the kernel, not the thread kernel.

Change the signal dispatch to no longer use a signal thread, and
call the signal handler using the stack of the thread that has the
signal pending.

Change the atomic lock method to use test-and-set asm code with
a yield if blocked. This introduces separate locks for each type
of object instead of blocking signals to prevent a context
switch. It was this blocking of signals that caused the performance
degradation the people have noted.

This is a *big* change!
1998-04-29 09:59:34 +00:00
John Birrell
af139b98d4 Allow a thread dump to report the thread's sigmask when in the
PS_SIGWAIT state.
1998-04-17 09:39:37 +00:00
John Birrell
334fa8f215 When in PS_SIGWAIT state, still call signal handlers and set errno
to EINTR.
1998-04-17 09:37:41 +00:00
John Birrell
d60f0fa60d Change the FILE locking to be by FILE, not by the underlying fd as
it was. Add a FILE_WAIT state and queue threads waiting for a FILE
lock. Start using the sys/queue.h macros instead of the way that MIT
pthreads did it.

Add a thread name to the private thread structure and a non-POSIX
function to set this. This helps (me at least) when sending a SIGINFO
to a threaded process to get a /tmp/uthread.dump to see what the
<expletive deleted> threads are doing this time. It is nice to be
able to recognise (yes, I spell that with an 's' too) which threads
are which.
1998-04-11 07:47:22 +00:00