Commit Graph

86 Commits

Author SHA1 Message Date
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
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
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
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
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
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
Jonathan Mini
faa8342f9f Deliver signals posted via an upcall to the appropriate thread. 2003-02-17 10:05:18 +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
2d9a293b4e Use KSE to schedule threads. 2002-10-30 06:07:18 +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
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
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
Daniel Eischen
9e9c4443f6 Don't rely on <sys/signal.h> to include <sys/ucontext.h> 2002-02-17 17:21:27 +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
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
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
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
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
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
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
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
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
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
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
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
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
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
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