freebsd-skq/lib/libpthread/thread/thr_setschedparam.c
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

137 lines
4.6 KiB
C

/*
* Copyright (c) 1998 Daniel Eischen <eischen@vigrid.com>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Daniel Eischen.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY DANIEL EISCHEN AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <errno.h>
#include <sys/param.h>
#include <pthread.h>
#include "thr_private.h"
__weak_reference(_pthread_setschedparam, pthread_setschedparam);
int
_pthread_setschedparam(pthread_t pthread, int policy,
const struct sched_param *param)
{
struct pthread *curthread = _get_curthread();
int in_syncq;
int in_readyq = 0;
int old_prio;
int ret = 0;
if ((param == NULL) || (policy < SCHED_FIFO) || (policy > SCHED_RR)) {
/* Return an invalid argument error: */
ret = EINVAL;
} else if ((param->sched_priority < THR_MIN_PRIORITY) ||
(param->sched_priority > THR_MAX_PRIORITY)) {
/* Return an unsupported value error. */
ret = ENOTSUP;
/* Find the thread in the list of active threads: */
} else if ((ret = _thr_ref_add(curthread, pthread, /*include dead*/0))
== 0) {
/*
* Lock the threads scheduling queue while we change
* its priority:
*/
THR_SCHED_LOCK(curthread, pthread);
if ((pthread->state == PS_DEAD) ||
(pthread->state == PS_DEADLOCK) ||
((pthread->flags & THR_FLAGS_EXITING) != 0)) {
THR_SCHED_UNLOCK(curthread, pthread);
_thr_ref_delete(curthread, pthread);
return (ESRCH);
}
in_syncq = pthread->sflags & THR_FLAGS_IN_SYNCQ;
/* Set the scheduling policy: */
pthread->attr.sched_policy = policy;
if (param->sched_priority ==
THR_BASE_PRIORITY(pthread->base_priority))
/*
* There is nothing to do; unlock the threads
* scheduling queue.
*/
THR_SCHED_UNLOCK(curthread, pthread);
else {
/*
* Remove the thread from its current priority
* queue before any adjustments are made to its
* active priority:
*/
old_prio = pthread->active_priority;
if ((pthread->flags & THR_FLAGS_IN_RUNQ) != 0) {
in_readyq = 1;
THR_RUNQ_REMOVE(pthread);
}
/* Set the thread base priority: */
pthread->base_priority &=
(THR_SIGNAL_PRIORITY | THR_RT_PRIORITY);
pthread->base_priority = param->sched_priority;
/* Recalculate the active priority: */
pthread->active_priority = MAX(pthread->base_priority,
pthread->inherited_priority);
if (in_readyq) {
if ((pthread->priority_mutex_count > 0) &&
(old_prio > pthread->active_priority)) {
/*
* POSIX states that if the priority is
* being lowered, the thread must be
* inserted at the head of the queue for
* its priority if it owns any priority
* protection or inheritence mutexes.
*/
THR_RUNQ_INSERT_HEAD(pthread);
}
else
THR_RUNQ_INSERT_TAIL(pthread);
}
/* Unlock the threads scheduling queue: */
THR_SCHED_UNLOCK(curthread, pthread);
/*
* Check for any mutex priority adjustments. This
* includes checking for a priority mutex on which
* this thread is waiting.
*/
_mutex_notify_priochange(curthread, pthread, in_syncq);
}
_thr_ref_delete(curthread, pthread);
}
return (ret);
}