55613576f5
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.
139 lines
3.7 KiB
C
139 lines
3.7 KiB
C
/*
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* Copyright (c) 2003 Daniel M. Eischen <deischen@freebsd.org>
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* Copyright (c) 2003 Sergey Osokin <osa@freebsd.org.ru>.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Neither the name of the author nor the names of any co-contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <errno.h>
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#include <pthread.h>
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#include <sys/types.h>
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#include <sys/sysctl.h>
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#include "thr_private.h"
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/*#define DEBUG_CONCURRENCY */
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#ifdef DEBUG_CONCURRENCY
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#define DBG_MSG stdout_debug
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#else
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#define DBG_MSG(x...)
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#endif
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static int level = 0;
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__weak_reference(_pthread_getconcurrency, pthread_getconcurrency);
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__weak_reference(_pthread_setconcurrency, pthread_setconcurrency);
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int
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_pthread_getconcurrency(void)
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{
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return (level);
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}
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int
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_pthread_setconcurrency(int new_level)
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{
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int ret;
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if (new_level < 0)
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ret = EINVAL;
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else if (new_level == level)
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ret = 0;
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else if (new_level == 0) {
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level = 0;
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ret = 0;
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} else if ((_kse_isthreaded() == 0) && (_kse_setthreaded(1) != 0)) {
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DBG_MSG("Can't enable threading.\n");
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ret = EAGAIN;
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} else {
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ret = _thr_setconcurrency(new_level);
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if (ret == 0)
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level = new_level;
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}
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return (ret);
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}
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int
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_thr_setconcurrency(int new_level)
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{
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struct pthread *curthread;
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struct kse *newkse;
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kse_critical_t crit;
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int kse_count;
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int i;
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int ret;
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ret = 0;
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curthread = _get_curthread();
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/* Race condition, but so what. */
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kse_count = _kse_initial->k_kseg->kg_ksecount;
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for (i = kse_count; i < new_level; i++) {
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newkse = _kse_alloc(curthread);
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if (newkse == NULL) {
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DBG_MSG("Can't alloc new KSE.\n");
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ret = EAGAIN;
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break;
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}
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newkse->k_kseg = _kse_initial->k_kseg;
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newkse->k_schedq = _kse_initial->k_schedq;
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newkse->k_curthread = NULL;
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crit = _kse_critical_enter();
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KSE_SCHED_LOCK(curthread->kse, newkse->k_kseg);
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TAILQ_INSERT_TAIL(&newkse->k_kseg->kg_kseq,
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newkse, k_kgqe);
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newkse->k_kseg->kg_ksecount++;
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KSE_SCHED_UNLOCK(curthread->kse, newkse->k_kseg);
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if (kse_create(&newkse->k_mbx, 0) != 0) {
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KSE_SCHED_LOCK(curthread->kse, newkse->k_kseg);
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TAILQ_REMOVE(&newkse->k_kseg->kg_kseq,
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newkse, k_kgqe);
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newkse->k_kseg->kg_ksecount--;
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KSE_SCHED_UNLOCK(curthread->kse, newkse->k_kseg);
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_kse_critical_leave(crit);
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_kse_free(curthread, newkse);
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DBG_MSG("kse_create syscall failed.\n");
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ret = EAGAIN;
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break;
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} else {
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_kse_critical_leave(crit);
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}
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}
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return (ret);
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}
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int
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_thr_setmaxconcurrency(void)
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{
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int vcpu;
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int len;
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int ret;
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len = sizeof(vcpu);
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ret = sysctlbyname("kern.threads.virtual_cpu", &vcpu, &len, NULL, NULL);
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if (ret == 0 && vcpu > 0)
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ret = _thr_setconcurrency(vcpu);
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return (ret);
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}
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