FreeBSD-5.3/sys/kern/kern_thr.c
/*
* Copyright (c) 2003, Jeffrey Roberson <jeff@freebsd.org>
* 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 unmodified, 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/kern/kern_thr.c,v 1.23.2.6 2004/10/09 15:12:33 mtm Exp $");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/sched.h>
#include <sys/sysctl.h>
#include <sys/smp.h>
#include <sys/sysent.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/signalvar.h>
#include <sys/ucontext.h>
#include <sys/thr.h>
#include <machine/frame.h>
extern int max_threads_per_proc;
extern int max_groups_per_proc;
SYSCTL_DECL(_kern_threads);
static int thr_scope_sys = 0;
SYSCTL_INT(_kern_threads, OID_AUTO, thr_scope_sys, CTLFLAG_RW,
&thr_scope_sys, 0, "sys or proc scope scheduling");
static int thr_concurrency = 0;
SYSCTL_INT(_kern_threads, OID_AUTO, thr_concurrency, CTLFLAG_RW,
&thr_concurrency, 0, "a concurrency value if not default");
/*
* Back end support functions.
*/
#define RANGEOF(type, start, end) (offsetof(type, end) - offsetof(type, start))
/*
* System call interface.
*/
int
thr_create(struct thread *td, struct thr_create_args *uap)
/* ucontext_t *ctx, long *id, int flags */
{
struct thread *newtd;
ucontext_t ctx;
long id;
int error;
struct ksegrp *kg, *newkg;
struct proc *p;
int scope_sys;
p = td->td_proc;
kg = td->td_ksegrp;
if ((error = copyin(uap->ctx, &ctx, sizeof(ctx))))
return (error);
/* Have race condition but it is cheap */
if ((p->p_numksegrps >= max_groups_per_proc) ||
(p->p_numthreads >= max_threads_per_proc)) {
return (EPROCLIM);
}
/*
* Use a local copy to close a race against the user
* changing thr_scope_sys.
*/
scope_sys = thr_scope_sys;
/* Initialize our td and new ksegrp.. */
newtd = thread_alloc();
if (scope_sys)
newkg = ksegrp_alloc();
else
newkg = kg;
/*
* Try the copyout as soon as we allocate the td so we don't have to
* tear things down in a failure case below.
*/
id = newtd->td_tid;
if ((error = copyout(&id, uap->id, sizeof(long)))) {
if (scope_sys)
ksegrp_free(newkg);
thread_free(newtd);
return (error);
}
bzero(&newtd->td_startzero,
(unsigned) RANGEOF(struct thread, td_startzero, td_endzero));
bcopy(&td->td_startcopy, &newtd->td_startcopy,
(unsigned) RANGEOF(struct thread, td_startcopy, td_endcopy));
if (scope_sys) {
bzero(&newkg->kg_startzero,
(unsigned)RANGEOF(struct ksegrp, kg_startzero, kg_endzero));
bcopy(&kg->kg_startcopy, &newkg->kg_startcopy,
(unsigned)RANGEOF(struct ksegrp, kg_startcopy, kg_endcopy));
}
newtd->td_proc = td->td_proc;
newtd->td_ucred = crhold(td->td_ucred);
/* Set up our machine context. */
cpu_set_upcall(newtd, td);
error = set_mcontext(newtd, &ctx.uc_mcontext);
if (error != 0) {
if (scope_sys)
ksegrp_free(newkg);
thread_free(newtd);
crfree(td->td_ucred);
goto out;
}
/* Link the thread and kse into the ksegrp and make it runnable. */
PROC_LOCK(td->td_proc);
if (scope_sys) {
sched_init_concurrency(newkg);
} else {
if ((td->td_proc->p_flag & P_HADTHREADS) == 0) {
sched_set_concurrency(kg,
thr_concurrency ? thr_concurrency : (2*mp_ncpus));
}
}
td->td_proc->p_flag |= P_HADTHREADS;
newtd->td_sigmask = td->td_sigmask;
mtx_lock_spin(&sched_lock);
if (scope_sys)
ksegrp_link(newkg, p);
thread_link(newtd, newkg);
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(p);
/* let the scheduler know about these things. */
mtx_lock_spin(&sched_lock);
if (scope_sys)
sched_fork_ksegrp(td, newkg);
sched_fork_thread(td, newtd);
TD_SET_CAN_RUN(newtd);
if ((uap->flags & THR_SUSPENDED) == 0)
setrunqueue(newtd, SRQ_BORING);
mtx_unlock_spin(&sched_lock);
out:
return (error);
}
int
thr_self(struct thread *td, struct thr_self_args *uap)
/* long *id */
{
long id;
int error;
id = td->td_tid;
if ((error = copyout(&id, uap->id, sizeof(long))))
return (error);
return (0);
}
int
thr_exit(struct thread *td, struct thr_exit_args *uap)
/* long *state */
{
struct proc *p;
p = td->td_proc;
/* Signal userland that it can free the stack. */
if ((void *)uap->state != NULL)
suword((void *)uap->state, 1);
PROC_LOCK(p);
mtx_lock_spin(&sched_lock);
/*
* Shutting down last thread in the proc. This will actually
* call exit() in the trampoline when it returns.
*/
if (p->p_numthreads != 1) {
thread_exit();
/* NOTREACHED */
}
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(p);
return (0);
}
int
thr_kill(struct thread *td, struct thr_kill_args *uap)
/* long id, int sig */
{
struct thread *ttd;
struct proc *p;
int error;
p = td->td_proc;
error = 0;
PROC_LOCK(p);
FOREACH_THREAD_IN_PROC(p, ttd) {
if (ttd->td_tid == uap->id)
break;
}
if (ttd == NULL) {
error = ESRCH;
goto out;
}
if (uap->sig == 0)
goto out;
if (!_SIG_VALID(uap->sig)) {
error = EINVAL;
goto out;
}
tdsignal(ttd, uap->sig, SIGTARGET_TD);
out:
PROC_UNLOCK(p);
return (error);
}
int
thr_suspend(struct thread *td, struct thr_suspend_args *uap)
/* const struct timespec *timeout */
{
struct timespec ts;
struct timeval tv;
int error;
int hz;
hz = 0;
error = 0;
if (uap->timeout != NULL) {
error = copyin((const void *)uap->timeout, (void *)&ts,
sizeof(struct timespec));
if (error != 0)
return (error);
if (ts.tv_nsec < 0 || ts.tv_nsec > 1000000000)
return (EINVAL);
if (ts.tv_sec == 0 && ts.tv_nsec == 0)
return (ETIMEDOUT);
TIMESPEC_TO_TIMEVAL(&tv, &ts);
hz = tvtohz(&tv);
}
PROC_LOCK(td->td_proc);
if ((td->td_flags & TDF_THRWAKEUP) == 0)
error = msleep((void *)td, &td->td_proc->p_mtx,
td->td_priority | PCATCH, "lthr", hz);
mtx_lock_spin(&sched_lock);
td->td_flags &= ~TDF_THRWAKEUP;
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(td->td_proc);
return (error == EWOULDBLOCK ? ETIMEDOUT : error);
}
int
thr_wake(struct thread *td, struct thr_wake_args *uap)
/* long id */
{
struct thread *ttd;
PROC_LOCK(td->td_proc);
FOREACH_THREAD_IN_PROC(td->td_proc, ttd) {
if (ttd->td_tid == uap->id)
break;
}
if (ttd == NULL) {
PROC_UNLOCK(td->td_proc);
return (ESRCH);
}
mtx_lock_spin(&sched_lock);
ttd->td_flags |= TDF_THRWAKEUP;
mtx_unlock_spin(&sched_lock);
wakeup_one((void *)ttd);
PROC_UNLOCK(td->td_proc);
return (0);
}