freebsd-dev/sys/kern/kern_thr.c
2006-02-05 02:18:46 +00:00

439 lines
11 KiB
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("$FreeBSD$");
#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 <sys/umtx.h>
#include <sys/limits.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 = 0;
SYSCTL_INT(_kern_threads, OID_AUTO, thr_scope, CTLFLAG_RW,
&thr_scope, 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");
static int create_thread(struct thread *td, mcontext_t *ctx,
void (*start_func)(void *), void *arg,
char *stack_base, size_t stack_size,
char *tls_base,
long *child_tid, long *parent_tid,
int flags);
/*
* System call interface.
*/
int
thr_create(struct thread *td, struct thr_create_args *uap)
/* ucontext_t *ctx, long *id, int flags */
{
ucontext_t ctx;
int error;
if ((error = copyin(uap->ctx, &ctx, sizeof(ctx))))
return (error);
error = create_thread(td, &ctx.uc_mcontext, NULL, NULL,
NULL, 0, NULL, uap->id, NULL, uap->flags);
return (error);
}
int
thr_new(struct thread *td, struct thr_new_args *uap)
/* struct thr_param * */
{
struct thr_param param;
int error;
if (uap->param_size < sizeof(param))
return (EINVAL);
if ((error = copyin(uap->param, &param, sizeof(param))))
return (error);
error = create_thread(td, NULL, param.start_func, param.arg,
param.stack_base, param.stack_size, param.tls_base,
param.child_tid, param.parent_tid, param.flags);
return (error);
}
static int
create_thread(struct thread *td, mcontext_t *ctx,
void (*start_func)(void *), void *arg,
char *stack_base, size_t stack_size,
char *tls_base,
long *child_tid, long *parent_tid,
int flags)
{
stack_t stack;
struct thread *newtd;
struct ksegrp *kg, *newkg;
struct proc *p;
long id;
int error, scope_sys, linkkg;
error = 0;
p = td->td_proc;
kg = td->td_ksegrp;
/* Have race condition but it is cheap. */
if ((p->p_numksegrps >= max_groups_per_proc) ||
(p->p_numthreads >= max_threads_per_proc)) {
return (EPROCLIM);
}
/* Check PTHREAD_SCOPE_SYSTEM */
scope_sys = (flags & THR_SYSTEM_SCOPE) != 0;
/* sysctl overrides user's flag */
if (thr_scope == 1)
scope_sys = 0;
else if (thr_scope == 2)
scope_sys = 1;
/* Initialize our td and new ksegrp.. */
newtd = thread_alloc();
/*
* Try the copyout as soon as we allocate the td so we don't
* have to tear things down in a failure case below.
* Here we copy out tid to two places, one for child and one
* for parent, because pthread can create a detached thread,
* if parent wants to safely access child tid, it has to provide
* its storage, because child thread may exit quickly and
* memory is freed before parent thread can access it.
*/
id = newtd->td_tid;
if ((child_tid != NULL &&
(error = copyout(&id, child_tid, sizeof(long)))) ||
(parent_tid != NULL &&
(error = copyout(&id, parent_tid, sizeof(long))))) {
thread_free(newtd);
return (error);
}
bzero(&newtd->td_startzero,
__rangeof(struct thread, td_startzero, td_endzero));
bcopy(&td->td_startcopy, &newtd->td_startcopy,
__rangeof(struct thread, td_startcopy, td_endcopy));
newtd->td_proc = td->td_proc;
newtd->td_ucred = crhold(td->td_ucred);
cpu_set_upcall(newtd, td);
if (ctx != NULL) { /* old way to set user context */
error = set_mcontext(newtd, ctx);
if (error != 0) {
thread_free(newtd);
crfree(td->td_ucred);
return (error);
}
} else {
/* Set up our machine context. */
stack.ss_sp = stack_base;
stack.ss_size = stack_size;
/* Set upcall address to user thread entry function. */
cpu_set_upcall_kse(newtd, start_func, arg, &stack);
/* Setup user TLS address and TLS pointer register. */
error = cpu_set_user_tls(newtd, tls_base);
if (error != 0) {
thread_free(newtd);
crfree(td->td_ucred);
return (error);
}
}
if ((td->td_proc->p_flag & P_HADTHREADS) == 0) {
/* Treat initial thread as it has PTHREAD_SCOPE_PROCESS. */
p->p_procscopegrp = kg;
mtx_lock_spin(&sched_lock);
sched_set_concurrency(kg,
thr_concurrency ? thr_concurrency : (2*mp_ncpus));
mtx_unlock_spin(&sched_lock);
}
linkkg = 0;
if (scope_sys) {
linkkg = 1;
newkg = ksegrp_alloc();
bzero(&newkg->kg_startzero,
__rangeof(struct ksegrp, kg_startzero, kg_endzero));
bcopy(&kg->kg_startcopy, &newkg->kg_startcopy,
__rangeof(struct ksegrp, kg_startcopy, kg_endcopy));
sched_init_concurrency(newkg);
PROC_LOCK(td->td_proc);
} else {
/*
* Try to create a KSE group which will be shared
* by all PTHREAD_SCOPE_PROCESS threads.
*/
retry:
PROC_LOCK(td->td_proc);
if ((newkg = p->p_procscopegrp) == NULL) {
PROC_UNLOCK(p);
newkg = ksegrp_alloc();
bzero(&newkg->kg_startzero,
__rangeof(struct ksegrp, kg_startzero, kg_endzero));
bcopy(&kg->kg_startcopy, &newkg->kg_startcopy,
__rangeof(struct ksegrp, kg_startcopy, kg_endcopy));
PROC_LOCK(p);
if (p->p_procscopegrp == NULL) {
p->p_procscopegrp = newkg;
sched_init_concurrency(newkg);
sched_set_concurrency(newkg,
thr_concurrency ? thr_concurrency : (2*mp_ncpus));
linkkg = 1;
} else {
PROC_UNLOCK(p);
ksegrp_free(newkg);
goto retry;
}
}
}
td->td_proc->p_flag |= P_HADTHREADS;
newtd->td_sigmask = td->td_sigmask;
mtx_lock_spin(&sched_lock);
if (linkkg)
ksegrp_link(newkg, p);
thread_link(newtd, newkg);
PROC_UNLOCK(p);
/* let the scheduler know about these things. */
if (linkkg)
sched_fork_ksegrp(td, newkg);
sched_fork_thread(td, newtd);
TD_SET_CAN_RUN(newtd);
/* if ((flags & THR_SUSPENDED) == 0) */
setrunqueue(newtd, SRQ_BORING);
mtx_unlock_spin(&sched_lock);
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);
kern_umtx_wake(td, uap->state, INT_MAX);
}
PROC_LOCK(p);
sigqueue_flush(&td->td_sigqueue);
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);
if (uap->id == -1) {
if (uap->sig != 0 && !_SIG_VALID(uap->sig)) {
error = EINVAL;
} else {
error = ESRCH;
FOREACH_THREAD_IN_PROC(p, ttd) {
if (ttd != td) {
error = 0;
if (uap->sig == 0)
break;
tdsignal(p, ttd, uap->sig, NULL);
}
}
}
} else {
if (uap->id != td->td_tid)
ttd = thread_find(p, uap->id);
else
ttd = td;
if (ttd == NULL)
error = ESRCH;
else if (uap->sig == 0)
;
else if (!_SIG_VALID(uap->sig))
error = EINVAL;
else
tdsignal(p, ttd, uap->sig, NULL);
}
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);
if (td->td_flags & TDF_THRWAKEUP) {
mtx_lock_spin(&sched_lock);
td->td_flags &= ~TDF_THRWAKEUP;
mtx_unlock_spin(&sched_lock);
PROC_UNLOCK(td->td_proc);
return (0);
}
PROC_UNLOCK(td->td_proc);
if (error == EWOULDBLOCK)
error = ETIMEDOUT;
else if (error == ERESTART) {
if (hz != 0)
error = EINTR;
}
return (error);
}
int
thr_wake(struct thread *td, struct thr_wake_args *uap)
/* long id */
{
struct proc *p;
struct thread *ttd;
p = td->td_proc;
PROC_LOCK(p);
ttd = thread_find(p, uap->id);
if (ttd == NULL) {
PROC_UNLOCK(p);
return (ESRCH);
}
mtx_lock_spin(&sched_lock);
ttd->td_flags |= TDF_THRWAKEUP;
mtx_unlock_spin(&sched_lock);
wakeup((void *)ttd);
PROC_UNLOCK(p);
return (0);
}
int
thr_set_name(struct thread *td, struct thr_set_name_args *uap)
{
struct proc *p = td->td_proc;
char name[MAXCOMLEN + 1];
struct thread *ttd;
int error;
error = 0;
name[0] = '\0';
if (uap->name != NULL) {
error = copyinstr(uap->name, name, sizeof(name),
NULL);
if (error)
return (error);
}
PROC_LOCK(p);
if (uap->id == td->td_tid)
ttd = td;
else
ttd = thread_find(p, uap->id);
if (ttd != NULL)
strcpy(ttd->td_name, name);
else
error = ESRCH;
PROC_UNLOCK(p);
return (error);
}