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/* $NetBSD: kern_kthread.c,v 1.27 2009/10/21 21:12:06 rmind Exp $ */
/*-
* Copyright (c) 1998, 1999, 2007, 2009 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
* NASA Ames Research Center, and by Andrew Doran.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_kthread.c,v 1.27 2009/10/21 21:12:06 rmind Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/proc.h>
#include <sys/sched.h>
#include <sys/kmem.h>
#include <uvm/uvm_extern.h>
/*
* note that stdarg.h and the ansi style va_start macro is used for both
* ansi and traditional c complers.
* XXX: this requires that stdarg.h define: va_alist and va_dcl
*/
#include <machine/stdarg.h>
/*
* Fork a kernel thread. Any process can request this to be done.
*/
int
kthread_create(pri_t pri, int flag, struct cpu_info *ci,
void (*func)(void *), void *arg,
lwp_t **lp, const char *fmt, ...)
{
lwp_t *l;
vaddr_t uaddr;
int error;
va_list ap;
int lc;
uaddr = uvm_uarea_alloc();
if (uaddr == 0) {
return ENOMEM;
}
if ((flag & KTHREAD_TS) != 0) {
lc = SCHED_OTHER;
} else {
lc = SCHED_RR;
}
error = lwp_create(&lwp0, &proc0, uaddr, LWP_DETACHED, NULL,
0, func, arg, &l, lc);
if (error) {
uvm_uarea_free(uaddr);
return error;
}
if (fmt != NULL) {
l->l_name = kmem_alloc(MAXCOMLEN, KM_SLEEP);
if (l->l_name == NULL) {
lwp_exit(l);
return ENOMEM;
}
va_start(ap, fmt);
vsnprintf(l->l_name, MAXCOMLEN, fmt, ap);
va_end(ap);
}
/*
* Set parameters.
*/
if ((flag & KTHREAD_INTR) != 0) {
KASSERT((flag & KTHREAD_MPSAFE) != 0);
}
if (pri == PRI_NONE) {
if ((flag & KTHREAD_TS) != 0) {
/* Maximum user priority level. */
pri = MAXPRI_USER;
} else {
/* Minimum kernel priority level. */
pri = PRI_KTHREAD;
}
}
mutex_enter(proc0.p_lock);
lwp_lock(l);
l->l_priority = pri;
if (ci != NULL) {
if (ci != l->l_cpu) {
lwp_unlock_to(l, ci->ci_schedstate.spc_mutex);
lwp_lock(l);
}
l->l_pflag |= LP_BOUND;
l->l_cpu = ci;
}
if ((flag & KTHREAD_INTR) != 0)
l->l_pflag |= LP_INTR;
if ((flag & KTHREAD_MPSAFE) == 0)
l->l_pflag &= ~LP_MPSAFE;
/*
* Set the new LWP running, unless the caller has requested
* otherwise.
*/
if ((flag & KTHREAD_IDLE) == 0) {
l->l_stat = LSRUN;
sched_enqueue(l, false);
lwp_unlock(l);
} else
lwp_unlock_to(l, ci->ci_schedstate.spc_lwplock);
/*
* The LWP is not created suspended or stopped and cannot be set
* into those states later, so must be considered runnable.
*/
proc0.p_nrlwps++;
mutex_exit(proc0.p_lock);
/* All done! */
if (lp != NULL)
*lp = l;
return (0);
}
/*
* Cause a kernel thread to exit. Assumes the exiting thread is the
* current context.
*/
void
kthread_exit(int ecode)
{
const char *name;
lwp_t *l = curlwp;
/* We can't do much with the exit code, so just report it. */
if (ecode != 0) {
if ((name = l->l_name) == NULL)
name = "unnamed";
printf("WARNING: kthread `%s' (%d) exits with status %d\n",
name, l->l_lid, ecode);
}
/* And exit.. */
lwp_exit(l);
/*
* XXX Fool the compiler. Making exit1() __noreturn__ is a can
* XXX of worms right now.
*/
for (;;)
;
}
/*
* Destroy an inactive kthread. The kthread must be in the LSIDL state.
*/
void
kthread_destroy(lwp_t *l)
{
KASSERT((l->l_flag & LW_SYSTEM) != 0);
KASSERT(l->l_stat == LSIDL);
lwp_exit(l);
}
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