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kern_kthread.c revision 1.1 
      1 /*	$NetBSD: kern_kthread.c,v 1.1 1998/11/11 22:44:24 thorpej Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
      9  * NASA Ames Research Center.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  * 3. All advertising materials mentioning features or use of this software
     20  *    must display the following acknowledgement:
     21  *	This product includes software developed by the NetBSD
     22  *	Foundation, Inc. and its contributors.
     23  * 4. Neither the name of The NetBSD Foundation nor the names of its
     24  *    contributors may be used to endorse or promote products derived
     25  *    from this software without specific prior written permission.
     26  *
     27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     37  * POSSIBILITY OF SUCH DAMAGE.
     38  */
     39 
     40 #include <sys/param.h>
     41 #include <sys/systm.h>
     42 #include <sys/kernel.h>
     43 #include <sys/kthread.h>
     44 #include <sys/proc.h>
     45 #include <sys/wait.h>
     46 
     47 /*
     48  * note that stdarg.h and the ansi style va_start macro is used for both
     49  * ansi and traditional c complers.
     50  * XXX: this requires that stdarg.h define: va_alist and va_dcl
     51  */
     52 #include <machine/stdarg.h>
     53 
     54 /*
     55  * Fork a kernel thread.  Any process can request this to be done.
     56  * The VM space and limits, etc. will be shared with proc0.
     57  */
     58 int
     59 #ifdef __STDC__
     60 kthread_create(void (*func)(void *), void *arg,
     61     struct proc **newpp, const char *fmt, ...)
     62 #else
     63 kthread_create(func, arg, newpp, fmt, va_alist)
     64 	void (*func) __P((void *));
     65 	void *arg;
     66 	struct proc **newpp;
     67 	const char *fmt;
     68 	va_dcl
     69 #endif
     70 {
     71 	struct proc *p2;
     72 	int error;
     73 	va_list ap;
     74 
     75 	/* First, create the new process. */
     76 	error = fork1(&proc0, FORK_SHAREVM, NULL, &p2);
     77 	if (error)
     78 		return (error);
     79 
     80 	/*
     81 	 * Mark it as a system process and not a candidate for
     82 	 * swapping.  Set P_NOCLDWAIT so that children are reparented
     83 	 * to init(8) when they exit.  init(8) can easily wait them
     84 	 * out for us.
     85 	 */
     86 	p2->p_flag |= P_INMEM | P_SYSTEM | P_NOCLDWAIT;	/* XXX */
     87 
     88 	/* Name it as specified. */
     89 	va_start(ap, fmt);
     90 	vsprintf(p2->p_comm, fmt, ap);
     91 	va_end(ap);
     92 
     93 	/* Arrange for it to start at the specified function. */
     94 	cpu_set_kpc(p2, func, arg);
     95 
     96 	/* All done! */
     97 	if (newpp != NULL)
     98 		*newpp = p2;
     99 	return (0);
    100 }
    101 
    102 /*
    103  * Cause a kernel thread to exit.  Assumes the exiting thread is the
    104  * current context.
    105  */
    106 void
    107 kthread_exit(ecode)
    108 	int ecode;
    109 {
    110 
    111 	/*
    112 	 * XXX What do we do with the exit code?  Should we even bother
    113 	 * XXX with it?  The parent (proc0) isn't going to do much with
    114 	 * XXX it.
    115 	 */
    116 	if (ecode != 0)
    117 		printf("WARNING: thread `%s' (%d) exits with status %d\n",
    118 		    curproc->p_comm, curproc->p_pid, ecode);
    119 
    120 	exit1(curproc, W_EXITCODE(ecode, 0));
    121 
    122 	/*
    123 	 * XXX Fool the compiler.  Making exit1() __noreturn__ is a can
    124 	 * XXX of worms right now.
    125 	 */
    126 	for (;;);
    127 }
    128