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 */
58int
59#ifdef __STDC__
60kthread_create(void (*func)(void *), void *arg,
61    struct proc **newpp, const char *fmt, ...)
62#else
63kthread_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 */
106void
107kthread_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