kern_kthread.c revision 1.2
1/* $NetBSD: kern_kthread.c,v 1.2 1998/11/14 00:08:49 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#include <sys/malloc.h> 47#include <sys/queue.h> 48 49/* 50 * note that stdarg.h and the ansi style va_start macro is used for both 51 * ansi and traditional c complers. 52 * XXX: this requires that stdarg.h define: va_alist and va_dcl 53 */ 54#include <machine/stdarg.h> 55 56/* 57 * Fork a kernel thread. Any process can request this to be done. 58 * The VM space and limits, etc. will be shared with proc0. 59 */ 60int 61#ifdef __STDC__ 62kthread_create(void (*func)(void *), void *arg, 63 struct proc **newpp, const char *fmt, ...) 64#else 65kthread_create(func, arg, newpp, fmt, va_alist) 66 void (*func) __P((void *)); 67 void *arg; 68 struct proc **newpp; 69 const char *fmt; 70 va_dcl 71#endif 72{ 73 struct proc *p2; 74 int error; 75 va_list ap; 76 77 /* First, create the new process. */ 78 error = fork1(&proc0, FORK_SHAREVM, NULL, &p2); 79 if (error) 80 return (error); 81 82 /* 83 * Mark it as a system process and not a candidate for 84 * swapping. Set P_NOCLDWAIT so that children are reparented 85 * to init(8) when they exit. init(8) can easily wait them 86 * out for us. 87 */ 88 p2->p_flag |= P_INMEM | P_SYSTEM | P_NOCLDWAIT; /* XXX */ 89 90 /* Name it as specified. */ 91 va_start(ap, fmt); 92 vsprintf(p2->p_comm, fmt, ap); 93 va_end(ap); 94 95 /* Arrange for it to start at the specified function. */ 96 cpu_set_kpc(p2, func, arg); 97 98 /* All done! */ 99 if (newpp != NULL) 100 *newpp = p2; 101 return (0); 102} 103 104/* 105 * Cause a kernel thread to exit. Assumes the exiting thread is the 106 * current context. 107 */ 108void 109kthread_exit(ecode) 110 int ecode; 111{ 112 113 /* 114 * XXX What do we do with the exit code? Should we even bother 115 * XXX with it? The parent (proc0) isn't going to do much with 116 * XXX it. 117 */ 118 if (ecode != 0) 119 printf("WARNING: thread `%s' (%d) exits with status %d\n", 120 curproc->p_comm, curproc->p_pid, ecode); 121 122 exit1(curproc, W_EXITCODE(ecode, 0)); 123 124 /* 125 * XXX Fool the compiler. Making exit1() __noreturn__ is a can 126 * XXX of worms right now. 127 */ 128 for (;;); 129} 130 131struct kthread_q { 132 SIMPLEQ_ENTRY(kthread_q) kq_q; 133 void (*kq_func) __P((void *)); 134 void *kq_arg; 135}; 136 137SIMPLEQ_HEAD(, kthread_q) kthread_q = SIMPLEQ_HEAD_INITIALIZER(kthread_q); 138 139/* 140 * Defer the creation of a kernel thread. Once the standard kernel threads 141 * and processes have been created, this queue will be run to callback to 142 * the caller to create threads for e.g. file systems and device drivers. 143 */ 144void 145kthread_create_deferred(func, arg) 146 void (*func) __P((void *)); 147 void *arg; 148{ 149 struct kthread_q *kq; 150 151 kq = malloc(sizeof(*kq), M_TEMP, M_NOWAIT); 152 if (kq == NULL) 153 panic("unable to allocate kthread_q"); 154 memset(kq, 0, sizeof(*kq)); 155 156 kq->kq_func = func; 157 kq->kq_arg = arg; 158 159 SIMPLEQ_INSERT_TAIL(&kthread_q, kq, kq_q); 160} 161 162void 163kthread_run_deferred_queue() 164{ 165 struct kthread_q *kq; 166 167 while ((kq = SIMPLEQ_FIRST(&kthread_q)) != NULL) { 168 SIMPLEQ_REMOVE_HEAD(&kthread_q, kq, kq_q); 169 (*kq->kq_func)(kq->kq_arg); 170 free(kq, M_TEMP); 171 } 172} 173