kern_kthread.c revision 1.8.2.1
1 /* $NetBSD: kern_kthread.c,v 1.8.2.1 2000/11/20 18:09:00 bouyer Exp $ */ 2 3 /*- 4 * Copyright (c) 1998, 1999 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 int kthread_create_now; 57 58 /* 59 * Fork a kernel thread. Any process can request this to be done. 60 * The VM space and limits, etc. will be shared with proc0. 61 */ 62 int 63 kthread_create1(void (*func)(void *), void *arg, 64 struct proc **newpp, const char *fmt, ...) 65 { 66 struct proc *p2; 67 int error; 68 va_list ap; 69 70 /* First, create the new process. */ 71 error = fork1(&proc0, FORK_SHAREVM | FORK_SHARECWD | FORK_SHAREFILES | 72 FORK_SHARESIGS, SIGCHLD, NULL, 0, func, arg, NULL, &p2); 73 if (__predict_false(error != 0)) 74 return (error); 75 76 /* 77 * Mark it as a system process and not a candidate for 78 * swapping. Set P_NOCLDWAIT so that children are reparented 79 * to init(8) when they exit. init(8) can easily wait them 80 * out for us. 81 */ 82 p2->p_flag |= P_INMEM | P_SYSTEM | P_NOCLDWAIT; /* XXX */ 83 84 /* Name it as specified. */ 85 va_start(ap, fmt); 86 vsnprintf(p2->p_comm, MAXCOMLEN, fmt, ap); 87 va_end(ap); 88 89 /* All done! */ 90 if (newpp != NULL) 91 *newpp = p2; 92 return (0); 93 } 94 95 /* 96 * Cause a kernel thread to exit. Assumes the exiting thread is the 97 * current context. 98 */ 99 void 100 kthread_exit(int ecode) 101 { 102 103 /* 104 * XXX What do we do with the exit code? Should we even bother 105 * XXX with it? The parent (proc0) isn't going to do much with 106 * XXX it. 107 */ 108 if (ecode != 0) 109 printf("WARNING: thread `%s' (%d) exits with status %d\n", 110 curproc->p_comm, curproc->p_pid, ecode); 111 112 exit1(curproc, W_EXITCODE(ecode, 0)); 113 114 /* 115 * XXX Fool the compiler. Making exit1() __noreturn__ is a can 116 * XXX of worms right now. 117 */ 118 for (;;); 119 } 120 121 struct kthread_q { 122 SIMPLEQ_ENTRY(kthread_q) kq_q; 123 void (*kq_func)(void *); 124 void *kq_arg; 125 }; 126 127 SIMPLEQ_HEAD(, kthread_q) kthread_q = SIMPLEQ_HEAD_INITIALIZER(kthread_q); 128 129 /* 130 * Defer the creation of a kernel thread. Once the standard kernel threads 131 * and processes have been created, this queue will be run to callback to 132 * the caller to create threads for e.g. file systems and device drivers. 133 */ 134 void 135 kthread_create(void (*func)(void *), void *arg) 136 { 137 struct kthread_q *kq; 138 139 if (kthread_create_now) { 140 (*func)(arg); 141 return; 142 } 143 144 kq = malloc(sizeof(*kq), M_TEMP, M_NOWAIT); 145 if (kq == NULL) 146 panic("unable to allocate kthread_q"); 147 memset(kq, 0, sizeof(*kq)); 148 149 kq->kq_func = func; 150 kq->kq_arg = arg; 151 152 SIMPLEQ_INSERT_TAIL(&kthread_q, kq, kq_q); 153 } 154 155 void 156 kthread_run_deferred_queue(void) 157 { 158 struct kthread_q *kq; 159 160 /* No longer need to defer kthread creation. */ 161 kthread_create_now = 1; 162 163 while ((kq = SIMPLEQ_FIRST(&kthread_q)) != NULL) { 164 SIMPLEQ_REMOVE_HEAD(&kthread_q, kq, kq_q); 165 (*kq->kq_func)(kq->kq_arg); 166 free(kq, M_TEMP); 167 } 168 } 169
Indexes created Mon Sep 29 21:09:56 GMT 2025