1 /* $OpenBSD: kern_kthread.c,v 1.14 2001/08/08 02:37:40 millert Exp $ */ 2 /* $NetBSD: kern_kthread.c,v 1.3 1998/12/22 21:21:36 kleink Exp $ */ 3 4 /*- 5 * Copyright (c) 1998 The NetBSD Foundation, Inc. 6 * All rights reserved. 7 * 8 * This code is derived from software contributed to The NetBSD Foundation 9 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility, 10 * NASA Ames Research Center. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the NetBSD 23 * Foundation, Inc. and its contributors. 24 * 4. Neither the name of The NetBSD Foundation nor the names of its 25 * contributors may be used to endorse or promote products derived 26 * from this software without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 29 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 30 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 31 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 32 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 33 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 34 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 35 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 36 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 37 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 38 * POSSIBILITY OF SUCH DAMAGE. 39 */ 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/kernel.h> 44 #include <sys/kthread.h> 45 #include <sys/proc.h> 46 #include <sys/wait.h> 47 #include <sys/malloc.h> 48 #include <sys/queue.h> 49 50 #include <machine/cpu.h> 51 52 /* 53 * note that stdarg.h and the ansi style va_start macro is used for both 54 * ansi and traditional c complers. 55 * XXX: this requires that stdarg.h define: va_alist and va_dcl 56 */ 57 #include <machine/stdarg.h> 58 59 /* 60 * Fork a kernel thread. Any process can request this to be done. 61 * The VM space and limits, etc. will be shared with proc0. 62 */ 63 int 64 #if __STDC__ 65 kthread_create(void (*func)(void *), void *arg, 66 struct proc **newpp, const char *fmt, ...) 67 #else 68 kthread_create(func, arg, newpp, fmt, va_alist) 69 void (*func) __P((void *)); 70 void *arg; 71 struct proc **newpp; 72 const char *fmt; 73 va_dcl 74 #endif 75 { 76 struct proc *p2; 77 register_t rv[2]; 78 int error; 79 va_list ap; 80 81 /* 82 * First, create the new process. Share the memory, file 83 * descriptors and don't leave the exit status around for the 84 * parent to wait for. 85 */ 86 error = fork1(&proc0, 0, 87 FORK_SHAREVM|FORK_NOZOMBIE|FORK_SIGHAND, NULL, 0, rv); 88 if (error) 89 return (error); 90 91 p2 = pfind(rv[0]); 92 93 /* Arrange for it to start at the specified function. */ 94 cpu_set_kpc(p2, func, arg); 95 96 /* 97 * Mark it as a system process and not a candidate for 98 * swapping. 99 */ 100 p2->p_flag |= P_INMEM | P_SYSTEM; /* XXX */ 101 102 /* Name it as specified. */ 103 va_start(ap, fmt); 104 vsprintf(p2->p_comm, fmt, ap); 105 va_end(ap); 106 107 /* All done! */ 108 if (newpp != NULL) 109 *newpp = p2; 110 return (0); 111 } 112 113 /* 114 * Cause a kernel thread to exit. Assumes the exiting thread is the 115 * current context. 116 */ 117 void 118 kthread_exit(ecode) 119 int ecode; 120 { 121 122 /* 123 * XXX What do we do with the exit code? Should we even bother 124 * XXX with it? The parent (proc0) isn't going to do much with 125 * XXX it. 126 */ 127 if (ecode != 0) 128 printf("WARNING: thread `%s' (%d) exits with status %d\n", 129 curproc->p_comm, curproc->p_pid, ecode); 130 131 exit1(curproc, W_EXITCODE(ecode, 0)); 132 133 /* 134 * XXX Fool the compiler. Making exit1() __dead is a can 135 * XXX of worms right now. 136 */ 137 for (;;); 138 } 139 140 struct kthread_q { 141 SIMPLEQ_ENTRY(kthread_q) kq_q; 142 void (*kq_func) __P((void *)); 143 void *kq_arg; 144 }; 145 146 SIMPLEQ_HEAD(, kthread_q) kthread_q = SIMPLEQ_HEAD_INITIALIZER(kthread_q); 147 148 /* 149 * Defer the creation of a kernel thread. Once the standard kernel threads 150 * and processes have been created, this queue will be run to callback to 151 * the caller to create threads for e.g. file systems and device drivers. 152 */ 153 void 154 kthread_create_deferred(func, arg) 155 void (*func) __P((void *)); 156 void *arg; 157 { 158 struct kthread_q *kq; 159 160 kq = malloc(sizeof *kq, M_TEMP, M_NOWAIT); 161 if (kq == NULL) 162 panic("unable to allocate kthread_q"); 163 bzero(kq, sizeof *kq); 164 165 kq->kq_func = func; 166 kq->kq_arg = arg; 167 168 SIMPLEQ_INSERT_TAIL(&kthread_q, kq, kq_q); 169 } 170 171 void 172 kthread_run_deferred_queue() 173 { 174 struct kthread_q *kq; 175 176 while ((kq = SIMPLEQ_FIRST(&kthread_q)) != NULL) { 177 SIMPLEQ_REMOVE_HEAD(&kthread_q, kq, kq_q); 178 (*kq->kq_func)(kq->kq_arg); 179 free(kq, M_TEMP); 180 } 181 } 182