1 /* $NetBSD: kern_kthread.c,v 1.10 2000/05/28 05:49:06 thorpej 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 #if __STDC__ 64 kthread_create1(void (*func)(void *), void *arg, 65 struct proc **newpp, const char *fmt, ...) 66 #else 67 kthread_create1(func, arg, newpp, fmt, va_alist) 68 void (*func) __P((void *)); 69 void *arg; 70 struct proc **newpp; 71 const char *fmt; 72 va_dcl 73 #endif 74 { 75 struct proc *p2; 76 int error; 77 va_list ap; 78 79 /* First, create the new process. */ 80 error = fork1(&proc0, FORK_SHAREVM | FORK_SHARECWD | FORK_SHAREFILES | 81 FORK_SHARESIGS, SIGCHLD, NULL, 0, func, arg, NULL, &p2); 82 if (__predict_false(error != 0)) 83 return (error); 84 85 /* 86 * Mark it as a system process and not a candidate for 87 * swapping. Set P_NOCLDWAIT so that children are reparented 88 * to init(8) when they exit. init(8) can easily wait them 89 * out for us. 90 */ 91 p2->p_flag |= P_INMEM | P_SYSTEM | P_NOCLDWAIT; /* XXX */ 92 93 /* Name it as specified. */ 94 va_start(ap, fmt); 95 vsnprintf(p2->p_comm, MAXCOMLEN, fmt, ap); 96 va_end(ap); 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 */ 108 void 109 kthread_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 } 130 131 struct kthread_q { 132 SIMPLEQ_ENTRY(kthread_q) kq_q; 133 void (*kq_func) __P((void *)); 134 void *kq_arg; 135 }; 136 137 SIMPLEQ_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 */ 144 void 145 kthread_create(func, arg) 146 void (*func) __P((void *)); 147 void *arg; 148 { 149 struct kthread_q *kq; 150 151 if (kthread_create_now) { 152 (*func)(arg); 153 return; 154 } 155 156 kq = malloc(sizeof(*kq), M_TEMP, M_NOWAIT); 157 if (kq == NULL) 158 panic("unable to allocate kthread_q"); 159 memset(kq, 0, sizeof(*kq)); 160 161 kq->kq_func = func; 162 kq->kq_arg = arg; 163 164 SIMPLEQ_INSERT_TAIL(&kthread_q, kq, kq_q); 165 } 166 167 void 168 kthread_run_deferred_queue() 169 { 170 struct kthread_q *kq; 171 172 /* No longer need to defer kthread creation. */ 173 kthread_create_now = 1; 174 175 while ((kq = SIMPLEQ_FIRST(&kthread_q)) != NULL) { 176 SIMPLEQ_REMOVE_HEAD(&kthread_q, kq, kq_q); 177 (*kq->kq_func)(kq->kq_arg); 178 free(kq, M_TEMP); 179 } 180 } 181