kern_kthread.c revision 1.24
1/* $NetBSD: kern_kthread.c,v 1.24 2008/04/28 20:24:03 martin Exp $ */ 2 3/*- 4 * Copyright (c) 1998, 1999, 2007 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, and by Andrew Doran. 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 * 20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 30 * POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33#include <sys/cdefs.h> 34__KERNEL_RCSID(0, "$NetBSD: kern_kthread.c,v 1.24 2008/04/28 20:24:03 martin Exp $"); 35 36#include <sys/param.h> 37#include <sys/systm.h> 38#include <sys/kernel.h> 39#include <sys/kthread.h> 40#include <sys/proc.h> 41#include <sys/sched.h> 42#include <sys/kmem.h> 43 44#include <uvm/uvm_extern.h> 45 46/* 47 * note that stdarg.h and the ansi style va_start macro is used for both 48 * ansi and traditional c complers. 49 * XXX: this requires that stdarg.h define: va_alist and va_dcl 50 */ 51#include <machine/stdarg.h> 52 53/* 54 * Fork a kernel thread. Any process can request this to be done. 55 */ 56int 57kthread_create(pri_t pri, int flag, struct cpu_info *ci, 58 void (*func)(void *), void *arg, 59 lwp_t **lp, const char *fmt, ...) 60{ 61 lwp_t *l; 62 vaddr_t uaddr; 63 bool inmem; 64 int error; 65 va_list ap; 66 67 inmem = uvm_uarea_alloc(&uaddr); 68 if (uaddr == 0) 69 return ENOMEM; 70 error = lwp_create(&lwp0, &proc0, uaddr, inmem, LWP_DETACHED, NULL, 71 0, func, arg, &l, SCHED_FIFO); 72 if (error) { 73 uvm_uarea_free(uaddr, curcpu()); 74 return error; 75 } 76 uvm_lwp_hold(l); 77 if (fmt != NULL) { 78 l->l_name = kmem_alloc(MAXCOMLEN, KM_SLEEP); 79 if (l->l_name == NULL) { 80 lwp_exit(l); 81 return ENOMEM; 82 } 83 va_start(ap, fmt); 84 vsnprintf(l->l_name, MAXCOMLEN, fmt, ap); 85 va_end(ap); 86 } 87 88 /* 89 * Set parameters. 90 */ 91 if ((flag & KTHREAD_INTR) != 0) { 92 KASSERT((flag & KTHREAD_MPSAFE) != 0); 93 } 94 95 if (pri == PRI_NONE) { 96 /* Minimum kernel priority level. */ 97 pri = PRI_KTHREAD; 98 } 99 mutex_enter(proc0.p_lock); 100 lwp_lock(l); 101 l->l_priority = pri; 102 if (ci != NULL) { 103 if (ci != l->l_cpu) { 104 lwp_unlock_to(l, ci->ci_schedstate.spc_mutex); 105 lwp_lock(l); 106 } 107 l->l_pflag |= LP_BOUND; 108 l->l_cpu = ci; 109 } 110 if ((flag & KTHREAD_INTR) != 0) 111 l->l_pflag |= LP_INTR; 112 if ((flag & KTHREAD_MPSAFE) == 0) 113 l->l_pflag &= ~LP_MPSAFE; 114 115 /* 116 * Set the new LWP running, unless the caller has requested 117 * otherwise. 118 */ 119 if ((flag & KTHREAD_IDLE) == 0) { 120 l->l_stat = LSRUN; 121 sched_enqueue(l, false); 122 lwp_unlock(l); 123 } else 124 lwp_unlock_to(l, ci->ci_schedstate.spc_lwplock); 125 126 /* 127 * The LWP is not created suspended or stopped and cannot be set 128 * into those states later, so must be considered runnable. 129 */ 130 proc0.p_nrlwps++; 131 mutex_exit(proc0.p_lock); 132 133 /* All done! */ 134 if (lp != NULL) 135 *lp = l; 136 137 return (0); 138} 139 140/* 141 * Cause a kernel thread to exit. Assumes the exiting thread is the 142 * current context. 143 */ 144void 145kthread_exit(int ecode) 146{ 147 const char *name; 148 lwp_t *l = curlwp; 149 150 /* We can't do much with the exit code, so just report it. */ 151 if (ecode != 0) { 152 if ((name = l->l_name) == NULL) 153 name = "unnamed"; 154 printf("WARNING: kthread `%s' (%d) exits with status %d\n", 155 name, l->l_lid, ecode); 156 } 157 158 /* And exit.. */ 159 lwp_exit(l); 160 161 /* 162 * XXX Fool the compiler. Making exit1() __noreturn__ is a can 163 * XXX of worms right now. 164 */ 165 for (;;) 166 ; 167} 168 169/* 170 * Destroy an inactive kthread. The kthread must be in the LSIDL state. 171 */ 172void 173kthread_destroy(lwp_t *l) 174{ 175 176 KASSERT((l->l_flag & LW_SYSTEM) != 0); 177 KASSERT(l->l_stat == LSIDL); 178 179 lwp_exit(l); 180} 181