sys/rump/librump/rumpkern/threads.c

   1 /*      $NetBSD: threads.c,v 1.5 2009/12/03 12:16:36 pooka Exp $        */
   2
   3 /*
   4  * Copyright (c) 2007-2009 Antti Kantee.  All Rights Reserved.
   5  *
   6  * Development of this software was supported by
   7  * The Finnish Cultural Foundation.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
  19  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  21  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 #include <sys/cdefs.h>
  32 __KERNEL_RCSID(0, "$NetBSD: threads.c,v 1.5 2009/12/03 12:16:36 pooka Exp $");
  33
  34 #include <sys/param.h>
  35 #include <sys/kmem.h>
  36 #include <sys/kthread.h>
  37 #include <sys/systm.h>
  38
  39 #include <machine/stdarg.h>
  40
  41 #include <rump/rumpuser.h>
  42
  43 #include "rump_private.h"
  44
  45 struct kthdesc {
  46         void (*f)(void *);
  47         void *arg;
  48         struct lwp *mylwp;
  49 };
  50
  51 static void *
  52 threadbouncer(void *arg)
  53 {
  54         struct kthdesc *k = arg;
  55         struct lwp *l = k->mylwp;
  56         void (*f)(void *);
  57         void *thrarg;
  58
  59         f = k->f;
  60         thrarg = k->arg;
  61         rumpuser_free(k);
  62
  63         /* schedule ourselves */
  64         rumpuser_set_curlwp(l);
  65         rump_schedule();
  66
  67         if ((curlwp->l_pflag & LP_MPSAFE) == 0)
  68                 KERNEL_LOCK(1, NULL);
  69
  70         f(thrarg);
  71
  72         panic("unreachable, should kthread_exit()");
  73 }
  74
  75 int
  76 kthread_create(pri_t pri, int flags, struct cpu_info *ci,
  77         void (*func)(void *), void *arg, lwp_t **newlp, const char *fmt, ...)
  78 {
  79         char thrstore[MAXCOMLEN];
  80         const char *thrname = NULL;
  81         va_list ap;
  82         struct kthdesc *k;
  83         struct lwp *l;
  84         int rv;
  85
  86         thrstore[0] = '\0';
  87         if (fmt) {
  88                 va_start(ap, fmt);
  89                 vsnprintf(thrstore, sizeof(thrstore), fmt, ap);
  90                 va_end(ap);
  91                 thrname = thrstore;
  92         }
  93
  94         /*
  95          * We don't want a module unload thread.
  96          * (XXX: yes, this is a kludge too, and the kernel should
  97          * have a more flexible method for configuring which threads
  98          * we want).
  99          */
 100         if (strcmp(thrstore, "modunload") == 0) {
 101                 return 0;
 102         }
 103
 104         if (!rump_threads) {
 105                 /* fake them */
 106                 if (strcmp(thrstore, "vrele") == 0) {
 107                         printf("rump warning: threads not enabled, not starting"
 108                            " vrele thread\n");
 109                         return 0;
 110                 } else if (strcmp(thrstore, "cachegc") == 0) {
 111                         printf("rump warning: threads not enabled, not starting"
 112                            " namecache g/c thread\n");
 113                         return 0;
 114                 } else if (strcmp(thrstore, "nfssilly") == 0) {
 115                         printf("rump warning: threads not enabled, not enabling"
 116                            " nfs silly rename\n");
 117                         return 0;
 118                 } else if (strcmp(thrstore, "unpgc") == 0) {
 119                         printf("rump warning: threads not enabled, not enabling"
 120                            " UNP garbage collection\n");
 121                         return 0;
 122                 } else if (strncmp(thrstore, "xcall", sizeof("xcall")-1) == 0) {
 123                         printf("rump warning: threads not enabled, CPU xcall"
 124                            " not functional\n");
 125                         return 0;
 126                 } else
 127                         panic("threads not available, setenv RUMP_THREADS 1");
 128         }
 129         KASSERT(fmt != NULL);
 130
 131         k = rumpuser_malloc(sizeof(struct kthdesc), 0);
 132         k->f = func;
 133         k->arg = arg;
 134         k->mylwp = l = rump_lwp_alloc(0, rump_nextlid());
 135         if (flags & KTHREAD_MPSAFE)
 136                 l->l_pflag |= LP_MPSAFE;
 137         if (flags & KTHREAD_INTR)
 138                 l->l_pflag |= LP_INTR;
 139         if (ci) {
 140                 l->l_pflag |= LP_BOUND;
 141                 l->l_cpu = ci;
 142         }
 143         rv = rumpuser_thread_create(threadbouncer, k, thrname);
 144         if (rv)
 145                 return rv;
 146
 147         if (newlp)
 148                 *newlp = l;
 149         return 0;
 150 }
 151
 152 void
 153 kthread_exit(int ecode)
 154 {
 155
 156         if ((curlwp->l_pflag & LP_MPSAFE) == 0)
 157                 KERNEL_UNLOCK_LAST(NULL);
 158         rump_lwp_release(curlwp);
 159         rump_unschedule();
 160         rumpuser_thread_exit();
 161 }