xref: /netbsd-src/sys/rump/librump/rumpkern/threads.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: threads.c,v 1.12 2010/09/01 19:37:59 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 1.12 2010/09/01 19:37:59 pooka Exp $");
33 
34 #include <sys/param.h>
35 #include <sys/atomic.h>
36 #include <sys/kmem.h>
37 #include <sys/kthread.h>
38 #include <sys/malloc.h>
39 #include <sys/systm.h>
40 
41 #include <machine/stdarg.h>
42 
43 #include <rump/rumpuser.h>
44 
45 #include "rump_private.h"
46 
47 struct kthdesc {
48 	void (*f)(void *);
49 	void *arg;
50 	struct lwp *mylwp;
51 };
52 
53 static void *
54 threadbouncer(void *arg)
55 {
56 	struct kthdesc *k = arg;
57 	struct lwp *l = k->mylwp;
58 	void (*f)(void *);
59 	void *thrarg;
60 
61 	f = k->f;
62 	thrarg = k->arg;
63 
64 	/* schedule ourselves */
65 	rumpuser_set_curlwp(l);
66 	rump_schedule();
67 
68 	/* free dance struct */
69 	free(k, M_TEMP);
70 
71 	if ((curlwp->l_pflag & LP_MPSAFE) == 0)
72 		KERNEL_LOCK(1, NULL);
73 
74 	f(thrarg);
75 
76 	panic("unreachable, should kthread_exit()");
77 }
78 
79 int
80 kthread_create(pri_t pri, int flags, struct cpu_info *ci,
81 	void (*func)(void *), void *arg, lwp_t **newlp, const char *fmt, ...)
82 {
83 	char thrstore[MAXCOMLEN];
84 	const char *thrname = NULL;
85 	va_list ap;
86 	struct kthdesc *k;
87 	struct lwp *l;
88 	int rv;
89 
90 	thrstore[0] = '\0';
91 	if (fmt) {
92 		va_start(ap, fmt);
93 		vsnprintf(thrstore, sizeof(thrstore), fmt, ap);
94 		va_end(ap);
95 		thrname = thrstore;
96 	}
97 
98 	/*
99 	 * We don't want a module unload thread.
100 	 * (XXX: yes, this is a kludge too, and the kernel should
101 	 * have a more flexible method for configuring which threads
102 	 * we want).
103 	 */
104 	if (strcmp(thrstore, "modunload") == 0) {
105 		return 0;
106 	}
107 
108 	if (!rump_threads) {
109 		/* fake them */
110 		if (strcmp(thrstore, "vrele") == 0) {
111 			printf("rump warning: threads not enabled, not starting"
112 			   " vrele thread\n");
113 			return 0;
114 		} else if (strcmp(thrstore, "cachegc") == 0) {
115 			printf("rump warning: threads not enabled, not starting"
116 			   " namecache g/c thread\n");
117 			return 0;
118 		} else if (strcmp(thrstore, "nfssilly") == 0) {
119 			printf("rump warning: threads not enabled, not enabling"
120 			   " nfs silly rename\n");
121 			return 0;
122 		} else if (strcmp(thrstore, "unpgc") == 0) {
123 			printf("rump warning: threads not enabled, not enabling"
124 			   " UNP garbage collection\n");
125 			return 0;
126 		} else if (strncmp(thrstore, "pmf", sizeof("pmf")-1) == 0) {
127 			printf("rump warning: threads not enabled, not enabling"
128 			   " pmf thread\n");
129 			return 0;
130 		} else if (strncmp(thrstore, "xcall", sizeof("xcall")-1) == 0) {
131 			printf("rump warning: threads not enabled, CPU xcall"
132 			   " not functional\n");
133 			return 0;
134 		} else
135 			panic("threads not available, setenv RUMP_THREADS 1");
136 	}
137 	KASSERT(fmt != NULL);
138 
139 	k = malloc(sizeof(*k), M_TEMP, M_WAITOK);
140 	k->f = func;
141 	k->arg = arg;
142 	k->mylwp = l = rump__lwproc_allockernlwp();
143 	l->l_flag |= LW_SYSTEM;
144 	if (flags & KTHREAD_MPSAFE)
145 		l->l_pflag |= LP_MPSAFE;
146 	if (flags & KTHREAD_INTR)
147 		l->l_pflag |= LP_INTR;
148 	if (ci) {
149 		l->l_pflag |= LP_BOUND;
150 		l->l_target_cpu = ci;
151 	}
152 	if (thrname) {
153 		l->l_name = kmem_alloc(MAXCOMLEN, KM_SLEEP);
154 		strlcpy(l->l_name, thrname, MAXCOMLEN);
155 	}
156 
157 	rv = rumpuser_thread_create(threadbouncer, k, thrname,
158 	    (flags & KTHREAD_JOINABLE) == KTHREAD_JOINABLE, &l->l_ctxlink);
159 	if (rv)
160 		return rv;
161 
162 	if (newlp) {
163 		*newlp = l;
164 	} else {
165 		KASSERT((flags & KTHREAD_JOINABLE) == 0);
166 	}
167 
168 	return 0;
169 }
170 
171 void
172 kthread_exit(int ecode)
173 {
174 
175 	if ((curlwp->l_pflag & LP_MPSAFE) == 0)
176 		KERNEL_UNLOCK_LAST(NULL);
177 	rump_lwproc_releaselwp();
178 	/* unschedule includes membar */
179 	rump_unschedule();
180 	rumpuser_thread_exit();
181 }
182 
183 int
184 kthread_join(struct lwp *l)
185 {
186 	int rv;
187 
188 	KASSERT(l->l_ctxlink != NULL);
189 	rv = rumpuser_thread_join(l->l_ctxlink);
190 	membar_consumer();
191 
192 	return rv;
193 }
194