xref: /freebsd/lib/libthr/thread/thr_create.c (revision 77b7cdf1999ee965ad494fddd184b18f532ac91a)
1 /*
2  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by John Birrell.
16  * 4. Neither the name of the author nor the names of any co-contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  * $FreeBSD$
33  */
34 #include <errno.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <fcntl.h>
38 #include <unistd.h>
39 #include <stddef.h>
40 #include <sys/time.h>
41 #include <machine/reg.h>
42 #include <pthread.h>
43 #include "thr_private.h"
44 #include "libc_private.h"
45 
46 static u_int64_t next_uniqueid = 1;
47 
48 #define OFF(f)	offsetof(struct pthread, f)
49 int _thread_next_offset			= OFF(tle.tqe_next);
50 int _thread_uniqueid_offset		= OFF(uniqueid);
51 int _thread_state_offset		= OFF(state);
52 int _thread_name_offset			= OFF(name);
53 int _thread_ctx_offset			= OFF(ctx);
54 #undef OFF
55 
56 int _thread_PS_RUNNING_value		= PS_RUNNING;
57 int _thread_PS_DEAD_value		= PS_DEAD;
58 
59 __weak_reference(_pthread_create, pthread_create);
60 
61 int
62 _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
63 	       void *(*start_routine) (void *), void *arg)
64 {
65 	struct itimerval itimer;
66 	int		f_gc = 0;
67 	int             ret = 0;
68 	pthread_t       gc_thread;
69 	pthread_t       new_thread;
70 	pthread_attr_t	pattr;
71 	int		flags;
72 	void           *stack;
73 
74 	/*
75 	 * Locking functions in libc are required when there are
76 	 * threads other than the initial thread.
77 	 */
78 	__isthreaded = 1;
79 
80 	/* Allocate memory for the thread structure: */
81 	if ((new_thread = (pthread_t) malloc(sizeof(struct pthread))) == NULL)
82 		return (EAGAIN);
83 
84 	/* Check if default thread attributes are required: */
85 	if (attr == NULL || *attr == NULL)
86 		pattr = &pthread_attr_default;
87 	else
88 		pattr = *attr;
89 
90 	/* Check if a stack was specified in the thread attributes: */
91 	if ((stack = pattr->stackaddr_attr) == NULL) {
92 		stack = _thread_stack_alloc(pattr->stacksize_attr,
93 		    pattr->guardsize_attr);
94 		if (stack == NULL) {
95 			free(new_thread);
96 			return (EAGAIN);
97 		}
98 	}
99 
100 	/* Initialise the thread structure: */
101 	memset(new_thread, 0, sizeof(struct pthread));
102 	new_thread->stack = stack;
103 	new_thread->start_routine = start_routine;
104 	new_thread->arg = arg;
105 
106 	new_thread->cancelflags = PTHREAD_CANCEL_ENABLE |
107 	    PTHREAD_CANCEL_DEFERRED;
108 
109 	/*
110 	 * Write a magic value to the thread structure
111 	 * to help identify valid ones:
112 	 */
113 	new_thread->magic = PTHREAD_MAGIC;
114 
115 	/* Initialise the machine context: */
116 	getcontext(&new_thread->ctx);
117 	new_thread->ctx.uc_stack.ss_sp = new_thread->stack;
118 	new_thread->ctx.uc_stack.ss_size = pattr->stacksize_attr;
119 	makecontext(&new_thread->ctx, _thread_start, 0);
120 	new_thread->arch_id = _set_curthread(&new_thread->ctx, new_thread);
121 
122 	/* Copy the thread attributes: */
123 	memcpy(&new_thread->attr, pattr, sizeof(struct pthread_attr));
124 
125 	/*
126 	 * Check if this thread is to inherit the scheduling
127 	 * attributes from its parent:
128 	 */
129 	if (new_thread->attr.flags & PTHREAD_INHERIT_SCHED) {
130 		/* Copy the scheduling attributes: */
131 		new_thread->base_priority = curthread->base_priority &
132 		    ~PTHREAD_SIGNAL_PRIORITY;
133 		new_thread->attr.prio = curthread->base_priority &
134 		    ~PTHREAD_SIGNAL_PRIORITY;
135 		new_thread->attr.sched_policy = curthread->attr.sched_policy;
136 	} else {
137 		/*
138 		 * Use just the thread priority, leaving the
139 		 * other scheduling attributes as their
140 		 * default values:
141 		 */
142 		new_thread->base_priority = new_thread->attr.prio;
143 	}
144 	new_thread->active_priority = new_thread->base_priority;
145 	new_thread->inherited_priority = 0;
146 
147 	/* Initialize joiner to NULL (no joiner): */
148 	new_thread->joiner = NULL;
149 
150 	/* Initialize the mutex queue: */
151 	TAILQ_INIT(&new_thread->mutexq);
152 
153 	/* Initialise hooks in the thread structure: */
154 	new_thread->specific = NULL;
155 	new_thread->cleanup = NULL;
156 	new_thread->flags = 0;
157 
158 	/*
159 	 * Protect the scheduling queues.
160 	 */
161 	GIANT_LOCK(curthread);
162 
163 	/*
164 	 * Initialise the unique id which GDB uses to
165 	 * track threads.
166 	 */
167 	new_thread->uniqueid = next_uniqueid++;
168 
169 	/*
170 	 * Check if the garbage collector thread
171 	 * needs to be started.
172 	 */
173 	f_gc = (TAILQ_FIRST(&_thread_list) == _thread_initial);
174 
175 	/* Add the thread to the linked list of all threads: */
176 	TAILQ_INSERT_HEAD(&_thread_list, new_thread, tle);
177 
178 	/*
179 	 * Create the thread.
180 	 *
181 	 */
182 	if (pattr->suspend == PTHREAD_FLAGS_SUSPENDED)
183 		flags = THR_SUSPENDED;
184 	else
185 		flags = 0;
186 
187 	ret = thr_create(&new_thread->ctx, &new_thread->thr_id, flags);
188 
189 	if (ret != 0) {
190 		_thread_printf(STDERR_FILENO, "thr_create() == %d\n", ret);
191 		PANIC("thr_create");
192 	}
193 
194 	GIANT_UNLOCK(curthread);
195 
196 	/* Return a pointer to the thread structure: */
197 	(*thread) = new_thread;
198 
199 	/*
200 	 * Start a garbage collector thread
201 	 * if necessary.
202 	 */
203 #if 0
204 	if (f_gc && pthread_create(&gc_thread,NULL, _thread_gc,NULL) != 0)
205 		PANIC("Can't create gc thread");
206 #endif
207 
208 	return (0);
209 }
210 
211 void
212 _thread_start(void)
213 {
214 
215 	/* Run the current thread's start routine with argument: */
216 	pthread_exit(curthread->start_routine(curthread->arg));
217 
218 	/* This point should never be reached. */
219 	PANIC("Thread has resumed after exit");
220 }
221