xref: /freebsd/lib/libthr/thread/thr_create.c (revision d37ea99837e6ad50837fd9fe1771ddf1c3ba6002)
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 #define OFF(f)	offsetof(struct pthread, f)
47 int _thread_next_offset			= OFF(tle.tqe_next);
48 int _thread_name_offset			= OFF(name);
49 int _thread_ctx_offset			= OFF(ctx);
50 #undef OFF
51 
52 int _thread_PS_RUNNING_value		= PS_RUNNING;
53 int _thread_PS_DEAD_value		= PS_DEAD;
54 
55 __weak_reference(_pthread_create, pthread_create);
56 
57 int
58 _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
59 	       void *(*start_routine) (void *), void *arg)
60 {
61 	int             ret = 0;
62 	pthread_t       new_thread;
63 	pthread_attr_t	pattr;
64 	int		flags;
65 	void           *stack;
66 
67 	/*
68 	 * Locking functions in libc are required when there are
69 	 * threads other than the initial thread.
70 	 */
71 	__isthreaded = 1;
72 
73 	/* Allocate memory for the thread structure: */
74 	if ((new_thread = (pthread_t) malloc(sizeof(struct pthread))) == NULL)
75 		return (EAGAIN);
76 
77 	/* Check if default thread attributes are required: */
78 	if (attr == NULL || *attr == NULL)
79 		pattr = &pthread_attr_default;
80 	else
81 		pattr = *attr;
82 
83 	/* Check if a stack was specified in the thread attributes: */
84 	if ((stack = pattr->stackaddr_attr) == NULL) {
85 		stack = _thread_stack_alloc(pattr->stacksize_attr,
86 		    pattr->guardsize_attr);
87 		if (stack == NULL) {
88 			free(new_thread);
89 			return (EAGAIN);
90 		}
91 	}
92 
93 	/* Initialise the thread structure: */
94 	init_td_common(new_thread, pattr, 0);
95 	new_thread->stack = stack;
96 	new_thread->start_routine = start_routine;
97 	new_thread->arg = arg;
98 
99 	/* Initialise the machine context: */
100 	getcontext(&new_thread->ctx);
101 	new_thread->ctx.uc_stack.ss_sp = new_thread->stack;
102 	new_thread->ctx.uc_stack.ss_size = pattr->stacksize_attr;
103 	makecontext(&new_thread->ctx, _thread_start, 0);
104 	new_thread->arch_id = _set_curthread(&new_thread->ctx, new_thread, &ret);
105 	if (ret != 0) {
106 		if (pattr->stackaddr_attr == NULL) {
107 			STACK_LOCK;
108 			_thread_stack_free(new_thread->stack,
109 			    pattr->stacksize_attr, pattr->guardsize_attr);
110 			STACK_UNLOCK;
111 		}
112 		free(new_thread);
113 		return (ret);
114 	}
115 
116 	/*
117 	 * Check if this thread is to inherit the scheduling
118 	 * attributes from its parent:
119 	 */
120 	if (new_thread->attr.flags & PTHREAD_INHERIT_SCHED) {
121 		/* Copy the scheduling attributes: */
122 		new_thread->base_priority = curthread->base_priority &
123 		    ~PTHREAD_SIGNAL_PRIORITY;
124 		new_thread->attr.prio = curthread->base_priority &
125 		    ~PTHREAD_SIGNAL_PRIORITY;
126 		new_thread->attr.sched_policy = curthread->attr.sched_policy;
127 	} else {
128 		/*
129 		 * Use just the thread priority, leaving the
130 		 * other scheduling attributes as their
131 		 * default values:
132 		 */
133 		new_thread->base_priority = new_thread->attr.prio;
134 	}
135 	new_thread->active_priority = new_thread->base_priority;
136 
137 	THREAD_LIST_LOCK;
138 
139 	/* Add the thread to the linked list of all threads: */
140 	TAILQ_INSERT_HEAD(&_thread_list, new_thread, tle);
141 
142 	/*
143 	 * Create the thread.
144 	 */
145 	if (pattr->suspend == PTHREAD_CREATE_SUSPENDED)
146 		new_thread->flags |= PTHREAD_FLAGS_SUSPENDED;
147 	ret = thr_create(&new_thread->ctx, &new_thread->thr_id, flags);
148 	if (ret != 0) {
149 		_thread_printf(STDERR_FILENO, "thr_create() == %d\n", ret);
150 		PANIC("thr_create");
151 	}
152 
153 	THREAD_LIST_UNLOCK;
154 
155 	/* Return a pointer to the thread structure: */
156 	(*thread) = new_thread;
157 
158 	return (0);
159 }
160 
161 void
162 _thread_start(void)
163 {
164 	if ((curthread->flags & PTHREAD_FLAGS_SUSPENDED) != 0)
165 		_thread_suspend(curthread, NULL);
166 	pthread_exit(curthread->start_routine(curthread->arg));
167 
168 	/* This point should never be reached. */
169 	PANIC("Thread has resumed after exit");
170 }
171