xref: /freebsd/lib/libthr/thread/thr_create.c (revision 56cb1e8cca78396cb5cb2bb3e16066707ed8f43f)
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_name_offset			= OFF(name);
52 int _thread_ctx_offset			= OFF(ctx);
53 #undef OFF
54 
55 int _thread_PS_RUNNING_value		= PS_RUNNING;
56 int _thread_PS_DEAD_value		= PS_DEAD;
57 
58 __weak_reference(_pthread_create, pthread_create);
59 
60 int
61 _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
62 	       void *(*start_routine) (void *), void *arg)
63 {
64 	int             ret = 0;
65 	pthread_t       new_thread;
66 	pthread_attr_t	pattr;
67 	int		flags;
68 	void           *stack;
69 
70 	/*
71 	 * Locking functions in libc are required when there are
72 	 * threads other than the initial thread.
73 	 */
74 	__isthreaded = 1;
75 
76 	/* Allocate memory for the thread structure: */
77 	if ((new_thread = (pthread_t) malloc(sizeof(struct pthread))) == NULL)
78 		return (EAGAIN);
79 
80 	/* Check if default thread attributes are required: */
81 	if (attr == NULL || *attr == NULL)
82 		pattr = &pthread_attr_default;
83 	else
84 		pattr = *attr;
85 
86 	/* Check if a stack was specified in the thread attributes: */
87 	if ((stack = pattr->stackaddr_attr) == NULL) {
88 		stack = _thread_stack_alloc(pattr->stacksize_attr,
89 		    pattr->guardsize_attr);
90 		if (stack == NULL) {
91 			free(new_thread);
92 			return (EAGAIN);
93 		}
94 	}
95 
96 	/* Initialise the thread structure: */
97 	init_td_common(new_thread, pattr, 0);
98 	new_thread->stack = stack;
99 	new_thread->start_routine = start_routine;
100 	new_thread->arg = arg;
101 
102 	/* Initialise the machine context: */
103 	getcontext(&new_thread->ctx);
104 	new_thread->ctx.uc_stack.ss_sp = new_thread->stack;
105 	new_thread->ctx.uc_stack.ss_size = pattr->stacksize_attr;
106 	makecontext(&new_thread->ctx, _thread_start, 0);
107 	new_thread->arch_id = _set_curthread(&new_thread->ctx, new_thread, &ret);
108 	if (ret != 0) {
109 		if (pattr->stackaddr_attr == NULL) {
110 			STACK_LOCK;
111 			_thread_stack_free(new_thread->stack,
112 			    pattr->stacksize_attr, pattr->guardsize_attr);
113 			STACK_UNLOCK;
114 		}
115 		free(new_thread);
116 		return (ret);
117 	}
118 
119 	/*
120 	 * Check if this thread is to inherit the scheduling
121 	 * attributes from its parent:
122 	 */
123 	if (new_thread->attr.flags & PTHREAD_INHERIT_SCHED) {
124 		/* Copy the scheduling attributes: */
125 		new_thread->base_priority = curthread->base_priority &
126 		    ~PTHREAD_SIGNAL_PRIORITY;
127 		new_thread->attr.prio = curthread->base_priority &
128 		    ~PTHREAD_SIGNAL_PRIORITY;
129 		new_thread->attr.sched_policy = curthread->attr.sched_policy;
130 	} else {
131 		/*
132 		 * Use just the thread priority, leaving the
133 		 * other scheduling attributes as their
134 		 * default values:
135 		 */
136 		new_thread->base_priority = new_thread->attr.prio;
137 	}
138 	new_thread->active_priority = new_thread->base_priority;
139 
140 	/*
141 	 * Initialise the unique id which GDB uses to
142 	 * track threads.
143 	 */
144 	new_thread->uniqueid = next_uniqueid++;
145 
146 	THREAD_LIST_LOCK;
147 
148 	/* Add the thread to the linked list of all threads: */
149 	TAILQ_INSERT_HEAD(&_thread_list, new_thread, tle);
150 
151 	/*
152 	 * Create the thread.
153 	 *
154 	 */
155 	if (pattr->suspend == PTHREAD_CREATE_SUSPENDED) {
156 		new_thread->flags |= PTHREAD_FLAGS_SUSPENDED;
157 		flags = THR_SUSPENDED;
158 	} else {
159 		flags = 0;
160 	}
161 
162 	ret = thr_create(&new_thread->ctx, &new_thread->thr_id, flags);
163 
164 	if (ret != 0) {
165 		_thread_printf(STDERR_FILENO, "thr_create() == %d\n", ret);
166 		PANIC("thr_create");
167 	}
168 
169 	THREAD_LIST_UNLOCK;
170 
171 	/* Return a pointer to the thread structure: */
172 	(*thread) = new_thread;
173 
174 	return (0);
175 }
176 
177 void
178 _thread_start(void)
179 {
180 
181 	/* Run the current thread's start routine with argument: */
182 	pthread_exit(curthread->start_routine(curthread->arg));
183 
184 	/* This point should never be reached. */
185 	PANIC("Thread has resumed after exit");
186 }
187