1 /*
2  * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
3  * Copyright (c) 2003 Daniel M. Eischen <deischen@gdeb.com>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD: src/lib/libpthread/thread/thr_create.c,v 1.58 2004/10/23 23:28:36 davidxu Exp $
27  */
28 
29 #include "namespace.h"
30 #include <errno.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <fcntl.h>
34 #include <unistd.h>
35 #include <stddef.h>
36 #include <sys/time.h>
37 #include <machine/reg.h>
38 #include <machine/tls.h>
39 #include <pthread.h>
40 #include <sys/signalvar.h>
41 #include <sys/lwp.h>
42 #include "un-namespace.h"
43 
44 #include "libc_private.h"
45 #include "thr_private.h"
46 
47 static int  create_stack(struct pthread_attr *pattr);
48 static void thread_start(void *);
49 
50 int
51 _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
52     void *(*start_routine) (void *), void *arg)
53 {
54 	struct lwp_params create_params;
55 	void *stack;
56 	sigset_t sigmask, oldsigmask;
57 	struct pthread *curthread, *new_thread;
58 	const cpu_set_t *cpumask = NULL;
59 	int ret = 0, locked;
60 
61 	_thr_check_init();
62 
63 	/*
64 	 * Tell libc and others now they need lock to protect their data.
65 	 */
66 	if (_thr_isthreaded() == 0 && _thr_setthreaded(1))
67 		return (EAGAIN);
68 
69 	curthread = tls_get_curthread();
70 	if ((new_thread = _thr_alloc(curthread)) == NULL)
71 		return (EAGAIN);
72 
73 	if (attr == NULL || *attr == NULL) {
74 		/* Use the default thread attributes: */
75 		new_thread->attr = _pthread_attr_default;
76 	} else {
77 		new_thread->attr = *(*attr);
78 	}
79 	if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
80 		/* inherit scheduling contention scope */
81 		if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
82 			new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
83 		else
84 			new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
85 		/*
86 		 * scheduling policy and scheduling parameters will be
87 		 * inherited in following code.
88 		 */
89 	}
90 	if (new_thread->attr.flags & THR_CPUMASK)
91 		cpumask = &new_thread->attr.cpumask;
92 
93 	if (create_stack(&new_thread->attr) != 0) {
94 		/* Insufficient memory to create a stack: */
95 		new_thread->terminated = 1;
96 		_thr_free(curthread, new_thread);
97 		return (EAGAIN);
98 	}
99 	/*
100 	 * Write a magic value to the thread structure
101 	 * to help identify valid ones:
102 	 */
103 	new_thread->magic = THR_MAGIC;
104 	new_thread->start_routine = start_routine;
105 	new_thread->arg = arg;
106 	new_thread->cancelflags = PTHREAD_CANCEL_ENABLE |
107 	    PTHREAD_CANCEL_DEFERRED;
108 	/*
109 	 * Check if this thread is to inherit the scheduling
110 	 * attributes from its parent:
111 	 */
112 	if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
113 		/*
114 		 * Copy the scheduling attributes. Lock the scheduling
115 		 * lock to get consistent scheduling parameters.
116 		 */
117 		THR_LOCK(curthread);
118 		new_thread->base_priority = curthread->base_priority;
119 		new_thread->attr.prio = curthread->attr.prio;
120 		new_thread->attr.sched_policy = curthread->attr.sched_policy;
121 		THR_UNLOCK(curthread);
122 	} else {
123 		/*
124 		 * Use just the thread priority, leaving the
125 		 * other scheduling attributes as their
126 		 * default values:
127 		 */
128 		new_thread->base_priority = new_thread->attr.prio;
129 	}
130 	new_thread->active_priority = new_thread->base_priority;
131 
132 	/* Initialize the mutex queue: */
133 	TAILQ_INIT(&new_thread->mutexq);
134 
135 	/* Initialise hooks in the thread structure: */
136 	if (new_thread->attr.suspend == THR_CREATE_SUSPENDED)
137 		new_thread->flags = THR_FLAGS_NEED_SUSPEND;
138 
139 	new_thread->state = PS_RUNNING;
140 
141 	if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED)
142 		new_thread->tlflags |= TLFLAGS_DETACHED;
143 
144 	/* Add the new thread. */
145 	new_thread->refcount = 1;
146 	_thr_link(curthread, new_thread);
147 	/* Return thread pointer eariler so that new thread can use it. */
148 	(*thread) = new_thread;
149 	if (SHOULD_REPORT_EVENT(curthread, TD_CREATE)) {
150 		THR_THREAD_LOCK(curthread, new_thread);
151 		locked = 1;
152 	} else
153 		locked = 0;
154 	/* Schedule the new thread. */
155 	stack = (char *)new_thread->attr.stackaddr_attr +
156 			new_thread->attr.stacksize_attr;
157 	bzero(&create_params, sizeof(create_params));
158 	create_params.lwp_func = thread_start;
159 	create_params.lwp_arg = new_thread;
160 	create_params.lwp_stack = stack;
161 	create_params.lwp_tid1 = &new_thread->tid;
162 	/*
163 	 * Thread created by thr_create() inherits currrent thread
164 	 * sigmask, however, before new thread setup itself correctly,
165 	 * it can not handle signal, so we should mask all signals here.
166 	 * We do this at the very last moment, so that we don't run
167 	 * into problems while we have all signals disabled.
168 	 */
169 	SIGFILLSET(sigmask);
170 	__sys_sigprocmask(SIG_SETMASK, &sigmask, &oldsigmask);
171 	new_thread->sigmask = oldsigmask;
172 	ret = lwp_create2(&create_params, cpumask);
173 	__sys_sigprocmask(SIG_SETMASK, &oldsigmask, NULL);
174 	if (ret != 0) {
175 		if (!locked)
176 			THR_THREAD_LOCK(curthread, new_thread);
177 		new_thread->state = PS_DEAD;
178 		new_thread->terminated = 1;
179 		if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
180 			new_thread->cycle++;
181 			_thr_umtx_wake(&new_thread->cycle, INT_MAX);
182 		}
183 		THR_THREAD_UNLOCK(curthread, new_thread);
184 		THREAD_LIST_LOCK(curthread);
185 		_thread_active_threads--;
186 		new_thread->tlflags |= TLFLAGS_DETACHED;
187 		_thr_ref_delete_unlocked(curthread, new_thread);
188 		THREAD_LIST_UNLOCK(curthread);
189 		(*thread) = NULL;
190 		ret = EAGAIN;
191 	} else if (locked) {
192 		_thr_report_creation(curthread, new_thread);
193 		THR_THREAD_UNLOCK(curthread, new_thread);
194 	}
195 	return (ret);
196 }
197 
198 static int
199 create_stack(struct pthread_attr *pattr)
200 {
201 	int ret;
202 
203 	/* Check if a stack was specified in the thread attributes: */
204 	if ((pattr->stackaddr_attr) != NULL) {
205 		pattr->guardsize_attr = 0;
206 		pattr->flags |= THR_STACK_USER;
207 		ret = 0;
208 	}
209 	else
210 		ret = _thr_stack_alloc(pattr);
211 	return (ret);
212 }
213 
214 static void
215 thread_start(void *arg)
216 {
217 	struct pthread *curthread = (struct pthread *)arg;
218 
219 	tls_set_tcb(curthread->tcb);
220 
221 	/* Thread was created with all signals blocked, unblock them. */
222 	__sys_sigprocmask(SIG_SETMASK, &curthread->sigmask, NULL);
223 
224 	THR_LOCK(curthread);
225 	THR_UNLOCK(curthread);
226 
227 	if (curthread->flags & THR_FLAGS_NEED_SUSPEND)
228 		_thr_suspend_check(curthread);
229 	_nmalloc_thr_init();
230 
231 	/* Run the current thread's start routine with argument: */
232 	_pthread_exit(curthread->start_routine(curthread->arg));
233 
234 	/* This point should never be reached. */
235 	PANIC("Thread has resumed after exit");
236 }
237 
238 __strong_reference(_pthread_create, pthread_create);
239