xref: /freebsd/lib/libthr/thread/thr_create.c (revision 195ebc7e9e4b129de810833791a19dfb4349d6a9)
1 /*
2  * Copyright (c) 2003 Daniel M. Eischen <deischen@gdeb.com>
3  * Copyright (c) 2005, David Xu <davidxu@freebsd.org>
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 unmodified, this list of conditions, and the following
11  *    disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  * $FreeBSD$
28  */
29 
30 #include "namespace.h"
31 #include <sys/types.h>
32 #include <sys/rtprio.h>
33 #include <sys/signalvar.h>
34 #include <errno.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <stddef.h>
38 #include <pthread.h>
39 #include <pthread_np.h>
40 #include "un-namespace.h"
41 
42 #include "thr_private.h"
43 
44 static int  create_stack(struct pthread_attr *pattr);
45 static void thread_start(struct pthread *curthread);
46 
47 __weak_reference(_pthread_create, pthread_create);
48 
49 int
50 _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
51 	       void *(*start_routine) (void *), void *arg)
52 {
53 	struct pthread *curthread, *new_thread;
54 	struct thr_param param;
55 	struct sched_param sched_param;
56 	struct rtprio rtp;
57 	int ret = 0, locked, create_suspended;
58 	sigset_t set, oset;
59 	cpuset_t *cpusetp = NULL;
60 	int cpusetsize = 0;
61 
62 	_thr_check_init();
63 
64 	/*
65 	 * Tell libc and others now they need lock to protect their data.
66 	 */
67 	if (_thr_isthreaded() == 0 && _thr_setthreaded(1))
68 		return (EAGAIN);
69 
70 	curthread = _get_curthread();
71 	if ((new_thread = _thr_alloc(curthread)) == NULL)
72 		return (EAGAIN);
73 
74 	memset(&param, 0, sizeof(param));
75 
76 	if (attr == NULL || *attr == NULL)
77 		/* Use the default thread attributes: */
78 		new_thread->attr = _pthread_attr_default;
79 	else {
80 		new_thread->attr = *(*attr);
81 		cpusetp = new_thread->attr.cpuset;
82 		cpusetsize = new_thread->attr.cpusetsize;
83 		new_thread->attr.cpuset = NULL;
84 		new_thread->attr.cpusetsize = 0;
85 	}
86 	if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
87 		/* inherit scheduling contention scope */
88 		if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
89 			new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
90 		else
91 			new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
92 
93 		new_thread->attr.prio = curthread->attr.prio;
94 		new_thread->attr.sched_policy = curthread->attr.sched_policy;
95 	}
96 
97 	new_thread->tid = TID_TERMINATED;
98 
99 	if (create_stack(&new_thread->attr) != 0) {
100 		/* Insufficient memory to create a stack: */
101 		_thr_free(curthread, new_thread);
102 		return (EAGAIN);
103 	}
104 	/*
105 	 * Write a magic value to the thread structure
106 	 * to help identify valid ones:
107 	 */
108 	new_thread->magic = THR_MAGIC;
109 	new_thread->start_routine = start_routine;
110 	new_thread->arg = arg;
111 	new_thread->cancel_enable = 1;
112 	new_thread->cancel_async = 0;
113 	/* Initialize the mutex queue: */
114 	TAILQ_INIT(&new_thread->mutexq);
115 	TAILQ_INIT(&new_thread->pp_mutexq);
116 
117 	/* Initialise hooks in the thread structure: */
118 	if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) {
119 		new_thread->flags = THR_FLAGS_NEED_SUSPEND;
120 		create_suspended = 1;
121 	} else {
122 		create_suspended = 0;
123 	}
124 
125 	new_thread->state = PS_RUNNING;
126 
127 	if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED)
128 		new_thread->tlflags |= TLFLAGS_DETACHED;
129 
130 	if (curthread->in_sigcancel_handler)
131 		new_thread->unblock_sigcancel = 1;
132 	else
133 		new_thread->unblock_sigcancel = 0;
134 
135 	/* Add the new thread. */
136 	new_thread->refcount = 1;
137 	_thr_link(curthread, new_thread);
138 	/* Return thread pointer eariler so that new thread can use it. */
139 	(*thread) = new_thread;
140 	if (SHOULD_REPORT_EVENT(curthread, TD_CREATE) || cpusetp != NULL) {
141 		THR_THREAD_LOCK(curthread, new_thread);
142 		locked = 1;
143 	} else
144 		locked = 0;
145 	param.start_func = (void (*)(void *)) thread_start;
146 	param.arg = new_thread;
147 	param.stack_base = new_thread->attr.stackaddr_attr;
148 	param.stack_size = new_thread->attr.stacksize_attr;
149 	param.tls_base = (char *)new_thread->tcb;
150 	param.tls_size = sizeof(struct tcb);
151 	param.child_tid = &new_thread->tid;
152 	param.parent_tid = &new_thread->tid;
153 	param.flags = 0;
154 	if (new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM)
155 		param.flags |= THR_SYSTEM_SCOPE;
156 	if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED)
157 		param.rtp = NULL;
158 	else {
159 		sched_param.sched_priority = new_thread->attr.prio;
160 		_schedparam_to_rtp(new_thread->attr.sched_policy,
161 			&sched_param, &rtp);
162 		param.rtp = &rtp;
163 	}
164 
165 	/* Schedule the new thread. */
166 	if (create_suspended) {
167 		SIGFILLSET(set);
168 		SIGDELSET(set, SIGTRAP);
169 		__sys_sigprocmask(SIG_SETMASK, &set, &oset);
170 		new_thread->sigmask = oset;
171 		SIGDELSET(new_thread->sigmask, SIGCANCEL);
172 	}
173 
174 	ret = thr_new(&param, sizeof(param));
175 
176 	if (ret != 0) {
177 		ret = errno;
178 		/*
179 		 * Translate EPROCLIM into well-known POSIX code EAGAIN.
180 		 */
181 		if (ret == EPROCLIM)
182 			ret = EAGAIN;
183 	}
184 
185 	if (create_suspended)
186 		__sys_sigprocmask(SIG_SETMASK, &oset, NULL);
187 
188 	if (ret != 0) {
189 		if (!locked)
190 			THR_THREAD_LOCK(curthread, new_thread);
191 		new_thread->state = PS_DEAD;
192 		new_thread->tid = TID_TERMINATED;
193 		if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
194 			new_thread->cycle++;
195 			_thr_umtx_wake(&new_thread->cycle, INT_MAX, 0);
196 		}
197 		THR_THREAD_UNLOCK(curthread, new_thread);
198 		THREAD_LIST_LOCK(curthread);
199 		_thread_active_threads--;
200 		new_thread->tlflags |= TLFLAGS_DETACHED;
201 		_thr_ref_delete_unlocked(curthread, new_thread);
202 		THREAD_LIST_UNLOCK(curthread);
203 	} else if (locked) {
204 		if (cpusetp != NULL) {
205 			if (cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TID,
206 				TID(new_thread), cpusetsize, cpusetp)) {
207 				ret = errno;
208 				/* kill the new thread */
209 				new_thread->force_exit = 1;
210 				THR_THREAD_UNLOCK(curthread, new_thread);
211 				goto out;
212 			}
213 		}
214 
215 		_thr_report_creation(curthread, new_thread);
216 		THR_THREAD_UNLOCK(curthread, new_thread);
217 out:
218 		if (ret) {
219 			THREAD_LIST_LOCK(curthread);
220 			new_thread->tlflags |= TLFLAGS_DETACHED;
221 			THR_GCLIST_ADD(new_thread);
222 			THREAD_LIST_UNLOCK(curthread);
223 		}
224 	}
225 
226 	if (ret)
227 		(*thread) = 0;
228 	return (ret);
229 }
230 
231 static int
232 create_stack(struct pthread_attr *pattr)
233 {
234 	int ret;
235 
236 	/* Check if a stack was specified in the thread attributes: */
237 	if ((pattr->stackaddr_attr) != NULL) {
238 		pattr->guardsize_attr = 0;
239 		pattr->flags |= THR_STACK_USER;
240 		ret = 0;
241 	}
242 	else
243 		ret = _thr_stack_alloc(pattr);
244 	return (ret);
245 }
246 
247 static void
248 thread_start(struct pthread *curthread)
249 {
250 	sigset_t set;
251 
252 	if (curthread->attr.suspend == THR_CREATE_SUSPENDED)
253 		set = curthread->sigmask;
254 
255 	/*
256 	 * This is used as a serialization point to allow parent
257 	 * to report 'new thread' event to debugger or tweak new thread's
258 	 * attributes before the new thread does real-world work.
259 	 */
260 	THR_LOCK(curthread);
261 	THR_UNLOCK(curthread);
262 
263 	if (curthread->force_exit)
264 		_pthread_exit(PTHREAD_CANCELED);
265 
266 	if (curthread->unblock_sigcancel) {
267 		sigset_t set1;
268 
269 		SIGEMPTYSET(set1);
270 		SIGADDSET(set1, SIGCANCEL);
271 		__sys_sigprocmask(SIG_UNBLOCK, &set1, NULL);
272 	}
273 
274 	if (curthread->attr.suspend == THR_CREATE_SUSPENDED) {
275 #if 0
276 		/* Done in THR_UNLOCK() */
277 		_thr_ast(curthread);
278 #endif
279 
280 		/*
281 		 * Parent thread have stored signal mask for us,
282 		 * we should restore it now.
283 		 */
284 		__sys_sigprocmask(SIG_SETMASK, &set, NULL);
285 	}
286 
287 	/* Run the current thread's start routine with argument: */
288 	_pthread_exit(curthread->start_routine(curthread->arg));
289 
290 	/* This point should never be reached. */
291 	PANIC("Thread has resumed after exit");
292 }
293