xref: /freebsd/lib/libthr/thread/thr_create.c (revision aca5021d5f7dcab1e11692923266373e35322d9a)
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 <link.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <stddef.h>
39 #include <pthread.h>
40 #include <pthread_np.h>
41 #include "un-namespace.h"
42 
43 #include "thr_private.h"
44 
45 static int  create_stack(struct pthread_attr *pattr);
46 static void thread_start(struct pthread *curthread);
47 
48 __weak_reference(_pthread_create, pthread_create);
49 
50 int
51 _pthread_create(pthread_t * thread, const pthread_attr_t * attr,
52 	       void *(*start_routine) (void *), void *arg)
53 {
54 	struct pthread *curthread, *new_thread;
55 	struct thr_param param;
56 	struct sched_param sched_param;
57 	struct rtprio rtp;
58 	int ret = 0, locked, create_suspended;
59 	sigset_t set, oset;
60 	cpuset_t *cpusetp = NULL;
61 	int cpusetsize = 0;
62 	int old_stack_prot;
63 
64 	_thr_check_init();
65 
66 	/*
67 	 * Tell libc and others now they need lock to protect their data.
68 	 */
69 	if (_thr_isthreaded() == 0 && _thr_setthreaded(1))
70 		return (EAGAIN);
71 
72 	curthread = _get_curthread();
73 	if ((new_thread = _thr_alloc(curthread)) == NULL)
74 		return (EAGAIN);
75 
76 	memset(&param, 0, sizeof(param));
77 
78 	if (attr == NULL || *attr == NULL)
79 		/* Use the default thread attributes: */
80 		new_thread->attr = _pthread_attr_default;
81 	else {
82 		new_thread->attr = *(*attr);
83 		cpusetp = new_thread->attr.cpuset;
84 		cpusetsize = new_thread->attr.cpusetsize;
85 		new_thread->attr.cpuset = NULL;
86 		new_thread->attr.cpusetsize = 0;
87 	}
88 	if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED) {
89 		/* inherit scheduling contention scope */
90 		if (curthread->attr.flags & PTHREAD_SCOPE_SYSTEM)
91 			new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
92 		else
93 			new_thread->attr.flags &= ~PTHREAD_SCOPE_SYSTEM;
94 
95 		new_thread->attr.prio = curthread->attr.prio;
96 		new_thread->attr.sched_policy = curthread->attr.sched_policy;
97 	}
98 
99 	new_thread->tid = TID_TERMINATED;
100 
101 	old_stack_prot = _rtld_get_stack_prot();
102 	if (create_stack(&new_thread->attr) != 0) {
103 		/* Insufficient memory to create a stack: */
104 		_thr_free(curthread, new_thread);
105 		return (EAGAIN);
106 	}
107 	/*
108 	 * Write a magic value to the thread structure
109 	 * to help identify valid ones:
110 	 */
111 	new_thread->magic = THR_MAGIC;
112 	new_thread->start_routine = start_routine;
113 	new_thread->arg = arg;
114 	new_thread->cancel_enable = 1;
115 	new_thread->cancel_async = 0;
116 	/* Initialize the mutex queue: */
117 	TAILQ_INIT(&new_thread->mutexq);
118 	TAILQ_INIT(&new_thread->pp_mutexq);
119 
120 	/* Initialise hooks in the thread structure: */
121 	if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) {
122 		new_thread->flags = THR_FLAGS_NEED_SUSPEND;
123 		create_suspended = 1;
124 	} else {
125 		create_suspended = 0;
126 	}
127 
128 	new_thread->state = PS_RUNNING;
129 
130 	if (new_thread->attr.flags & PTHREAD_CREATE_DETACHED)
131 		new_thread->flags |= THR_FLAGS_DETACHED;
132 
133 	/* Add the new thread. */
134 	new_thread->refcount = 1;
135 	_thr_link(curthread, new_thread);
136 
137 	/*
138 	 * Handle the race between __pthread_map_stacks_exec and
139 	 * thread linkage.
140 	 */
141 	if (old_stack_prot != _rtld_get_stack_prot())
142 		_thr_stack_fix_protection(new_thread);
143 
144 	/* Return thread pointer eariler so that new thread can use it. */
145 	(*thread) = new_thread;
146 	if (SHOULD_REPORT_EVENT(curthread, TD_CREATE) || cpusetp != NULL) {
147 		THR_THREAD_LOCK(curthread, new_thread);
148 		locked = 1;
149 	} else
150 		locked = 0;
151 	param.start_func = (void (*)(void *)) thread_start;
152 	param.arg = new_thread;
153 	param.stack_base = new_thread->attr.stackaddr_attr;
154 	param.stack_size = new_thread->attr.stacksize_attr;
155 	param.tls_base = (char *)new_thread->tcb;
156 	param.tls_size = sizeof(struct tcb);
157 	param.child_tid = &new_thread->tid;
158 	param.parent_tid = &new_thread->tid;
159 	param.flags = 0;
160 	if (new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM)
161 		param.flags |= THR_SYSTEM_SCOPE;
162 	if (new_thread->attr.sched_inherit == PTHREAD_INHERIT_SCHED)
163 		param.rtp = NULL;
164 	else {
165 		sched_param.sched_priority = new_thread->attr.prio;
166 		_schedparam_to_rtp(new_thread->attr.sched_policy,
167 			&sched_param, &rtp);
168 		param.rtp = &rtp;
169 	}
170 
171 	/* Schedule the new thread. */
172 	if (create_suspended) {
173 		SIGFILLSET(set);
174 		SIGDELSET(set, SIGTRAP);
175 		__sys_sigprocmask(SIG_SETMASK, &set, &oset);
176 		new_thread->sigmask = oset;
177 		SIGDELSET(new_thread->sigmask, SIGCANCEL);
178 	}
179 
180 	ret = thr_new(&param, sizeof(param));
181 
182 	if (ret != 0) {
183 		ret = errno;
184 		/*
185 		 * Translate EPROCLIM into well-known POSIX code EAGAIN.
186 		 */
187 		if (ret == EPROCLIM)
188 			ret = EAGAIN;
189 	}
190 
191 	if (create_suspended)
192 		__sys_sigprocmask(SIG_SETMASK, &oset, NULL);
193 
194 	if (ret != 0) {
195 		if (!locked)
196 			THR_THREAD_LOCK(curthread, new_thread);
197 		new_thread->state = PS_DEAD;
198 		new_thread->tid = TID_TERMINATED;
199 		new_thread->flags |= THR_FLAGS_DETACHED;
200 		new_thread->refcount--;
201 		if (new_thread->flags & THR_FLAGS_NEED_SUSPEND) {
202 			new_thread->cycle++;
203 			_thr_umtx_wake(&new_thread->cycle, INT_MAX, 0);
204 		}
205 		_thr_try_gc(curthread, new_thread); /* thread lock released */
206 		atomic_add_int(&_thread_active_threads, -1);
207 	} else if (locked) {
208 		if (cpusetp != NULL) {
209 			if (cpuset_setaffinity(CPU_LEVEL_WHICH, CPU_WHICH_TID,
210 				TID(new_thread), cpusetsize, cpusetp)) {
211 				ret = errno;
212 				/* kill the new thread */
213 				new_thread->force_exit = 1;
214 				new_thread->flags |= THR_FLAGS_DETACHED;
215 				_thr_try_gc(curthread, new_thread);
216 				 /* thread lock released */
217 				goto out;
218 			}
219 		}
220 
221 		_thr_report_creation(curthread, new_thread);
222 		THR_THREAD_UNLOCK(curthread, new_thread);
223 	}
224 out:
225 	if (ret)
226 		(*thread) = 0;
227 	return (ret);
228 }
229 
230 static int
231 create_stack(struct pthread_attr *pattr)
232 {
233 	int ret;
234 
235 	/* Check if a stack was specified in the thread attributes: */
236 	if ((pattr->stackaddr_attr) != NULL) {
237 		pattr->guardsize_attr = 0;
238 		pattr->flags |= THR_STACK_USER;
239 		ret = 0;
240 	}
241 	else
242 		ret = _thr_stack_alloc(pattr);
243 	return (ret);
244 }
245 
246 static void
247 thread_start(struct pthread *curthread)
248 {
249 	sigset_t set;
250 
251 	if (curthread->attr.suspend == THR_CREATE_SUSPENDED)
252 		set = curthread->sigmask;
253 
254 	/*
255 	 * This is used as a serialization point to allow parent
256 	 * to report 'new thread' event to debugger or tweak new thread's
257 	 * attributes before the new thread does real-world work.
258 	 */
259 	THR_LOCK(curthread);
260 	THR_UNLOCK(curthread);
261 
262 	if (curthread->force_exit)
263 		_pthread_exit(PTHREAD_CANCELED);
264 
265 	if (curthread->attr.suspend == THR_CREATE_SUSPENDED) {
266 #if 0
267 		/* Done in THR_UNLOCK() */
268 		_thr_ast(curthread);
269 #endif
270 
271 		/*
272 		 * Parent thread have stored signal mask for us,
273 		 * we should restore it now.
274 		 */
275 		__sys_sigprocmask(SIG_SETMASK, &set, NULL);
276 	}
277 
278 #ifdef _PTHREAD_FORCED_UNWIND
279 	curthread->unwind_stackend = (char *)curthread->attr.stackaddr_attr +
280 		curthread->attr.stacksize_attr;
281 #endif
282 
283 	/* Run the current thread's start routine with argument: */
284 	_pthread_exit(curthread->start_routine(curthread->arg));
285 
286 	/* This point should never be reached. */
287 	PANIC("Thread has resumed after exit");
288 }
289