1/*
2 * Copyright (c) 2003 Daniel M. Eischen <deischen@gdeb.com>
3 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
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 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by John Birrell.
17 * 4. Neither the name of the author nor the names of any co-contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * $FreeBSD: head/lib/libkse/thread/thr_create.c 118514 2003-08-06 00:23:40Z marcel $
34 */
35#include <errno.h>
36#include <stdlib.h>
37#include <string.h>
38#include <fcntl.h>
39#include <unistd.h>
40#include <stddef.h>
41#include <sys/time.h>
42#include <machine/reg.h>
43#include <pthread.h>
44#include "thr_private.h"
45#include "libc_private.h"
46
47#define OFF(f) offsetof(struct pthread, f)
48int _thread_next_offset = OFF(tle.tqe_next);
49int _thread_uniqueid_offset = OFF(uniqueid);
50int _thread_state_offset = OFF(state);
51int _thread_name_offset = OFF(name);
52void *_thread_tcb_offset = OFF(tcb);
53#undef OFF
54#define OFF(f) offsetof(struct tcb, f)
55int _thread_ctx_offset = OFF(tcb_tmbx.tm_context);
56#undef OFF
57
58int _thread_PS_RUNNING_value = PS_RUNNING;
59int _thread_PS_DEAD_value = PS_DEAD;
60
61static void free_thread(struct pthread *curthread, struct pthread *thread);
62static int create_stack(struct pthread_attr *pattr);
63static void free_stack(struct pthread_attr *pattr);
64static void thread_start(struct pthread *curthread,
65 void *(*start_routine) (void *), void *arg);
66
67__weak_reference(_pthread_create, pthread_create);
68
69/*
70 * Some notes on new thread creation and first time initializion
71 * to enable multi-threading.
72 *
73 * There are basically two things that need to be done.
74 *
75 * 1) The internal library variables must be initialized.
76 * 2) Upcalls need to be enabled to allow multiple threads
77 * to be run.
78 *
79 * The first may be done as a result of other pthread functions
80 * being called. When _thr_initial is null, _libpthread_init is
81 * called to initialize the internal variables; this also creates
82 * or sets the initial thread. It'd be nice to automatically
83 * have _libpthread_init called on program execution so we don't
84 * have to have checks throughout the library.
85 *
86 * The second part is only triggered by the creation of the first
87 * thread (other than the initial/main thread). If the thread
88 * being created is a scope system thread, then a new KSE/KSEG
89 * pair needs to be allocated. Also, if upcalls haven't been
90 * enabled on the initial thread's KSE, they must be now that
91 * there is more than one thread; this could be delayed until
92 * the initial KSEG has more than one thread.
93 */
94int
95_pthread_create(pthread_t * thread, const pthread_attr_t * attr,
96 void *(*start_routine) (void *), void *arg)
97{
98 struct pthread *curthread, *new_thread;
99 struct kse *kse = NULL;
100 struct kse_group *kseg = NULL;
101 kse_critical_t crit;
102 int i;
103 int ret = 0;
104
105 if (_thr_initial == NULL)
106 _libpthread_init(NULL);
107
108 /*
109 * Turn on threaded mode, if failed, it is unnecessary to
110 * do further work.
111 */
112 if (_kse_isthreaded() == 0 && _kse_setthreaded(1)) {
113 return (EAGAIN);
114 }
115 curthread = _get_curthread();
116
117 /*
118 * Allocate memory for the thread structure.
119 * Some functions use malloc, so don't put it
120 * in a critical region.
121 */
122 if ((new_thread = _thr_alloc(curthread)) == NULL) {
123 /* Insufficient memory to create a thread: */
124 ret = EAGAIN;
125 } else {
126 /* Check if default thread attributes are required: */
127 if (attr == NULL || *attr == NULL)
128 /* Use the default thread attributes: */
129 new_thread->attr = _pthread_attr_default;
130 else
131 new_thread->attr = *(*attr);
132#ifdef SYSTEM_SCOPE_ONLY
133 new_thread->attr.flags |= PTHREAD_SCOPE_SYSTEM;
134#endif
135 if (create_stack(&new_thread->attr) != 0) {
136 /* Insufficient memory to create a stack: */
137 ret = EAGAIN;
138 _thr_free(curthread, new_thread);
139 }
140 else if (((new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) &&
141 (((kse = _kse_alloc(curthread, 1)) == NULL)
142 || ((kseg = _kseg_alloc(curthread)) == NULL))) {
143 /* Insufficient memory to create a new KSE/KSEG: */
144 ret = EAGAIN;
145 if (kse != NULL) {
146 kse->k_kcb->kcb_kmbx.km_flags |= KMF_DONE;
147 _kse_free(curthread, kse);
148 }
149 free_stack(&new_thread->attr);
150 _thr_free(curthread, new_thread);
151 }
152 else {
153 if (kseg != NULL) {
154 /* Add the KSE to the KSEG's list of KSEs. */
155 TAILQ_INSERT_HEAD(&kseg->kg_kseq, kse, k_kgqe);
156 kseg->kg_ksecount = 1;
157 kse->k_kseg = kseg;
158 kse->k_schedq = &kseg->kg_schedq;
159 }
160 /*
161 * Write a magic value to the thread structure
162 * to help identify valid ones:
163 */
164 new_thread->magic = THR_MAGIC;
165
166 new_thread->slice_usec = -1;
167 new_thread->start_routine = start_routine;
168 new_thread->arg = arg;
169 new_thread->cancelflags = PTHREAD_CANCEL_ENABLE |
170 PTHREAD_CANCEL_DEFERRED;
171
172 /* No thread is wanting to join to this one: */
173 new_thread->joiner = NULL;
174
175 /* Initialize the signal frame: */
176 new_thread->curframe = NULL;
177
178 /*
179 * Initialize the machine context.
180 * Enter a critical region to get consistent context.
181 */
182 crit = _kse_critical_enter();
183 THR_GETCONTEXT(&new_thread->tcb->tcb_tmbx.tm_context);
184 /* Initialize the thread for signals: */
185 new_thread->sigmask = curthread->sigmask;
186 _kse_critical_leave(crit);
187
188 new_thread->tcb->tcb_tmbx.tm_udata = new_thread;
189 new_thread->tcb->tcb_tmbx.tm_context.uc_sigmask =
190 new_thread->sigmask;
191 new_thread->tcb->tcb_tmbx.tm_context.uc_stack.ss_size =
192 new_thread->attr.stacksize_attr;
193 new_thread->tcb->tcb_tmbx.tm_context.uc_stack.ss_sp =
194 new_thread->attr.stackaddr_attr;
195 makecontext(&new_thread->tcb->tcb_tmbx.tm_context,
196 (void (*)(void))thread_start, 3, new_thread,
197 start_routine, arg);
198 /*
199 * Check if this thread is to inherit the scheduling
200 * attributes from its parent:
201 */
202 if ((new_thread->attr.flags & PTHREAD_INHERIT_SCHED) != 0) {
203 /*
204 * Copy the scheduling attributes.
205 * Lock the scheduling lock to get consistent
206 * scheduling parameters.
207 */
208 THR_SCHED_LOCK(curthread, curthread);
209 new_thread->base_priority =
210 curthread->base_priority &
211 ~THR_SIGNAL_PRIORITY;
212 new_thread->attr.prio =
213 curthread->base_priority &
214 ~THR_SIGNAL_PRIORITY;
215 new_thread->attr.sched_policy =
216 curthread->attr.sched_policy;
217 THR_SCHED_UNLOCK(curthread, curthread);
218 } else {
219 /*
220 * Use just the thread priority, leaving the
221 * other scheduling attributes as their
222 * default values:
223 */
224 new_thread->base_priority =
225 new_thread->attr.prio;
226 }
227 new_thread->active_priority = new_thread->base_priority;
228 new_thread->inherited_priority = 0;
229
230 /* Initialize the mutex queue: */
231 TAILQ_INIT(&new_thread->mutexq);
232
233 /*
234 * Initialize thread locking.
235 * Lock initializing needs malloc, so don't
236 * enter critical region before doing this!
237 */
238 if (_lock_init(&new_thread->lock, LCK_ADAPTIVE,
239 _thr_lock_wait, _thr_lock_wakeup) != 0)
240 PANIC("Cannot initialize thread lock");
241 for (i = 0; i < MAX_THR_LOCKLEVEL; i++) {
242 _lockuser_init(&new_thread->lockusers[i],
243 (void *)new_thread);
244 _LCK_SET_PRIVATE2(&new_thread->lockusers[i],
245 (void *)new_thread);
246 }
247
248 /* Initialise hooks in the thread structure: */
249 new_thread->specific = NULL;
250 new_thread->cleanup = NULL;
251 new_thread->flags = 0;
252 new_thread->continuation = NULL;
253
254 if (new_thread->attr.suspend == THR_CREATE_SUSPENDED) {
255 new_thread->state = PS_SUSPENDED;
256 new_thread->flags = THR_FLAGS_SUSPENDED;
257 }
258 else
259 new_thread->state = PS_RUNNING;
260
261 /*
262 * System scope threads have their own kse and
263 * kseg. Process scope threads are all hung
264 * off the main process kseg.
265 */
266 if ((new_thread->attr.flags & PTHREAD_SCOPE_SYSTEM) == 0) {
267 new_thread->kseg = _kse_initial->k_kseg;
268 new_thread->kse = _kse_initial;
269 }
270 else {
271 kse->k_curthread = NULL;
272 kse->k_kseg->kg_flags |= KGF_SINGLE_THREAD;
273 new_thread->kse = kse;
274 new_thread->kseg = kse->k_kseg;
275 kse->k_kcb->kcb_kmbx.km_udata = kse;
276 kse->k_kcb->kcb_kmbx.km_curthread = NULL;
277 }
278
279 /*
280 * Schedule the new thread starting a new KSEG/KSE
281 * pair if necessary.
282 */
283 ret = _thr_schedule_add(curthread, new_thread);
284 if (ret != 0)
285 free_thread(curthread, new_thread);
286 else {
287 /* Return a pointer to the thread structure: */
288 (*thread) = new_thread;
289 }
290 }
291 }
292
293 /* Return the status: */
294 return (ret);
295}
296
297static void
298free_thread(struct pthread *curthread, struct pthread *thread)
299{
300 free_stack(&thread->attr);
301 if ((thread->attr.flags & PTHREAD_SCOPE_SYSTEM) != 0) {
302 /* Free the KSE and KSEG. */
303 _kseg_free(thread->kseg);
304 _kse_free(curthread, thread->kse);
305 }
306 _thr_free(curthread, thread);
307}
308
309static int
310create_stack(struct pthread_attr *pattr)
311{
312 int ret;
313
314 /* Check if a stack was specified in the thread attributes: */
315 if ((pattr->stackaddr_attr) != NULL) {
316 pattr->guardsize_attr = 0;
317 pattr->flags |= THR_STACK_USER;
318 ret = 0;
319 }
320 else
321 ret = _thr_stack_alloc(pattr);
322 return (ret);
323}
324
325static void
326free_stack(struct pthread_attr *pattr)
327{
328 struct kse *curkse;
329 kse_critical_t crit;
330
331 if ((pattr->flags & THR_STACK_USER) == 0) {
332 crit = _kse_critical_enter();
333 curkse = _get_curkse();
334 KSE_LOCK_ACQUIRE(curkse, &_thread_list_lock);
335 /* Stack routines don't use malloc/free. */
336 _thr_stack_free(pattr);
337 KSE_LOCK_RELEASE(curkse, &_thread_list_lock);
338 _kse_critical_leave(crit);
339 }
340}
341
342static void
343thread_start(struct pthread *curthread, void *(*start_routine) (void *),
344 void *arg)
345{
346 /* Run the current thread's start routine with argument: */
347 pthread_exit(start_routine(arg));
348
349 /* This point should never be reached. */
350 PANIC("Thread has resumed after exit");
351}