1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26 /*
27 * Copyright 2016 Joyent, Inc.
28 */
29
30 #include "lint.h"
31 #include "thr_uberdata.h"
32
33 /*
34 * pthread_once related data
35 * This structure is exported as pthread_once_t in pthread.h.
36 * We export only the size of this structure. so check
37 * pthread_once_t in pthread.h before making a change here.
38 */
39 typedef struct __once {
40 mutex_t mlock;
41 union {
42 uint32_t pad32_flag[2];
43 uint64_t pad64_flag;
44 } oflag;
45 } __once_t;
46
47 #define once_flag oflag.pad32_flag[1]
48
49 static int
50 _thr_setinherit(pthread_t tid, int inherit)
51 {
52 ulwp_t *ulwp;
53 int error = 0;
54
55 if ((ulwp = find_lwp(tid)) == NULL) {
56 error = ESRCH;
57 } else {
58 ulwp->ul_ptinherit = inherit;
59 ulwp_unlock(ulwp, curthread->ul_uberdata);
60 }
61
62 return (error);
63 }
64
65 static int
66 _thr_setparam(pthread_t tid, int policy, int prio)
67 {
68 ulwp_t *ulwp;
69 id_t cid;
70 int error = 0;
71
72 if ((ulwp = find_lwp(tid)) == NULL) {
73 error = ESRCH;
74 } else {
75 if (policy == ulwp->ul_policy &&
76 (policy == SCHED_FIFO || policy == SCHED_RR) &&
77 ulwp->ul_epri != 0) {
78 /*
79 * Don't change the ceiling priority,
80 * just the base priority.
81 */
82 if (prio > ulwp->ul_epri)
83 error = EPERM;
84 else
85 ulwp->ul_pri = prio;
86 } else if ((cid = setparam(P_LWPID, tid, policy, prio)) == -1) {
87 error = errno;
88 } else {
89 if (policy == SCHED_FIFO || policy == SCHED_RR)
90 ulwp->ul_rtclassid = cid;
91 ulwp->ul_cid = cid;
92 ulwp->ul_pri = prio;
93 membar_producer();
94 ulwp->ul_policy = policy;
95 }
96 ulwp_unlock(ulwp, curthread->ul_uberdata);
97 }
98 return (error);
99 }
100
101 /*
102 * pthread_create: creates a thread in the current process.
103 * calls common _thrp_create() after copying the attributes.
104 */
105 #pragma weak _pthread_create = pthread_create
106 int
107 pthread_create(pthread_t *thread, const pthread_attr_t *attr,
108 void * (*start_routine)(void *), void *arg)
109 {
110 ulwp_t *self = curthread;
111 const thrattr_t *ap = attr? attr->__pthread_attrp : def_thrattr();
112 const pcclass_t *pccp;
113 long flag;
114 pthread_t tid;
115 int error;
116
117 update_sched(self);
118
119 if (ap == NULL)
120 return (EINVAL);
121
122 /* validate explicit scheduling attributes */
123 if (ap->inherit == PTHREAD_EXPLICIT_SCHED &&
124 (ap->policy == SCHED_SYS ||
125 (pccp = get_info_by_policy(ap->policy)) == NULL ||
126 ap->prio < pccp->pcc_primin || ap->prio > pccp->pcc_primax))
127 return (EINVAL);
128
129 flag = ap->scope | ap->detachstate | ap->daemonstate | THR_SUSPENDED;
130 error = _thrp_create(ap->stkaddr, ap->stksize, start_routine, arg,
131 flag, &tid, ap->guardsize);
132 if (error == 0) {
133 /*
134 * Record the original inheritence value for
135 * pthread_getattr_np(). We should always be able to find the
136 * thread.
137 */
138 (void) _thr_setinherit(tid, ap->inherit);
139
140 if (ap->inherit == PTHREAD_EXPLICIT_SCHED &&
141 (ap->policy != self->ul_policy ||
142 ap->prio != (self->ul_epri ? self->ul_epri :
143 self->ul_pri))) {
144 /*
145 * The SUSv3 specification requires pthread_create()
146 * to fail with EPERM if it cannot set the scheduling
147 * policy and parameters on the new thread.
148 */
149 error = _thr_setparam(tid, ap->policy, ap->prio);
150 }
151
152 if (error) {
153 /*
154 * We couldn't determine this error before
155 * actually creating the thread. To recover,
156 * mark the thread detached and cancel it.
157 * It is as though it was never created.
158 */
159 ulwp_t *ulwp = find_lwp(tid);
160 if (ulwp->ul_detached == 0) {
161 ulwp->ul_detached = 1;
162 ulwp->ul_usropts |= THR_DETACHED;
163 (void) __lwp_detach(tid);
164 }
165 ulwp->ul_cancel_pending = 2; /* cancelled on creation */
166 ulwp->ul_cancel_disabled = 0;
167 ulwp_unlock(ulwp, self->ul_uberdata);
168 } else if (thread) {
169 *thread = tid;
170 }
171 (void) thr_continue(tid);
172 }
173
174 /* posix version expects EAGAIN for lack of memory */
175 if (error == ENOMEM)
176 error = EAGAIN;
177 return (error);
178 }
179
180 /*
181 * pthread_once: calls given function only once.
182 * it synchronizes via mutex in pthread_once_t structure
183 */
184 int
185 pthread_once(pthread_once_t *once_control, void (*init_routine)(void))
186 {
187 __once_t *once = (__once_t *)once_control;
188
189 if (once == NULL || init_routine == NULL)
190 return (EINVAL);
191
192 if (once->once_flag == PTHREAD_ONCE_NOTDONE) {
193 (void) mutex_lock(&once->mlock);
194 if (once->once_flag == PTHREAD_ONCE_NOTDONE) {
195 pthread_cleanup_push(mutex_unlock, &once->mlock);
196 (*init_routine)();
197 pthread_cleanup_pop(0);
198 membar_producer();
199 once->once_flag = PTHREAD_ONCE_DONE;
200 }
201 (void) mutex_unlock(&once->mlock);
202 }
203 membar_consumer();
204
205 return (0);
206 }
207
208 /*
209 * pthread_equal: equates two thread ids.
210 */
211 int
212 pthread_equal(pthread_t t1, pthread_t t2)
213 {
214 return (t1 == t2);
215 }
216
217 /*
218 * pthread_getschedparam: get the thread's sched parameters.
219 */
220 #pragma weak _pthread_getschedparam = pthread_getschedparam
221 int
222 pthread_getschedparam(pthread_t tid, int *policy, struct sched_param *param)
223 {
224 ulwp_t *ulwp;
225 id_t cid;
226 int error = 0;
227
228 if ((ulwp = find_lwp(tid)) == NULL) {
229 error = ESRCH;
230 } else {
231 cid = getparam(P_LWPID, ulwp->ul_lwpid, policy, param);
232 if (cid == -1) {
233 error = errno;
234 } else if (*policy == ulwp->ul_policy && cid == ulwp->ul_cid &&
235 (*policy == SCHED_FIFO || *policy == SCHED_RR)) {
236 /*
237 * Return the defined priority, not the effective
238 * priority from priority ceiling mutexes.
239 */
240 param->sched_priority = ulwp->ul_pri;
241 } else {
242 if (*policy == SCHED_FIFO || *policy == SCHED_RR)
243 ulwp->ul_rtclassid = cid;
244 ulwp->ul_cid = cid;
245 ulwp->ul_pri = param->sched_priority;
246 membar_producer();
247 ulwp->ul_policy = *policy;
248 }
249 ulwp_unlock(ulwp, curthread->ul_uberdata);
250 }
251
252 return (error);
253 }
254
255 #pragma weak _thr_getprio = thr_getprio
256 int
257 thr_getprio(thread_t tid, int *priority)
258 {
259 struct sched_param param;
260 int policy;
261 int error;
262
263 if ((error = pthread_getschedparam(tid, &policy, ¶m)) == 0)
264 *priority = param.sched_priority;
265 return (error);
266 }
267
268 /*
269 * pthread_setschedparam: sets the sched parameters for a thread.
270 */
271 int
272 pthread_setschedparam(pthread_t tid,
273 int policy, const struct sched_param *param)
274 {
275 return (_thr_setparam(tid, policy, param->sched_priority));
276 }
277
278 #pragma weak pthread_setschedprio = thr_setprio
279 int
280 thr_setprio(thread_t tid, int prio)
281 {
282 struct sched_param param;
283 int policy;
284 int error;
285
286 /*
287 * pthread_getschedparam() has the side-effect of setting
288 * the target thread's ul_policy, ul_pri and ul_cid correctly.
289 */
290 if ((error = pthread_getschedparam(tid, &policy, ¶m)) != 0)
291 return (error);
292 if (param.sched_priority == prio) /* no change */
293 return (0);
294 return (_thr_setparam(tid, policy, prio));
295 }