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 #pragma ident "%Z%%M% %I% %E% SMI" 28 29 #include "lint.h" 30 #include "thr_uberdata.h" 31 32 /* 33 * pthread_once related data 34 * This structure is exported as pthread_once_t in pthread.h. 35 * We export only the size of this structure. so check 36 * pthread_once_t in pthread.h before making a change here. 37 */ 38 typedef struct __once { 39 mutex_t mlock; 40 union { 41 uint32_t pad32_flag[2]; 42 uint64_t pad64_flag; 43 } oflag; 44 } __once_t; 45 46 #define once_flag oflag.pad32_flag[1] 47 48 static int 49 _thr_setparam(pthread_t tid, int policy, int prio) 50 { 51 ulwp_t *ulwp; 52 id_t cid; 53 int error = 0; 54 55 if ((ulwp = find_lwp(tid)) == NULL) { 56 error = ESRCH; 57 } else { 58 if (policy == ulwp->ul_policy && 59 (policy == SCHED_FIFO || policy == SCHED_RR) && 60 ulwp->ul_epri != 0) { 61 /* 62 * Don't change the ceiling priority, 63 * just the base priority. 64 */ 65 if (prio > ulwp->ul_epri) 66 error = EPERM; 67 else 68 ulwp->ul_pri = prio; 69 } else if ((cid = setparam(P_LWPID, tid, policy, prio)) == -1) { 70 error = errno; 71 } else { 72 if (policy == SCHED_FIFO || policy == SCHED_RR) 73 ulwp->ul_rtclassid = cid; 74 ulwp->ul_cid = cid; 75 ulwp->ul_pri = prio; 76 _membar_producer(); 77 ulwp->ul_policy = policy; 78 } 79 ulwp_unlock(ulwp, curthread->ul_uberdata); 80 } 81 return (error); 82 } 83 84 /* 85 * pthread_create: creates a thread in the current process. 86 * calls common _thrp_create() after copying the attributes. 87 */ 88 #pragma weak pthread_create = _pthread_create 89 int 90 _pthread_create(pthread_t *thread, const pthread_attr_t *attr, 91 void * (*start_routine)(void *), void *arg) 92 { 93 ulwp_t *self = curthread; 94 const thrattr_t *ap = attr? attr->__pthread_attrp : def_thrattr(); 95 const pcclass_t *pccp; 96 long flag; 97 pthread_t tid; 98 int error; 99 100 update_sched(self); 101 102 if (ap == NULL) 103 return (EINVAL); 104 105 /* validate explicit scheduling attributes */ 106 if (ap->inherit == PTHREAD_EXPLICIT_SCHED && 107 (ap->policy == SCHED_SYS || 108 (pccp = get_info_by_policy(ap->policy)) == NULL || 109 ap->prio < pccp->pcc_primin || ap->prio > pccp->pcc_primax)) 110 return (EINVAL); 111 112 flag = ap->scope | ap->detachstate | ap->daemonstate | THR_SUSPENDED; 113 error = _thrp_create(ap->stkaddr, ap->stksize, start_routine, arg, 114 flag, &tid, ap->guardsize); 115 if (error == 0) { 116 if (ap->inherit == PTHREAD_EXPLICIT_SCHED && 117 (ap->policy != self->ul_policy || 118 ap->prio != (self->ul_epri? self->ul_epri : self->ul_pri))) 119 /* 120 * The SUSv3 specification requires pthread_create() 121 * to fail with EPERM if it cannot set the scheduling 122 * policy and parameters on the new thread. 123 */ 124 error = _thr_setparam(tid, ap->policy, ap->prio); 125 if (error) { 126 /* 127 * We couldn't determine this error before 128 * actually creating the thread. To recover, 129 * mark the thread detached and cancel it. 130 * It is as though it was never created. 131 */ 132 ulwp_t *ulwp = find_lwp(tid); 133 if (ulwp->ul_detached == 0) { 134 ulwp->ul_detached = 1; 135 ulwp->ul_usropts |= THR_DETACHED; 136 (void) __lwp_detach(tid); 137 } 138 ulwp->ul_cancel_pending = 2; /* cancelled on creation */ 139 ulwp->ul_cancel_disabled = 0; 140 ulwp_unlock(ulwp, self->ul_uberdata); 141 } else if (thread) { 142 *thread = tid; 143 } 144 (void) _thr_continue(tid); 145 } 146 147 /* posix version expects EAGAIN for lack of memory */ 148 if (error == ENOMEM) 149 error = EAGAIN; 150 return (error); 151 } 152 153 /* 154 * pthread_once: calls given function only once. 155 * it synchronizes via mutex in pthread_once_t structure 156 */ 157 #pragma weak pthread_once = _pthread_once 158 int 159 _pthread_once(pthread_once_t *once_control, void (*init_routine)(void)) 160 { 161 __once_t *once = (__once_t *)once_control; 162 163 if (once == NULL || init_routine == NULL) 164 return (EINVAL); 165 166 if (once->once_flag == PTHREAD_ONCE_NOTDONE) { 167 (void) _private_mutex_lock(&once->mlock); 168 if (once->once_flag == PTHREAD_ONCE_NOTDONE) { 169 pthread_cleanup_push(_private_mutex_unlock, 170 &once->mlock); 171 (*init_routine)(); 172 pthread_cleanup_pop(0); 173 _membar_producer(); 174 once->once_flag = PTHREAD_ONCE_DONE; 175 } 176 (void) _private_mutex_unlock(&once->mlock); 177 } 178 _membar_consumer(); 179 180 return (0); 181 } 182 183 /* 184 * pthread_equal: equates two thread ids. 185 */ 186 #pragma weak pthread_equal = _pthread_equal 187 int 188 _pthread_equal(pthread_t t1, pthread_t t2) 189 { 190 return (t1 == t2); 191 } 192 193 /* 194 * pthread_getschedparam: get the thread's sched parameters. 195 */ 196 #pragma weak pthread_getschedparam = _pthread_getschedparam 197 int 198 _pthread_getschedparam(pthread_t tid, int *policy, struct sched_param *param) 199 { 200 ulwp_t *ulwp; 201 id_t cid; 202 int error = 0; 203 204 if ((ulwp = find_lwp(tid)) == NULL) { 205 error = ESRCH; 206 } else { 207 cid = getparam(P_LWPID, ulwp->ul_lwpid, policy, param); 208 if (cid == -1) { 209 error = errno; 210 } else if (*policy == ulwp->ul_policy && cid == ulwp->ul_cid && 211 (*policy == SCHED_FIFO || *policy == SCHED_RR)) { 212 /* 213 * Return the defined priority, not the effective 214 * priority from priority ceiling mutexes. 215 */ 216 param->sched_priority = ulwp->ul_pri; 217 } else { 218 if (*policy == SCHED_FIFO || *policy == SCHED_RR) 219 ulwp->ul_rtclassid = cid; 220 ulwp->ul_cid = cid; 221 ulwp->ul_pri = param->sched_priority; 222 _membar_producer(); 223 ulwp->ul_policy = *policy; 224 } 225 ulwp_unlock(ulwp, curthread->ul_uberdata); 226 } 227 228 return (error); 229 } 230 231 #pragma weak thr_getprio = _thr_getprio 232 int 233 _thr_getprio(thread_t tid, int *priority) 234 { 235 struct sched_param param; 236 int policy; 237 int error; 238 239 if ((error = _pthread_getschedparam(tid, &policy, ¶m)) == 0) 240 *priority = param.sched_priority; 241 return (error); 242 } 243 244 /* 245 * pthread_setschedparam: sets the sched parameters for a thread. 246 */ 247 #pragma weak pthread_setschedparam = _pthread_setschedparam 248 int 249 _pthread_setschedparam(pthread_t tid, 250 int policy, const struct sched_param *param) 251 { 252 return (_thr_setparam(tid, policy, param->sched_priority)); 253 } 254 255 #pragma weak thr_setprio = _thr_setprio 256 #pragma weak pthread_setschedprio = _thr_setprio 257 #pragma weak _pthread_setschedprio = _thr_setprio 258 int 259 _thr_setprio(thread_t tid, int prio) 260 { 261 struct sched_param param; 262 int policy; 263 int error; 264 265 /* 266 * _pthread_getschedparam() has the side-effect of setting 267 * the target thread's ul_policy, ul_pri and ul_cid correctly. 268 */ 269 if ((error = _pthread_getschedparam(tid, &policy, ¶m)) != 0) 270 return (error); 271 if (param.sched_priority == prio) /* no change */ 272 return (0); 273 return (_thr_setparam(tid, policy, prio)); 274 } 275