linuxthreads/attr.c

   1 /* Linuxthreads - a simple clone()-based implementation of Posix        */
   2 /* threads for Linux.                                                   */
   3 /* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr)              */
   4 /*                                                                      */
   5 /* This program is free software; you can redistribute it and/or        */
   6 /* modify it under the terms of the GNU Library General Public License  */
   7 /* as published by the Free Software Foundation; either version 2       */
   8 /* of the License, or (at your option) any later version.               */
   9 /*                                                                      */
  10 /* This program is distributed in the hope that it will be useful,      */
  11 /* but WITHOUT ANY WARRANTY; without even the implied warranty of       */
  12 /* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        */
  13 /* GNU Library General Public License for more details.                 */
  14
  15 /* Handling of thread attributes */
  16
  17 #include <errno.h>
  18 #include <string.h>
  19 #include <unistd.h>
  20 #include <sys/param.h>
  21 #include <sys/resource.h>
  22 #include "pthread.h"
  23 #include "internals.h"
  24 #include <shlib-compat.h>
  25 #include <stackinfo.h>
  26
  27 int __pthread_attr_init_2_1(pthread_attr_t *attr)
  28 {
  29   size_t ps = __getpagesize ();
  30
  31   attr->__detachstate = PTHREAD_CREATE_JOINABLE;
  32   attr->__schedpolicy = SCHED_OTHER;
  33   attr->__schedparam.sched_priority = 0;
  34   attr->__inheritsched = PTHREAD_EXPLICIT_SCHED;
  35   attr->__scope = PTHREAD_SCOPE_SYSTEM;
  36   attr->__guardsize = ps;
  37   attr->__stackaddr = NULL;
  38   attr->__stackaddr_set = 0;
  39   attr->__stacksize = STACK_SIZE - ps;
  40   return 0;
  41 }
  42
  43 versioned_symbol (libpthread, __pthread_attr_init_2_1, pthread_attr_init,
  44                   GLIBC_2_1);
  45
  46 #if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1)
  47 int __pthread_attr_init_2_0(pthread_attr_t *attr)
  48 {
  49   attr->__detachstate = PTHREAD_CREATE_JOINABLE;
  50   attr->__schedpolicy = SCHED_OTHER;
  51   attr->__schedparam.sched_priority = 0;
  52   attr->__inheritsched = PTHREAD_EXPLICIT_SCHED;
  53   attr->__scope = PTHREAD_SCOPE_SYSTEM;
  54   return 0;
  55 }
  56 compat_symbol (libpthread, __pthread_attr_init_2_0, pthread_attr_init,
  57                GLIBC_2_0);
  58 #endif
  59
  60 int pthread_attr_destroy(pthread_attr_t *attr)
  61 {
  62   return 0;
  63 }
  64
  65 int pthread_attr_setdetachstate(pthread_attr_t *attr, int detachstate)
  66 {
  67   if (detachstate < PTHREAD_CREATE_JOINABLE ||
  68       detachstate > PTHREAD_CREATE_DETACHED)
  69     return EINVAL;
  70   attr->__detachstate = detachstate;
  71   return 0;
  72 }
  73
  74 int pthread_attr_getdetachstate(const pthread_attr_t *attr, int *detachstate)
  75 {
  76   *detachstate = attr->__detachstate;
  77   return 0;
  78 }
  79
  80 int pthread_attr_setschedparam(pthread_attr_t *attr,
  81                                const struct sched_param *param)
  82 {
  83   int max_prio = __sched_get_priority_max(attr->__schedpolicy);
  84   int min_prio = __sched_get_priority_min(attr->__schedpolicy);
  85
  86   if (param->sched_priority < min_prio || param->sched_priority > max_prio)
  87     return EINVAL;
  88   memcpy (&attr->__schedparam, param, sizeof (struct sched_param));
  89   return 0;
  90 }
  91
  92 int pthread_attr_getschedparam(const pthread_attr_t *attr,
  93                                struct sched_param *param)
  94 {
  95   memcpy (param, &attr->__schedparam, sizeof (struct sched_param));
  96   return 0;
  97 }
  98
  99 int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy)
 100 {
 101   if (policy != SCHED_OTHER && policy != SCHED_FIFO && policy != SCHED_RR)
 102     return EINVAL;
 103   attr->__schedpolicy = policy;
 104   return 0;
 105 }
 106
 107 int pthread_attr_getschedpolicy(const pthread_attr_t *attr, int *policy)
 108 {
 109   *policy = attr->__schedpolicy;
 110   return 0;
 111 }
 112
 113 int pthread_attr_setinheritsched(pthread_attr_t *attr, int inherit)
 114 {
 115   if (inherit != PTHREAD_INHERIT_SCHED && inherit != PTHREAD_EXPLICIT_SCHED)
 116     return EINVAL;
 117   attr->__inheritsched = inherit;
 118   return 0;
 119 }
 120
 121 int pthread_attr_getinheritsched(const pthread_attr_t *attr, int *inherit)
 122 {
 123   *inherit = attr->__inheritsched;
 124   return 0;
 125 }
 126
 127 int pthread_attr_setscope(pthread_attr_t *attr, int scope)
 128 {
 129   switch (scope) {
 130   case PTHREAD_SCOPE_SYSTEM:
 131     attr->__scope = scope;
 132     return 0;
 133   case PTHREAD_SCOPE_PROCESS:
 134     return ENOTSUP;
 135   default:
 136     return EINVAL;
 137   }
 138 }
 139
 140 int pthread_attr_getscope(const pthread_attr_t *attr, int *scope)
 141 {
 142   *scope = attr->__scope;
 143   return 0;
 144 }
 145
 146 int __pthread_attr_setguardsize(pthread_attr_t *attr, size_t guardsize)
 147 {
 148   /* The guard size must not be larger than the stack itself */
 149   if (guardsize >= attr->__stacksize) return EINVAL;
 150
 151   attr->__guardsize = guardsize;
 152
 153   return 0;
 154 }
 155 weak_alias (__pthread_attr_setguardsize, pthread_attr_setguardsize)
 156
 157 int __pthread_attr_getguardsize(const pthread_attr_t *attr, size_t *guardsize)
 158 {
 159   *guardsize = attr->__guardsize;
 160   return 0;
 161 }
 162 weak_alias (__pthread_attr_getguardsize, pthread_attr_getguardsize)
 163
 164 int __pthread_attr_setstackaddr(pthread_attr_t *attr, void *stackaddr)
 165 {
 166   attr->__stackaddr = stackaddr;
 167   attr->__stackaddr_set = 1;
 168   return 0;
 169 }
 170 weak_alias (__pthread_attr_setstackaddr, pthread_attr_setstackaddr)
 171
 172 link_warning (pthread_attr_setstackaddr,
 173               "the use of `pthread_attr_setstackaddr' is deprecated, use `pthread_attr_setstack'")
 174
 175 int __pthread_attr_getstackaddr(const pthread_attr_t *attr, void **stackaddr)
 176 {
 177   /* XXX This function has a stupid definition.  The standard specifies
 178      no error value but what is if no stack address was set?  We simply
 179      return the value we have in the member.  */
 180   *stackaddr = attr->__stackaddr;
 181   return 0;
 182 }
 183 weak_alias (__pthread_attr_getstackaddr, pthread_attr_getstackaddr)
 184
 185 link_warning (pthread_attr_getstackaddr,
 186               "the use of `pthread_attr_getstackaddr' is deprecated, use `pthread_attr_getstack'")
 187
 188
 189 int __pthread_attr_setstacksize(pthread_attr_t *attr, size_t stacksize)
 190 {
 191 #ifdef FLOATING_STACKS
 192   /* We have to check against the maximum allowed stack size.  This is no
 193      problem if the manager is already started and we determined it.  If
 194      this hasn't happened, we have to find the limit outself.  */
 195   if (__pthread_max_stacksize == 0)
 196     __pthread_init_max_stacksize ();
 197
 198   if (stacksize > __pthread_max_stacksize)
 199     return EINVAL;
 200 #else
 201   /* We have a fixed size limit.  */
 202   if (stacksize > STACK_SIZE)
 203     return EINVAL;
 204 #endif
 205
 206   /* We don't accept value smaller than PTHREAD_STACK_MIN.  */
 207   if (stacksize < PTHREAD_STACK_MIN)
 208     return EINVAL;
 209
 210   attr->__stacksize = stacksize;
 211   return 0;
 212 }
 213 weak_alias (__pthread_attr_setstacksize, pthread_attr_setstacksize)
 214
 215 int __pthread_attr_getstacksize(const pthread_attr_t *attr, size_t *stacksize)
 216 {
 217   *stacksize = attr->__stacksize;
 218   return 0;
 219 }
 220 weak_alias (__pthread_attr_getstacksize, pthread_attr_getstacksize)
 221
 222 int __pthread_attr_setstack (pthread_attr_t *attr, void *stackaddr,
 223                              size_t stacksize)
 224 {
 225   int err;
 226
 227   if ((((uintptr_t) stackaddr)
 228        & (__alignof__ (struct _pthread_descr_struct) - 1)) != 0)
 229     err = EINVAL;
 230   else
 231     err = __pthread_attr_setstacksize (attr, stacksize);
 232   if (err == 0)
 233     {
 234 #ifndef _STACK_GROWS_UP
 235       attr->__stackaddr = (char *) stackaddr + stacksize;
 236 #else
 237       attr->__stackaddr = stackaddr;
 238 #endif
 239       attr->__stackaddr_set = 1;
 240     }
 241
 242   return err;
 243 }
 244 weak_alias (__pthread_attr_setstack, pthread_attr_setstack)
 245
 246 int __pthread_attr_getstack (const pthread_attr_t *attr, void **stackaddr,
 247                              size_t *stacksize)
 248 {
 249   /* XXX This function has a stupid definition.  The standard specifies
 250      no error value but what is if no stack address was set?  We simply
 251      return the value we have in the member.  */
 252 #ifndef _STACK_GROWS_UP
 253   *stackaddr = (char *) attr->__stackaddr - attr->__stacksize;
 254 #else
 255   *stackaddr = attr->__stackaddr;
 256 #endif
 257   *stacksize = attr->__stacksize;
 258   return 0;
 259 }
 260 weak_alias (__pthread_attr_getstack, pthread_attr_getstack)
 261
 262 int pthread_getattr_np (pthread_t thread, pthread_attr_t *attr)
 263 {
 264   pthread_handle handle = thread_handle (thread);
 265   pthread_descr descr;
 266
 267   if (handle == NULL)
 268     return ENOENT;
 269
 270   descr = handle->h_descr;
 271
 272   attr->__detachstate = (descr->p_detached
 273                          ? PTHREAD_CREATE_DETACHED
 274                          : PTHREAD_CREATE_JOINABLE);
 275
 276   attr->__schedpolicy = __sched_getscheduler (descr->p_pid);
 277   if (attr->__schedpolicy == -1)
 278     return errno;
 279
 280   if (__sched_getparam (descr->p_pid,
 281                         (struct sched_param *) &attr->__schedparam) != 0)
 282     return errno;
 283
 284   attr->__inheritsched = descr->p_inheritsched;
 285   attr->__scope = PTHREAD_SCOPE_SYSTEM;
 286   attr->__stacksize = (char *)(descr + 1) - (char *)descr->p_guardaddr
 287                       - descr->p_guardsize;
 288   attr->__guardsize = descr->p_guardsize;
 289   attr->__stackaddr_set = descr->p_userstack;
 290 #ifdef NEED_SEPARATE_REGISTER_STACK
 291   if (descr->p_userstack == 0)
 292     attr->__stacksize *= 2;
 293   /* XXX This is awkward.  The guard pages are in the middle of the
 294      two stacks.  We must count the guard size in the stack size since
 295      otherwise the range of the stack area cannot be computed.  */
 296   attr->__stacksize += attr->__guardsize;
 297 #endif
 298 #ifndef _STACK_GROWS_UP
 299   attr->__stackaddr = (char *)(descr + 1);
 300 #else
 301 # error __stackaddr not handled
 302 #endif
 303
 304   return 0;
 305 }