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     {
 197       struct rlimit limit;
 198
 199       getrlimit(RLIMIT_STACK, &limit);
 200 # ifdef NEED_SEPARATE_REGISTER_STACK
 201       __pthread_max_stacksize = limit.rlim_max / 2;
 202 # else
 203       __pthread_max_stacksize = limit.rlim_max;
 204 # endif
 205     }
 206
 207   if (stacksize > __pthread_max_stacksize)
 208     return EINVAL;
 209 #else
 210   /* We have a fixed size limit.  */
 211   if (stacksize > STACK_SIZE)
 212     return EINVAL;
 213 #endif
 214
 215   /* We don't accept value smaller than PTHREAD_STACK_MIN.  */
 216   if (stacksize < PTHREAD_STACK_MIN)
 217     return EINVAL;
 218
 219   attr->__stacksize = stacksize;
 220   return 0;
 221 }
 222 weak_alias (__pthread_attr_setstacksize, pthread_attr_setstacksize)
 223
 224 int __pthread_attr_getstacksize(const pthread_attr_t *attr, size_t *stacksize)
 225 {
 226   *stacksize = attr->__stacksize;
 227   return 0;
 228 }
 229 weak_alias (__pthread_attr_getstacksize, pthread_attr_getstacksize)
 230
 231 int __pthread_attr_setstack (pthread_attr_t *attr, void *stackaddr,
 232                              size_t stacksize)
 233 {
 234   int err;
 235
 236   if ((((uintptr_t) stackaddr)
 237        & ~__alignof__ (struct _pthread_descr_struct)) != 0)
 238     err = EINVAL;
 239   else
 240     err = __pthread_attr_setstacksize (attr, stacksize);
 241   if (err == 0)
 242     {
 243 #ifndef _STACK_GROWS_UP
 244       attr->__stackaddr = (char *) stackaddr + stacksize;
 245 #else
 246       attr->__stackaddr = stackaddr;
 247 #endif
 248       attr->__stackaddr_set = 1;
 249     }
 250
 251   return err;
 252 }
 253 weak_alias (__pthread_attr_setstack, pthread_attr_setstack)
 254
 255 int __pthread_attr_getstack (const pthread_attr_t *attr, void **stackaddr,
 256                              size_t *stacksize)
 257 {
 258   /* XXX This function has a stupid definition.  The standard specifies
 259      no error value but what is if no stack address was set?  We simply
 260      return the value we have in the member.  */
 261 #ifndef _STACK_GROWS_UP
 262   *stackaddr = (char *) attr->__stackaddr - attr->__stacksize;
 263 #else
 264   *stackaddr = attr->__stackaddr;
 265 #endif
 266   *stacksize = attr->__stacksize;
 267   return 0;
 268 }
 269 weak_alias (__pthread_attr_getstack, pthread_attr_getstack)