glibc/linuxthreads/attr.c

/* Linuxthreads - a simple clone()-based implementation of Posix        */
/* threads for Linux.                                                   */
/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr)              */
/*                                                                      */
/* This program is free software; you can redistribute it and/or        */
/* modify it under the terms of the GNU Library General Public License  */
/* as published by the Free Software Foundation; either version 2       */
/* of the License, or (at your option) any later version.               */
/*                                                                      */
/* This program is distributed in the hope that it will be useful,      */
/* but WITHOUT ANY WARRANTY; without even the implied warranty of       */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        */
/* GNU Library General Public License for more details.                 */

/* Handling of thread attributes */

#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/resource.h>
#include "pthread.h"
#include "internals.h"
#include <shlib-compat.h>
#include <stackinfo.h>

int __pthread_attr_init_2_1(pthread_attr_t *attr)
{
  size_t ps = __getpagesize ();

  attr->__detachstate = PTHREAD_CREATE_JOINABLE;
  attr->__schedpolicy = SCHED_OTHER;
  attr->__schedparam.sched_priority = 0;
  attr->__inheritsched = PTHREAD_EXPLICIT_SCHED;
  attr->__scope = PTHREAD_SCOPE_SYSTEM;
  attr->__guardsize = ps;
  attr->__stackaddr = NULL;
  attr->__stackaddr_set = 0;
  attr->__stacksize = STACK_SIZE - ps;
  return 0;
}

versioned_symbol (libpthread, __pthread_attr_init_2_1, pthread_attr_init,
		  GLIBC_2_1);

#if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1)
int __pthread_attr_init_2_0(pthread_attr_t *attr)
{
  attr->__detachstate = PTHREAD_CREATE_JOINABLE;
  attr->__schedpolicy = SCHED_OTHER;
  attr->__schedparam.sched_priority = 0;
  attr->__inheritsched = PTHREAD_EXPLICIT_SCHED;
  attr->__scope = PTHREAD_SCOPE_SYSTEM;
  return 0;
}
compat_symbol (libpthread, __pthread_attr_init_2_0, pthread_attr_init,
	       GLIBC_2_0);
#endif

int pthread_attr_destroy(pthread_attr_t *attr)
{
  return 0;
}

int pthread_attr_setdetachstate(pthread_attr_t *attr, int detachstate)
{
  if (detachstate < PTHREAD_CREATE_JOINABLE ||
      detachstate > PTHREAD_CREATE_DETACHED)
    return EINVAL;
  attr->__detachstate = detachstate;
  return 0;
}

int pthread_attr_getdetachstate(const pthread_attr_t *attr, int *detachstate)
{
  *detachstate = attr->__detachstate;
  return 0;
}

int pthread_attr_setschedparam(pthread_attr_t *attr,
                               const struct sched_param *param)
{
  int max_prio = __sched_get_priority_max(attr->__schedpolicy);
  int min_prio = __sched_get_priority_min(attr->__schedpolicy);

  if (param->sched_priority < min_prio || param->sched_priority > max_prio)
    return EINVAL;
  memcpy (&attr->__schedparam, param, sizeof (struct sched_param));
  return 0;
}

int pthread_attr_getschedparam(const pthread_attr_t *attr,
                               struct sched_param *param)
{
  memcpy (param, &attr->__schedparam, sizeof (struct sched_param));
  return 0;
}

int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy)
{
  if (policy != SCHED_OTHER && policy != SCHED_FIFO && policy != SCHED_RR)
    return EINVAL;
  attr->__schedpolicy = policy;
  return 0;
}

int pthread_attr_getschedpolicy(const pthread_attr_t *attr, int *policy)
{
  *policy = attr->__schedpolicy;
  return 0;
}

int pthread_attr_setinheritsched(pthread_attr_t *attr, int inherit)
{
  if (inherit != PTHREAD_INHERIT_SCHED && inherit != PTHREAD_EXPLICIT_SCHED)
    return EINVAL;
  attr->__inheritsched = inherit;
  return 0;
}

int pthread_attr_getinheritsched(const pthread_attr_t *attr, int *inherit)
{
  *inherit = attr->__inheritsched;
  return 0;
}

int pthread_attr_setscope(pthread_attr_t *attr, int scope)
{
  switch (scope) {
  case PTHREAD_SCOPE_SYSTEM:
    attr->__scope = scope;
    return 0;
  case PTHREAD_SCOPE_PROCESS:
    return ENOTSUP;
  default:
    return EINVAL;
  }
}

int pthread_attr_getscope(const pthread_attr_t *attr, int *scope)
{
  *scope = attr->__scope;
  return 0;
}

int __pthread_attr_setguardsize(pthread_attr_t *attr, size_t guardsize)
{
  /* The guard size must not be larger than the stack itself */
  if (guardsize >= attr->__stacksize) return EINVAL;

  attr->__guardsize = guardsize;

  return 0;
}
weak_alias (__pthread_attr_setguardsize, pthread_attr_setguardsize)

int __pthread_attr_getguardsize(const pthread_attr_t *attr, size_t *guardsize)
{
  *guardsize = attr->__guardsize;
  return 0;
}
weak_alias (__pthread_attr_getguardsize, pthread_attr_getguardsize)

int __pthread_attr_setstackaddr(pthread_attr_t *attr, void *stackaddr)
{
  attr->__stackaddr = stackaddr;
  attr->__stackaddr_set = 1;
  return 0;
}
weak_alias (__pthread_attr_setstackaddr, pthread_attr_setstackaddr)

int __pthread_attr_getstackaddr(const pthread_attr_t *attr, void **stackaddr)
{
  /* XXX This function has a stupid definition.  The standard specifies
     no error value but what is if no stack address was set?  We simply
     return the value we have in the member.  */
  *stackaddr = attr->__stackaddr;
  return 0;
}
weak_alias (__pthread_attr_getstackaddr, pthread_attr_getstackaddr)

int __pthread_attr_setstacksize(pthread_attr_t *attr, size_t stacksize)
{
#ifdef FLOATING_STACKS
  /* We have to check against the maximum allowed stack size.  This is no
     problem if the manager is already started and we determined it.  If
     this hasn't happened, we have to find the limit outself.  */
  if (__pthread_max_stacksize == 0)
    {
      struct rlimit limit;

      getrlimit(RLIMIT_STACK, &limit);
# ifdef NEED_SEPARATE_REGISTER_STACK
      __pthread_max_stacksize = limit.rlim_max / 2;
# else
      __pthread_max_stacksize = limit.rlim_max;
# endif
    }

  if (stacksize > __pthread_max_stacksize)
    return EINVAL;
#else
  /* We have a fixed size limit.  */
  if (stacksize > STACK_SIZE)
    return EINVAL;
#endif

  /* We don't accept value smaller than PTHREAD_STACK_MIN.  */
  if (stacksize < PTHREAD_STACK_MIN)
    return EINVAL;

  attr->__stacksize = stacksize;
  return 0;
}
weak_alias (__pthread_attr_setstacksize, pthread_attr_setstacksize)

int __pthread_attr_getstacksize(const pthread_attr_t *attr, size_t *stacksize)
{
  *stacksize = attr->__stacksize;
  return 0;
}
weak_alias (__pthread_attr_getstacksize, pthread_attr_getstacksize)

int __pthread_attr_setstack (pthread_attr_t *attr, void *stackaddr,
			     size_t stacksize)
{
  int err;

  if ((((uintptr_t) stackaddr)
       & ~__alignof__ (struct _pthread_descr_struct)) != 0)
    err = EINVAL;
  else
    err = __pthread_attr_setstacksize (attr, stacksize);
  if (err == 0)
    {
#ifdef _STACK_GROWS_UP
      attr->__stackaddr = (char *) stackaddr + stacksize;
#else
      attr->__stackaddr = stackaddr;
#endif
      attr->__stackaddr_set = 1;
    }

  return err;
}
weak_alias (__pthread_attr_setstack, pthread_attr_setstack)

int __pthread_attr_getstack (const pthread_attr_t *attr, void **stackaddr,
			     size_t *stacksize)
{
  /* XXX This function has a stupid definition.  The standard specifies
     no error value but what is if no stack address was set?  We simply
     return the value we have in the member.  */
  *stackaddr = attr->__stackaddr;
  *stacksize = attr->__stacksize;
  return 0;
}
weak_alias (__pthread_attr_getstack, pthread_attr_getstack)