tls.h

/* Definitions for thread-local data handling.  linuxthreads/sparc version.
   Copyright (C) 2002, 2003 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef _TLS_H
#define _TLS_H

#ifndef __ASSEMBLER__

# include <pt-machine.h>
# include <stddef.h>

/* Type for the dtv.  */
typedef union dtv
{
  size_t counter;
  void *pointer;
} dtv_t;

typedef struct
{
  void *tcb;		/* Pointer to the TCB.  Not necessary the
			   thread descriptor used by libpthread.  */
  dtv_t *dtv;
  void *self;		/* Pointer to the thread descriptor.  */
  int multiple_threads;
} tcbhead_t;

#else /* __ASSEMBLER__ */
# include <tcb-offsets.h>
#endif /* __ASSEMBLER__ */

#ifdef HAVE_TLS_SUPPORT

/* Signal that TLS support is available.  */
# define USE_TLS	1

# ifndef __ASSEMBLER__
/* Get system call information.  */
#  include <sysdep.h>

/* Get the thread descriptor definition.  */
#  include <linuxthreads/descr.h>

/* This is the size of the initial TCB.  */
#  define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)

/* Alignment requirements for the initial TCB.  */
#  define TLS_INIT_TCB_ALIGN __alignof__ (tcbhead_t)

/* This is the size of the TCB.  */
#  define TLS_TCB_SIZE sizeof (struct _pthread_descr_struct)

/* Alignment requirements for the TCB.  */
#  define TLS_TCB_ALIGN __alignof__ (struct _pthread_descr_struct)

/* The TCB can have any size and the memory following the address the
   thread pointer points to is unspecified.  Allocate the TCB there.  */
#  define TLS_TCB_AT_TP	1

/* Install the dtv pointer.  The pointer passed is to the element with
   index -1 which contain the length.  */
#  define INSTALL_DTV(descr, dtvp) \
  ((tcbhead_t *) (descr))->dtv = (dtvp) + 1

/* Install new dtv for current thread.  */
#  define INSTALL_NEW_DTV(DTV) \
  (((tcbhead_t *) __thread_self)->dtv = (DTV))

/* Return dtv of given thread descriptor.  */
#  define GET_DTV(descr) \
  (((tcbhead_t *) (descr))->dtv)

/* Code to initially initialize the thread pointer.  */
# define TLS_INIT_TP(descr, secondcall) \
  (__thread_self = (__typeof (__thread_self)) (descr), NULL)

/* Return the address of the dtv for the current thread.  */
#  define THREAD_DTV() \
  (((tcbhead_t *) __thread_self)->dtv)

# endif

#else

#define NONTLS_INIT_TP \
  do { 								\
    static const tcbhead_t nontls_init_tp			\
      = { .multiple_threads = 0 };				\
    __thread_self = (__typeof (__thread_self)) &nontls_init_tp;	\
  } while (0)

#endif /* USE_TLS */

#endif	/* tls.h */