sysdeps/mach/hurd/tls.h

   1 /* Definitions for thread-local data handling.  Hurd version.
   2    Copyright (C) 2003, 2005, 2007 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _TLS_H
  21 #define _TLS_H
  22
  23 #if defined HAVE_TLS_SUPPORT && !defined __ASSEMBLER__
  24
  25 # include <stddef.h>
  26 # include <stdbool.h>
  27 # include <mach/mig_errors.h>
  28 # include <mach.h>
  29
  30
  31 /* Type for the dtv.  */
  32 typedef union dtv
  33 {
  34   size_t counter;
  35   struct
  36   {
  37     void *val;
  38     bool is_static;
  39   } pointer;
  40 } dtv_t;
  41
  42
  43 /* Type of the TCB.  */
  44 typedef struct
  45 {
  46   void *tcb;                    /* Points to this structure.  */
  47   dtv_t *dtv;                   /* Vector of pointers to TLS data.  */
  48   thread_t self;                /* This thread's control port.  */
  49 } tcbhead_t;
  50
  51
  52 /* This is the size of the initial TCB.  */
  53 # define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
  54
  55 /* Alignment requirements for the initial TCB.  */
  56 # define TLS_INIT_TCB_ALIGN __alignof__ (tcbhead_t)
  57
  58 /* This is the size of the TCB.  */
  59 # define TLS_TCB_SIZE TLS_INIT_TCB_SIZE /* XXX */
  60
  61 /* Alignment requirements for the TCB.  */
  62 # define TLS_TCB_ALIGN TLS_INIT_TCB_ALIGN /* XXX */
  63
  64
  65 /* Install the dtv pointer.  The pointer passed is to the element with
  66    index -1 which contain the length.  */
  67 # define INSTALL_DTV(descr, dtvp) \
  68   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
  69
  70 /* Return dtv of given thread descriptor.  */
  71 # define GET_DTV(descr) \
  72   (((tcbhead_t *) (descr))->dtv)
  73
  74 #endif /* HAVE_TLS_SUPPORT */
  75
  76
  77 #endif /* tls.h */