linuxthreads/sysdeps/sparc/tls.h

   1 /* Definitions for thread-local data handling.  linuxthreads/sparc version.
   2    Copyright (C) 2002, 2003 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 #ifndef __ASSEMBLER__
  24
  25 # include <pt-machine.h>
  26 # include <stddef.h>
  27
  28 /* Type for the dtv.  */
  29 typedef union dtv
  30 {
  31   size_t counter;
  32   void *pointer;
  33 } dtv_t;
  34
  35 typedef struct
  36 {
  37   void *tcb;            /* Pointer to the TCB.  Not necessary the
  38                            thread descriptor used by libpthread.  */
  39   dtv_t *dtv;
  40   void *self;           /* Pointer to the thread descriptor.  */
  41   int multiple_threads;
  42 } tcbhead_t;
  43
  44 #else /* __ASSEMBLER__ */
  45 # include <tcb-offsets.h>
  46 #endif /* __ASSEMBLER__ */
  47
  48 #ifdef HAVE_TLS_SUPPORT
  49
  50 /* Signal that TLS support is available.  */
  51 # define USE_TLS        1
  52
  53 # ifndef __ASSEMBLER__
  54 /* Get system call information.  */
  55 #  include <sysdep.h>
  56
  57 /* Get the thread descriptor definition.  */
  58 #  include <linuxthreads/descr.h>
  59
  60 /* This is the size of the initial TCB.  */
  61 #  define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
  62
  63 /* Alignment requirements for the initial TCB.  */
  64 #  define TLS_INIT_TCB_ALIGN __alignof__ (tcbhead_t)
  65
  66 /* This is the size of the TCB.  */
  67 #  ifndef IS_IN_rtld
  68 #   define TLS_TCB_SIZE sizeof (struct _pthread_descr_struct)
  69 #  else
  70 #   include <nptl-struct-pthread.h>
  71 #   define TLS_TCB_SIZE \
  72   (sizeof (struct _pthread_descr_struct) > NPTL_STRUCT_PTHREAD_SIZE     \
  73    ? sizeof (struct _pthread_descr_struct) : NPTL_STRUCT_PTHREAD_SIZE)
  74 #  endif
  75
  76 /* Alignment requirements for the TCB.  */
  77 #  define TLS_TCB_ALIGN __alignof__ (struct _pthread_descr_struct)
  78
  79 /* The TCB can have any size and the memory following the address the
  80    thread pointer points to is unspecified.  Allocate the TCB there.  */
  81 #  define TLS_TCB_AT_TP 1
  82
  83 /* Install the dtv pointer.  The pointer passed is to the element with
  84    index -1 which contain the length.  */
  85 #  define INSTALL_DTV(descr, dtvp) \
  86   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
  87
  88 /* Install new dtv for current thread.  */
  89 #  define INSTALL_NEW_DTV(DTV) \
  90   (((tcbhead_t *) __thread_self)->dtv = (DTV))
  91
  92 /* Return dtv of given thread descriptor.  */
  93 #  define GET_DTV(descr) \
  94   (((tcbhead_t *) (descr))->dtv)
  95
  96 /* Code to initially initialize the thread pointer.  */
  97 # define TLS_INIT_TP(descr, secondcall) \
  98   (__thread_self = (__typeof (__thread_self)) (descr), NULL)
  99
 100 /* Return the address of the dtv for the current thread.  */
 101 #  define THREAD_DTV() \
 102   (((tcbhead_t *) __thread_self)->dtv)
 103
 104 # endif
 105
 106 #else
 107
 108 # define NONTLS_INIT_TP \
 109   do {                                                                        \
 110     static const tcbhead_t nontls_init_tp                                     \
 111       = { .multiple_threads = 0 };                                            \
 112     __thread_self = (__typeof (__thread_self)) &nontls_init_tp;               \
 113   } while (0)
 114
 115 #endif /* USE_TLS */
 116
 117 #endif  /* tls.h */