linuxthreads/sysdeps/sparc/tls.h

   1 /* Definitions for thread-local data handling.  linuxthreads/sparc version.
   2    Copyright (C) 2002, 2003, 2005 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 <stdbool.h>
  27 # include <stddef.h>
  28
  29 /* Type for the dtv.  */
  30 typedef union dtv
  31 {
  32   size_t counter;
  33   struct
  34   {
  35     void *val;
  36     bool is_static;
  37   } pointer;
  38 } dtv_t;
  39
  40 typedef struct
  41 {
  42   void *tcb;            /* Pointer to the TCB.  Not necessary the
  43                            thread descriptor used by libpthread.  */
  44   dtv_t *dtv;
  45   void *self;           /* Pointer to the thread descriptor.  */
  46   int multiple_threads;
  47 } tcbhead_t;
  48
  49 #else /* __ASSEMBLER__ */
  50 # include <tcb-offsets.h>
  51 #endif /* __ASSEMBLER__ */
  52
  53 #ifdef HAVE_TLS_SUPPORT
  54
  55 /* Signal that TLS support is available.  */
  56 # define USE_TLS        1
  57
  58 # ifndef __ASSEMBLER__
  59 /* Get system call information.  */
  60 #  include <sysdep.h>
  61
  62 /* Get the thread descriptor definition.  */
  63 #  include <linuxthreads/descr.h>
  64
  65 /* This is the size of the initial TCB.  */
  66 #  define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)
  67
  68 /* Alignment requirements for the initial TCB.  */
  69 #  define TLS_INIT_TCB_ALIGN __alignof__ (tcbhead_t)
  70
  71 /* This is the size of the TCB.  */
  72 #  ifndef IS_IN_rtld
  73 #   define TLS_TCB_SIZE sizeof (struct _pthread_descr_struct)
  74 #  else
  75 #   include <nptl-struct-pthread.h>
  76 #   define TLS_TCB_SIZE \
  77   (sizeof (struct _pthread_descr_struct) > NPTL_STRUCT_PTHREAD_SIZE     \
  78    ? sizeof (struct _pthread_descr_struct) : NPTL_STRUCT_PTHREAD_SIZE)
  79 #  endif
  80
  81 /* Alignment requirements for the TCB.  */
  82 #  define TLS_TCB_ALIGN __alignof__ (struct _pthread_descr_struct)
  83
  84 /* The TCB can have any size and the memory following the address the
  85    thread pointer points to is unspecified.  Allocate the TCB there.  */
  86 #  define TLS_TCB_AT_TP 1
  87
  88 /* Install the dtv pointer.  The pointer passed is to the element with
  89    index -1 which contain the length.  */
  90 #  define INSTALL_DTV(descr, dtvp) \
  91   ((tcbhead_t *) (descr))->dtv = (dtvp) + 1
  92
  93 /* Install new dtv for current thread.  */
  94 #  define INSTALL_NEW_DTV(DTV) \
  95   (((tcbhead_t *) __thread_self)->dtv = (DTV))
  96
  97 /* Return dtv of given thread descriptor.  */
  98 #  define GET_DTV(descr) \
  99   (((tcbhead_t *) (descr))->dtv)
 100
 101 /* Code to initially initialize the thread pointer.  */
 102 # define TLS_INIT_TP(descr, secondcall) \
 103   (__thread_self = (__typeof (__thread_self)) (descr), NULL)
 104
 105 /* Return the address of the dtv for the current thread.  */
 106 #  define THREAD_DTV() \
 107   (((tcbhead_t *) __thread_self)->dtv)
 108
 109 # endif
 110
 111 #else
 112
 113 # define NONTLS_INIT_TP \
 114   do {                                                                        \
 115     static const tcbhead_t nontls_init_tp                                     \
 116       = { .multiple_threads = 0 };                                            \
 117     __thread_self = (__typeof (__thread_self)) &nontls_init_tp;               \
 118   } while (0)
 119
 120 #endif /* USE_TLS */
 121
 122 #endif  /* tls.h */