sysdeps/arm/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/ARM version.
   2    Copyright (C) 2005-2022 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, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _ARM_NPTL_TLS_H
  20 #define _ARM_NPTL_TLS_H 1
  21
  22 #include <dl-sysdep.h>
  23
  24 #ifndef __ASSEMBLER__
  25 # include <stdbool.h>
  26 # include <stddef.h>
  27 # include <stdint.h>
  28 # include <dl-dtv.h>
  29 #endif /* __ASSEMBLER__ */
  30
  31
  32 #ifndef __ASSEMBLER__
  33
  34 /* The TP points to the start of the thread blocks.  */
  35 # define TLS_DTV_AT_TP  1
  36 # define TLS_TCB_AT_TP  0
  37
  38 /* Get the thread descriptor definition.  */
  39 # include <nptl/descr.h>
  40
  41 typedef struct
  42 {
  43   dtv_t *dtv;
  44   void *private;
  45 } tcbhead_t;
  46
  47 /* This is the size of the initial TCB.  */
  48 # define TLS_INIT_TCB_SIZE      sizeof (tcbhead_t)
  49
  50 /* This is the size of the TCB.  */
  51 # define TLS_TCB_SIZE           sizeof (tcbhead_t)
  52
  53 /* This is the size we need before TCB.  */
  54 # define TLS_PRE_TCB_SIZE       sizeof (struct pthread)
  55
  56 /* Install the dtv pointer.  The pointer passed is to the element with
  57    index -1 which contain the length.  */
  58 # define INSTALL_DTV(tcbp, dtvp) \
  59   (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
  60
  61 /* Install new dtv for current thread.  */
  62 # define INSTALL_NEW_DTV(dtv) \
  63   (THREAD_DTV() = (dtv))
  64
  65 /* Return dtv of given thread descriptor.  */
  66 # define GET_DTV(tcbp) \
  67   (((tcbhead_t *) (tcbp))->dtv)
  68
  69 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1
  70
  71 /* Return the address of the dtv for the current thread.  */
  72 # define THREAD_DTV() \
  73   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
  74
  75 /* Return the thread descriptor for the current thread.  */
  76 # define THREAD_SELF \
  77  ((struct pthread *)__builtin_thread_pointer () - 1)
  78
  79 /* Magic for libthread_db to know how to do THREAD_SELF.  */
  80 # define DB_THREAD_SELF \
  81   CONST_THREAD_AREA (32, sizeof (struct pthread))
  82
  83 # include <tcb-access.h>
  84
  85 /* Get and set the global scope generation counter in struct pthread.  */
  86 #define THREAD_GSCOPE_FLAG_UNUSED 0
  87 #define THREAD_GSCOPE_FLAG_USED   1
  88 #define THREAD_GSCOPE_FLAG_WAIT   2
  89 #define THREAD_GSCOPE_RESET_FLAG() \
  90   do                                                                         \
  91     { int __res                                                              \
  92         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
  93                                THREAD_GSCOPE_FLAG_UNUSED);                   \
  94       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
  95         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
  96     }                                                                        \
  97   while (0)
  98 #define THREAD_GSCOPE_SET_FLAG() \
  99   do                                                                         \
 100     {                                                                        \
 101       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 102       atomic_write_barrier ();                                               \
 103     }                                                                        \
 104   while (0)
 105
 106 #endif /* __ASSEMBLER__ */
 107
 108 #endif  /* tls.h */