sysdeps/alpha/nptl/tls.h

   1 /* Definition for thread-local data handling.  NPTL/Alpha version.
   2    Copyright (C) 2003-2021 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 _TLS_H
  20 #define _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
  30 /* Get system call information.  */
  31 # include <sysdep.h>
  32
  33 /* The TP points to the start of the thread blocks.  */
  34 # define TLS_DTV_AT_TP  1
  35 # define TLS_TCB_AT_TP  0
  36
  37 /* Get the thread descriptor definition.  */
  38 # include <nptl/descr.h>
  39
  40 typedef struct
  41 {
  42   dtv_t *dtv;
  43   void *__private;
  44 } tcbhead_t;
  45
  46 /* This is the size of the initial TCB.  */
  47 # define TLS_INIT_TCB_SIZE      sizeof (tcbhead_t)
  48
  49 /* Alignment requirements for the initial TCB.  */
  50 # define TLS_INIT_TCB_ALIGN     16
  51
  52 /* This is the size of the TCB.  */
  53 # define TLS_TCB_SIZE           sizeof (tcbhead_t)
  54
  55 /* This is the size we need before TCB.  */
  56 # define TLS_PRE_TCB_SIZE       sizeof (struct pthread)
  57
  58 /* Alignment requirements for the TCB.  */
  59 # define TLS_TCB_ALIGN          16
  60
  61 /* Install the dtv pointer.  The pointer passed is to the element with
  62    index -1 which contain the length.  */
  63 # define INSTALL_DTV(tcbp, dtvp) \
  64   (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
  65
  66 /* Install new dtv for current thread.  */
  67 # define INSTALL_NEW_DTV(dtv) \
  68   (THREAD_DTV() = (dtv))
  69
  70 /* Return dtv of given thread descriptor.  */
  71 # define GET_DTV(tcbp) \
  72   (((tcbhead_t *) (tcbp))->dtv)
  73
  74 /* Code to initially initialize the thread pointer.  This might need
  75    special attention since 'errno' is not yet available and if the
  76    operation can cause a failure 'errno' must not be touched.  */
  77 # define TLS_INIT_TP(tcbp) \
  78   (__builtin_set_thread_pointer ((void *)(tcbp)), NULL)
  79
  80 /* Value passed to 'clone' for initialization of the thread register.  */
  81 # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1
  82
  83 /* Return the address of the dtv for the current thread.  */
  84 # define THREAD_DTV() \
  85   (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
  86
  87 /* Return the thread descriptor for the current thread.  */
  88 # define THREAD_SELF \
  89  ((struct pthread *)__builtin_thread_pointer () - 1)
  90
  91 /* Magic for libthread_db to know how to do THREAD_SELF.  */
  92 # define DB_THREAD_SELF \
  93   REGISTER (64, 64, 32 * 8, -sizeof (struct pthread))
  94
  95 # include <tcb-access.h>
  96
  97 /* Get and set the global scope generation counter in struct pthread.  */
  98 #define THREAD_GSCOPE_FLAG_UNUSED 0
  99 #define THREAD_GSCOPE_FLAG_USED   1
 100 #define THREAD_GSCOPE_FLAG_WAIT   2
 101 #define THREAD_GSCOPE_RESET_FLAG() \
 102   do                                                                         \
 103     { int __res                                                              \
 104         = atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,             \
 105                                THREAD_GSCOPE_FLAG_UNUSED);                   \
 106       if (__res == THREAD_GSCOPE_FLAG_WAIT)                                  \
 107         lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
 108     }                                                                        \
 109   while (0)
 110 #define THREAD_GSCOPE_SET_FLAG() \
 111   do                                                                         \
 112     {                                                                        \
 113       THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;             \
 114       atomic_write_barrier ();                                               \
 115     }                                                                        \
 116   while (0)
 117
 118 #else /* __ASSEMBLER__ */
 119 # include <tcb-offsets.h>
 120 #endif /* __ASSEMBLER__ */
 121
 122 #endif  /* tls.h */