1  /* Definition for thread-local data handling.  NPTL/Alpha version.
       2     Copyright (C) 2003-2023 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  /* This is the size of the TCB.  */
      50  # define TLS_TCB_SIZE		sizeof (tcbhead_t)
      51  
      52  /* This is the size we need before TCB.  */
      53  # define TLS_PRE_TCB_SIZE	sizeof (struct pthread)
      54  
      55  /* Install the dtv pointer.  The pointer passed is to the element with
      56     index -1 which contain the length.  */
      57  # define INSTALL_DTV(tcbp, dtvp) \
      58    (((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1)
      59  
      60  /* Install new dtv for current thread.  */
      61  # define INSTALL_NEW_DTV(dtv) \
      62    (THREAD_DTV() = (dtv))
      63  
      64  /* Return dtv of given thread descriptor.  */
      65  # define GET_DTV(tcbp) \
      66    (((tcbhead_t *) (tcbp))->dtv)
      67  
      68  /* Code to initially initialize the thread pointer.  This might need
      69     special attention since 'errno' is not yet available and if the
      70     operation can cause a failure 'errno' must not be touched.  */
      71  # define TLS_INIT_TP(tcbp) \
      72    (__builtin_set_thread_pointer ((void *)(tcbp)), true)
      73  
      74  /* Value passed to 'clone' for initialization of the thread register.  */
      75  # define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1
      76  
      77  /* Return the address of the dtv for the current thread.  */
      78  # define THREAD_DTV() \
      79    (((tcbhead_t *) __builtin_thread_pointer ())->dtv)
      80  
      81  /* Return the thread descriptor for the current thread.  */
      82  # define THREAD_SELF \
      83   ((struct pthread *)__builtin_thread_pointer () - 1)
      84  
      85  /* Magic for libthread_db to know how to do THREAD_SELF.  */
      86  # define DB_THREAD_SELF \
      87    REGISTER (64, 64, 32 * 8, -sizeof (struct pthread))
      88  
      89  # include <tcb-access.h>
      90  
      91  /* Get and set the global scope generation counter in struct pthread.  */
      92  #define THREAD_GSCOPE_FLAG_UNUSED 0
      93  #define THREAD_GSCOPE_FLAG_USED   1
      94  #define THREAD_GSCOPE_FLAG_WAIT   2
      95  #define THREAD_GSCOPE_RESET_FLAG() \
      96    do									     \
      97      { int __res								     \
      98  	= atomic_exchange_release (&THREAD_SELF->header.gscope_flag,	     \
      99  			       THREAD_GSCOPE_FLAG_UNUSED);		     \
     100        if (__res == THREAD_GSCOPE_FLAG_WAIT)				     \
     101  	lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
     102      }									     \
     103    while (0)
     104  #define THREAD_GSCOPE_SET_FLAG() \
     105    do									     \
     106      {									     \
     107        THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;	     \
     108        atomic_write_barrier ();						     \
     109      }									     \
     110    while (0)
     111  
     112  #endif /* __ASSEMBLER__ */
     113  
     114  #endif	/* tls.h */