tls.h

/* Definition for thread-local data handling.  NPTL/SH version.
   Copyright (C) 2003-2014 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#ifndef _TLS_H
#define _TLS_H

# include <dl-sysdep.h>

#ifndef __ASSEMBLER__
# include <stdbool.h>
# include <stddef.h>
# include <stdint.h>
# include <stdlib.h>
# include <list.h>
# include <sysdep.h>

/* Type for the dtv.  */
typedef union dtv
{
  size_t counter;
  struct
  {
    void *val;
    bool is_static;
  } pointer;
} dtv_t;

typedef struct
{
  dtv_t *dtv;
  uintptr_t pointer_guard;
} tcbhead_t;

# define TLS_MULTIPLE_THREADS_IN_TCB 1

#else /* __ASSEMBLER__ */
# include <tcb-offsets.h>
#endif /* __ASSEMBLER__ */


#ifndef __ASSEMBLER__

/* Get system call information.  */
# include <sysdep.h>

/* This is the size of the initial TCB.  */
# define TLS_INIT_TCB_SIZE sizeof (tcbhead_t)

/* Alignment requirements for the initial TCB.  */
# define TLS_INIT_TCB_ALIGN __alignof__ (tcbhead_t)

/* This is the size of the TCB.  */
# define TLS_TCB_SIZE sizeof (tcbhead_t)

/* This is the size we need before TCB.  */
# define TLS_PRE_TCB_SIZE sizeof (struct pthread)

/* Alignment requirements for the TCB.  */
# define TLS_TCB_ALIGN __alignof__ (struct pthread)

/* The TLS blocks start right after the TCB.  */
# define TLS_DTV_AT_TP	1
# define TLS_TCB_AT_TP	0

/* Get the thread descriptor definition.  */
# include <nptl/descr.h>

/* Install the dtv pointer.  The pointer passed is to the element with
   index -1 which contain the length.  */
# define INSTALL_DTV(tcbp, dtvp) \
  ((tcbhead_t *) (tcbp))->dtv = (dtvp) + 1

/* Install new dtv for current thread.  */
# define INSTALL_NEW_DTV(dtv) \
  ({ tcbhead_t *__tcbp;							      \
     __asm __volatile ("stc gbr,%0" : "=r" (__tcbp));			      \
     __tcbp->dtv = (dtv);})

/* Return dtv of given thread descriptor.  */
# define GET_DTV(tcbp) \
  (((tcbhead_t *) (tcbp))->dtv)

/* Code to initially initialize the thread pointer.  This might need
   special attention since 'errno' is not yet available and if the
   operation can cause a failure 'errno' must not be touched.  */
# define TLS_INIT_TP(tcbp) \
  ({ __asm __volatile ("ldc %0,gbr" : : "r" (tcbp)); 0; })

# define TLS_DEFINE_INIT_TP(tp, pd) void *tp = (pd) + 1

/* Return the address of the dtv for the current thread.  */
# define THREAD_DTV() \
  ({ tcbhead_t *__tcbp;							      \
     __asm __volatile ("stc gbr,%0" : "=r" (__tcbp));			      \
     __tcbp->dtv;})

/* Return the thread descriptor for the current thread.
   The contained asm must *not* be marked volatile since otherwise
   assignments like
	struct pthread *self = thread_self();
   do not get optimized away.  */
# define THREAD_SELF \
  ({ struct pthread *__self;						      \
     __asm ("stc gbr,%0" : "=r" (__self));				      \
     __self - 1;})

/* Magic for libthread_db to know how to do THREAD_SELF.  */
# define DB_THREAD_SELF \
  REGISTER (32, 32, REG_GBR * 4, -sizeof (struct pthread))

/* Read member of the thread descriptor directly.  */
# define THREAD_GETMEM(descr, member) (descr->member)

/* Same as THREAD_GETMEM, but the member offset can be non-constant.  */
# define THREAD_GETMEM_NC(descr, member, idx) (descr->member[idx])

/* Set member of the thread descriptor directly.  */
# define THREAD_SETMEM(descr, member, value) \
    descr->member = (value)

/* Same as THREAD_SETMEM, but the member offset can be non-constant.  */
# define THREAD_SETMEM_NC(descr, member, idx, value) \
    descr->member[idx] = (value)

#define THREAD_GET_POINTER_GUARD() \
  ({ tcbhead_t *__tcbp;							      \
     __asm __volatile ("stc gbr,%0" : "=r" (__tcbp));			      \
     __tcbp->pointer_guard;})
 #define THREAD_SET_POINTER_GUARD(value) \
  ({ tcbhead_t *__tcbp;							      \
     __asm __volatile ("stc gbr,%0" : "=r" (__tcbp));			      \
     __tcbp->pointer_guard = (value);})
#define THREAD_COPY_POINTER_GUARD(descr) \
  ({ tcbhead_t *__tcbp;							      \
     __asm __volatile ("stc gbr,%0" : "=r" (__tcbp));			      \
     ((tcbhead_t *) (descr + 1))->pointer_guard	= __tcbp->pointer_guard;})

/* Get and set the global scope generation counter in struct pthread.  */
#define THREAD_GSCOPE_FLAG_UNUSED 0
#define THREAD_GSCOPE_FLAG_USED   1
#define THREAD_GSCOPE_FLAG_WAIT   2
#define THREAD_GSCOPE_RESET_FLAG() \
  do									     \
    { int __res								     \
	= atomic_exchange_rel (&THREAD_SELF->header.gscope_flag,	     \
			       THREAD_GSCOPE_FLAG_UNUSED);		     \
      if (__res == THREAD_GSCOPE_FLAG_WAIT)				     \
	lll_futex_wake (&THREAD_SELF->header.gscope_flag, 1, LLL_PRIVATE);   \
    }									     \
  while (0)
#define THREAD_GSCOPE_SET_FLAG() \
  do									     \
    {									     \
      THREAD_SELF->header.gscope_flag = THREAD_GSCOPE_FLAG_USED;	     \
      atomic_write_barrier ();						     \
    }									     \
  while (0)
#define THREAD_GSCOPE_WAIT() \
  GL(dl_wait_lookup_done) ()

#endif /* __ASSEMBLER__ */

#endif	/* tls.h */