1: /* libc-internal interface for thread-specific data.  Stub or TLS version.
    2:    Copyright (C) 1998,2001,02 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 _GENERIC_BITS_LIBC_TSD_H
   21: #define _GENERIC_BITS_LIBC_TSD_H 1
   22: 
   23: /* This file defines the following macros for accessing a small fixed
   24:    set of thread-specific `void *' data used only internally by libc.
   25: 
   26:    __libc_tsd_define(CLASS, KEY)        -- Define or declare a `void *' datum
   27:                                            for KEY.  CLASS can be `static' for
   28:                                            keys used in only one source file,
   29:                                            empty for global definitions, or
   30:                                            `extern' for global declarations.
   31:    __libc_tsd_address(KEY)              -- Return the `void **' pointing to
   32:                                            the current thread's datum for KEY.
   33:    __libc_tsd_get(KEY)                  -- Return the `void *' datum for KEY.
   34:    __libc_tsd_set(KEY, VALUE)           -- Set the datum for KEY to VALUE.
   35: 
   36:    The set of available KEY's will usually be provided as an enum,
   37:    and contains (at least):
   38:                 _LIBC_TSD_KEY_MALLOC
   39:                 _LIBC_TSD_KEY_DL_ERROR
   40:                 _LIBC_TSD_KEY_RPC_VARS
   41:    All uses must be the literal _LIBC_TSD_* name in the __libc_tsd_* macros.
   42:    Some implementations may not provide any enum at all and instead
   43:    using string pasting in the macros.  */
   44: 
   45: #include <tls.h>
   46: 
   47: /* When full support for __thread variables is available, this interface is
   48:    just a trivial wrapper for it.  Without TLS, this is the generic/stub
   49:    implementation for wholly single-threaded systems.
   50: 
   51:    We don't define an enum for the possible key values, because the KEYs
   52:    translate directly into variables by macro magic.  */
   53: 
   54: #if USE___THREAD
   55: # define __libc_tsd_define(CLASS, KEY)  \
   56:   CLASS __thread void *__libc_tsd_##KEY attribute_tls_model_ie;
   57: 
   58: # define __libc_tsd_address(KEY)        (&__libc_tsd_##KEY)
   59: # define __libc_tsd_get(KEY)            (__libc_tsd_##KEY)
   60: # define __libc_tsd_set(KEY, VALUE)     (__libc_tsd_##KEY = (VALUE))
   61: #else
   62: # define __libc_tsd_define(CLASS, KEY)  CLASS void *__libc_tsd_##KEY##_data;
   63: 
   64: # define __libc_tsd_address(KEY)        (&__libc_tsd_##KEY##_data)
   65: # define __libc_tsd_get(KEY)            (__libc_tsd_##KEY##_data)
   66: # define __libc_tsd_set(KEY, VALUE)     (__libc_tsd_##KEY##_data = (VALUE))
   67: #endif
   68: 
   69: #endif  /* bits/libc-tsd.h */