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Diffstat (limited to 'linuxthreads/sysdeps/i386/tls.h')
| -rw-r--r-- | linuxthreads/sysdeps/i386/tls.h | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/linuxthreads/sysdeps/i386/tls.h b/linuxthreads/sysdeps/i386/tls.h new file mode 100644 index 0000000000..17f6e0ae45 --- /dev/null +++ b/linuxthreads/sysdeps/i386/tls.h @@ -0,0 +1,95 @@ +/* Definition for thread-local data handling. linuxthreads/i386 version. + Copyright (C) 2002 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#ifndef _TLS_H +#define _TLS_H + +/* Type for the dtv. */ +typedef union dtv +{ + size_t counter; + void *pointer; +} dtv_t; + + +typedef struct +{ + void *tcb; + dtv_t *dtv; +} tcbhead_t; + + +/* Get the thread descriptor definition. */ +#include <linuxthreads/descr.h> + + +/* We can support TLS only if the floating-stack support is available. */ +#if FLOATING_STACKS && defined HAVE_TLS_SUPPORT + +/* Get system call information. */ +# include <sysdep.h> + +/* Signal that TLS support is available. */ +# define USE_TLS 1 + +/* 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 (struct _pthread_descr_struct) + +/* Alignment requirements for the TCB. */ +# define TLS_TCB_ALIGN __alignof__ (struct _pthread_descr_struct) + +/* The TCB can have any size and the memory following the address the + thread pointer points to is unspecified. Allocate the TCB there. */ +# define TLS_TCB_AT_TP 1 + +/* 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(descr, dtvp) \ + do { \ + void *_descr = (descr); \ + struct modify_ldt_ldt_s ldt_entry = \ + { 0, (unsigned long int) _descr, 1048576, 1, 0, 0, 1, 0, 1, 0 }; \ + int result; \ + tcbhead_t *head = _descr; \ + \ + head->tcb = _descr; \ + head->dtv = dtvp; \ + \ + asm ("pushl %%ebx\n\t" \ + "movl $1, %%ebx\n\t" \ + "int $0x80\n\t" \ + "popl %%ebx" \ + : "=a" (result) \ + : "0" (__NR_modify_ldt), "d" (sizeof (ldt_entry)), "c" (&ldt_entry));\ + \ + if (__builtin_expect (result, 0) != 0) \ + /* Nothing else we can do. */ \ + asm ("hlt"); \ + } while (0) + +#endif + +#endif /* tls.h */ |