/* Definitions for thread-local data handling. linuxthreads/s390 version. Copyright (C) 2002, 2003, 2005 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 #ifndef __ASSEMBLER__ # include <pt-machine.h> # include <stdbool.h> # include <stddef.h> /* Type for the dtv. */ typedef union dtv { size_t counter; struct { void *val; bool is_static; } pointer; } dtv_t; typedef struct { void *tcb; /* Pointer to the TCB. Not necessary the thread descriptor used by libpthread. */ dtv_t *dtv; void *self; /* Pointer to the thread descriptor. */ int multiple_threads; } tcbhead_t; #else /* __ASSEMBLER__ */ # include <tcb-offsets.h> #endif /* __ASSEMBLER__ */ /* TLS is always supported if the tools support it. There are no kernel dependencies. To avoid bothering with the TLS support code at all, use configure --without-tls. We need USE_TLS to be consistently defined, for ldsodefs.h conditionals. */ #ifdef HAVE_TLS_SUPPORT /* Signal that TLS support is available. */ # define USE_TLS 1 # ifndef __ASSEMBLER__ /* Get system call information. */ # include <sysdep.h> /* Get the thread descriptor definition. */ # include <linuxthreads/descr.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 (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 /* Install the dtv pointer. The pointer passed is to the element with index -1 which contain the length. */ # define INSTALL_DTV(descr, dtvp) \ ((tcbhead_t *) (descr))->dtv = (dtvp) + 1 /* Install new dtv for current thread. */ # define INSTALL_NEW_DTV(dtv) \ (((tcbhead_t *) __builtin_thread_pointer ())->dtv = (dtv)) /* Return dtv of given thread descriptor. */ # define GET_DTV(descr) \ (((tcbhead_t *) (descr))->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. The value of this macro is null if successful, or an error string. */ # define TLS_INIT_TP(descr, secondcall) \ ({ \ void *_descr = (descr); \ tcbhead_t *head = _descr; \ \ head->tcb = _descr; \ /* For now the thread descriptor is at the same address. */ \ head->self = _descr; \ \ __builtin_set_thread_pointer (_descr); \ NULL; \ }) /* Return the address of the dtv for the current thread. */ # define THREAD_DTV() \ (((tcbhead_t *) __builtin_thread_pointer ())->dtv) # endif /* __ASSEMBLER__ */ #else /* HAVE_TLS_SUPPORT && (FLOATING_STACKS || !IS_IN_libpthread) */ # ifndef __ASSEMBLER__ /* Get the thread descriptor definition. */ # include <linuxthreads/descr.h> # define NONTLS_INIT_TP \ do { \ static const tcbhead_t nontls_init_tp \ = { .multiple_threads = 0 }; \ INIT_THREAD_SELF (&nontls_init_tp, 0); \ } while (0) # endif /* __ASSEMBLER__ */ #endif /* HAVE_TLS_SUPPORT && (FLOATING_STACKS || !IS_IN_libpthread) */ #endif /* tls.h */