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/* Copyright (C) 2008-2020 Free Software Foundation, Inc.
Contributed by Richard Henderson <rth@redhat.com>.
This file is part of the GNU Transactional Memory Library (libitm).
Libitm is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
Libitm 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 General Public License for
more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#ifndef LIBITM_TLS_H
#define LIBITM_TLS_H 1
namespace GTM HIDDEN {
#if !defined(HAVE_ARCH_GTM_THREAD) || !defined(HAVE_ARCH_GTM_THREAD_DISP)
// Provides a single place to store all this libraries thread-local data.
struct gtm_thread_tls
{
#ifndef HAVE_ARCH_GTM_THREAD
// The currently active transaction. Elided if the target provides
// some efficient mechanism for storing this.
gtm_thread *thr;
#endif
#ifndef HAVE_ARCH_GTM_THREAD_DISP
// The dispatch table for the STM implementation currently in use. Elided
// if the target provides some efficient mechanism for storing this.
abi_dispatch *disp;
#endif
};
extern __thread gtm_thread_tls _gtm_thr_tls;
#endif
#ifndef HAVE_ARCH_GTM_THREAD
// If the target does not provide optimized access to the thread-local
// data, simply access the TLS variable defined above.
static inline gtm_thread *gtm_thr() { return _gtm_thr_tls.thr; }
static inline void set_gtm_thr(gtm_thread *x) { _gtm_thr_tls.thr = x; }
#endif
#ifndef HAVE_ARCH_GTM_THREAD_DISP
// If the target does not provide optimized access to the currently
// active dispatch table, simply access via GTM_THR.
static inline abi_dispatch * abi_disp() { return _gtm_thr_tls.disp; }
static inline void set_abi_disp(abi_dispatch *x) { _gtm_thr_tls.disp = x; }
#endif
#ifndef HAVE_ARCH_GTM_MASK_STACK
// To filter out any updates that overlap the libitm stack, we define
// gtm_mask_stack_top to the entry point to the library and
// gtm_mask_stack_bottom to below the calling function (enforced with the
// noinline attribute). This definition should be fine for all
// stack-grows-down architectures.
// FIXME We fake the bottom to be lower so that we are safe even if we might
// call further functions (compared to where we called gtm_mask_stack_bottom
// in the call hierarchy) to actually undo or redo writes (e.g., memcpy).
// This is a completely arbitrary value; can we instead ensure that there are
// no such calls, or can we determine a future-proof value otherwise?
static inline void *
mask_stack_top(gtm_thread *tx) { return tx->jb.cfa; }
void * __attribute__((noinline))
mask_stack_bottom(gtm_thread *tx);
#endif
} // namespace GTM
#endif // LIBITM_TLS_H