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/* Copyright (C) 2009-2023 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/>. */
#include "libitm_i.h"
namespace GTM HIDDEN {
void
gtm_thread::record_allocation (void *ptr, void (*free_fn)(void *))
{
// We do not deallocate before outermost commit, so we should never have
// an existing log entry for a new allocation.
gtm_alloc_action *a = this->alloc_actions.insert((uintptr_t) ptr);
a->free_fn = free_fn;
a->free_fn_sz = 0;
a->allocated = true;
}
void
gtm_thread::forget_allocation (void *ptr, void (*free_fn)(void *))
{
// We do not deallocate before outermost commit, so we should never have
// an existing log entry for a deallocation at the same address. We may
// have an existing entry for a matching allocation, but this is handled
// correctly because both are complementary in that only one of these will
// cause an action at commit or abort.
gtm_alloc_action *a = this->alloc_actions.insert((uintptr_t) ptr);
a->free_fn = free_fn;
a->free_fn_sz = 0;
a->allocated = false;
}
void
gtm_thread::forget_allocation (void *ptr, size_t sz,
void (*free_fn_sz)(void *, size_t))
{
// Same as forget_allocation but with a size.
gtm_alloc_action *a = this->alloc_actions.insert((uintptr_t) ptr);
a->free_fn = 0;
a->free_fn_sz = free_fn_sz;
a->sz = sz;
a->allocated = false;
}
namespace {
struct commit_cb_data {
aa_tree<uintptr_t, gtm_alloc_action>* parent;
bool revert_p;
};
}
static void
commit_allocations_2 (uintptr_t key, gtm_alloc_action *a, void *data)
{
void *ptr = (void *)key;
commit_cb_data *cb_data = static_cast<commit_cb_data *>(data);
if (cb_data->revert_p)
{
// Roll back nested allocations, discard deallocations.
if (a->allocated)
{
if (a->free_fn_sz != 0)
a->free_fn_sz (ptr, a->sz);
else
a->free_fn (ptr);
}
}
else
{
// Add allocations and deallocations to parent.
// ??? We could eliminate a (parent) allocation that matches this
// a deallocation, if we had support for removing all accesses
// to this allocation from the transaction's undo and redo logs
// (otherwise, the parent transaction's undo or redo might write to
// data that is already shared again because of calling free()).
// We don't have this support currently, and the benefit of this
// optimization is unknown, so just add it to the parent.
gtm_alloc_action* a_parent = cb_data->parent->insert(key);
*a_parent = *a;
}
}
static void
commit_allocations_1 (uintptr_t key, gtm_alloc_action *a, void *cb_data)
{
void *ptr = (void *)key;
bool revert_p = (bool) (uintptr_t) cb_data;
if (revert_p == a->allocated)
{
if (a->free_fn_sz != 0)
a->free_fn_sz (ptr, a->sz);
else
a->free_fn (ptr);
}
}
/* Permanently commit allocated memory during transaction.
REVERT_P is true if instead of committing the allocations, we want
to roll them back (and vice versa). */
void
gtm_thread::commit_allocations (bool revert_p,
aa_tree<uintptr_t, gtm_alloc_action>* parent)
{
if (parent)
{
commit_cb_data cb_data;
cb_data.parent = parent;
cb_data.revert_p = revert_p;
this->alloc_actions.traverse (commit_allocations_2, &cb_data);
}
else
this->alloc_actions.traverse (commit_allocations_1,
(void *)(uintptr_t)revert_p);
this->alloc_actions.clear ();
}
} // namespace GTM
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