diff options
Diffstat (limited to 'libitm/alloc.cc')
| -rw-r--r-- | libitm/alloc.cc | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/libitm/alloc.cc b/libitm/alloc.cc new file mode 100644 index 00000000000..ec36269e6c8 --- /dev/null +++ b/libitm/alloc.cc @@ -0,0 +1,129 @@ +/* Copyright (C) 2009, 2011 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 *)) +{ + uintptr_t iptr = (uintptr_t) ptr; + + gtm_alloc_action *a = this->alloc_actions.find(iptr); + if (a == 0) + a = this->alloc_actions.insert(iptr); + + a->free_fn = free_fn; + a->allocated = true; +} + +void +gtm_thread::forget_allocation (void *ptr, void (*free_fn)(void *)) +{ + uintptr_t iptr = (uintptr_t) ptr; + + gtm_alloc_action *a = this->alloc_actions.find(iptr); + if (a == 0) + a = this->alloc_actions.insert(iptr); + + a->free_fn = free_fn; + 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. + if (a->allocated) + a->free_fn (ptr); + } + else + { + if (a->allocated) + { + // Add nested allocations to parent transaction. + gtm_alloc_action* a_parent = cb_data->parent->insert(key); + *a_parent = *a; + } + else + { + // ??? We could eliminate a parent allocation that matches this + // memory release, 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; + 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; + uintptr_t revert_p = (uintptr_t) cb_data; + + if (a->allocated == revert_p) + 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 |