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/* wmem_scopes.c
* Wireshark Memory Manager Scopes
* Copyright 2012, Evan Huus <eapache@gmail.com>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* This program 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 2 of the License, or
* (at your option) any later version.
*
* This program 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <glib.h>
#include "wmem_core.h"
#include "wmem_scopes.h"
#include "wmem_allocator.h"
/* One of the supposed benefits of wmem over the old emem was going to be that
* the scoping of the various memory pools would be obvious, since they would
* no longer be global. Instead, the pools would be managed as variables scoped
* by the compiler, so functions outside of that scope wouldn't have access to
* the pools and wouldn't be able to allocate memory in a scope to which they
* didn't belong.
*
* That idea fell apart rather quickly :P
*
* The principle still stands, and most pools should be managed in that way.
* The three in this file are *exceptions*. They are the three scopes that emem
* provided as globals. Converting all of the code that used them to pass an
* extra parameter (or three) around would have been a nightmare of epic
* proportions, so we provide these three as globals still.
*
* We do, however, use some extra booleans and a mountain of assertions to try
* and catch anybody accessing the pools out of the correct scope. It's not
* perfect, but it should stop most of the bad behaviour that emem permitted.
*/
/* TODO: Make these thread-local */
static wmem_allocator_t *packet_scope = NULL;
static wmem_allocator_t *file_scope = NULL;
static wmem_allocator_t *epan_scope = NULL;
/* Packet Scope */
wmem_allocator_t *
wmem_packet_scope(void)
{
g_assert(packet_scope);
return packet_scope;
}
void
wmem_enter_packet_scope(void)
{
g_assert(packet_scope);
g_assert(file_scope->in_scope);
g_assert(!packet_scope->in_scope);
packet_scope->in_scope = TRUE;
}
void
wmem_leave_packet_scope(void)
{
g_assert(packet_scope);
g_assert(packet_scope->in_scope);
wmem_free_all(packet_scope);
packet_scope->in_scope = FALSE;
}
/* File Scope */
wmem_allocator_t *
wmem_file_scope(void)
{
g_assert(file_scope);
return file_scope;
}
void
wmem_enter_file_scope(void)
{
g_assert(file_scope);
g_assert(!file_scope->in_scope);
file_scope->in_scope = TRUE;
}
void
wmem_leave_file_scope(void)
{
g_assert(file_scope);
g_assert(file_scope->in_scope);
g_assert(!packet_scope->in_scope);
wmem_free_all(file_scope);
file_scope->in_scope = FALSE;
/* this seems like a good time to do garbage collection */
wmem_gc(file_scope);
wmem_gc(packet_scope);
}
/* Epan Scope */
wmem_allocator_t *
wmem_epan_scope(void)
{
g_assert(epan_scope);
return epan_scope;
}
/* Scope Management */
void
wmem_init_scopes(void)
{
g_assert(packet_scope == NULL);
g_assert(file_scope == NULL);
g_assert(epan_scope == NULL);
packet_scope = wmem_allocator_new(WMEM_ALLOCATOR_BLOCK_FAST);
file_scope = wmem_allocator_new(WMEM_ALLOCATOR_BLOCK);
epan_scope = wmem_allocator_new(WMEM_ALLOCATOR_SIMPLE);
/* Scopes are initialized to TRUE by default on creation */
packet_scope->in_scope = FALSE;
file_scope->in_scope = FALSE;
}
void
wmem_cleanup_scopes(void)
{
g_assert(packet_scope);
g_assert(file_scope);
g_assert(epan_scope);
g_assert(packet_scope->in_scope == FALSE);
g_assert(file_scope->in_scope == FALSE);
wmem_destroy_allocator(packet_scope);
wmem_destroy_allocator(file_scope);
wmem_destroy_allocator(epan_scope);
packet_scope = NULL;
file_scope = NULL;
epan_scope = NULL;
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
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