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// $Id: undo.c 1676 2004-08-19 15:02:57Z ensc $ --*- c -*--
// Copyright (C) 2004 Enrico Scholz <enrico.scholz@informatik.tu-chemnitz.de>
//
// 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; version 2 of the License.
//
// 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include "undo.h"
#include <lib_internal/util.h>
#include <ensc_vector/vector.h>
#include <stdlib.h>
#include <unistd.h>
#include <assert.h>
struct FuncData
{
ExitFunction fn;
void const * args;
};
struct Undo
{
pid_t pid_;
struct Vector funcs;
};
static struct Undo undo_data = {
.pid_ = -1
};
static void
atexitHandler()
{
struct FuncData const * ptr;
if (undo_data.pid_ != getpid())
return; // skip 'exit()' from forked processes
for (ptr=Vector_end(&undo_data.funcs);
ptr!=Vector_begin(&undo_data.funcs);
--ptr)
(ptr[-1].fn)(ptr[-1].args);
}
void
Undo_init()
{
if (undo_data.pid_!=-1) {
WRITE_MSG(2, "Undo already initialized; internal error...\n");
_exit(1);
}
undo_data.pid_ = getpid();
Vector_init(&undo_data.funcs, sizeof(struct FuncData));
atexit(&atexitHandler);
}
void
Undo_addTask(ExitFunction fn, void const *args)
{
struct FuncData *tmp = Vector_pushback(&undo_data.funcs);
assert(tmp!=0); // Vector_pushback never returns a null-pointer
tmp->fn = fn;
tmp->args = args;
}
void
Undo_detach()
{
Vector_free(&undo_data.funcs);
undo_data.pid_ = -1;
}
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