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/*
* Copyright (c) 2008 - 2011, Nicolas François
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the copyright holders or contributors may not be used to
* endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <config.h>
#include <assert.h>
#include <stdio.h>
#include "prototypes.h"
/*
* The cleanup_functions stack.
*/
#define CLEANUP_FUNCTIONS 10
typedef /*@null@*/void * parg_t;
static cleanup_function cleanup_functions[CLEANUP_FUNCTIONS];
static parg_t cleanup_function_args[CLEANUP_FUNCTIONS];
static pid_t cleanup_pid = 0;
/*
* - Cleanup functions shall not fail.
* - You should register do_cleanups with atexit.
* - You should add cleanup functions to the stack with add_cleanup when
* an operation is expected to be executed later, and remove it from the
* stack with del_cleanup when it has been executed.
*
**/
/*
* do_cleanups - perform the actions stored in the cleanup_functions stack.
*
* Cleanup action are not executed on exit of the processes started by the
* parent (first caller of add_cleanup).
*
* It is intended to be used as:
* atexit (do_cleanups);
*/
void do_cleanups (void)
{
unsigned int i;
/* Make sure there were no overflow */
assert (NULL == cleanup_functions[CLEANUP_FUNCTIONS-1]);
if (getpid () != cleanup_pid) {
return;
}
i = CLEANUP_FUNCTIONS;
do {
i--;
if (cleanup_functions[i] != NULL) {
cleanup_functions[i] (cleanup_function_args[i]);
}
} while (i>0);
}
/*
* add_cleanup - Add a cleanup_function to the cleanup_functions stack.
*/
void add_cleanup (/*@notnull@*/cleanup_function pcf, /*@null@*/void *arg)
{
unsigned int i;
assert (NULL != pcf);
assert (NULL == cleanup_functions[CLEANUP_FUNCTIONS-2]);
if (0 == cleanup_pid) {
cleanup_pid = getpid ();
}
/* Add the cleanup_function at the end of the stack */
for (i=0; NULL != cleanup_functions[i]; i++);
cleanup_functions[i] = pcf;
cleanup_function_args[i] = arg;
}
/*
* del_cleanup - Remove a cleanup_function from the cleanup_functions stack.
*/
void del_cleanup (/*@notnull@*/cleanup_function pcf)
{
unsigned int i;
assert (NULL != pcf);
/* Find the pcf cleanup function */
for (i=0; i<CLEANUP_FUNCTIONS; i++) {
if (cleanup_functions[i] == pcf) {
break;
}
}
/* Make sure the cleanup function was found */
assert (i<CLEANUP_FUNCTIONS);
/* Move the rest of the cleanup functions */
for (; i<CLEANUP_FUNCTIONS; i++) {
/* Make sure the cleanup function was specified only once */
assert ( (i == (CLEANUP_FUNCTIONS -1))
|| (cleanup_functions[i+1] != pcf));
if (i == (CLEANUP_FUNCTIONS -1)) {
cleanup_functions[i] = NULL;
cleanup_function_args[i] = NULL;
} else {
cleanup_functions[i] = cleanup_functions[i+1];
cleanup_function_args[i] = cleanup_function_args[i+1];
}
/* A NULL indicates the end of the stack */
if (NULL == cleanup_functions[i]) {
break;
}
}
}
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