05b55446da
actions. Make sure only the parent (initial caller) perform the cleanup actions.
142 lines
4.1 KiB
C
142 lines
4.1 KiB
C
/*
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* Copyright (c) 2008 - 2011, Nicolas François
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the copyright holders or contributors may not be used to
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* endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
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* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <config.h>
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#include <assert.h>
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#include <stdio.h>
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#include "prototypes.h"
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/*
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* The cleanup_functions stack.
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*/
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#define CLEANUP_FUNCTIONS 10
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static cleanup_function cleanup_functions[CLEANUP_FUNCTIONS];
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static void * cleanup_function_args[CLEANUP_FUNCTIONS];
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static pid_t cleanup_pid = 0;
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/*
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* - Cleanup functions shall not fail.
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* - You should register do_cleanups with atexit.
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* - You should add cleanup functions to the stack with add_cleanup when
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* an operation is expected to be executed later, and remove it from the
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* stack with del_cleanup when it has been executed.
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*
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**/
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/*
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* do_cleanups - perform the actions stored in the cleanup_functions stack.
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*
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* Cleanup action are not executed on exit of the processes started by the
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* parent (first caller of add_cleanup).
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*
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* It is intended to be used as:
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* atexit (do_cleanups);
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*/
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void do_cleanups (void)
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{
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unsigned int i;
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/* Make sure there were no overflow */
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assert (NULL == cleanup_functions[CLEANUP_FUNCTIONS-1]);
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if (getpid () != cleanup_pid) {
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return;
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}
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i = CLEANUP_FUNCTIONS;
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do {
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i--;
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if (cleanup_functions[i] != NULL) {
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cleanup_functions[i] (cleanup_function_args[i]);
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}
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} while (i>0);
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}
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/*
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* add_cleanup - Add a cleanup_function to the cleanup_functions stack.
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*/
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void add_cleanup (cleanup_function pcf, /*@null@*/void *arg)
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{
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unsigned int i;
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assert (NULL != pcf);
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assert (NULL == cleanup_functions[CLEANUP_FUNCTIONS-2]);
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if (0 == cleanup_pid) {
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cleanup_pid = getpid ();
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}
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/* Add the cleanup_function at the end of the stack */
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for (i=0; NULL != cleanup_functions[i]; i++);
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cleanup_functions[i] = pcf;
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cleanup_function_args[i] = arg;
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}
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/*
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* del_cleanup - Remove a cleanup_function from the cleanup_functions stack.
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*/
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void del_cleanup (cleanup_function pcf)
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{
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unsigned int i;
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assert (NULL != pcf);
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/* Find the pcf cleanup function */
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for (i=0; i<CLEANUP_FUNCTIONS; i++) {
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if (cleanup_functions[i] == pcf) {
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break;
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}
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}
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/* Make sure the cleanup function was found */
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assert (i<CLEANUP_FUNCTIONS);
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/* Move the rest of the cleanup functions */
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for (; i<CLEANUP_FUNCTIONS; i++) {
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/* Make sure the cleanup function was specified only once */
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assert ( (i == (CLEANUP_FUNCTIONS -1))
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|| (cleanup_functions[i+1] != pcf));
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if (i == (CLEANUP_FUNCTIONS -1)) {
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cleanup_functions[i] = NULL;
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cleanup_function_args[i] = NULL;
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} else {
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cleanup_functions[i] = cleanup_functions[i+1];
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cleanup_function_args[i] = cleanup_function_args[i+1];
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}
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/* A NULL indicates the end of the stack */
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if (NULL == cleanup_functions[i]) {
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break;
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}
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}
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}
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