99 lines
3.3 KiB
C
99 lines
3.3 KiB
C
/* Linuxthreads - a simple clone()-based implementation of Posix */
|
|
/* threads for Linux. */
|
|
/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
|
|
/* */
|
|
/* This program is free software; you can redistribute it and/or */
|
|
/* modify it under the terms of the GNU Library 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 Library General Public License for more details. */
|
|
|
|
/* The "atfork" stuff */
|
|
|
|
#include <errno.h>
|
|
#include <stddef.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include "pthread.h"
|
|
#include "internals.h"
|
|
|
|
struct handler_list {
|
|
void (*handler)(void);
|
|
struct handler_list * next;
|
|
};
|
|
|
|
static pthread_mutex_t pthread_atfork_lock = PTHREAD_MUTEX_INITIALIZER;
|
|
static struct handler_list * pthread_atfork_prepare = NULL;
|
|
static struct handler_list * pthread_atfork_parent = NULL;
|
|
static struct handler_list * pthread_atfork_child = NULL;
|
|
|
|
static void pthread_insert_list(struct handler_list ** list,
|
|
void (*handler)(void),
|
|
struct handler_list * newlist,
|
|
int at_end)
|
|
{
|
|
if (handler == NULL) return;
|
|
if (at_end) {
|
|
while(*list != NULL) list = &((*list)->next);
|
|
}
|
|
newlist->handler = handler;
|
|
newlist->next = *list;
|
|
*list = newlist;
|
|
}
|
|
|
|
struct handler_list_block {
|
|
struct handler_list prepare, parent, child;
|
|
};
|
|
|
|
int __pthread_atfork(void (*prepare)(void),
|
|
void (*parent)(void),
|
|
void (*child)(void))
|
|
{
|
|
struct handler_list_block * block =
|
|
(struct handler_list_block *) malloc(sizeof(struct handler_list_block));
|
|
if (block == NULL) return ENOMEM;
|
|
pthread_mutex_lock(&pthread_atfork_lock);
|
|
/* "prepare" handlers are called in LIFO */
|
|
pthread_insert_list(&pthread_atfork_prepare, prepare, &block->prepare, 0);
|
|
/* "parent" handlers are called in FIFO */
|
|
pthread_insert_list(&pthread_atfork_parent, parent, &block->parent, 1);
|
|
/* "child" handlers are called in FIFO */
|
|
pthread_insert_list(&pthread_atfork_child, child, &block->child, 1);
|
|
pthread_mutex_unlock(&pthread_atfork_lock);
|
|
return 0;
|
|
}
|
|
strong_alias (__pthread_atfork, pthread_atfork)
|
|
|
|
static inline void pthread_call_handlers(struct handler_list * list)
|
|
{
|
|
for (/*nothing*/; list != NULL; list = list->next) (list->handler)();
|
|
}
|
|
|
|
extern int __fork(void);
|
|
|
|
int fork(void)
|
|
{
|
|
int pid;
|
|
struct handler_list * prepare, * child, * parent;
|
|
|
|
pthread_mutex_lock(&pthread_atfork_lock);
|
|
prepare = pthread_atfork_prepare;
|
|
child = pthread_atfork_child;
|
|
parent = pthread_atfork_parent;
|
|
pthread_mutex_unlock(&pthread_atfork_lock);
|
|
pthread_call_handlers(prepare);
|
|
pid = __fork();
|
|
if (pid == 0) {
|
|
__pthread_reset_main_thread();
|
|
__fresetlockfiles();
|
|
pthread_call_handlers(child);
|
|
} else {
|
|
pthread_call_handlers(parent);
|
|
}
|
|
return pid;
|
|
}
|