/* 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. */ /* mods for uClibc: removed strong alias and defined funcs properly */ /* The "atfork" stuff */ #include <errno.h> #ifdef __ARCH_HAS_MMU__ #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 __libc_fork(void); pid_t __fork(void) { pid_t 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 = __libc_fork(); if (pid == 0) { __pthread_reset_main_thread(); __fresetlockfiles(); pthread_call_handlers(child); } else { pthread_call_handlers(parent); } return pid; } weak_alias (__fork, fork); pid_t __vfork(void) { return __fork(); } weak_alias (__vfork, vfork); #else /* We can't support pthread_atfork without MMU, since we don't have fork(), and we can't offer the correct semantics for vfork(). */ int pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void)) { /* ENOMEM is probably pushing it a little bit. Take it as `no *virtual* memory' :-) */ errno = ENOMEM; return -1; } #endif