/* Copyright (C) 1995,1996 Robert de Bath <rdebath@cix.compulink.co.uk> * This file is part of the Linux-8086 C library and is distributed * under the GNU Library General Public License. */ /* * Dec 2000 Manuel Novoa III * * Made atexit handling conform to standards... i.e. no args. * Removed on_exit since it did not match gnu libc definition. * Combined atexit and __do_exit into one object file. * * Feb 2001 Manuel Novoa III * * Reworked file after addition of __uClibc_main. * Changed name of __do_exit to atexit_handler. * Changed name of __cleanup to __uClibc_cleanup. * Moved declaration of __uClibc_cleanup to __uClibc_main * where it is initialized with (possibly weak alias) * _stdio_term. * * Jul 2001 Steve Thayer * * Added an on_exit implementation (that now matches gnu libc definition.) * Pulled atexit_handler out of the atexit object since it is now required by * on_exit as well. Renamed it to __exit_handler. * Fixed a problem where exit functions stop getting called if one of * them calls exit(). * As a side effect of these changes, abort() no longer calls the exit * functions (it now matches the gnu libc definition). * * August 2002 Erik Andersen * Added locking so atexit and friends can be thread safe * */ #define _GNU_SOURCE #include <features.h> #include <unistd.h> #include <stdlib.h> #include <errno.h> #ifdef __UCLIBC_HAS_THREADS__ #include <pthread.h> extern pthread_mutex_t mylock; # define LOCK pthread_mutex_lock(&mylock) # define UNLOCK pthread_mutex_unlock(&mylock); #else # define LOCK # define UNLOCK #endif typedef void (*aefuncp) (void); /* atexit function pointer */ typedef void (*oefuncp) (int, void *); /* on_exit function pointer */ typedef enum { ef_atexit, ef_on_exit } ef_type; /* exit function types */ /* this is in the L_exit object */ extern void (*__exit_cleanup) (int); /* these are in the L___do_exit object */ extern int __exit_slots; extern int __exit_count; extern void __exit_handler(int); struct exit_function { ef_type type; /* ef_atexit or ef_on_exit */ union { aefuncp atexit; struct { oefuncp func; void *arg; } on_exit; } funcs; }; #ifdef __UCLIBC_DYNAMIC_ATEXIT__ extern struct exit_function *__exit_function_table; #else extern struct exit_function __exit_function_table[__UCLIBC_MAX_ATEXIT]; #endif #ifdef L_atexit /* * register a function to be called at normal program termination * (the registered function takes no arguments) */ int atexit(aefuncp func) { struct exit_function *efp; LOCK; if (func) { #ifdef __UCLIBC_DYNAMIC_ATEXIT__ /* If we are out of function table slots, make some more */ if (__exit_slots < __exit_count+1) { __exit_function_table=realloc(__exit_function_table, (__exit_slots+20)*sizeof(struct exit_function)); if (__exit_function_table==NULL) { UNLOCK; __set_errno(ENOMEM); return -1; } __exit_slots+=20; } #else if (__exit_count >= __UCLIBC_MAX_ATEXIT) { UNLOCK; __set_errno(ENOMEM); return -1; } #endif __exit_cleanup = __exit_handler; /* enable cleanup */ efp = &__exit_function_table[__exit_count++]; efp->type = ef_atexit; efp->funcs.atexit = func; } UNLOCK; return 0; } #endif #ifdef L_on_exit /* * register a function to be called at normal program termination * the registered function takes two arguments: * status - the exit status that was passed to the exit() function * arg - generic argument */ int on_exit(oefuncp func, void *arg) { struct exit_function *efp; LOCK; if (func) { #ifdef __UCLIBC_DYNAMIC_ATEXIT__ /* If we are out of function table slots, make some more */ if (__exit_slots < __exit_count+1) { __exit_function_table=realloc(__exit_function_table, (__exit_slots+20)*sizeof(struct exit_function)); if (__exit_function_table==NULL) { UNLOCK; __set_errno(ENOMEM); return -1; } __exit_slots+=20; } #else if (__exit_count >= __UCLIBC_MAX_ATEXIT) { UNLOCK; __set_errno(ENOMEM); return -1; } #endif __exit_cleanup = __exit_handler; /* enable cleanup */ efp = &__exit_function_table[__exit_count++]; efp->type = ef_on_exit; efp->funcs.on_exit.func = func; efp->funcs.on_exit.arg = arg; } UNLOCK; return 0; } #endif #ifdef L___exit_handler int __exit_count = 0; /* Number of registered exit functions */ #ifdef __UCLIBC_DYNAMIC_ATEXIT__ struct exit_function *__exit_function_table = NULL; int __exit_slots = 0; /* Size of __exit_function_table */ #else struct exit_function __exit_function_table[__UCLIBC_MAX_ATEXIT]; #endif /* * Handle the work of executing the registered exit functions * This is called while we are locked, so no additional locking * is needed... */ void __exit_handler(int status) { struct exit_function *efp; /* In reverse order */ while ( __exit_count ) { efp = &__exit_function_table[--__exit_count]; switch (efp->type) { case ef_on_exit: if (efp->funcs.on_exit.func) { (efp->funcs.on_exit.func) (status, efp->funcs.on_exit.arg); } break; case ef_atexit: if (efp->funcs.atexit) { (efp->funcs.atexit) (); } break; } } #ifdef __UCLIBC_DYNAMIC_ATEXIT__ /* Free up memory used by the __exit_function_table structure */ if (__exit_function_table) free(__exit_function_table); #endif } #endif #ifdef L_exit extern void weak_function _stdio_term(void); void (*__exit_cleanup) (int) = 0; #ifdef __UCLIBC_HAS_THREADS__ pthread_mutex_t mylock = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP; #endif /* * Normal program termination */ void exit(int rv) { /* Perform exit-specific cleanup (atexit and on_exit) */ LOCK; if (__exit_cleanup) { __exit_cleanup(rv); } UNLOCK; /* If we are using stdio, try to shut it down. At the very least, * this will attempt to commit all buffered writes. It may also * unbuffer all writable files, or close them outright. * Check the stdio routines for details. */ if (_stdio_term) _stdio_term(); _exit(rv); } #endif