1 /* ATEXIT.C

     2  * 

     3  * Portions Copyright (c) 1990-2006 Nokia Corporation and/or its subsidiary(-ies).

     4  * All rights reserved.

     5  */

     6 

     7 /*

     8  * Copyright (c) 1990 Regents of the University of California.

     9  * All rights reserved.

    10  *

    11  * %sccs.include.redist.c%

    12  */

    13 

    14 /*

    15 FUNCTION

    16 <<atexit>>---request execution of functions at program exit

    17 

    18 INDEX

    19 	atexit

    20 

    21 ANSI_SYNOPSIS

    22 	#include <stdlib.h>

    23 	int atexit(void (*<[function]>)(void);

    24 

    25 TRAD_SYNOPSIS

    26 	#include <stdlib.h>

    27 	int atexit((<[function]>)

    28 	void (*<[function]>)();

    29 

    30 DESCRIPTION

    31 You can use <<atexit>> to enroll functions in a list of functions that

    32 will be called when your program terminates normally.  The argument is

    33 a pointer to a user-defined function (which must not require arguments and

    34 must not return a result).

    35 

    36 The functions are kept in a LIFO stack; that is, the last function

    37 enrolled by <<atexit>> will be the first to execute when your program

    38 exits.

    39 

    40 There is no built-in limit to the number of functions you can enroll

    41 in this list; however, after every group of 32 functions is enrolled,

    42 <<atexit>> will call <<malloc>> to get space for the next part of the

    43 list.   The initial list of 32 functions is statically allocated, so

    44 you can always count on at least that many slots available.

    45 

    46 RETURNS

    47 <<atexit>> returns <<0>> if it succeeds in enrolling your function,

    48 <<-1>> if it fails (possible only if no space was available for

    49 <<malloc>> to extend the list of functions or the library globals could not

    50 be allocated).

    51 

    52 PORTABILITY

    53 <<atexit>> is required by the ANSI standard, which also specifies that

    54 implementations must support enrolling at least 32 functions.

    55 

    56 Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,

    57 <<lseek>>, <<read>>, <<sbrk>>, <<write>>.

    58 */

    59 

    60 #include <stddef.h>

    61 #include <stdlib.h>

    62 #include <reent.h>

    63 

    64 /*

    65  * Register a function to be performed at exit.

    66  * NB. MSVC 5.0 has a built-in prototype for atexit, so we have to use a #define

    67  * to map the name atexit to _epoc32_atexit

    68  */

    69 

    70 /*

    71 @return On Success, returns 0.

    72 		On Failure, returns -1.

    73 */

    74 

    75 EXPORT_C int

    76 _epoc32_atexit (void (*fn)(void))

    77 {

    78   register struct _atexit *p;

    79   struct _reent *rp = _REENT2;

    80   if (!rp)

    81 	return -1; // Memory for library globals is not allocated (errno not set). 

    82  

    83   if ((p = rp->_atexit) == NULL)

    84     rp->_atexit = p = &rp->_atexit0;

    85   if (p->_ind >= _ATEXIT_SIZE)

    86     {

    87       if ((p = (struct _atexit *) malloc (sizeof *p)) == NULL)

    88 		return -1;

    89       p->_ind = 0;

    90       p->_next = rp->_atexit;

    91       rp->_atexit = p;

    92     }

    93   p->_fns[p->_ind++] = fn;

    94   return 0;

    95 }

    96 

    97 EXPORT_C void 

    98 _atexit_processing_r (struct _reent *rp)

    99 {

   100   register struct _atexit *p;

   101   register int n;

   102 

   103   for (p = rp->_atexit; p; p = p->_next)

   104     for (n = p->_ind; --n >= 0;)

   105       (*p->_fns[n]) ();

   106   if (rp->__cleanup)

   107     (*rp->__cleanup) (rp);

   108 }