/* * This test program will register the maximum number of exit functions * with atexit(). When this program exits, each exit function should get * called in the reverse order in which it was registered. (If the system * supports more than 25 exit functions, the function names will loop, but * the effect will be the same. Feel free to add more functions if desired) */ #include <stdio.h> #include <stdlib.h> typedef void (*vfuncp) (void); /* All functions call exit(), in order to test that exit functions can call * exit() without screwing everything up. :) */ static void exitfunc0(void) { printf("Executing exitfunc0.\n"); exit(0);} static void exitfunc1(void) { printf("Executing exitfunc1.\n"); exit(0);} static void exitfunc2(void) { printf("Executing exitfunc2.\n"); exit(0);} static void exitfunc3(void) { printf("Executing exitfunc3.\n"); exit(0);} static void exitfunc4(void) { printf("Executing exitfunc4.\n"); exit(0);} static void exitfunc5(void) { printf("Executing exitfunc5.\n"); exit(0);} static void exitfunc6(void) { printf("Executing exitfunc6.\n"); exit(0);} static void exitfunc7(void) { printf("Executing exitfunc7.\n"); exit(0);} static void exitfunc8(void) { printf("Executing exitfunc8.\n"); exit(0);} static void exitfunc9(void) { printf("Executing exitfunc9.\n"); exit(0);} static void exitfunc10(void) { printf("Executing exitfunc10.\n"); exit(0);} static void exitfunc11(void) { printf("Executing exitfunc11.\n"); exit(0);} static void exitfunc12(void) { printf("Executing exitfunc12.\n"); exit(0);} static void exitfunc13(void) { printf("Executing exitfunc13.\n"); exit(0);} static void exitfunc14(void) { printf("Executing exitfunc14.\n"); exit(0);} static void exitfunc15(void) { printf("Executing exitfunc15.\n"); exit(0);} static void exitfunc16(void) { printf("Executing exitfunc16.\n"); exit(0);} static void exitfunc17(void) { printf("Executing exitfunc17.\n"); exit(0);} static void exitfunc18(void) { printf("Executing exitfunc18.\n"); exit(0);} static void exitfunc19(void) { printf("Executing exitfunc19.\n"); exit(0);} static void exitfunc20(void) { printf("Executing exitfunc20.\n"); exit(0);} static void exitfunc21(void) { printf("Executing exitfunc21.\n"); exit(0);} static void exitfunc22(void) { printf("Executing exitfunc22.\n"); exit(0);} static void exitfunc23(void) { printf("Executing exitfunc23.\n"); exit(0);} static void exitfunc24(void) { printf("Executing exitfunc24.\n"); exit(0);} static vfuncp func_table[] = { exitfunc0, exitfunc1, exitfunc2, exitfunc3, exitfunc4, exitfunc5, exitfunc6, exitfunc7, exitfunc8, exitfunc9, exitfunc10, exitfunc11, exitfunc12, exitfunc13, exitfunc14, exitfunc15, exitfunc16, exitfunc17, exitfunc18, exitfunc19, exitfunc20, exitfunc21, exitfunc22, exitfunc23, exitfunc24 }; /* glibc dynamically adds exit functions, so it will keep adding until * it runs out of memory! So this will limit the number of exit functions * we add in the loop below. uClibc has a set limit (currently 20), so the * loop will go until it can't add any more (so it should not hit this limit). */ #define ATEXIT_LIMIT 20 int main ( void ) { int i = 0; int count = 0; int numfuncs = sizeof(func_table)/sizeof(vfuncp); /* loop until no more can be added */ while(count < ATEXIT_LIMIT && atexit(func_table[i]) >= 0) { printf("Registered exitfunc%d with atexit()\n", i); count++; i = (i+1) % numfuncs; } printf("%d functions registered with atexit.\n", count); return 0; }