source: src/tests/init_once.c@ 07c178f0

//
// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// init_once.c --
//
// Author           : Rob Schluntz
// Created On       : Tue Jun 14 15:43:35 2016
// Last Modified By : Peter A. Buhr
// Last Modified On : Sat Jul  9 11:30:29 2016
// Update Count     : 3
//

// want to ensure ctor/dtor called at most once per object.
// whole point of ctor/dtor is that you don't know what's in
// memory when it's first called, so can't rely on member to
// determine if this is true. instead, keep an array
// of addresses that have been constructed and remove the element
// when it's destructed (and vice-versa)

//*** setup
extern "C" {
#define NULL 0
void * malloc(size_t);
void free(void *);
#define assert(cond) if (! (cond)) { printf("Assertion failed: (%s) at %s:%d\n", #cond, __FILE__, __LINE__); abort(); }
void *memset(void *s, int c, size_t n);
}

// dummy type
struct init_once { int * x; };

// array and operations
// const int size = 1024;
#define size 1024
struct array {
        init_once * elems[size];
        int length;
};
void remove(array * arr, init_once * x) {
        for (int i = 0; i < arr->length; i++) {
                if ( arr->elems[i] == x ) {
                        arr->elems[i] = arr->elems[--arr->length];
                        return;
                }
        }
}
void insert(array * arr, init_once * x) {
        assert( arr->length < size );
        arr->elems[arr->length++] = x;
}
int find(array * arr, init_once * x) {
        for (int i = 0; i < arr->length; i++) {
                if ( arr->elems[i] == x ) {
                        return i;
                }
        }
        return -1;
}
void ?{}(array & arr) {
        memset(arr.elems, 0, sizeof(arr.elems));
        arr.length = 0;
}
array constructed;
array destructed;

void ?{}(init_once & x) {
        assert( find( &constructed, &x ) == -1 );
        remove( &destructed, &x );
        insert( &constructed, &x );

        x.x = (int *)malloc(sizeof(int));
}

void ?{}(init_once & x, init_once other) {
        x{};  // reuse default ctor
}

void ^?{}(init_once & x) {
        assert( find( &destructed, &x ) == -1 );
        remove( &constructed, &x );
        insert( &destructed, &x );

        free(x.x);
}
//*** end setup

// test globals
init_once x;
init_once y = x;

void static_variable() {
        static init_once x;
}

int main() {
        // local variables
        init_once x;
        init_once y = x;

        // block scoped variables
        {
                init_once x;
                init_once y = x;
        }

        // loop variables
        for (int i = 0 ; i < 10; i++) {
                init_once x;
                init_once y = x;
        }
        int i = 0;
        while (i < 10) {
                init_once x;
                init_once y = x;
                i++;
        }

        // declared in a switch block with a break
        for (int i = 0; i < 10; i++) {
                switch (10) {
                        case 1: {
                                init_once x;
                                init_once y = x;
                                x{}; // ensure this doesn't execute
                                break;
                        }
                        case 10: {
                                init_once x;
                                init_once y = x;
                        } // fall through
                        default: {
                                init_once x;
                                init_once y = x;
                                break;
                        }
                }
        }

        // labeled break/continue
        L3: for (int k = 0; k < 10; k++) {
                init_once x;
                init_once y = x;
                L1: for (int i = 0; i < 10; i++){
                        init_once x;
                        init_once y = x;
                        L2: for (int j = 0; j < 10; j++) {
                                init_once x;
                                init_once y = x;

                                if (i == 0) continue L1;
                                if (i == 1) continue L2;
                                if (i == 2) break L2;
                                if (i == 3) break L1;
                                if (i == 4) continue L3;
                                if (i == 9) break L3;
                                // if (i == 5) goto ;
                        }
                }
        }

        // labeled break/continue with if
        LL1: for (int k = 0; k < 10; k++) {
                init_once x;
                init_once y = x;
                LL2: for (int i = 0; i < 10; i++){
                        init_once x;
                        init_once y = x;
                        LL3: if( i < 5) {
                                init_once x;
                                init_once y = x;

                                if (i == 0) continue LL2;
                                if (i == 2) break LL3;
                                if (i == 3) break LL2;
                                if (i == 4) continue LL1;
                        } else {
                                if (i == 9) break LL1;
                                // if (i == 5) goto ;
                        }
                }
        }

        // function-scoped static variable
        for (int i = 0; i < 10; i++) {
                static_variable();
        }
}

// Local Variables: //
// tab-width: 4 //
// compile-command: "cfa init_once.c" //
// End: //