static VALUE initialize(VALUE self, VALUE io)
{
struct readerdata *reader;
Data_Get_Struct(self, struct readerdata, reader);
if (reader->info) {
png_destroy_read_struct(&reader->png, &reader->info, NULL);
allocate2(reader);
reader->locked = 0;
}
reader->source_io = io;
png_set_read_fn(reader->png, (void*)io, read_data);
png_read_info(reader->png, reader->info);
png_set_packing(reader->png);
png_set_strip_16(reader->png);
png_set_expand(reader->png);
png_read_update_info(reader->png, reader->info);
reader->scale_width = png_get_image_width(reader->png, reader->info);
reader->scale_height = png_get_image_height(reader->png, reader->info);
return self;
}
static VALUE allocate(VALUE klass)
{
struct readerdata *reader;
VALUE self;
self = Data_Make_Struct(klass, struct readerdata, mark, deallocate, reader);
allocate2(reader);
return self;
}
int
main(void)
{
char * b = NULL;
// This fails because allocate1 changes the _value_ of the passed parameter,
// not the value pointed by the passed parameter.
allocate1(b);
printf("Allocate 1: %s\n", b);
b = NULL;
// This is OK, because the allocate2 changes the value _pointed_ by the passed parameter.
allocate2(&b);
printf("Allocate 2: %s\n", b);
b = NULL;
}
int main (int argc, char const *argv[])
{
int * ptr1;
int * ptr2;
bool allocate1Success = false;
bool allocate2Success = false;
try
{
allocate1(10, ptr1);
allocate1Success = true;
}
catch(std::bad_alloc &e)
{
}
if (allocate1Success)
delete [] ptr1;
allocate2(10, ptr1, ptr2);
/* code */
return 0;
}
