[Swig-user] "custom" constructor and destructor

[marco g. <mar...@gm...>]

Hello,

i have to "swig" a c library with several structures
that have some fields are pointers to some
other malloc-ed memory.

for example,

struct foo {
  char *boo;
}

in c they are allocated ad deallocated with
pair of functions

struct foo* CreateFoo()
{
     struct foo *ret = malloc(sizeof (*ret));
     ret ->boo = malloc(100);
     return ret;
}

void DeleteFoo(struct foo* f)
{
      free(f->boo);
      free(f);
}

I am targeting cshap; to avoid having memory leaks
and invalid structures, and aving to call manually
DeleteFoo(), I am doing this:

// this is to avoid invalid foo allocated by new foo()
%nodefaultctor foo;

// this is to get the swigclass to own the memory
%newobject CreateFoo;

//this is to call lib.DeleteFoo when the object is destroyed
%typemap(csdestruct, methodname="Dispose") foo {
     lock (this) {
         if(swigCPtr.Handle != IntPtr.Zero && swigCMemOwn) {
             swigCMemOwn = false;
             lib.DeleteFoo(this);
         }
         swigCPtr = new HandleRef(null, IntPtr.Zero);
         GC.SuppressFinalize(this);
     }
}

Is this correct?
Any better way to do ?
Can I factor the typemap(csdestruct ...)
instead of compypaste for every class in the library?

Thank You in advance..
   Ciao, Marco.


-- 
"Reality continues to ruin my life." - Calvin.