[Win32utils-devel] Patch for Callback [win32utils-Bugs-21275]

[Berger, Daniel]

Hi Park, 

> -----Original Message-----
> From: win32utils-devel-bounces at rubyforge.org 
> [mailto:win32utils-devel-bounces at rubyforge.org] On Behalf Of 
> Heesob Park
> Sent: Sunday, July 20, 2008 8:49 PM
> To: Development and ideas for win32utils projects
> Subject: [Win32utils-devel] Patch for Callback [win32utils-Bugs-21275]
> 
> Hi,
> 
> Here is a patch for callback support:
> 
> --- api.c.org   2008-07-21 11:30:55.000000000 +0900
> +++ api.c       2008-07-21 11:29:49.000000000 +0900
> @@ -470,16 +470,18 @@
>     DWORD params[1];
>  } PARAM;
> 
> -static VALUE ActiveCallback;
> +static VALUE CallbackTable = Qnil;
> 
> -DWORD CallbackFunction(PARAM param)
> +DWORD CallbackFunction(void* fptr,PARAM param)
>  {
>      VALUE v_proto, v_return, v_proc, v_retval;
>      VALUE argv[16];
>      int i, argc;
>      char *a_proto;
>      char *a_return;
> +    VALUE ActiveCallback;
> 
> +    ActiveCallback = 
> rb_hash_aref(CallbackTable,INT2NUM((DWORD)fptr));
>      if(!NIL_P(ActiveCallback)){
>          v_proto = rb_iv_get(ActiveCallback, "@prototype");
>          a_proto = RSTRING(v_proto)->ptr; @@ -547,6 +549,43 @@
>      return 0;
>  }
> 
> +DWORD CallbackFunction1(PARAM param)
> +{
> +    return CallbackFunction(CallbackFunction1,param);
> +}
> +DWORD CallbackFunction2(PARAM param)
> +{
> +    return CallbackFunction(CallbackFunction2,param);
> +}
> +DWORD CallbackFunction3(PARAM param)
> +{
> +    return CallbackFunction(CallbackFunction3,param);
> +}
> +DWORD CallbackFunction4(PARAM param)
> +{
> +    return CallbackFunction(CallbackFunction4,param);
> +}
> +DWORD CallbackFunction5(PARAM param)
> +{
> +    return CallbackFunction(CallbackFunction5,param);
> +}
> +DWORD CallbackFunction6(PARAM param)
> +{
> +    return CallbackFunction(CallbackFunction6,param);
> +}
> +DWORD CallbackFunction7(PARAM param)
> +{
> +    return CallbackFunction(CallbackFunction7,param);
> +}
> +DWORD CallbackFunction8(PARAM param)
> +{
> +    return CallbackFunction(CallbackFunction8,param);
> +}
> +
> +static void *CallbackArray[] = {CallbackFunction1,CallbackFunction2,
> +       
> CallbackFunction3,CallbackFunction4,CallbackFunction5,Callback
> Function6,
> +       CallbackFunction7,CallbackFunction8};
> +
>  /*
>   * call-seq:
>   *    Win32::API#call(arg1, arg2, ...)
> @@ -563,7 +602,7 @@
>     VALUE v_proto, v_args, v_arg, v_return;
>     Win32API* ptr;
>     unsigned long return_value;
> -   int i = 0;
> +   int i,j;
> 
>     struct{
>        unsigned long params[16];
> @@ -618,8 +657,17 @@
>                 }
>                 break;
>              case _T_CALLBACK:
> -               ActiveCallback = v_arg;
> -               param.params[i] = (LPARAM)CallbackFunction;
> +                if(CallbackTable==Qnil) CallbackTable = 
> rb_hash_new();
> +                for(j=0;j<8;j++) {
> +
> if(rb_hash_aref(CallbackTable,INT2NUM((DWORD)CallbackArray[j]))==Qnil)
> {
> +                    param.params[i] = (LPARAM)CallbackArray[j];
> +
> rb_hash_aset(CallbackTable,INT2NUM((DWORD)CallbackArray[j]),v_arg);
> +                     break;
> +                   }
> +                   if(j==7) {
> +                       rb_raise(rb_eArgError,"Callback function table
> overflow");
> +                   }
> +                }
>                 break;

Hi Park

Thanks for this. However, I'm wondering if we have to hard code an 8
callback limit. Can't we dynamically add callbacks to the
CallbackArray[] as needed? If we need to use a struct to store
additional information, and store an array of those structs internally,
that's fine.
 
> I'm not sure this will fix segfault in test suite, but it 
> will fix multiple callback handling problem.
> Here is test code
> 
>       require 'win32/api'
>       include Win32
> 
>       api_ew   = API.new('EnumWindows', 'KP', 'L', 'user32')
>       api_gwt  = API.new('GetWindowText', 'LPI', 'I', 'user32')
> 
>       callback1 = API::Callback.new('LP', 'I'){ |handle, param|
>          	buf = "\0" * 200
>          	p "CALLBACK1"
>             api_gwt.call(handle, buf, 200);
>            buf.index(param).nil? ? true : false
>       }
>       callback2 = API::Callback.new('LP', 'I'){ |handle, param|
>          	buf = "\0" * 200
>          	p "CALLBACK2"
>             api_gwt.call(handle, buf, 200);
>            buf.index(param).nil? ? true : false
>       }
> 
>       a = Thread.new {
>          api_ew.call(callback1, 'UEDIT32')
>       }
>       b = Thread.new {
>          api_ew.call(callback2, 'UEDIT32')
>       }
>       a.join
>       b.join

Thanks, I'll create some tests modelled on this.

Regards,

Dan


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