<div dir="ltr"><div dir="ltr"><div>hi,</div><div><br></div><div>I would say the problem comes from you declaring send_test_class as static in both files, so 2 independent variables are created.</div><div><br></div><div>What you can do is declaring send_test_class without "static" in the first file:</div><div><div dir="ltr">t_class *send_test_class;</div><div dir="ltr"><br></div><div>then using the "extern" keyword in the second file:</div><div>extern t_class *send_test_class;</div><div><br></div><div>Even better, you could create a header file like "sender_test_class.h", in which you put both the "extern" class declaration and <br></div><div>the definition of the t_send_test structure, so you don't have to repeat yourself (you'll still need to actually declare the class, without "extern", in the first file).<br></div><div><br></div><div>You also need to be sure that the first class is loaded before, like:</div><div>[declare -lib sender -lib receiver]</div><div>else the receiver object won't load because of link error due to missing symbol "send_test_class".<br></div></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Le mar. 19 janv. 2021 à 21:39, Miller Puckette via Pd-dev <<a href="mailto:pd-dev@lists.iem.at">pd-dev@lists.iem.at</a>> a écrit :<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">That's indeed the difference - a c object like "send_test_class" can't<br>
be shared beteen different object modules loaded separately into Pd. This<br>
is one reason people have sometimes put multiple externals into a single<br>
object file.<br>
<br>
You could have both externs have the same "family name" (like<br>
"array define" and "array set") - then they can both be defined in the<br>
same C object file "binarytree.[extent]".<br>
<br>
cheers<br>
Miller<br>
<br>
On Tue, Jan 19, 2021 at 11:38:22AM -0800, Eric Lennartson wrote:<br>
> Hello all,<br>
> <br>
> I've been working on trying to send data between different externals, but<br>
> I'm not doing something quite right. I've looked at the code in d_global.c<br>
> as well as for send and receive.<br>
> The only difference I can see is that mine is not all in the same .c file<br>
> while in the pd source it is.<br>
> <br>
> Here's the external with the data. Just an int for now, but it will be<br>
> holding a binary tree later.<br>
> <br>
> static t_class *send_test_class;<br>
> typedef struct _send_test {<br>
> t_object x_obj;<br>
> t_symbol* name;<br>
> int value;<br>
> }t_send_test;<br>
> <br>
> static void *send_test_new(t_symbol *s, t_floatarg f) {<br>
> t_send_test *x = (t_send_test *)pd_new(send_test_class);<br>
> x->name = s;<br>
> x->value = f;<br>
> pd_bind(&x->x_obj.ob_pd, s); // bind to the name we're given<br>
> post("send_test created with name %s, and value %d", x->name->s_name,<br>
> x->value);<br>
> return(x);<br>
> }<br>
> <br>
> static void send_test_free(t_send_test *x) {<br>
> pd_unbind(&x->x_obj.ob_pd, x->name); // unbind when deleted<br>
> }<br>
> <br>
> void send_test_setup(void) {<br>
> send_test_class = class_new(gensym("send_test"),<br>
> (t_newmethod)send_test_new,<br>
> (t_method)send_test_free,<br>
> sizeof(t_send_test),<br>
> CLASS_NOINLET,<br>
> A_DEFSYM,<br>
> A_DEFFLOAT,<br>
> 0);<br>
> }<br>
> <br>
> And here's the receiver.<br>
> <br>
> static t_class *send_test_class;<br>
> <br>
> static t_class *rcv_test_class;<br>
> <br>
> typedef struct _send_test {<br>
> t_object x_obj;<br>
> t_symbol* name;<br>
> int value;<br>
> }t_send_test;<br>
> <br>
> typedef struct _rcv_test {<br>
> t_object x_obj;<br>
> t_symbol* name;<br>
> <br>
> int value;<br>
> } t_rcv_test;<br>
> <br>
> static void *rcv_test_new(t_symbol *s) {<br>
> t_rcv_test *x = (t_rcv_test *)pd_new(rcv_test_class);<br>
> x->name = s;<br>
> t_send_test* sender = (t_send_test*)pd_findbyclass(x->name,<br>
> send_test_class);<br>
> <br>
> x->value = sender->value;<br>
> post("sender value is %d", sender->value);<br>
> post("rcv_test created with name %s, and value %d", x->name->s_name,<br>
> x->value);<br>
> return(x);<br>
> }<br>
> <br>
> static void rcv_test_free(t_rcv_test *x) {}<br>
> <br>
> void rcv_test_setup(void) {<br>
> rcv_test_class = class_new(gensym("rcv_test"),<br>
> (t_newmethod)rcv_test_new,<br>
> (t_method)rcv_test_free,<br>
> sizeof(t_rcv_test),<br>
> CLASS_NOINLET,<br>
> A_DEFSYM,<br>
> <br>
> 0);<br>
> }<br>
> <br>
> What exactly is it that I'm doing wrong?<br>
<br>
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