Re: Wrapping a C shared library with Perl and XS

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Re^2: Wrapping a C shared library with Perl and XS by stevieb (Canon) on Mar 28, 2017 at 16:35 UTC
ohhh, right! I completely forgot about that :) Thanks for pointing it out!	[reply]
Re^2: Wrapping a C shared library with Perl and XS by stevieb (Canon) on Mar 29, 2017 at 03:31 UTC
It is honestly a bit elusive to me exactly how and when to `free()` within the XS in the case I've shown explicitly, but using the same repo I used to generate this example tutorial, I'm going to play around a bit here. I will post back here and update my OP once I figure it out. As always, feedback welcome ;)	[reply] [d/l]
Re^3: Wrapping a C shared library with Perl and XS by Anonymous Monk on Mar 31, 2017 at 20:11 UTC
One of the approaches to freeing memory is to call `free` right after the last usage of a pointer (in our case it's the loop which calls `inline_stack_push(sv_2mortal(newSViv(c_array[i])));`) and set it to `NULL` afterwards. Setting a pointer to NULL serves double purpose: Checking for NULL is very easy, checking if non-NULL pointer is valid is very complex at best If you defensively call `free(c_array)` in another part of the program, `free(NULL)` would be safe on modern `libc`s, while `free` of a `free`d pointer causes memory corruption	[reply] [d/l] [select]
Re^4: Wrapping a C shared library with Perl and XS by stevieb (Canon) on Mar 31, 2017 at 23:23 UTC
Thank you very much AnonyMonk! I especially appreciated the fact you used the term "our" in your reply, as it shows that even Anonymous Monk cares and has interest ;) I'll pull this back out over the weekend sometime and play around with it and run things against `valgrind`. Your feedback is appreciated in my curve of learning. I'll update the OP after I've played around.	[reply] [d/l]
Re^5: Wrapping a C shared library with Perl and XS by Anonymous Monk on Apr 06, 2017 at 17:38 UTC
Re^6: Wrapping a C shared library with Perl and XS by stevieb (Canon) on Apr 08, 2017 at 03:34 UTC
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