How do I execute SystemVerilog code at garbage collection?

Question

I have a SystemVerilog class that encapsulates a C++ class using a chandle and the DPI. I want to be sure that the C++ class’s destructor is called when the SystemVerilog object is destroyed. As far as I can tell, this is not being done automatically and I have to manually call the C++ destructor through the DPI when I think that I no longer need the instance. Not very elegant.

Is there a way to specify that certain code should be run for a SV class at GC? Similar to a Java finalize method.

An interesting question. I've never heard of such a thing. I think you're going to have to do it manually. Or perhaps semi-automatically: could you have a thread that checks for null references and calls the destructor when it detects one? — Matthew Taylor, May 16 '19 at 07:45

score 3 · Accepted Answer · answered May 16 '19 at 07:46

3

There is no construct similar to finalize within SystemVerilog. However, you can register a VPI callback (cbReclaimObj) on the handle. See section 38.36.1 of the 1800-2017 LRM.

answered May 16 '19 at 07:46

dave_59

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This only works if you want to schedule some C/C++ code to run, since you can't invoke SV from VPI. – Tudor Timi May 16 '19 at 11:11
@TudorTimi I think that will be fine for what they have ask for so far. – dave_59 May 16 '19 at 15:41
Mentioned only as a note for others who read the answer and might think of calling SV code when an object gets reclaimed. – Tudor Timi May 16 '19 at 16:00
*Some* tools do allow mixing of VPI and DPI within certain restrictions. – dave_59 May 16 '19 at 20:50
You know my "dream" of being able to call any SV function (even non-DPI exported ones) from VPI to be able to build a true reflection library. – Tudor Timi May 17 '19 at 08:22

How do I execute SystemVerilog code at garbage collection?

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