Hello Monks,

I am working on a perl5 adapter for the gRPC api, using perlxs (https://github.com/joyrex2001/grpc-perl). In this implementation I am passing xs-objects as input to other xs-objects. The problem I have it that when I use these objects, the reference count is not increased, and the objects are de-scoped to early.

As an example, consider the following setup: 
    Grpc::XS::Call                T_PTROBJ
    Grpc::XS::Channel             T_PTROBJ
    Grpc::XS::Timeval             T_PTROBJ

[download]
In the call constructor, I pass both a Channel and Timeval instance, see: 
Grpc::XS::Call
new(const char *class,  Grpc::XS::Channel channel,  \
    const char* method, Grpc::XS::Timeval deadline, ... )
  PREINIT:
    CallCTX* ctx = (CallCTX *)malloc( sizeof(CallCTX) );
    ctx->wrapped = NULL;
  CODE:
    ## some code removed ##
    ctx->wrapped = grpc_channel_create_call(
              channel->wrapped, NULL, GRPC_PROPAGATE_DEFAULTS,
              completion_queue, method, host_override, 
              deadline->wrapped, NULL);

    RETVAL = ctx;
  OUTPUT: RETVAL

[download]
When the constructor is called, the timeval object is already out-of-scope, and gets dereferenced by perl. However, this is actually not correct, since it's only out of scope in perl, not in my xs scope.

I think the best way forward would be to increase the refcount of the object so the object is not destoyed yet, any tips how to do that? Or maybe there is another approach?

Gr., Vincent

In reply to PerlXS typemap and reference counting by joyrex2001

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