#681: Cannot use a PIR object for IO
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Reporter: flh | Owner: whiteknight
Type: bug | Status: assigned
Priority: normal | Milestone:
Component: none | Version: trunk
Severity: medium | Keywords:
Lang: | Patch:
Platform: |
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Comment(by whiteknight):
Okay, I've figured out the problem. I'm sorry that it's taken me so long
to do it! The problem, in a nutshell, is that the IO system currently uses
Parrot_PCCINVOKE to perform the sub call instead of calling the more
versatile Parrot_invoke_from_sig_object() family of functions.
Parrot_PCCINVOKE is designed to run methods which are written in C, not
methods which are written in PIR. You can see around line
src/call/pcc.c:2870 that Parrot_PCCINVOKE calls the invoke vtable method
on the Sub PMC, but never calls runops. For NCI subs, invoke executes the
function directly. However, for PIR-defined Subs, it only sets up the
execution environment for later execution by the current runcore (if we're
using the invokecc opcode) or from the runops* family of functions.
The short answer is that if we switch the call in Parrot_io_reads from
Parrot_PCCINVOKE to Parrot_pcc_invoke_method_from_c_args, the example code
you posted magically works. I'm attaching a patch to that affect in a
moment.
The long answer is that this function is considered "experimental", and it
likely won't work perfectly until Allison's pcc_rewiring branch gets
merged into trunk. In fact, I can tell you for certain that if we switch
over all the calls in src/io/api.c, it will cause unexplained segfaults
and test failures, so most of the API functions cannot be used with PIR-
defined objects. Since Allison is converting all the Parrot_PCCINVOKE
calls as part of her branch work, this ticket should be resolved as soon
as she merges.
--
Ticket URL: <https://trac.parrot.org/parrot/ticket/681#comment:3>
Parrot <https://trac.parrot.org/parrot/>
Parrot Development
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