Re: [HACKERS] [PATCHES] PL instrumentation plugin and Rendezvous variable support - version 2
[EMAIL PROTECTED] [EMAIL PROTECTED] writes:
This is an updated version of the PL instrumentation plugin patch that I
submitted on July-28. The new version re-implements the plugin loader
code to use rendezvous variables as suggested by Tom Lane (thanks Tom,
very elegant design).
Applied with a few small changes --- I renamed the GUC variables after a
suggestion by Simon Riggs, and fixed things so that
backend_load_libraries could actually do something useful (you had it as
PGC_POSTMASTER, making it effectively no more flexible than the existing
preload_libraries list).
The only change that will directly impact your code is that I thought
it'd be better to provide plpgsql_exec_error_callback and
exec_assign_expr as separate fields instead of arguments to func_setup,
viz
if (*plugin_ptr)
{
(*plugin_ptr)-error_callback = plpgsql_exec_error_callback;
(*plugin_ptr)-assign_expr = exec_assign_expr;
if ((*plugin_ptr)-func_setup)
((*plugin_ptr)-func_setup)(estate, func);
}
I'm not totally wedded to this if you don't like it, but my thought was
that passing these as arguments to func_setup would mean a lot of pain
anytime we wanted to change the set of function pointers provided:
every plugin would need textual changes whether it actually used these
functions or not.
I have not implemented any support for unloading shared libraries. Once
we've finalized the design for rendezvous variables, I'll submit a
separate documentation patch.
I added docs for the GUC variables but didn't do more than that. I
think the code comments are probably sufficient as far as rendezvous
variables and PLpgSQL_plugin go ... did you have something else in mind?
regards, tom lane
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Re: [HACKERS] [PATCHES] PL instrumentation plugin and Rendezvous variable
Applied with a few small changes --- I renamed the GUC variables after a
suggestion by Simon Riggs, and fixed things so that
backend_load_libraries could actually do something useful (you had it as
PGC_POSTMASTER, making it effectively no more flexible than the existing
preload_libraries list).
'Doh! That was a cut/paste error on my part. Thanks.
The only change that will directly impact your code is that I thought
it'd be better to provide plpgsql_exec_error_callback and
exec_assign_expr as separate fields instead of arguments to func_setup,
viz
if (*plugin_ptr)
{
(*plugin_ptr)-error_callback = plpgsql_exec_error_callback;
(*plugin_ptr)-assign_expr = exec_assign_expr;
if ((*plugin_ptr)-func_setup)
((*plugin_ptr)-func_setup)(estate, func);
}
I'm not totally wedded to this if you don't like it, but my thought was
that passing these as arguments to func_setup would mean a lot of pain
anytime we wanted to change the set of function pointers provided:
every plugin would need textual changes whether it actually used these
functions or not.
Good idea, those two function pointers are sort of necessary-evil required only by the debugger plugin (other plugins presumably won't need them).
I have not implemented any support for unloading shared libraries. Once
we've finalized the design for rendezvous variables, I'll submit a
separate documentation patch.
I added docs for the GUC variables but didn't do more than that. I
think the code comments are probably sufficient as far as rendezvous
variables and PLpgSQL_plugin go ... did you have something else in mind?
I'll look around the existing documentation to see if I can find an appropriate place, but we don't really have an implementor's guide.
Thanks for your help and suggestions.
-- Korry
--
Korry Douglas [EMAIL PROTECTED]
EnterpriseDB http://www.enterprisedb.com
