Ken McDonell wrote:
Apologies for my tardiness in responding, but I'm travelling at the
moment (typing this on a train and then on a ferry somewhere in Norway).
Sounds like fun :)
On 3/09/2010 5:39 AM, Frank Ch. Eigler wrote:
...
OK, then it looks like we'd have at least a few separate pieces to
work on:
* extensions to the PMCD<->PMDA API/protocol to allow PMDAs to push
event data, and corresponding extensions for PMclients<->PMCD
I'd really like to see some more discussion on how people think this is
going to work. None of the PCP libraries are thread-safe (again a
deliberate design decision at the original point of conception),
I've made a brief survey of the place in the libpcp code which are not
threadsafe; there's *lots* of them but most are easily fixed without
breaking external interfaces. I'd estimate a few weeks' work is
involved. I'm interested in helping on this for my own reasons (I'd
like kmchart to be more robust when communication with pmdas is disrupted).
and
asynchronous delivery of data from pmdas through pmcd to clients
increases the likelihood that people will want to use multiple threads
to handle PCP calls. There are some asynchronous calls that were
grafted onto libpcp later on, but these have very little use in existing
code and no QA coverage.
They're also a right bugger to program with, as we've discovered. I
would be happy to see them deprecated in favour of full libpcp thread
safety.
--
Greg.
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