[armedbear-devel] Better multithreading support (was Re: [Bordeaux-threads-devel] [Updated4] Patch for ABCL against BORDEAUX-THREADS HEAD)
evenson at panix.com
Mon Mar 21 15:04:21 UTC 2011
On 3/21/11 15:21 , Chun Tian (binghe) wrote:
> Hi, Mark
> I'm interesting in your work.
> First, I'd like to know, how to do a "condition variable wait with
> timeout" with your exist work,
It should be pretty easy, as THREADS:OBJECT-WAIT has an optional
parameter for TIMEOUT (see [the Java API for the semantics associated
with this value])
So, one could naively extend my BORDEAUX-THREADS implementation as follows:
(defun condition-wait (condition lock &optional timeout)
(threads:object-wait condition timeout)
But then a wait on the condition variable which exceeded the timeout
would be the same as a thread which was notified, which probably isn't
what we want.
If you don't need to follow the B-T API, then I might go for an
encapsulation [of the actual Condition class] which returns a boolean
indicating whether the wait has returned because the timeout has expired.
I'm not sure of your comfort with ABCL's Java FFI, but I would be happy
to mentor you through an implementation that suits your needs, subject
to possible time delays on my part due to other tasks.
> Second, do you think it's possible to make ABCL supporting some
> atomic operations, something like ATOMIC-INCF or ATOMIC-PUSH, this
> can be very useful to implement some lockless algorithms.
Here, I would use the [atomic lock-free implementation in the JVM],
which could give us such things quite cheaply.
Do you have a Lisp-side API to recommend?
"A screaming comes across the sky. It has happened before, but there
is nothing to compare to it now."
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