Hi Alan,
Thanks for taking a look.
On 04/21/2016 10:41 PM, Alan Bateman wrote:
On 21/04/2016 20:52, Rémi Forax wrote:
I remember seeing this codd an thinking that synchronized should do
the job.
I don't believe this use case requires something more complex.
Remi
I've taken a first pass over it and WeakPairMap seems straight-forward
to use but its implementation, with Pair/Weak/Primary/Secondary/Lookup
is complex.
Prior to #ReflectionWithoutReadability then transientReads was
important, less so now although I think we should continue to allow
concurrent lookups.
-Alan
I tried to reduce the complexity of WeakPairMap as much as I could. I
added some docs that describe the architecture. Hopefully this is now
easier to grasp:
http://cr.openjdk.java.net/~plevart/jdk9-dev/Module.WeakSet.multithreadUnsafe/webrev.03/
Another possibility for transientReads and transientExports (but not for
transientUses) could be if each instance of Module object held a unique
long id allocated at its creation from say AtomicLong. You could then
construct maps with Long ids instead of Module(s), but that has a
drawback that some Module (say a system module or a module of an app
server) could accumulate ids from modules long gone (for example when
some app in an app server is redeployed multiple times) so this would be
a memory leak...
a single global WeakPairMap has an advantage over individual WeakSet(s)
per Module instance because it is accessed more frequently so expunging
of stale entries happens more promptly.
Regards, Peter
