Quasar / Pulsar
Languages and libraries
concurrency library for the jvm
SHOW HN2013
How HN took it
4 positive, 18 neutral or asking, 0 mixed, 6 critical, out of 28 comments about the project. Thread score -0.01.
Idea: 1 for, 3 againstExecution: 0 for, 2 againstPerformance: 1 for, 0 againstDesign: 0 for, 1 against
The thread, comment by comment
Each row is a top-level comment and its replies, in HN's order. Select a cell to open that comment on HN.
positive neutral or mixed critical about another commenter or something else the maker
What HN said
What people liked
Lightweight threads are a clear improvement over OS threads for memory and switching
From 2 comments
Good question. In general the non-preemptive green-thread/fiber/lightweight-thread is a pretty well understood notion. Some OS support it, e.g. Windows supports manually…
ww520 on HNIn general, higher levels have more knowledge of the specific problem domain, and can therefore make more assumptions, while the kernel has to cater to all needs. In this…
pron on HN
Erlang-style selective receive is a useful feature
From 1 comment
Selective Receive sounds great. Any idea how to handle messages that continue to pile up behind your actor when they're never handled? Do they get culled somehow after a period…
shinolajla1234 on HN
Objections
Cannot isolate GC pauses per actor like Erlang on HotSpot
From 1 comment
Jetlang doesn't offer lightweight-threads. It uses an event-driven processing of messages (like Akka), so fibers can't block and you can't do selective receives. The JVM's GC…
pron on HN
Cooperative threads are not true preemptive scheduling
From 1 comment
This starts turning into a semantics problem. GHC is a compiler that modifies the code it has compiled to add "synchronization points" that are used under a cooperative threading…
saurik on HN
Unbounded mailboxes and lack of supervision are risks
From 2 comments
Selective Receive sounds great. Any idea how to handle messages that continue to pile up behind your actor when they're never handled? Do they get culled somehow after a period…
shinolajla1234 on HNIf you're not replaying unhandled messages, you're not doing selective receive. To quote LYSEFGG, "Ignoring some messages to handle them later in the manner described above is…
shinolajla1234 on HN
Requests
Documentation and Java code examples
From 1 comment
Am i the only one who had to smile at the sentence "At Parallel Universe we develop complex data structures and distributed data grids, which require a lot of low-level…
buster on HN
Distribution story and comparison to Akka
From 1 comment
Looks cool, but what's the distribution story? I'm not sure I understand the comparisons to Akka without one.
alexatkeplar on HN
Questions
Why are lightweight threads more efficient than OS threads
From 1 comment
Ignorant newbie here, but would love to hear views on this: I always treat with great skepticism claims that you can implement an inherent operating system function (eg: threads)…
zmmmmm on HN
How selective receive handles unhandled messages
From 1 comment
Selective Receive sounds great. Any idea how to handle messages that continue to pile up behind your actor when they're never handled? Do they get culled somehow after a period…
shinolajla1234 on HN
Alternatives named
Akka
From 2 comments
Could you enumerate your specific perceived shortcomings of akka that you allude to in blog post?
gtani on HNIf you're not replaying unhandled messages, you're not doing selective receive. To quote LYSEFGG, "Ignoring some messages to handle them later in the manner described above is…
shinolajla1234 on HN
Kilim
From 1 comment
``` There have been several attempts of porting actors to the JVM. Quasar and Pulsar’s main contribution — from which many of their advantages stem — is true lightweight…
rektide on HN
Jetlang
From 1 comment
How does this compare with http://code.google.com/p/jetlang/ ? How does this work with garbage collection? Is the GC per-process ("fiber"), like in Erlang?
oinksoft on HN
Erlang
From 1 comment
http://stackoverflow.com/questions/2708033/technically-why-is-processes-in-erlang-more-efficient-than-os-threads No concrete benchmarks but everything I can find makes the same…
stonemetal on HN