[concurrency-interest] OpenJDK Project Loom - lightweight threads for Java

Andrig Miller anmiller at redhat.com
Wed Oct 25 15:45:51 EDT 2017


On Wed, Oct 25, 2017 at 1:34 PM, Joshua Bloch <jbloch at gmail.com> wrote:

> This is very similar in spirit to the "many-to-few" threading model that
> was popular in the '90s. You can read about it in Butenhof's *Programming
> with POSIX Threads (Addison-Wesley, 1997)*, §5.6.3. The concept pretty
> much died on the vine when kernel threads got faster and cheaper, but
> everything old is new again.
>

​Solaris had a M-to-N threading model, at least at one point, but I'm not
sure if they kept that in the latest versions.

Andy
​

>
> BTW, I believe that by far the most important thing this project could do
> for the average Java programmer is to provide yield iterators, à la C#.
> Writing your own iterator is difficult, and writing one for collections
> whose traversal is inherently recursive is extremely difficult: you have to
> translate the recursive algorithm into an iterative one by maintaining an
> explicit stack instead of using the thread's stack. Giving people yield
> iterators makes it trivial to write iterators. This should be a tier 1 use
> case: If a proposed solution can't handle it, the solution should be
> repaired or discarded.
>
> Josh
>
> On Wed, Oct 25, 2017 at 11:42 AM, Andrig Miller <anmiller at redhat.com>
> wrote:
>
>>
>>
>> On Wed, Oct 25, 2017 at 11:31 AM, thurstonn <thurston at nomagicsoftware.com
>> > wrote:
>>
>>> Love it.
>>>
>>> BTW, for those with institutional memory, isn't that what "green threads"
>>> more or less were meant to be, back in the earlier days of Java?  Before
>>> my
>>> time, and I never used them . . .
>>>
>>
>> ​If memory serves me correctly, green threads were only present for
>> platforms that didn't have threads in their kernel.
>>
>> Andy
>>>>
>>>
>>>
>>>
>>> --
>>> Sent from: http://jsr166-concurrency.10961.n7.nabble.com/
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>>
>>
>>
>> --
>> Andrig (Andy) T. Miller
>> Global Platform Director, Middleware
>> Red Hat, Inc.
>>
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>>
>


-- 
Andrig (Andy) T. Miller
Global Platform Director, Middleware
Red Hat, Inc.
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