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Re: [Vm-dev] hello

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Eliot Miranda-2

Re: [Vm-dev] hello

Hi Sebastián,

and welcome! Forgive me for not replying earlier.

On Mon, Oct 12, 2015 at 4:54 AM, Sebastián Krynski <[hidden email]> wrote:

Hello my name is Sebastián Krynski from Buenos Aires, Argentina.
Just writing to let you know that I'm starting to work on adding an atomic swap operator in Pharo , guaranteed not to be interrupted by the VM. The operator will be used this way:

a :=: b

meaning 'swap variable a with variable b'.
In order to do this I will be modifying the VM and the Compiler .

I'm working under the direction of INRIA and Gabriela Arévalo.

Give my regards to Gabriela!

One thing is to consider multiple approaches. My friend Maurice Rabb (in the cc line) did a concurrent VM for a smalltalk-like language a few years ago now and he used something more akin to compare-and-swap. e.g.

var ?= value := expr

would set var to expire if it held the value var and answer true, otherwise it would not change the value of var and answer false.

Talk also to Igor Stasenko (also in the cc line) who has thought a lot about this and has written a prototype image-level scheduler based on (IIRC) a couple of different atomic operators.

Another thing to think about is goals. Making it convenient to implement lock-free data structures such as a lock-free thread-safe dictionary would be very good. Make sure you look at Cliff Click's work, e.g. at Azul such as A Lock-Free, Wait-Free Hash Table. Google cliff click azul lock-free data structures.

Finally, decide where you want to discuss this. My preference is for you to at least include vm-dev, since this is definitely to do with the byte code set and the VM. But the data structure piece and the use is more generally useful. So I see no problem including vm-dev, pharos-dev and the general purpose squeak list. The more the merrier.

A couple of questions: How long will your work with Gabriela last? Is this a master's project or a PhD or...?

Good luck!

_,,,^..^,,,_

best, Eliot

skrynski

Re: [Vm-dev] hello

Hi Eliot, I'm sorry for the delay, I seem to have missed this email.

Just to put you in context, the idea of implementing this operator came from Igor.

I think the goals are being able to implement lock free algorithms so in the future we can have real concurrent threads. I'll make sure to read the works you suggested.

About the communication, I will write different mails one per list (pharodev, squeakdev ,squeakvm and rmod). Is that ok?

By the way,this is for my Phd (I'm just starting)

Seba

2015-10-12 16:04 GMT-03:00 Eliot Miranda <[hidden email]>:

Hi Sebastián,

and welcome! Forgive me for not replying earlier.

On Mon, Oct 12, 2015 at 4:54 AM, Sebastián Krynski <[hidden email]> wrote:

Hello my name is Sebastián Krynski from Buenos Aires, Argentina.
Just writing to let you know that I'm starting to work on adding an atomic swap operator in Pharo , guaranteed not to be interrupted by the VM. The operator will be used this way:

a :=: b

meaning 'swap variable a with variable b'.
In order to do this I will be modifying the VM and the Compiler .

I'm working under the direction of INRIA and Gabriela Arévalo.

Give my regards to Gabriela!

One thing is to consider multiple approaches. My friend Maurice Rabb (in the cc line) did a concurrent VM for a smalltalk-like language a few years ago now and he used something more akin to compare-and-swap. e.g.

var ?= value := expr

would set var to expire if it held the value var and answer true, otherwise it would not change the value of var and answer false.

Talk also to Igor Stasenko (also in the cc line) who has thought a lot about this and has written a prototype image-level scheduler based on (IIRC) a couple of different atomic operators.

Another thing to think about is goals. Making it convenient to implement lock-free data structures such as a lock-free thread-safe dictionary would be very good. Make sure you look at Cliff Click's work, e.g. at Azul such as A Lock-Free, Wait-Free Hash Table. Google cliff click azul lock-free data structures.

Finally, decide where you want to discuss this. My preference is for you to at least include vm-dev, since this is definitely to do with the byte code set and the VM. But the data structure piece and the use is more generally useful. So I see no problem including vm-dev, pharos-dev and the general purpose squeak list. The more the merrier.

A couple of questions: How long will your work with Gabriela last? Is this a master's project or a PhD or...?

Good luck!
_,,,^..^,,,_
best, Eliot