• zz (8/8) Nov 28 2006 While having a discussion about GC's with a friend, he brought up this
• Sean Kelly (14/19) Nov 28 2006 Don't be. Chris Thomasson may talk a bit big at times, but he has a
• Craig Black (11/28) Nov 29 2006 Why not? If someone has discovered a good GC solution via smart pointer...
• Sean Kelly (6/28) Nov 29 2006 I suppose it depends how the smart pointers are implemented. As D
• Craig Black (5/34) Nov 29 2006 Right. I forgot about that. Specifically, what language features would...
• Sean Kelly (7/40) Nov 29 2006 I'm not sure, without looking at the code. But for general smart
• Craig Black (5/43) Nov 29 2006 Perhaps someone could invent a cleaner solution that doesn't muck up the...

zz <zz zz.com> writes:

While having a discussion about GC's with a friend, he brought up this 
link which I found quite interesting (at the first reading) and I 
thought others would also find it interesting.

I'm still very skeptical of the claims.

http://home.comcast.net/~vzoom/

and some code which I still have to run.

http://home.comcast.net/~vzoom/demos/pc_sample.c

Zz

Sean Kelly <sean f4.ca> writes:

zz wrote:
 While having a discussion about GC's with a friend, he brought up this 
 link which I found quite interesting (at the first reading) and I 
 thought others would also find it interesting.
 
 I'm still very skeptical of the claims.

Don't be.  Chris Thomasson may talk a bit big at times, but he has a 
solid grasp of the problems involved and VZOOM has gotten a lot of 
attention lately from some pretty respectable sources (I think it just 
won some kind of award in a contest sponsored by Sun or some such).  I 
haven't given VZOOM a very close look myself, but what I've heard Chris 
say about it makes me believe that it probably lives up to his claims. 
What makes VZOOM so fast, from what I've heard, is that it almost 
completely avoids the use of memory synchronization instructions through 
the use of some clever tricks, along the lines of RCU + SMR.  Last I 
heard Chris was working on a lock-free GC which sounded fairly 
promising, though it was smart-pointer based and therefore not really 
suitable for D.


Sean

"Craig Black" <cblack ara.com> writes:

"Sean Kelly" <sean f4.ca> wrote in message 
news:ekiu16$1ndk$1 digitaldaemon.com...
 zz wrote:
 While having a discussion about GC's with a friend, he brought up this 
 link which I found quite interesting (at the first reading) and I thought 
 others would also find it interesting.

 I'm still very skeptical of the claims.

 Don't be.  Chris Thomasson may talk a bit big at times, but he has a solid 
 grasp of the problems involved and VZOOM has gotten a lot of attention 
 lately from some pretty respectable sources (I think it just won some kind 
 of award in a contest sponsored by Sun or some such).  I haven't given 
 VZOOM a very close look myself, but what I've heard Chris say about it 
 makes me believe that it probably lives up to his claims. What makes VZOOM 
 so fast, from what I've heard, is that it almost completely avoids the use 
 of memory synchronization instructions through the use of some clever 
 tricks, along the lines of RCU + SMR.  Last I heard Chris was working on a 
 lock-free GC which sounded fairly promising, though it was smart-pointer 
 based and therefore not really suitable for D.

Why not?  If someone has discovered a good GC solution via smart pointers 
and reference counting, why couldn't D leverage this new technology somehow? 
I'm not talking about dumping our current GC for another, but rather 
providing options.  This could probably be done using a mixin that provides 
an overloaded new and delete. (Correct me if I'm wrong.)

I believe that one huge criticism of reference counting was that it was slow 
for multi-threading.  Well, if there is a lock-free algorithm becomes 
available, then that argument can no longer be used.

-Craig 

Sean Kelly <sean f4.ca> writes:

Craig Black wrote:
 "Sean Kelly" <sean f4.ca> wrote in message 
 news:ekiu16$1ndk$1 digitaldaemon.com...
 zz wrote:
 While having a discussion about GC's with a friend, he brought up this 
 link which I found quite interesting (at the first reading) and I thought 
 others would also find it interesting.

 I'm still very skeptical of the claims.

 Don't be.  Chris Thomasson may talk a bit big at times, but he has a solid 
 grasp of the problems involved and VZOOM has gotten a lot of attention 
 lately from some pretty respectable sources (I think it just won some kind 
 of award in a contest sponsored by Sun or some such).  I haven't given 
 VZOOM a very close look myself, but what I've heard Chris say about it 
 makes me believe that it probably lives up to his claims. What makes VZOOM 
 so fast, from what I've heard, is that it almost completely avoids the use 
 of memory synchronization instructions through the use of some clever 
 tricks, along the lines of RCU + SMR.  Last I heard Chris was working on a 
 lock-free GC which sounded fairly promising, though it was smart-pointer 
 based and therefore not really suitable for D.

 
 Why not?  If someone has discovered a good GC solution via smart pointers 
 and reference counting, why couldn't D leverage this new technology somehow? 

I suppose it depends how the smart pointers are implemented.  As D 
doesn't support copy semantics for objects, there is really no way to 
implement traditional smart pointers.  Rather, the reference counting 
has to be done somewhat manually.


Sean

"Craig Black" <cblack ara.com> writes:

"Sean Kelly" <sean f4.ca> wrote in message 
news:ekkja0$i6p$1 digitaldaemon.com...
 Craig Black wrote:
 "Sean Kelly" <sean f4.ca> wrote in message 
 news:ekiu16$1ndk$1 digitaldaemon.com...
 zz wrote:
 While having a discussion about GC's with a friend, he brought up this 
 link which I found quite interesting (at the first reading) and I 
 thought others would also find it interesting.

 I'm still very skeptical of the claims.

 Don't be.  Chris Thomasson may talk a bit big at times, but he has a 
 solid grasp of the problems involved and VZOOM has gotten a lot of 
 attention lately from some pretty respectable sources (I think it just 
 won some kind of award in a contest sponsored by Sun or some such).  I 
 haven't given VZOOM a very close look myself, but what I've heard Chris 
 say about it makes me believe that it probably lives up to his claims. 
 What makes VZOOM so fast, from what I've heard, is that it almost 
 completely avoids the use of memory synchronization instructions through 
 the use of some clever tricks, along the lines of RCU + SMR.  Last I 
 heard Chris was working on a lock-free GC which sounded fairly 
 promising, though it was smart-pointer based and therefore not really 
 suitable for D.

 Why not?  If someone has discovered a good GC solution via smart pointers 
 and reference counting, why couldn't D leverage this new technology 
 somehow?

 I suppose it depends how the smart pointers are implemented.  As D doesn't 
 support copy semantics for objects, there is really no way to implement 
 traditional smart pointers.  Rather, the reference counting has to be done 
 somewhat manually.

Right.  I forgot about that.  Specifically, what language features would 
have to be in place to provide for this?

-Craig 

Sean Kelly <sean f4.ca> writes:

Craig Black wrote:
 "Sean Kelly" <sean f4.ca> wrote in message 
 news:ekkja0$i6p$1 digitaldaemon.com...
 Craig Black wrote:
 "Sean Kelly" <sean f4.ca> wrote in message 
 news:ekiu16$1ndk$1 digitaldaemon.com...
 zz wrote:
 While having a discussion about GC's with a friend, he brought up this 
 link which I found quite interesting (at the first reading) and I 
 thought others would also find it interesting.

 I'm still very skeptical of the claims.

 Don't be.  Chris Thomasson may talk a bit big at times, but he has a 
 solid grasp of the problems involved and VZOOM has gotten a lot of 
 attention lately from some pretty respectable sources (I think it just 
 won some kind of award in a contest sponsored by Sun or some such).  I 
 haven't given VZOOM a very close look myself, but what I've heard Chris 
 say about it makes me believe that it probably lives up to his claims. 
 What makes VZOOM so fast, from what I've heard, is that it almost 
 completely avoids the use of memory synchronization instructions through 
 the use of some clever tricks, along the lines of RCU + SMR.  Last I 
 heard Chris was working on a lock-free GC which sounded fairly 
 promising, though it was smart-pointer based and therefore not really 
 suitable for D.

 Why not?  If someone has discovered a good GC solution via smart pointers 
 and reference counting, why couldn't D leverage this new technology 
 somehow?

 I suppose it depends how the smart pointers are implemented.  As D doesn't 
 support copy semantics for objects, there is really no way to implement 
 traditional smart pointers.  Rather, the reference counting has to be done 
 somewhat manually.

 
 Right.  I forgot about that.  Specifically, what language features would 
 have to be in place to provide for this?

I'm not sure, without looking at the code.  But for general smart 
pointers we'd need C++ style initialization and copy semantics for value 
objects (ie. structs), and an overloaded dot operator would be a "nice 
to have."  The thing is that I actually like that these features are not 
in D.


Sean

"Craig Black" <cblack ara.com> writes:

"Sean Kelly" <sean f4.ca> wrote in message 
news:ekkn5d$o3u$1 digitaldaemon.com...
 Craig Black wrote:
 "Sean Kelly" <sean f4.ca> wrote in message 
 news:ekkja0$i6p$1 digitaldaemon.com...
 Craig Black wrote:
 "Sean Kelly" <sean f4.ca> wrote in message 
 news:ekiu16$1ndk$1 digitaldaemon.com...
 zz wrote:
 While having a discussion about GC's with a friend, he brought up 
 this link which I found quite interesting (at the first reading) and 
 I thought others would also find it interesting.

 I'm still very skeptical of the claims.

 Don't be.  Chris Thomasson may talk a bit big at times, but he has a 
 solid grasp of the problems involved and VZOOM has gotten a lot of 
 attention lately from some pretty respectable sources (I think it just 
 won some kind of award in a contest sponsored by Sun or some such).  I 
 haven't given VZOOM a very close look myself, but what I've heard 
 Chris say about it makes me believe that it probably lives up to his 
 claims. What makes VZOOM so fast, from what I've heard, is that it 
 almost completely avoids the use of memory synchronization 
 instructions through the use of some clever tricks, along the lines of 
 RCU + SMR.  Last I heard Chris was working on a lock-free GC which 
 sounded fairly promising, though it was smart-pointer based and 
 therefore not really suitable for D.

 Why not?  If someone has discovered a good GC solution via smart 
 pointers and reference counting, why couldn't D leverage this new 
 technology somehow?

 I suppose it depends how the smart pointers are implemented.  As D 
 doesn't support copy semantics for objects, there is really no way to 
 implement traditional smart pointers.  Rather, the reference counting 
 has to be done somewhat manually.

 Right.  I forgot about that.  Specifically, what language features would 
 have to be in place to provide for this?

 I'm not sure, without looking at the code.  But for general smart pointers 
 we'd need C++ style initialization and copy semantics for value objects 
 (ie. structs), and an overloaded dot operator would be a "nice to have." 
 The thing is that I actually like that these features are not in D.

Perhaps someone could invent a cleaner solution that doesn't muck up the 
syntax with problematic C++ language features.  D has a habit of doing this.

-Craig