Re: [jamboost] Semaphores

From: Vladimir Prus (ghost_at_[hidden])
Date: 2002-11-22 02:49:32

Rene Rivera wrote:
> [2002-11-21] Vladimir Prus wrote:
> 
> 
>>I commonly use "-j 4" flag to bjam, because it's possible to
>>distribute compilation to four machines. Unfortunately, linking
>>is not distributed, and this seems affecting performance ---
>>those four linkers are all accessing the same drive.
>>
>>To overcome this, I plan to adopt the extension described in
>>
>>http://maillist.perforce.com/pipermail/jamming/2002-April/001667.html
>>
>>which allows to serialize executing of certain build actions.
>>
>>Are there any objections?
> 
> 
> I don't see how this can solve your problem.

Simply: it'll make only one linking working at the time.

> How is it that the linking is not distributed?

Because I'm using distcc for distributing compilation. It preprocesses
sources and sends them for compilation to other hosts. But linking is
still done locally.

>>If not, I've a question to Rene. I need to skip targets for which the
>>corresponding semaphore is locked. I.e. instead of extracting it from
>>stack and processing, I'd like to put it to the end of stack. Which way is
>>best? Should I simply store a pointer to the last state?
> 
> 
> Here I don't think that will work. If you put it at the end of the stack
> won't that make it break the build dependency order?

Why, no. You can't build things before it's dependencies are built, but you
can delay building.

> -- I'm a little foggy on the stack code... as I didn't write it... 

I had an impression you were the author...

> Steve
> Anichini did. Steve you still paying attention to this list?

I've got a fresh idea and will try to pursue it right now.

- Volodya