Re: LuaTask needs your help

[Daniel Quintela <dq@...>]

Duck escribió:
> It seems to work across TASK_SLOTS_STEP boundaries when I use the test
> code I had before. I tried creating 10 simultanous tasks, then 20, 40, 
> 80,
> 160, 320 -- all good!
:-)
> However, I can't create more than 509 tasks, i.e. 510 in total, including
> the "_main_".
>
> When I call task.create() for the 510th time, I get error -3 (can't 
> create message queue). This happens with PTHREAD_STACK_SIZE set to 1m 
> or to 2m. With the default PTHREAD_STACK_SIZE of 8m I get error -4 
> (can't create os thread) at the 383rd task, presumably because I have 
> exhausted all 3g of virtual memory at that point.
>
> Note that this isn't a new problem -- it exists with the 1.6.1 code as
> well. I didn't realise it before because the segfault after
> (TASK_SLOT_STEP-1) calls to task.create() got in the way :-) I just went
> back to 1.6.1 and compiled with TASK_SLOT_STEP set to 600 in order to see
> what happens: you get err -3 from the 510th call to task.create().
The real error is "EMFILE 24  /* Too many open files */" trying to 
create a pipe inside "QueCreate".
See your Linux limit with "ulimit -n".
Remember that each Queue needs one pipe == two file descriptors.
> About the code itself, I have two suggestions.
>
> Firstly, when you allocate space for the TASK_ENTRYs themselves (not the
> list of pointers to TASK_ENTRYs), you don't check the return value of
> malloc() for NULL.
You are right... but remember it is a "candidate". ;-)
> Secondly, I'd strongly suggest factoring the actual malloc/realloc code
> out into a function so it appears only once. At the moment you are
> repeating code (except for a malloc() versus a realloc() -- and realloc()
> behaves like malloc() when you feed it NULL). This means there are two
> places to introduce errors or discrepancies.
Good idea.
> My 2c.
Thanks,
Daniel