Re: [naviserver-devel] Upload Progress

[Vlad S. <vl...@cr...>]

It was kind of random, sometimes SIGBUS, next time SIGEGV, it needs 
another round of testing. The goal was just simple replace with and see 
if aio_write may work, looks like it does not.

I checked samba and squid, they use some kind of high level wrappers 
around AIO, most of the time their own re-implemenation using threads.

Will it be more generic way just to set upper limit, if we see that 
upload exceeds that limit, pass control to conn thread and let it finish 
reading, this way, even spooling to file will work, because each upload 
conn thread will use their own file and will not hold driver thread.

Every conn thread calls NsGetRequest which uses SockRead, so somewhere 
in the driver.c we can check for max upload limit and mark Sock for conn 
queueing, so NsGetRequest will finish upload.

Yes, too many connections will take all threads but that's how it works 
anyway, nsd can be configured with maxconn that corresponds to any 
particular system/load.

Zoran Vasiljevic wrote:
> 
> Am 02.01.2006 um 19:13 schrieb Vlad Seryakov:
> 
>> I did very simple test, replaced write with aio_write and at the  end 
>> checked aio_error/aio_return, they all returned 0 so mmap  should work 
>> because file is synced. when i was doing aio_write i  used aio_offset, 
>> so each aio_write would put data into separate  region on the file.
>>
>> Unfortunately i removed modified driver.c by accident, so i will  have 
>> to do it again but something is not right in simply replacing  write 
>> with aio_write and mmap. Without mmap, GetForm will have to  read the 
>> file manually and parse it, it makes it more complicated  and still, 
>> if writes are not complete we may get SIGBUS again.
>>
>> The problem i see here i cannot be sure that all writes are  
>> completed, aio_error/aio_return are used to check only one last  
>> operation, not the batch of writes.
> 
> 
> Hmmm... that means that before writing the next chunk, you should  check 
> the
> status of the last and skip if still  not written?
> 
> OTOH, how come you get SIGBUS? And where? Normally this might be only
> if you mmap the file as some structure, not char array?
> 
> Zoran
> 
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-- 
Vlad Seryakov
571 262-8608 office
vl...@cr...
http://www.crystalballinc.com/vlad/