CGI Hung Process Help!

[Dave Cragg]

On 5 May 2007, at 23:09, Sivakatirswami wrote:

>
> 	repeat until length(PostIn) >= $CONTENT_LENGTH
> 		read from stdin until ""
>     		put it after PostIn
>   	end repeat
>

I'd suspect this part. I used to use this approach, but ran into  
trouble after moving some scripts to a new server. If something  
happens to stall the connection during the read process, you'll be in  
an endless loop, possibly with high CPU usage.

I've started using something like this. It puts a limit on how many  
"empty reads" happen before bailing out.  (I copied this quickly, and  
modified slightly to remove some application specific code. Check  
before using.):

local sPostdata = ""
local sDataRead = false
local sReadCount = 0
local sEmptyReadCount = 0
local sEmptyReadLimit = 200
local sShortRead = false


on startup

  readData
  repeat while sDataRead = false
     wait for messages
   end repeat
   if sShortRead then
        ## exit routine needed here
   end if

   ## carry on

end startup

on readData
    read from stdin for $CONTENT_LENGTH
    put it into tTemp
    add 1 to sReadCount
    if tTemp <> empty then
      put tTemp after sPostdata
     else
       add 1 to sEmptyReadCount

    end if
    if length(sPostdata) < $CONTENT_LENGTH then
      if sEmptyReadCount < sEmptyReadLimit then
        send readData to me in 50 milliseconds
      else
        put true into sDataRead
        put true into sShortRead
      end if
    else
      put true into sDataRead
    end if
end readData