too many open files due to LOADAVG message

[vschiavoni]

The controller sends a LOADAVG message to each splayd.
On PlanetLab, the following can happen:

Seen on planetlab deployment, ple01.fc.univie.ac.at, 25/07/2011:

Command: PING
Command: PING
Command: LOADAVG
Disconnected: splayd.lua:541: attempt to index a nil value
Trying to re-connect to the Controller in average 180 seconds (23 this time).
C daemon: splayd.lua:892: Too many open files in system
End of splayd (C deamon)

At the time of the crash, line 541 was:

local f = string.gmatch(io.open("/proc/loadavg"):read(), "%d+.%d+")

Check if there are pending open file-descriptors (maybe io.open does not lose the FD upon return?).