concurrency in mongrel

[Mr_Tibs]

Hi,

I would like to know if it is possible to implement concurrency in
mongrel. I have a simple controller in my application which writes
data to a file. How can I synchronize the file access?
I've read a few posts on the net regarding the issue, and everyone is
saying that it should not be done since Rails is not thread-safe.
However, this seems to be a pretty common thing. Is there no solution
for this problem?

Thanks,
Tiberiu