This path adds an additional cache to the module system for caching the location of previously required modules. Since it is embedded in the loop that iterates over all require.paths, this patch also handles the case where require.paths is being modified. The patch also cleans up some code around it. See: https://groups.google.com/forum/#!topic/nodejs-dev/QGGlrvLDHVs
require is caching the compiled code but still stating the filenames. https://groups.google.com/d/topic/nodejs-dev/QGGlrvLDHVs/discussion
Avoids race. openssl s_server is a terrible program.