Ara.T.Howard / noaa.gov wrote: > On Tue, 10 May 2005, Glenn Parker wrote: >> >> Not very thread-safe, at least not in your example's implementation. > > even this is not: > > class C > attr_accessor :x > end Yes, if instances of class C are to be accessed from multiple threads, then some extra care is needed, but that depends very much on the actual uses of the class. A lot of classes never need to worry about it, even in highly threaded applications. In the OP's code, it's clear that all threads using class Text will be in contention for Text.color. In that style of interface, a per-thread variable is practically mandatory. -- Glenn Parker | glenn.parker-AT-comcast.net | <http://www.tetrafoil.com/>