An
adjective describing a
program or
library written such that should it be implemented in a
thread-based
system, it would not
interfere with other
threads (especially
threads running
instances of
itself).
If a
program/
library was written in an
unsafe manner, it might access
global data structures without heed to other
threads possibly accessing the same
global data structures. If it were written in a
safe manner, it would somehow (through
mutexes,
semaphores or
the like)
protect areas of
code that
accessed common
data structures between possibly
co-existing threads.