On 10/02/2015 06:57 PM, Martin Sebor wrote: > Readdir isn't required to be thread-safe (it may reference global > data) so calling it in multiple threads even with a different dirp > argument is undefined. A thread-unsafe implementation can meet the > POSIX requirement and still access global data but without locking.
A readdir implementation which is not thread-safe when used with different directory streams is just buggy. It may be conforming, but so is an implementation that always fails with EOVERFLOW. > The Solaris implementation, for example, is explicitly documented > as thread unsafe. MT-safety is ambiguous for functions which operate on pointer arguments. It is not clear if it is permitted to call the function without synchronization on overlapping objects. memcpy has the same thread-safety level as readdir on Solaris (operations on overlapping objects are not thread-safe, non-overlapping objects are), and is documented to be MT-safe. Florian
