I mean, OpenMP dates back to 1997 (1998 for C and C++). Apple, however, has never supported it for what can only be selfish reasons (particularly since Clang has a quite good implementation provided by Intel, which can easily be installed on a Mac if you want). GCD came a decade later.
For basic parallelism, nothing beats OpenMP for ease of adapting existing code (often a single "#pragma omp parallel for" directive is enough). Even for more complex parallelism, particularly where per-thread resources need to be managed, OpenMP still provides a much simpler programming model than the alternatives.
For basic parallelism, nothing beats OpenMP for ease of adapting existing code (often a single "#pragma omp parallel for" directive is enough). Even for more complex parallelism, particularly where per-thread resources need to be managed, OpenMP still provides a much simpler programming model than the alternatives.