Is there? There are multiple papers describing cond vars implementations. Many have been found to have errors after years.
I'm sure the BSDs have posix cond vars implementations, but they won't use futexes but some BSD specific signalling primitive, and will likely have different scalability profiles than the one in gilibc, which has been tuned mostly for the needs of Red Hat, Oracle and other big Linux vendors.
I'm sure the BSDs have posix cond vars implementations, but they won't use futexes but some BSD specific signalling primitive, and will likely have different scalability profiles than the one in gilibc, which has been tuned mostly for the needs of Red Hat, Oracle and other big Linux vendors.