nodejs (via libuv) transparently switches from fork to pthread_spawn on Darwin when the options passed support it. The dup2/cloexec is a mess, but there are som

nodejs (via libuv) transparently switches from fork to pthread_spawn on Darwin when the options passed support it. The dup2/cloexec is a mess, but there are some Darwin-specific enhancements to work around it. There is work done to make it also do the same on Linux, but seems it hasn’t been merged yet. The reason glibc uses clone is that it can specify an extra flag to avoid some undefined behavior inherent in the way vfork was originally designed, so it can get all of the equivalent speed with none of the pointy edges