# ifdef _WIN32
# define WIN32_LEAN_AND_MEAN
# include <windows.h>
-# elif defined (__sun) || defined(__GNU__)
+# elif defined (__sun) || defined(__GNU__) || defined(__CYGWIN__)
# include <unistd.h>
# elif defined (__FreeBSD__) || defined (__OpenBSD__) || \
defined (__NetBSD__) || defined (__DragonFly__) || defined (__MacOSX__) || \
GetSystemInfo(&sysinfo);
return sysinfo.dwNumberOfProcessors;
-# elif defined (__sun) || defined(__GNU__)
+# elif defined (__sun) || defined(__GNU__) || defined(__CYGWIN__)
/*
* _SC_NPROCESSORS_ONLN: number of processors that are online, that
is available when sysconf is called. The number