+#include <errno.h>
+
+#include <unistd.h>
+
+
+enum { BILLION = 1000 * 1000 * 1000 };
+
+#if HAVE_BUG_BIG_NANOSLEEP
+
+int
+nanosleep (const struct timespec *requested_delay,
+ struct timespec *remaining_delay)
+#undef nanosleep
+{
+ /* nanosleep mishandles large sleeps due to internal overflow
+ problems. The worst known case of this is cygwin 1.5.x, which
+ can't sleep more than 49.7 days (2**32 milliseconds). Solve this
+ by breaking the sleep up into smaller chunks. Verify that time_t
+ is large enough. */
+ verify (TYPE_MAXIMUM (time_t) / 49 / 24 / 60 / 60);
+ const time_t limit = 49 * 24 * 60 * 60;
+ time_t seconds = requested_delay->tv_sec;
+ struct timespec intermediate;
+ intermediate.tv_nsec = 0;
+
+ while (limit < seconds)
+ {
+ int result;
+ intermediate.tv_sec = limit;
+ result = nanosleep (&intermediate, remaining_delay);
+ seconds -= limit;
+ if (result)
+ {
+ if (remaining_delay)
+ {
+ remaining_delay->tv_sec += seconds;
+ remaining_delay->tv_nsec += requested_delay->tv_nsec;
+ if (BILLION <= requested_delay->tv_nsec)
+ {
+ remaining_delay->tv_sec++;
+ remaining_delay->tv_nsec -= BILLION;
+ }
+ }
+ return result;
+ }
+ }
+ intermediate.tv_sec = seconds;
+ intermediate.tv_nsec = requested_delay->tv_nsec;
+ return nanosleep (&intermediate, remaining_delay);
+}
+
+#elif (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Windows platforms. */
+
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+
+/* The Win32 function Sleep() has a resolution of about 15 ms and takes
+ at least 5 ms to execute. We use this function for longer time periods.
+ Additionally, we use busy-looping over short time periods, to get a
+ resolution of about 0.01 ms. In order to measure such short timespans,
+ we use the QueryPerformanceCounter() function. */
+
+int
+nanosleep (const struct timespec *requested_delay,
+ struct timespec *remaining_delay)
+{
+ static bool initialized;
+ /* Number of performance counter increments per nanosecond,
+ or zero if it could not be determined. */
+ static double ticks_per_nanosecond;