index 1e2c74dbab8d8ad8034638c4be8e6673ea499b21..3e6b66562574470ff851c125a9f4f88171bc4fca 100644 (file)
* the requested delay to be rounded up to the next resolution boundary.
*
* On machines where "long" is 32 bits, the maximum delay is ~2000 seconds.
+ *
+ * CAUTION: the behavior when a signal arrives during the sleep is platform
+ * dependent. On most Unix-ish platforms, a signal does not terminate the
+ * sleep; but on some, it will (the Windows implementation also allows signals
+ * to terminate pg_usleep). And there are platforms where not only does a
+ * signal not terminate the sleep, but it actually resets the timeout counter
+ * so that the sleep effectively starts over! It is therefore rather hazardous
+ * to use this for long sleeps; a continuing stream of signal events could
+ * prevent the sleep from ever terminating. Better practice for long sleeps
+ * is to use WaitLatch() with a timeout.
*/
void
pg_usleep(long microsec)