Timer services provide functions that allow your application to wait for or respond to the completion of a specified time interval on the system clock.

Any HLC function that requires timer services should not use the sleep() or other operating system functions to access the system clock. Access the following HLC library functions for timer services on Unix: prosleep(), proevt(), prowait(), and procncel(). Access prosleep for timer services in Windows. The proevt(), prowait(), and procncel() timer services are available only on Unix. See HLC Library Function Reference for information on these functions.

The timer-service functions provide all the tools you need to determine whether a timer is expired. The Unix-specific program fragment shows examples of timer-service functions proevt(), prockint(), and procncel(), as shown in the following figure.

Figure 1. Timer-service functions on Unix