ChorusOS 4.0 Introduction

Time Management Services

The following time management services are available:

The tick service enables the system to manage the clock, counting ticks since the boot of the system. Thus the only time available is the time elapsed since the last reboot.
The date service enables the ChorusOS operating system to maintain a current date, usually expressed in seconds since the 01/01/1970. Calls to set and get the time of day are available, through standard C libraries ctime and localtime, and are not detailed in this document.
The time-out service enables supervisor actors to set up time-outs. A time-out may be roughly described as a callback which will be performed when a given delay has expired. Callbacks are performed using a special invocation mechanism (called Local Access Point or LAP) reserved for supervisor actors.
The timer service is an extension of the time-out mechanism, enabling user and supervisor actors to set up call backs in a more flexible fashion.
The virtual time and time-out service allows you to measure the CPU time used by threads, and to define handlers which will be called if a per-thread or per-actor CPU quota is reached.

Table 9-1 shows which services are available for a given configuration:

Table 9-1 Time Management Service Availability