Timer manipulation

NAMES

: start_timer, stop_timer, stop_timers, is_timer, is_a_timer - Timer Handling.

SYNTAX

:

       start_timer( int t, int s )

       stop_timer( int t )

       stop_timers()

       int is_timer()

       int is_a_timer( int t )

DESCRIPTION

:

• start_timer starts timer t of current node me and schedules it to time-out after s steps of node me. It adds the product of PCB[me].step and s to the current time TIME to compute the time for timeout. start_timer puts that value in PCB[me].clock[t].value and schedules the corresponding event TIMEOUT_1, TIMEOUT_2, ..., TIMEOUT_5, depending on the timer number t. The value of t can have any of the predefined values TIMER1, TIMER2, ..., TIMER5.

• stop_timer stops timer t of current node me i.e. sets the PCB[me].clock[t].value to the predefined value NOT_STARTED. stop_timer also, cancels the event of corresponding timeout.

• stop_timers stops all the timers of current node me in the way stop_timer does.

• is_timer returns TRUE if there is a timer active in current node me, else returns FALSE.

• is_a_timer returns TRUE if timer t is active in current node me, else returns FALSE.

DIAGNOSTICS

stop_timer and stop_timers print error message and stop execution if there is a timer active and no corresponding event found or event found but corresponding timer is inactive.

SEE ALSO: System Structure (Section 5.2) and Timers.h.