pSOSystem System Calls - Read

tm_evafter pSOS+ System Calls
tm_evafter Sends events to the calling task after a specified interval.
#include
unsigned long tm_evafter(
unsigned long ticks, /* delay */
unsigned long events, /* event list */
unsigned long *tmid /* timer identifier */
)
Description
Arguments
Return Value
This system call enables the calling task to arm a timer so that it expires after the
specified interval, at which time the pSOS+ kernel internally calls ev_send() to
send the designated events to this task. Unlike tm_wkafter(), tm_evafter()
does not block the caller. A task can use multiple tm_evafter() calls to arm two
or more concurrent timers.
The timer interval is specified in system clock ticks. For example, if the system clock
frequency is 60 ticks per second and the caller requires a timer to interrupt in 20
seconds, the input specification should be 60x20 (ticks=1200). A timer interval of n
ticks causes the events to be sent on the nth next tick. Because tm_evafter() can
happen anywhere between two ticks, the actual interval is between n-1 and n ticks.
ticks Specifies the timer interval.
events Specifies the events to deliver upon expiration of the timer interval.
The events are encoded into a long word with bits 31-16 reserved for
system use and bits 15 - 0 available for application use.
tmid Points to the variable where tm_evafter() stores a timer identifier,
which can be used if the armed timer must be cancelled.
This system call returns 0 on success, or an error code on failure.
1-166 pSOSystem System Calls