pSOSystem System Calls - Read

tm_wkafter pSOS+ System Calls
tm_wkafter Blocks the calling task and wakes it after a specified interval.
#include
unsigned long tm_wkafter(
unsigned long ticks /* clock ticks */
)
Description
Arguments
Return Value
Error Codes
This system call enables the calling task to block unconditionally for a specified
interval. This call resembles self-suspension (t_suspend(0)), except that
tm_wkafter() schedules an automatic resumption after the specified time interval
has lapsed. The interval is in system clock ticks. For example, if the system clock
frequency is 60 ticks per second and the caller requires a pause of 20 seconds, the
input specification should be 60x20 (ticks=1200).
ticks Specifies the number of ticks to elapse during the block.
An interval of n ticks awakens the calling task on the nth next tick. Because
tm_wkafter() can happen anywhere between two ticks, the actual interval is
between n-1 and n ticks.
An interval of 0 ticks has a special function: if no ready tasks have the same priority
as the calling (or running) task, the calling task continues. On the other hand, if one
or more ready tasks with the same priority as the caller exist, the pSOS+ kernel
executes a round-robin by placing the caller behind all ready tasks of the same
priority and giving the CPU to one of those tasks. This provides a manual roundrobin
technique to voluntarily give the CPU to another ready task of the same
priority.
This call always returns 0.
None.
1-180 pSOSystem System Calls