Summary
Start a timer.
Declaration
#include <zircon/syscalls.h>
zx_status_t zx_timer_set(zx_handle_t handle,
zx_time_t deadline,
zx_duration_t slack);
Description
zx_timer_set() starts a one-shot timer that will fire when
deadline passes. If a previous call to zx_timer_set() was
pending, the previous timer is canceled and
ZX_TIMER_SIGNALED is de-asserted as needed.
The deadline parameter specifies a deadline with respect to
ZX_CLOCK_MONOTONIC. To wait for a relative interval,
use zx_deadline_after() returned value in deadline.
To fire the timer immediately pass a deadline less than or equal to 0.
When the timer fires it asserts ZX_TIMER_SIGNALED. To de-assert this
signal call zx_timer_cancel() or zx_timer_set() again.
The slack parameter specifies a range from deadline - slack to deadline + slack during which the timer is allowed to fire. The system uses this parameter as a hint to coalesce nearby timers.
The precise coalescing behavior is controlled by the options parameter
specified when the timer was created. ZX_TIMER_SLACK_EARLY allows only
firing in the deadline - slack interval and ZX_TIMER_SLACK_LATE
allows only firing in the deadline + slack interval. The default
option value of 0 is ZX_TIMER_SLACK_CENTER and allows both early and
late firing with an effective interval of deadline - slack to
deadline + slack
Rights
handle must be of type ZX_OBJ_TYPE_TIMER and have ZX_RIGHT_WRITE.
Return value
zx_timer_set() returns ZX_OK on success.
In the event of failure, a negative error value is returned.
Errors
ZX_ERR_BAD_HANDLE handle is not a valid handle.
ZX_ERR_ACCESS_DENIED handle lacks the right ZX_RIGHT_WRITE.
ZX_ERR_OUT_OF_RANGE slack is negative.