zx_timer_create

Summary

Create a timer.

Declaration

#include <zircon/syscalls.h>

zx_status_t zx_timer_create(uint32_t options,
                            zx_clock_t clock_id,
                            zx_handle_t* out);

Description

zx_timer_create() creates a timer, an object that can signal when a specified point in time has been reached. The only valid clock_id is ZX_CLOCK_MONOTONIC.

The options value specifies the coalescing behavior, which controls whether the system can fire the time earlier or later depending on other pending timers.

The possible values are:

  • ZX_TIMER_SLACK_CENTER
  • ZX_TIMER_SLACK_EARLY
  • ZX_TIMER_SLACK_LATE

Passing 0 in options is equivalent to ZX_TIMER_SLACK_CENTER.

See timer slack for more information.

The returned handle has the ZX_RIGHT_DUPLICATE, ZX_RIGHT_TRANSFER, ZX_RIGHT_WRITE, ZX_RIGHT_SIGNAL, ZX_RIGHT_WAIT, and ZX_RIGHT_INSPECT rights.

Rights

Caller job policy must allow ZX_POL_NEW_TIMER.

Return value

zx_timer_create() returns ZX_OK on success. In the event of failure, a negative error value is returned.

Errors

ZX_ERR_INVALID_ARGS out is an invalid pointer or NULL or options is not one of the ZX_TIMER_SLACK values or clock_id is any value other than ZX_CLOCK_MONOTONIC.

ZX_ERR_NO_MEMORY Failure due to lack of memory. There is no good way for userspace to handle this (unlikely) error. In a future build this error will no longer occur.

See also