Clock services

Functions
int	xnclock_register (struct xnclock *clock, const cpumask_t *affinity)
	Register a Xenomai clock. More...
void	xnclock_deregister (struct xnclock *clock)
	Deregister a Xenomai clock. More...
void	xnclock_tick (struct xnclock *clock)
	Process a clock tick. More...
void	xnclock_adjust (struct xnclock *clock, xnsticks_t delta)
	Adjust a clock time. More...

Detailed Description

Function Documentation

void xnclock_adjust	(	struct xnclock *	clock,
		xnsticks_t	delta
	)

Adjust a clock time.

This service changes the epoch for the given clock by applying the specified tick delta on its wallclock offset.

Parameters

clock	The clock to adjust.
delta	The adjustment value expressed in nanoseconds.

Tags^^ cobalt-core-tags "task-unrestricted, atomic-entry"

Note

Xenomai tracks the system time in nkclock, as a monotonously increasing count of ticks since the epoch. The epoch is initially the same as the underlying machine time.

References cobalt_vfroot, xnvfile_snapshot_ops::rewind, xnvfile_regular_ops::show, xnvfile_regular_iterator::vfile, xnvfile_snapshot_iterator::vfile, xntimer_get_timeout(), xntimer_interval(), xnvfile_get_string(), xnvfile_init_dir(), xnvfile_init_regular(), and xnvfile_init_snapshot().

void xnclock_deregister

(

struct xnclock *

clock

)

Deregister a Xenomai clock.

This service uninstalls a Xenomai clock previously registered with xnclock_register().

This service may be called once all timers driven by clock have been stopped.

Parameters

clock

The clock to deregister.

Tags^^ cobalt-core-tags "secondary-only"

Referenced by xnclock_tick().

int xnclock_register	(	struct xnclock *	clock,
		const cpumask_t *	affinity
	)

Register a Xenomai clock.

This service installs a new clock which may be used to drive Xenomai timers.

Parameters

clock	The new clock to register.
affinity	The set of CPUs we may expect the backing clock device to tick on. As a special case, passing a NULL affinity mask means that timer IRQs cannot be seen as percpu events, in which case all outstanding timers will be maintained into a single global queue instead of percpu timer queues.

Tags^^ cobalt-core-tags "secondary-only"

Referenced by xnclock_tick().

void xnclock_tick

(

struct xnclock *

clock

)

Process a clock tick.

This routine processes an incoming clock event, firing elapsed timers as appropriate.

Parameters

clock

The clock for which a new event was received.

Tags^^ cobalt-core-tags "coreirq-only, atomic-entry"

Note

The current CPU must be part of the real-time affinity set unless the clock device has no particular IRQ affinity, otherwise weird things may happen.

References xnsched::htimer, xnsched::lflags, xnsched::status, xnclock_deregister(), and xnclock_register().