dxd::clock Class Reference

kernel-mode periodic software clock, mirroring dx::clock's tick()/run()/halt() shape More...

#include <dxd_clock.h>

Inheritance diagram for dxd::clock:

Collaboration diagram for dxd::clock:

Public Member Functions
	clock ()
void	halt () noexcept
	stop and join the clock thread; no-op if never run()
os_result	run (int64_t period)
	create and start the clock thread (autonomous mode)
virtual void	tick ()=0
	per-tick handler, called from the clock's own thread at PASSIVE_LEVEL in autonomous mode, or synchronously by the owning device in pod mode.
virtual	~clock ()
	virtual destructur

Protected Types
enum class	priority { low =LOW_PRIORITY , realtime =LOW_REALTIME_PRIORITY , high =HIGH_PRIORITY }

Protected Member Functions
os_result	prio (priority priority)
os_result	run ()
	IOKit process thread start.

Static Protected Member Functions
static unsigned int	prio ()
static unsigned int	prio ()

Protected Attributes
os_result	status

Detailed Description

kernel-mode periodic software clock, mirroring dx::clock's tick()/run()/halt() shape

A dxd::process (PASSIVE_LEVEL system thread) that re-arms an absolute-due-time KTIMER after every tick() and waits on it, so a derived class's tick() body runs without DISPATCH_LEVEL restrictions - unlike a DPC-driven timer. Re-arming against an accumulated absolute due time each iteration (rather than relying on KTIMER's own millisecond-granularity Period reload) avoids drift and keeps sub-millisecond period precision, needed at small buffer sizes.

A device that never calls run() and instead calls tick() directly (from an externally-driven IOCTL, e.g. ioctl::stream::clock::frame) gets the pod/puppet mode - no thread, no timer, purely reactive; see dxd/CLAUDE.md's kernel clock notes. Both modes are this same class; the difference is only whether run() was ever called.

Member Enumeration Documentation

priority

enum class dxd::process::priority

stronginherited

Enumerator
low	Lowest thread priority level.
realtime	Lowest realtime priority level.
high	Highest thread priority level.

Constructor & Destructor Documentation

clock()

dxd::clock::clock ( )

inline

~clock()

virtual dxd::clock::~clock ( )

inlinevirtual

virtual destructur

clock base class needs virtual destructor; although its a dummy; to ensure inherited and composite objects to be correctly destructed.

Here is the call graph for this function:

Member Function Documentation

halt()

void dxd::clock::halt ( )

inlinenoexcept

stop and join the clock thread; no-op if never run()

<wake launch()'s wait_any() so it observes running==false and exits

Here is the caller graph for this function:

prio() [1/3]

unsigned int dxd::process::prio ( )

inlinestaticinherited

prio() [2/3]

unsigned int dxd::process::prio ( )

inlinestaticinherited

prio() [3/3]

os_result dxd::process::prio ( priority priority )

inlineinherited

run() [1/2]

os_result dxd::clock::run ( int64_t period )

inline

create and start the clock thread (autonomous mode)

Parameters

period

tick period, 100ns units (see dxd::scale)

Here is the call graph for this function:

run() [2/2]

os_result dxd::process::run ( )

inlineinherited

IOKit process thread start.

run() starts this process. The internal mechanism blocks object termination until thread start() returns.

Here is the caller graph for this function:

tick()

virtual void dxd::clock::tick ( )

pure virtual

per-tick handler, called from the clock's own thread at PASSIVE_LEVEL in autonomous mode, or synchronously by the owning device in pod mode.

Member Data Documentation

status

os_result dxd::process::status

inherited

---

The documentation for this class was generated from the following file:

• dxd_clock.h