Watchdog Handler

This group contains the Watchdog Handler implementation. More...

Files
file	watchdog.h
	This header file provides interfaces of the Watchdog Handler which are used by the implementation and the Application Configuration.
file	watchdogimpl.h
	This header file provides interfaces of the Watchdog Handler which are only used by the implementation.
file	watchdogticks.h
	This header file provides the interfaces of the Watchdog Handler related to watchdog ticks which are used by the implementation and the Application Configuration.
file	watchdoginsert.c
	This source file contains the implementation of _Watchdog_Insert().
file	watchdogremove.c
	This source file contains the implementation of _Watchdog_Remove().
file	watchdogtick.c
	This source file contains the implementation of _Watchdog_Do_tickle() and _Watchdog_Tick().
file	watchdogtickssinceboot.c
	This source file contains the definition of _Watchdog_Ticks_since_boot.
file	watchdogtimeslicedefault.c
	This source file contains the default definition of _Watchdog_Ticks_per_timeslice.

Data Structures
struct	Watchdog_Header
	The watchdog header to manage scheduled watchdogs. More...
struct	Watchdog_Control
	The control block used to manage each watchdog timer. More...

Macros
#define	WATCHDOG_INITIALIZER(routine)
	Watchdog initializer for static initialization.
#define	_Watchdog_Tickle(header, first, now, lock, lock_context)    _Watchdog_Do_tickle( header, first, now, lock_context )
#define	WATCHDOG_MAXIMUM_TICKS   UINT64_MAX
	The maximum watchdog ticks value for the far future.
#define	WATCHDOG_NANOSECONDS_PER_SECOND   1000000000
#define	WATCHDOG_BITS_FOR_1E9_NANOSECONDS   30
	The bits necessary to store 1000000000 (= WATCHDOG_NANOSECONDS_PER_SECOND) nanoseconds.
#define	WATCHDOG_MAX_SECONDS   0x3ffffffff
	The maximum number of seconds representable in the nanoseconds watchdog format.
#define	WATCHDOG_NO_TIMEOUT   0
	Special watchdog ticks value to indicate an infinite wait.
#define	WATCHDOG_TICKS_PER_TIMESLICE_DEFAULT   50
	Default value for the watchdog ticks per timeslice.

Typedefs
typedef struct Watchdog_Control	Watchdog_Control
typedef void	Watchdog_Service_routine
	Return type from a Watchdog Service Routine.
typedef Watchdog_Service_routine(*	Watchdog_Service_routine_entry) (Watchdog_Control *)
	Pointer to a watchdog service routine.
typedef uint32_t	Watchdog_Interval
	Type is used to specify the length of intervals.

Enumerations
enum	Watchdog_State { WATCHDOG_SCHEDULED_BLACK , WATCHDOG_SCHEDULED_RED , WATCHDOG_INACTIVE , WATCHDOG_PENDING }
	Watchdog states. More...

Functions
void	_Watchdog_Tick (struct Per_CPU_Control *cpu)
	Performs a watchdog tick.
void	_Watchdog_Do_tickle (Watchdog_Header *header, Watchdog_Control *first, uint64_t now, ISR_lock_Context *lock_context)
	Calls the routine of each not expired watchdog control node.
void	_Watchdog_Insert (Watchdog_Header *header, Watchdog_Control *the_watchdog, uint64_t expire)
	Inserts a watchdog into the set of scheduled watchdogs according to the specified expiration time.
void	_Watchdog_Remove (Watchdog_Header *header, Watchdog_Control *the_watchdog)
	In the case the watchdog is scheduled, then it is removed from the set of scheduled watchdogs.

Variables
volatile Watchdog_Interval	_Watchdog_Ticks_since_boot
	The watchdog ticks counter.
const uint32_t	_Watchdog_Microseconds_per_tick
	The watchdog microseconds per tick.
const uint32_t	_Watchdog_Nanoseconds_per_tick
	The watchdog nanoseconds per tick.
const uint32_t	_Watchdog_Ticks_per_second
	The watchdog ticks per second.
const uint32_t	_Watchdog_Ticks_per_timeslice
	The watchdog ticks per timeslice.

Detailed Description

This group contains the Watchdog Handler implementation.

This handler encapsulates functionality related to the scheduling of watchdog functions to be called at specific times in the future. It provides mechanisms which can be used to initialize and manipulate watchdog timers.

Note

This handler does not have anything to do with hardware watchdog timers.

Macro Definition Documentation

WATCHDOG_BITS_FOR_1E9_NANOSECONDS

#define WATCHDOG_BITS_FOR_1E9_NANOSECONDS   30

The bits necessary to store 1000000000 (= WATCHDOG_NANOSECONDS_PER_SECOND) nanoseconds.

The expiration time is an unsigned 64-bit integer. To store nanoseconds timeouts we use 30 bits (2**30 == 1073741824) for the nanoseconds and 34 bits for the seconds since UNIX Epoch. This leads to a year 2514 problem.

WATCHDOG_INITIALIZER

#define WATCHDOG_INITIALIZER

(

routine

)

Value:

    { \
      { { { NULL, NULL, NULL, WATCHDOG_INACTIVE } } }, \
      ( routine ), \
      0 \
    }

Watchdog initializer for static initialization.

The processor of this watchdog is set to processor with index zero.

See also

_Watchdog_Preinitialize().

WATCHDOG_MAX_SECONDS

#define WATCHDOG_MAX_SECONDS   0x3ffffffff

The maximum number of seconds representable in the nanoseconds watchdog format.

We have 2**34 bits for the seconds part.

Typedef Documentation

Watchdog_Interval

typedef uint32_t Watchdog_Interval

Type is used to specify the length of intervals.

This type is used to specify the length of intervals.

Watchdog_Service_routine

typedef void Watchdog_Service_routine

Return type from a Watchdog Service Routine.

This type defines the return type from a Watchdog Service Routine.

Watchdog_Service_routine_entry

typedef Watchdog_Service_routine(* Watchdog_Service_routine_entry) (Watchdog_Control *)

Pointer to a watchdog service routine.

This type define a pointer to a watchdog service routine.

Enumeration Type Documentation

Watchdog_State

enum Watchdog_State

Watchdog states.

Enumerator
WATCHDOG_SCHEDULED_BLACK	The watchdog is scheduled and a black node in the red-black tree.
WATCHDOG_SCHEDULED_RED	The watchdog is scheduled and a red node in the red-black tree.
WATCHDOG_INACTIVE	The watchdog is inactive.
WATCHDOG_PENDING	The watchdog is on a chain of pending watchdogs. This state is used by the timer server for example.

Function Documentation

_Watchdog_Do_tickle()

void _Watchdog_Do_tickle	(	Watchdog_Header *	header,
		Watchdog_Control *	first,
		uint64_t	now,
		ISR_lock_Context *	lock_context
	)

Calls the routine of each not expired watchdog control node.

Parameters

header	The watchdog header.
first	The first watchdog control node.
now	The current time to check the expiration time against.
lock	The lock that is released before calling the routine and then acquired after the call.
lock_context	The lock context for the release before calling the routine and for the acquire after.

_Watchdog_Insert()

void _Watchdog_Insert	(	Watchdog_Header *	header,
		Watchdog_Control *	the_watchdog,
		uint64_t	expire
	)

Inserts a watchdog into the set of scheduled watchdogs according to the specified expiration time.

The watchdog must be inactive.

Parameters

[in,out]	header	The set of scheduler watchdogs to insert into.
[in,out]	the_watchdog	The watchdog to insert.
	expire	The expiration time for the watchdog.

_Watchdog_Remove()

void _Watchdog_Remove	(	Watchdog_Header *	header,
		Watchdog_Control *	the_watchdog
	)

In the case the watchdog is scheduled, then it is removed from the set of scheduled watchdogs.

The watchdog must be initialized before this call.

Parameters

[in,out]	header	The scheduled watchdogs.
[in,out]	the_watchdog	The watchdog to remove.

_Watchdog_Tick()

void _Watchdog_Tick

(

struct Per_CPU_Control *

cpu

)

Performs a watchdog tick.

Parameters

cpu	The processor for this watchdog tick.

Variable Documentation

_Watchdog_Microseconds_per_tick

const uint32_t _Watchdog_Microseconds_per_tick

extern

The watchdog microseconds per tick.

This constant is defined by the application configuration via <rtems/confdefs.h>.

_Watchdog_Nanoseconds_per_tick

const uint32_t _Watchdog_Nanoseconds_per_tick

extern

The watchdog nanoseconds per tick.

This constant is defined by the application configuration via <rtems/confdefs.h>.

_Watchdog_Ticks_per_second

const uint32_t _Watchdog_Ticks_per_second

extern

The watchdog ticks per second.

This constant is defined by the application configuration via <rtems/confdefs.h>.

_Watchdog_Ticks_per_timeslice

const uint32_t _Watchdog_Ticks_per_timeslice

extern

The watchdog ticks per timeslice.

This constant is defined by the application configuration via <rtems/confdefs.h>.

_Watchdog_Ticks_since_boot

volatile Watchdog_Interval _Watchdog_Ticks_since_boot

extern

The watchdog ticks counter.

With a 1ms watchdog tick, this counter overflows after 50 days since boot.