mod_watchdog

Collaboration diagram for mod_watchdog:

Macros
#define	AP_WATCHDOG_SINGLETON   "_singleton_"
#define	AP_WATCHDOG_DEFAULT   "_default_"
#define	AP_WD_TM_INTERVAL   APR_TIME_C(1000000) /* 1 second */
#define	AP_WD_TM_SLICE   APR_TIME_C(100000) /* 100 ms */
#define	AP_WATCHDOG_STATE_STARTING   1
#define	AP_WATCHDOG_STATE_RUNNING   2
#define	AP_WATCHDOG_STATE_STOPPING   3
#define	AP_WD_DECLARE(type)   type
#define	AP_WD_DECLARE_NONSTD(type)   type
#define	AP_WD_DECLARE_DATA

Typedefs
typedef struct ap_watchdog_t	ap_watchdog_t
typedef apr_status_t	ap_watchdog_callback_fn_t(int state, void *data, apr_pool_t *pool)

Functions
apr_status_t	ap_watchdog_get_instance (ap_watchdog_t **watchdog, const char *name, int parent, int singleton, apr_pool_t *p)
apr_status_t	ap_watchdog_register_callback (ap_watchdog_t *watchdog, apr_interval_time_t interval, const void *data, ap_watchdog_callback_fn_t *callback)
apr_status_t	ap_watchdog_set_callback_interval (ap_watchdog_t *w, apr_interval_time_t interval, const void *data, ap_watchdog_callback_fn_t *callback)
int	ap_hook_watchdog_need (server_rec *s, const char *name, int parent, int singleton)
int	ap_hook_watchdog_init (server_rec *s, const char *name, apr_pool_t *pool)
int	ap_hook_watchdog_exit (server_rec *s, const char *name, apr_pool_t *pool)
int	ap_hook_watchdog_step (server_rec *s, const char *name, apr_pool_t *pool)

Detailed Description

Macro Definition Documentation

AP_WATCHDOG_DEFAULT

#define AP_WATCHDOG_DEFAULT   "_default_"

Default watchdog instance name

AP_WATCHDOG_SINGLETON

#define AP_WATCHDOG_SINGLETON   "_singleton_"

Default singleton watchdog instance name. Singleton watchdog is protected by mutex and guaranteed to be run inside a single child process at any time.

AP_WATCHDOG_STATE_RUNNING

#define AP_WATCHDOG_STATE_RUNNING   2

AP_WATCHDOG_STATE_STARTING

#define AP_WATCHDOG_STATE_STARTING   1

AP_WATCHDOG_STATE_STOPPING

#define AP_WATCHDOG_STATE_STOPPING   3

AP_WD_DECLARE

#define AP_WD_DECLARE

(

type

)

type

AP_WD_DECLARE_DATA

#define AP_WD_DECLARE_DATA

AP_WD_DECLARE_NONSTD

#define AP_WD_DECLARE_NONSTD

(

type

)

type

AP_WD_TM_INTERVAL

#define AP_WD_TM_INTERVAL   APR_TIME_C(1000000) /* 1 second */

Default Watchdog interval

AP_WD_TM_SLICE

#define AP_WD_TM_SLICE   APR_TIME_C(100000) /* 100 ms */

Watchdog thread timer resolution

Typedef Documentation

ap_watchdog_callback_fn_t

typedef apr_status_t ap_watchdog_callback_fn_t(int state, void *data, apr_pool_t *pool)

Callback function used for watchdog.

Parameters

state	Watchdog state function. See AP_WATCHDOG_STATE_ .
data	is what was passed to ap_watchdog_register_callback function.
pool	Temporary callback pool destroyed after the call.

Returns

APR_SUCCESS to continue calling this callback.

ap_watchdog_t

typedef struct ap_watchdog_t ap_watchdog_t

Function Documentation

ap_hook_watchdog_exit()

int ap_hook_watchdog_exit	(	server_rec *	s,
		const char *	name,
		apr_pool_t *	pool
	)

Watchdog terminate hook. It is called when the watchdog thread is terminated.

Parameters

s	The server record
name	Watchdog name.
pool	The pool used to create the watchdog.

ap_hook_watchdog_init()

int ap_hook_watchdog_init	(	server_rec *	s,
		const char *	name,
		apr_pool_t *	pool
	)

Watchdog initialize hook. It is called after the watchdog thread is initialized.

Parameters

s	The server record
name	Watchdog name.
pool	The pool used to create the watchdog.

ap_hook_watchdog_need()

int ap_hook_watchdog_need	(	server_rec *	s,
		const char *	name,
		int	parent,
		int	singleton
	)

Watchdog require hook.

Parameters

s	The server record
name	Watchdog name.
parent	Non-zero to indicate the parent process watchdog mode.
singleton	Non-zero to indicate the singleton watchdog mode.

Returns

OK to enable notifications from this watchdog, DECLINED otherwise.

Remarks

This is called in post config phase for all watchdog instances that have no callbacks registered. Modules using this hook should ensure that their post_config hook is called after watchdog post_config.

ap_hook_watchdog_step()

int ap_hook_watchdog_step	(	server_rec *	s,
		const char *	name,
		apr_pool_t *	pool
	)

Fixed interval watchdog hook. It is called regularly on AP_WD_TM_INTERVAL interval.

Parameters

s	The server record
name	Watchdog name.
pool	Temporary pool destroyed after the call.

ap_watchdog_get_instance()

apr_status_t ap_watchdog_get_instance	(	ap_watchdog_t **	watchdog,
		const char *	name,
		int	parent,
		int	singleton,
		apr_pool_t *	p
	)

Get watchdog instance.

Parameters

watchdog	Storage for watchdog instance.
name	Watchdog name.
parent	Non-zero to get the parent process watchdog instance.
singleton	Non-zero to get the singleton watchdog instance.
p	The pool to use.

Returns

APR_SUCCESS if all went well

Remarks

Use AP_WATCHDOG_DEFAULT to get default watchdog instance. If separate watchdog thread is needed provide unique name and function will create a new watchdog instance. Note that default client process watchdog works in singleton mode.

ap_watchdog_register_callback()

apr_status_t ap_watchdog_register_callback	(	ap_watchdog_t *	watchdog,
		apr_interval_time_t	interval,
		const void *	data,
		ap_watchdog_callback_fn_t *	callback
	)

Register watchdog callback.

Parameters

watchdog	Watchdog to use
interval	Interval on which the callback function will execute.
callback	The function to call on watchdog event.
data	The data to pass to the callback function.

Returns

APR_SUCCESS if all went well. APR_EEXIST if already registered.

ap_watchdog_set_callback_interval()

apr_status_t ap_watchdog_set_callback_interval	(	ap_watchdog_t *	w,
		apr_interval_time_t	interval,
		const void *	data,
		ap_watchdog_callback_fn_t *	callback
	)

Update registered watchdog callback interval.

Parameters

w	Watchdog to use
interval	New interval on which the callback function will execute.
callback	The function to call on watchdog event.
data	The data to pass to the callback function.

Returns

APR_SUCCESS if all went well. APR_EOF if callback was not found.