cq.c File Reference

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Detailed Description

Callout queue.

Author:

Raphael Manfredi

Date:

2002-2003

#include "common.h"
#include "cq.h"
#include "misc.h"
#include "tm.h"
#include "walloc.h"
#include "override.h"

Data Structures
struct	cevent
	Callout queue event. More...
struct	chash
struct	cqueue
	Callout queue descriptor. More...
Defines
#define	HASH_SIZE   1024
	Hash list size, must be power of 2.
#define	HASH_MASK   (HASH_SIZE - 1)
#define	EV_MAGIC   0xc0110172U
	Magic number for event marking.
#define	EV_HASH(x)   (((x) >> 5) & HASH_MASK)
#define	EV_OVER(x)   (((x) >> 5) & ~HASH_MASK)
#define	valid_ptr(a)   (cast_to_gconstpointer(a) > GUINT_TO_POINTER(100U))
#define	CALLOUT_PERIOD   100
Functions
cqueue_t *	cq_make (cq_time_t now)
	Create a new callout queue object.
void	cq_free (cqueue_t *cq)
	Free the callout queue and all contained event objects.
void	ev_link (cqueue_t *cq, cevent_t *ev)
	Link event into the callout queue.
void	ev_unlink (cqueue_t *cq, cevent_t *ev)
	Unlink event from callout queue.
cevent_t *	cq_insert (cqueue_t *cq, gint delay, cq_service_t fn, gpointer arg)
	Insert a new event in the callout queue and return an opaque handle that can be used to cancel the event.
void	cq_cancel (cqueue_t *cq, cevent_t **handle_ptr)
	Cancel a recorded timeout.
void	cq_resched (cqueue_t *cq, cevent_t *handle, gint delay)
	Reschedule event at some other point in time.
void	cq_expire (cqueue_t *cq, cevent_t *ev)
	Expire timeout by removing it out of the queue and firing its callback.
void	cq_clock (cqueue_t *cq, gint elapsed)
	The heartbeat of our callout queue.
gboolean	callout_timer (gpointer unused_p)
	Called every CALLOUT_PERIOD to heartbeat the callout queue.
gdouble	callout_queue_coverage (gint old_ticks)
	Returns percentage of coverage of the callout timer, i.e.
gint	cq_ticks (cqueue_t *cq)
void	cq_init (void)
	Initialization.
void	cq_close (void)
	Final cleanup.
Variables
cqueue_t *	callout_queue

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Define Documentation

#define CALLOUT_PERIOD   100

#define EV_HASH (  x   )     (((x) >> 5) & HASH_MASK)

#define EV_MAGIC   0xc0110172U

Magic number for event marking.

#define EV_OVER (  x   )     (((x) >> 5) & ~HASH_MASK)

#define HASH_MASK   (HASH_SIZE - 1)

#define HASH_SIZE   1024

Hash list size, must be power of 2.

#define valid_ptr (  a   )     (cast_to_gconstpointer(a) > GUINT_TO_POINTER(100U))

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Function Documentation

gdouble callout_queue_coverage (  gint  old_ticks  )

Returns percentage of coverage of the callout timer, i.e. the real amount of ticks we processed divided by the theoretical number, yielding a number between 0.0 and 1.0. Parameters: old_ticks  the previous amount of processed ticks

gboolean callout_timer (  gpointer  unused_p  )  [static]

Called every CALLOUT_PERIOD to heartbeat the callout queue.

void cq_cancel (  cqueue_t *  cq, cevent_t **  handle_ptr )

Cancel a recorded timeout. They give us the opaque handle we returned via cq_insert(). Note: This routine is also used internally to remove an expired event from the list before firing it off.

void cq_clock (  cqueue_t *  cq, gint  elapsed )

The heartbeat of our callout queue. Called to notify us about the elapsed "time" so that we can expire timeouts and maintain our notion of "current time". NB: The time maintained by the callout queue is "virtual". It's the elapased delay given by regular calls to cq_clock() that define its unit. For gtk-gnutella, the time unit is the millisecond.

void cq_close (  void   )

Final cleanup.

void cq_expire (  cqueue_t *  cq, cevent_t *  ev )

Expire timeout by removing it out of the queue and firing its callback.

void cq_free (  cqueue_t *  cq  )

Free the callout queue and all contained event objects.

void cq_init (  void   )

Initialization.

cevent_t* cq_insert (  cqueue_t *  cq, gint  delay, cq_service_t  fn, gpointer  arg )

Insert a new event in the callout queue and return an opaque handle that can be used to cancel the event. The event is specified to occur in some "delay" amount of time, at which time we shall call fn(cq, arg), where cq is the callout queue from where we triggered, and arg is an additional argument. Parameters: cq  The callout queue delay  The delay, expressed in cq's "virtual time" (see cq_clock) fn  The callback function arg  The argument to be passed to the callback function Returns: the handle, or NULL on error.

cqueue_t* cq_make (  cq_time_t  now  )

Create a new callout queue object. The 'now' parameter is used to initialize the "current time". Use zero if you don't care...

void cq_resched (  cqueue_t *  cq, cevent_t *  handle, gint  delay )

Reschedule event at some other point in time. It is the responsibility of the user code to determine that the handle for the event has not yet expired, i.e. that the event has not triggered yet.

gint cq_ticks (  cqueue_t *  cq  )

void ev_link (  cqueue_t *  cq, cevent_t *  ev )  [static]

Link event into the callout queue.

void ev_unlink (  cqueue_t *  cq, cevent_t *  ev )  [static]

Unlink event from callout queue.

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Variable Documentation

cqueue_t* callout_queue

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