depend.h File Reference

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Data Structures
struct	updaterfunc_t
	Structure describing an updater function. More...
Typedefs
typedef int(*)	updater_f (int src, int dst, int typeid, int resid)
	Pointer to an updater function.
typedef updaterfunc_t	updaterfunc
Functions
int	updater_reorder ()
	Reorders dep_updaterlist linked list.
int	updater_check (int dst, int typeid)
	Checks if an updater function has been registered that has dst as a destination event.
updaterfunc *	updater_new (int src, int dst, int typeid, updater_f func)
	Register a new updater function.
int	updater_call (updaterfunc *updater, int resid)
	Calls an updater function.
void	updater_call_all (table *tab)
	Calls all registered updater functions.
int	updater_fix_domains ()
	Fixes resource domains when updater functions are used.

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Detailed Description

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Typedef Documentation

typedef int(*) updater_f(int src, int dst, int typeid, int resid)

Pointer to an updater function.

Updater function updates the assignment of one or more variable resources to an dependent event in a timetable structure.

The variable resources it assigns to this event depend on which variable resources have been assigned to a different, independent event.

Parameters:

	src	Tuple ID of the independent event.
	dst	Tuple ID of the dependent event.
	typeid	Resource type ID this updater function changes.
	tab	Pointer to the timetable structure.

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Function Documentation

int updater_call	(	updaterfunc *	updater,
		int	resid
	)

Calls an updater function.

Parameters:

	updater	Pointer to the updater function to be called.
	resid	Resource ID of the resource of the correct type that is assigned to the source tuple of the updater function.

Returns:

Resource ID that should be assigned to the destination tuple.

void updater_call_all

(

table *

tab

)

Calls all registered updater functions.

Functions are called in the order of the linked list. updater_reorder() must be called before the first call to updater_call_all() to properly reorder the linked list.

Parameters:

tab

Pointer to the timetable structure.

int updater_check	(	int	dst,
		int	typeid
	)

Checks if an updater function has been registered that has dst as a destination event.

If no such updater function has been registered, this means that it is safe to register a new updater function with dst as a destination event.

Parameters:

	dst	Tuple ID of the event to check.
	typeid	Resource type ID to check.

Returns:

0 if no such updater function has been registered or -1 otherwise.

int updater_fix_domains

(

)

Fixes resource domains when updater functions are used.

If no updater functions are used this function has no effect.

If updater functions are used in a problem description, the source tuples of updater functions must have their resource domains checked if any value in them causes the updater function to set a resource in the destination tuple outside its domain.

This function changes the resource domains of tuples so that this can not happen.

This function must be called after updater_reorder() and before data_init().

Returns:

0 on success and -1 if there was a memory allocation error.

updaterfunc* updater_new	(	int	src,
		int	dst,
		int	typeid,
		updater_f	func
	)

Register a new updater function.

It is recommended that updater_check() is called before calling this function to verify if there isn't another updater function registered for this dependent event.

Parameters:

	src	Tuple ID of the independent event.
	dst	Tuple ID of the dependent event.
	typeid	Resource type ID this updater function changes.
	func	Pointer to the updater function.

Returns:

Pointer to the updaterfunc structure or NULL on error.

int updater_reorder

(

)

Reorders dep_updaterlist linked list.

A source (independent) event for an updater function can infact be a destination (dependent) event of another updater function. This means that updater functions must be called in the correct order.

Example: Function A has a source event 2 and destination event 3. Function B has a source event 1 and destination event 2. In this case updater_reorder() puts function B in front of A.

Returns:

0 on success or -1 on error (there was a circular dependency and the correct order of calling can not be determined.

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