A class with an implementation of the Dynamic Loader Service. More...

#include <dynamic_loader_imp.h>

Public Types
typedef std::pair< my_component_registry::const_iterator, minimal_chassis::rwlock_scoped_lock >	component_iterator

Static Public Member Functions
static void	init ()
	Initializes loader for usage. More...

static void	deinit ()
	De-initializes loader. More...

static void	rw_lock_deinit ()
	De-initializes RW lock. More...

static mysql_service_status_t	load (const char *urns[], int component_count) noexcept
	Loads specified group of Components by URN, initializes them and registers all Service Implementations present in these Components. More...

static mysql_service_status_t	unload (const char *urns[], int component_count) noexcept
	Unloads specified group of Components by URN, deinitializes them and unregisters all Service Implementations present in these Components. More...

static mysql_service_status_t	iterator_create (my_h_component_iterator *out_iterator) noexcept
	Creates iterator that iterates through all loaded Components. More...

static void	iterator_release (my_h_component_iterator iterator) noexcept
	Releases Component iterator. More...

static mysql_service_status_t	iterator_get (my_h_component_iterator iterator, const char out_name, const char out_urn) noexcept
	Gets name and URN of Service pointed to by iterator. More...

static mysql_service_status_t	iterator_next (my_h_component_iterator iterator) noexcept
	Advances specified iterator to next element. More...

static mysql_service_status_t	iterator_is_valid (my_h_component_iterator iterator) noexcept
	Checks if specified iterator is valid, i.e. More...

Private Types
typedef std::unordered_map< my_string, my_service< const mysql_service_dynamic_loader_scheme_t > >	scheme_service_map

Static Private Member Functions
static bool	load_do_load_component_by_scheme (const char *urns[], int component_count)
	Loads specified group of Components by URN. More...

static bool	load_do_collect_services_provided (std::vector< std::unique_ptr< mysql_component > > &loaded_components, std::vector< const char * > &services_loaded)
	Prepares a list of all Services that are provided by specified Components. More...

static bool	load_do_check_dependencies (std::vector< std::unique_ptr< mysql_component > > &loaded_components, const std::set< my_string > &services_provided)
	Checks if all dependencies can be satisfied with existing or to be added Services. More...

static bool	load_do_register_services (std::vector< std::unique_ptr< mysql_component > > &loaded_components)
	Registers all Services that are provided by specified Components. More...

static bool	load_do_resolve_dependencies (std::vector< std::unique_ptr< mysql_component > > &loaded_components)
	Acquires Service Implementations for all dependencies of Components. More...

static bool	load_do_initialize_components (std::vector< std::unique_ptr< mysql_component > > &loaded_components)
	Calls Components initialization method to make Components ready to function. More...

static bool	load_do_commit (std::vector< std::unique_ptr< mysql_component > > &loaded_components)
	Adds all Components to main list of loaded Components. More...

static bool	unload_do_list_components (const char *urns[], int component_count)
	Unloads all Components specified in list. More...

static bool	unload_do_topological_order (const std::vector< mysql_component * > &components_to_unload)
	Orders components in a order that would allow allow deinitialization to be done always for components that have all their dependencies still not deinitialized. More...

static bool	unload_do_get_scheme_services (const std::vector< mysql_component * > &components_to_unload, const std::map< const void , std::vector< mysql_component > > &dependency_graph)
	Prefetch all scheme loading Services before we get a lock on a Registry. More...

static bool	unload_do_lock_provided_services (const std::vector< mysql_component * > &components_to_unload, const std::map< const void , std::vector< mysql_component > > &dependency_graph, scheme_service_map &scheme_services)
	Takes a lock on all services that are provided by the Components to be unloaded, to prevent reference count from being changed. More...

static bool	unload_do_check_provided_services_reference_count (const std::vector< mysql_component * > &components_to_unload, const std::map< const void , std::vector< mysql_component > > &dependency_graph, scheme_service_map &scheme_services)
	Checks if all Service Implementations provided by the Components to be unloaded have no references outside the group of Components to be unloaded. More...

static bool	unload_do_deinitialize_components (const std::vector< mysql_component * > &components_to_unload, scheme_service_map &scheme_services)
	Deinitialize Components using their deinitialization method. More...

static bool	unload_do_unload_dependencies (const std::vector< mysql_component * > &components_to_unload, scheme_service_map &scheme_services)
	Releases Service Implementations acquired to satisfy dependencies. More...

static bool	unload_do_unregister_services (const std::vector< mysql_component * > &components_to_unload, scheme_service_map &scheme_services)
	Unregisters all Service Implementations of specified Components. More...

static bool	unload_do_unload_components (const std::vector< mysql_component * > &components_to_unload, scheme_service_map &scheme_services)
	Uses Component URN to extract the scheme part of URN (part before "://") and use it to acquire Service Implementation of scheme Component loader Service for specified scheme, used then to unload specified Components. More...

static bool	unload_do_commit ()
	Finishes unloading process by marking changes to not be rolled back. More...

static bool	get_scheme_service_from_urn (const my_string &urn, const mysql_service_dynamic_loader_scheme_t **out_scheme_service, scheme_service_map &scheme_services)
	Returns scheme loading Service based on given URN. More...

Static Private Attributes
static my_component_registry	components_list

static mysql_rwlock_t	LOCK_dynamic_loader

static generation_urns_list	urns_with_gen_list

Detailed Description

A class with an implementation of the Dynamic Loader Service.

Member Typedef Documentation

◆ component_iterator

typedef std::pair<my_component_registry::const_iterator, minimal_chassis::rwlock_scoped_lock> mysql_dynamic_loader_imp::component_iterator

◆ scheme_service_map

typedef std::unordered_map<my_string, my_service<const mysql_service_dynamic_loader_scheme_t> > mysql_dynamic_loader_imp::scheme_service_map

private

Member Function Documentation

◆ deinit()

void mysql_dynamic_loader_imp::deinit ( )

static

De-initializes loader.

De-initializes RW lock, all other structures doesn't require any action.

◆ get_scheme_service_from_urn()

bool mysql_dynamic_loader_imp::get_scheme_service_from_urn	(	const my_string &	urn,
		const mysql_service_dynamic_loader_scheme_t **	out_scheme_service,
		scheme_service_map &	scheme_services
	)

staticprivate

Returns scheme loading Service based on given URN.

It uses supplied cache to reuse Services. If Service is not present in cache, it will be acquired from registry.

Parameters

	urn	URN of Components to get scheme loader Service for.
[out]	out_scheme_service	Pointer to store result scheme loader Service.
[in,out]	scheme_services	Map of scheme loader services already acquired.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ init()

void mysql_dynamic_loader_imp::init ( )

static

Initializes loader for usage.

Initializes RW lock, all other structures should be empty. Shouldn't be called multiple times.

◆ iterator_create()

mysql_service_status_t mysql_dynamic_loader_imp::iterator_create ( my_h_component_iterator * out_iterator )

staticnoexcept

Creates iterator that iterates through all loaded Components.

If successful it leaves read lock on dynamic loader until iterator is released.

Parameters

[out] out_iterator Pointer to Component iterator handle.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ iterator_get()

mysql_service_status_t mysql_dynamic_loader_imp::iterator_get	(	my_h_component_iterator	iterator,
		const char **	out_name,
		const char **	out_urn
	)

staticnoexcept

Gets name and URN of Service pointed to by iterator.

Parameters

	iterator	Component iterator handle.
[out]	out_name	Pointer to string with Component name to set result pointer to.
[out]	out_urn	Pointer to string with URN from which the Component was loaded from, to set result pointer to.

Returns: Status of performed operation

Return values

false	success
true	Failure, may be caused when called on iterator that went through all values already.

◆ iterator_is_valid()

mysql_service_status_t mysql_dynamic_loader_imp::iterator_is_valid ( my_h_component_iterator iterator )

staticnoexcept

Checks if specified iterator is valid, i.e.

have not reached one-past-last element.

Parameters

iterator Component iterator handle.

Returns: Validity of iterator

Return values

false	Valid
true	Invalid or reached one-past-last element.

◆ iterator_next()

mysql_service_status_t mysql_dynamic_loader_imp::iterator_next ( my_h_component_iterator iterator )

staticnoexcept

Advances specified iterator to next element.

Will succeed but return true if it reaches one-past-last element.

Parameters

iterator Component iterator handle.

Returns: Status of performed operation and validity of iterator after operation.

Return values

false	success
true	Failure or called on iterator that was on last element.

◆ iterator_release()

void mysql_dynamic_loader_imp::iterator_release ( my_h_component_iterator iterator )

staticnoexcept

Releases Component iterator.

Releases read lock on dynamic loader.

Parameters

iterator Component iterator handle.

◆ load()

mysql_service_status_t mysql_dynamic_loader_imp::load	(	const char *	urns[],
		int	component_count
	)

staticnoexcept

Loads specified group of Components by URN, initializes them and registers all Service Implementations present in these Components.

Assures all dependencies will be met after loading specified Components. The dependencies may be circular, in such case it's necessary to specify all Components on cycle to load in one batch. From URNs specified the scheme part of URN (part before "://") is extracted and used to acquire Service Implementation of scheme Component loader Service for specified scheme.

Parameters

urns	List of URNs of Components to load.
component_count	Number of Components on list to load.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ load_do_check_dependencies()

bool mysql_dynamic_loader_imp::load_do_check_dependencies	(	std::vector< std::unique_ptr< mysql_component > > &	loaded_components,
		const std::set< my_string > &	services_provided
	)

staticprivate

Checks if all dependencies can be satisfied with existing or to be added Services.

Parameters

loaded_components	List of Components to continue load of.
services_provided	List of Services that are being provided by Components to be loaded.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ load_do_collect_services_provided()

bool mysql_dynamic_loader_imp::load_do_collect_services_provided	(	std::vector< std::unique_ptr< mysql_component > > &	loaded_components,
		std::vector< const char * > &	services_loaded
	)

staticprivate

Prepares a list of all Services that are provided by specified Components.

This will enable us in next step to check if these may be used to satisfy other Components dependencies.

Parameters

loaded_components	List of Components to continue load of.
services_loaded	List of services loaded

Returns: Status of performed operation

Return values

false	success
true	failure

◆ load_do_commit()

bool mysql_dynamic_loader_imp::load_do_commit ( std::vector< std::unique_ptr< mysql_component > > & loaded_components )

staticprivate

Adds all Components to main list of loaded Components.

Marks changes done by all previous steps as not to be rolled back.

Parameters

loaded_components List of Components to continue load of.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ load_do_initialize_components()

bool mysql_dynamic_loader_imp::load_do_initialize_components ( std::vector< std::unique_ptr< mysql_component > > & loaded_components )

staticprivate

Calls Components initialization method to make Components ready to function.

In case of failure rollbacks all changes, i.e. calls deinitialization methods on initialized Components.

Parameters

loaded_components List of Components to continue load of.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ load_do_load_component_by_scheme()

bool mysql_dynamic_loader_imp::load_do_load_component_by_scheme	(	const char *	urns[],
		int	component_count
	)

staticprivate

Loads specified group of Components by URN.

From URNs specified the scheme part of URN (part before "://") is extracted and used to acquire Service Implementation of scheme Component loader Service for specified scheme. In case of failure rollbacks all changes, i.e. unloads loaded Components.

Parameters

urns	List of URNs of Components to load.
component_count	Number of Components on list to load.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ load_do_register_services()

bool mysql_dynamic_loader_imp::load_do_register_services ( std::vector< std::unique_ptr< mysql_component > > & loaded_components )

staticprivate

Registers all Services that are provided by specified Components.

In case of failure rollbacks all changes, i.e. unregister registered Service Implementations.

Parameters

loaded_components List of Components to continue load of.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ load_do_resolve_dependencies()

bool mysql_dynamic_loader_imp::load_do_resolve_dependencies ( std::vector< std::unique_ptr< mysql_component > > & loaded_components )

staticprivate

Acquires Service Implementations for all dependencies of Components.

In case of failure rollbacks all changes, i.e. release Services that were acquired.

Parameters

loaded_components List of Components to continue load of.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ rw_lock_deinit()

void mysql_dynamic_loader_imp::rw_lock_deinit ( )

static

De-initializes RW lock.

◆ unload()

mysql_service_status_t mysql_dynamic_loader_imp::unload	(	const char *	urns[],
		int	component_count
	)

staticnoexcept

Unloads specified group of Components by URN, deinitializes them and unregisters all Service Implementations present in these Components.

Assumes, thous does not check it, all dependencies of not unloaded Components will still be met after unloading specified Components. The dependencies may be circular, in such case it's necessary to specify all Components on cycle to unload in one batch. From URNs specified the scheme part of URN (part before "://") is extracted and used to acquire Service Implementation of scheme Component loader Service for specified scheme. URN specified should be identical to ones specified in load() method, i.e. all letters must have the same case.

Parameters

urns	List of URNs of Components to unload.
component_count	Number of Components on list to unload.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ unload_do_check_provided_services_reference_count()

bool mysql_dynamic_loader_imp::unload_do_check_provided_services_reference_count	(	const std::vector< mysql_component * > &	components_to_unload,
		const std::map< const void , std::vector< mysql_component > > &	dependency_graph,
		scheme_service_map &	scheme_services
	)

staticprivate

Checks if all Service Implementations provided by the Components to be unloaded have no references outside the group of Components to be unloaded.

This assures that continuing deinitialization of these Components in topological order, and by this also unregistration of all provided Service Implementations will succeed.

Parameters

components_to_unload	List of Components to continue unload of.
dependency_graph	A graph of dependencies between the Components to be unloaded.
scheme_services	Map of scheme loading Services prefetched with Service Implementations required to unload all Components to unload.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ unload_do_commit()

bool mysql_dynamic_loader_imp::unload_do_commit ( )

staticprivate

Finishes unloading process by marking changes to not be rolled back.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ unload_do_deinitialize_components()

bool mysql_dynamic_loader_imp::unload_do_deinitialize_components	(	const std::vector< mysql_component * > &	components_to_unload,
		scheme_service_map &	scheme_services
	)

staticprivate

Deinitialize Components using their deinitialization method.

In case of failure rollbacks all changes, i.e. calls initialization method again on deinitialized Components.

Parameters

components_to_unload	List of Components to continue unload of.
scheme_services	Map of scheme loading Services prefetched with Service Implementations required to unload all Components to unload.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ unload_do_get_scheme_services()

bool mysql_dynamic_loader_imp::unload_do_get_scheme_services	(	const std::vector< mysql_component * > &	components_to_unload,
		const std::map< const void , std::vector< mysql_component > > &	dependency_graph
	)

staticprivate

Prefetch all scheme loading Services before we get a lock on a Registry.

Parameters

components_to_unload	List of Components to continue unload of.
dependency_graph	A graph of dependencies between the Components to be unloaded.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ unload_do_list_components()

bool mysql_dynamic_loader_imp::unload_do_list_components	(	const char *	urns[],
		int	component_count
	)

staticprivate

Unloads all Components specified in list.

It does not acquire a write lock on dynamic loader, but requires it to be acquired by caller.

Parameters

urns	List of URNs of Components to unload.
component_count	Number of Components on list to unload.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ unload_do_lock_provided_services()

bool mysql_dynamic_loader_imp::unload_do_lock_provided_services	(	const std::vector< mysql_component * > &	components_to_unload,
		const std::map< const void , std::vector< mysql_component > > &	dependency_graph,
		scheme_service_map &	scheme_services
	)

staticprivate

Takes a lock on all services that are provided by the Components to be unloaded, to prevent reference count from being changed.

Parameters

components_to_unload	List of Components to continue unload of.
dependency_graph	A graph of dependencies between the Components to be unloaded.
scheme_services	Map of scheme loading Services prefetched with Service Implementations required to unload all Components to unload.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ unload_do_topological_order()

bool mysql_dynamic_loader_imp::unload_do_topological_order ( const std::vector< mysql_component * > & components_to_unload )

staticprivate

Orders components in a order that would allow allow deinitialization to be done always for components that have all their dependencies still not deinitialized.

It also creates a graph of dependencies between the Service Implementations provided by the Components to be unloaded and Components that use this Service Implementation.

Parameters

components_to_unload List of Components to continue unload of.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ unload_do_unload_components()

bool mysql_dynamic_loader_imp::unload_do_unload_components	(	const std::vector< mysql_component * > &	components_to_unload,
		scheme_service_map &	scheme_services
	)

staticprivate

Uses Component URN to extract the scheme part of URN (part before "://") and use it to acquire Service Implementation of scheme Component loader Service for specified scheme, used then to unload specified Components.

The unloaded Components are removed from the main list of all loaded Components. In case of failure rollbacks all changes, i.e. loads unloaded Components by their URN and add them to the main list of loaded Components again.

Parameters

components_to_unload	List of Components to continue unload of.
scheme_services	Map of scheme loading Services prefetched with Service Implementations required to unload all Components to unload.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ unload_do_unload_dependencies()

bool mysql_dynamic_loader_imp::unload_do_unload_dependencies	(	const std::vector< mysql_component * > &	components_to_unload,
		scheme_service_map &	scheme_services
	)

staticprivate

Releases Service Implementations acquired to satisfy dependencies.

In case of failure rollbacks all changes, i.e. acquires Services for released dependencies again.

Parameters

components_to_unload	List of Components to continue unload of.
scheme_services	Map of scheme loading Services prefetched with Service Implementations required to unload all Components to unload.

Returns: Status of performed operation

Return values

false	success
true	failure

◆ unload_do_unregister_services()

bool mysql_dynamic_loader_imp::unload_do_unregister_services	(	const std::vector< mysql_component * > &	components_to_unload,
		scheme_service_map &	scheme_services
	)

staticprivate

Unregisters all Service Implementations of specified Components.

In case of failure rollbacks all changes, i.e. registers unregistered Service Implementations again.

Parameters

components_to_unload	List of Components to continue unload of.
scheme_services	Map of scheme loading Services prefetched with Service Implementations required to unload all Components to unload.

Returns: Status of performed operation

Return values

false	success
true	failure

Member Data Documentation

◆ components_list

my_component_registry mysql_dynamic_loader_imp::components_list

staticprivate

◆ LOCK_dynamic_loader

mysql_rwlock_t mysql_dynamic_loader_imp::LOCK_dynamic_loader

staticprivate

◆ urns_with_gen_list

generation_urns_list mysql_dynamic_loader_imp::urns_with_gen_list

staticprivate

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

components/libminchassis/dynamic_loader_imp.h
components/libminchassis/dynamic_loader.cc

Public Types

Static Public Member Functions

Private Types

Static Private Member Functions

Static Private Attributes

Detailed Description

Member Typedef Documentation

◆ component_iterator

◆ scheme_service_map

Member Function Documentation

◆ deinit()

◆ get_scheme_service_from_urn()

◆ init()

◆ iterator_create()

◆ iterator_get()

◆ iterator_is_valid()

◆ iterator_next()

◆ iterator_release()

◆ load()

◆ load_do_check_dependencies()

◆ load_do_collect_services_provided()

◆ load_do_commit()

◆ load_do_initialize_components()

◆ load_do_load_component_by_scheme()

◆ load_do_register_services()

◆ load_do_resolve_dependencies()

◆ rw_lock_deinit()

◆ unload()

◆ unload_do_check_provided_services_reference_count()

◆ unload_do_commit()

◆ unload_do_deinitialize_components()

◆ unload_do_get_scheme_services()

◆ unload_do_list_components()

◆ unload_do_lock_provided_services()

◆ unload_do_topological_order()

◆ unload_do_unload_components()

◆ unload_do_unload_dependencies()

◆ unload_do_unregister_services()

Member Data Documentation

◆ components_list

◆ LOCK_dynamic_loader

◆ urns_with_gen_list