Collaboration diagram for Objects Caches:

Detailed Description

Cached objects flags
#define	OC_FLAG_INLRU 0x00000001U

#define	OC_FLAG_INHASH 0x00000002U

#define	OC_FLAG_SHARED 0x00000004U

#define	OC_FLAG_NOTSYNC 0x00000008U

#define	OC_FLAG_LAZYWRITE 0x00000010U

#define	OC_FLAG_FORGET 0x00000020U

Typedefs
typedef uint32_t	oc_flags_t
	Flags of cached objects. More...

typedef struct ch_oc_hash_header	oc_hash_header_t
	Type of an hash element header. More...

typedef struct ch_oc_lru_header	oc_lru_header_t
	Type of an LRU element header. More...

typedef struct ch_oc_object	oc_object_t
	Type of a cached object. More...

typedef struct ch_objects_cache	objects_cache_t
	Type of a cache object. More...

typedef bool(*	oc_readf_t) (objects_cache_t ocp, oc_object_t objp, bool async)
	Object read function. More...

typedef bool(*	oc_writef_t) (objects_cache_t ocp, oc_object_t objp, bool async)
	Object write function. More...

Data Structures
struct	ch_oc_hash_header
	Structure representing an hash table element. More...

struct	ch_oc_lru_header
	Structure representing an hash table element. More...

struct	ch_oc_object
	Structure representing a cached object. More...

struct	ch_objects_cache
	Structure representing a cache object. More...

Functions
static oc_object_t *	hash_get_s (objects_cache_t *ocp, uint32_t group, uint32_t key)
	Returns an object pointer from the cache, if present. More...

static oc_object_t *	lru_get_last_s (objects_cache_t *ocp)
	Gets the least recently used object buffer from the LRU list. More...

void	chCacheObjectInit (objects_cache_t ocp, ucnt_t hashn, oc_hash_header_t hashp, ucnt_t objn, size_t objsz, void *objvp, oc_readf_t readf, oc_writef_t writef)
	Initializes a `objects_cache_t` object. More...

oc_object_t *	chCacheGetObject (objects_cache_t *ocp, uint32_t group, uint32_t key)
	Retrieves an object from the cache. More...

void	chCacheReleaseObjectI (objects_cache_t ocp, oc_object_t objp)
	Releases an object into the cache. More...

bool	chCacheReadObject (objects_cache_t ocp, oc_object_t objp, bool async)
	Reads object data from the storage. More...

bool	chCacheWriteObject (objects_cache_t ocp, oc_object_t objp, bool async)
	Writes the object data back to storage. More...

static void	chCacheReleaseObject (objects_cache_t ocp, oc_object_t objp)
	Releases an object into the cache. More...

Typedef Documentation

◆ oc_flags_t

typedef uint32_t oc_flags_t

Flags of cached objects.

Definition at line 64 of file chobjcaches.h.

◆ oc_hash_header_t

typedef struct ch_oc_hash_header oc_hash_header_t

Type of an hash element header.

Definition at line 69 of file chobjcaches.h.

◆ oc_lru_header_t

typedef struct ch_oc_lru_header oc_lru_header_t

Type of an LRU element header.

Definition at line 74 of file chobjcaches.h.

◆ oc_object_t

typedef struct ch_oc_object oc_object_t

Type of a cached object.

Definition at line 79 of file chobjcaches.h.

◆ objects_cache_t

typedef struct ch_objects_cache objects_cache_t

Type of a cache object.

Definition at line 84 of file chobjcaches.h.

◆ oc_readf_t

typedef bool(* oc_readf_t) (objects_cache_t *ocp, oc_object_t *objp, bool async)

Object read function.

Parameters

[in]	ocp	pointer to the `objects_cache_t` structure
[in]	async	requests an asynchronous operation if supported, the function is then responsible for releasing the object

Definition at line 94 of file chobjcaches.h.

◆ oc_writef_t

typedef bool(* oc_writef_t) (objects_cache_t *ocp, oc_object_t *objp, bool async)

Object write function.

Parameters

[in]	ocp	pointer to the `objects_cache_t` structure
[in]	async	requests an asynchronous operation if supported, the function is then responsible for releasing the object

Definition at line 106 of file chobjcaches.h.

Function Documentation

◆ hash_get_s()

static oc_object_t* hash_get_s	(	objects_cache_t *	ocp,
		uint32_t	group,
		uint32_t	key
	)

static

Returns an object pointer from the cache, if present.

Parameters

[out]	ocp	pointer to the `objects_cache_t` structure to be
[in]	group	object group identifier
[in]	key	object identifier within the group initialized

Returns: The pointer to the retrieved object.

Return values

NULL	if the object is not in cache.

Function Class:: Not an API, this function is for internal use only.

Definition at line 134 of file chobjcaches.c.

References ch_objects_cache::hashp.

Referenced by chCacheGetObject().

◆ lru_get_last_s()

static oc_object_t* lru_get_last_s ( objects_cache_t * ocp )

static

Gets the least recently used object buffer from the LRU list.

Parameters

[out] ocp pointer to the objects_cache_t structure to be

Returns: The pointer to the retrieved object.

Function Class:: Not an API, this function is for internal use only.

Definition at line 165 of file chobjcaches.c.

References chDbgAssert, chSemWaitS(), ch_objects_cache::lru, ch_oc_lru_header::lru_prev, ch_objects_cache::lru_sem, and ch_oc_object::obj_flags.

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◆ chCacheObjectInit()

void chCacheObjectInit	(	objects_cache_t *	ocp,
		ucnt_t	hashn,
		oc_hash_header_t *	hashp,
		ucnt_t	objn,
		size_t	objsz,
		void *	objvp,
		oc_readf_t	readf,
		oc_writef_t	writef
	)

Initializes a objects_cache_t object.

Parameters

[out]	ocp	pointer to the `objects_cache_t` structure to be initialized
[in]	hashn	number of elements in the hash table array, must be a power of two and not lower than `objn`
[in]	hashp	pointer to the hash table as an array of `oc_hash_header_t`
[in]	objn	number of elements in the objects table array
[in]	objsz	size of elements in the objects table array, the minimum value is `sizeof (oc_object_t)`.
[in]	objvp	pointer to the hash objects as an array of structures starting with an `oc_object_t`
[in]	readf	pointer to an object reader function
[in]	writef	pointer to an object writer function

Function Class:: Initializer, this function just initializes an object and can be invoked before the kernel is initialized.

Definition at line 241 of file chobjcaches.c.

References ch_objects_cache::cache_sem, chDbgCheck, chSemObjectInit(), ch_oc_hash_header::hash_next, ch_oc_lru_header::hash_next, ch_oc_hash_header::hash_prev, ch_oc_lru_header::hash_prev, ch_objects_cache::hashn, ch_objects_cache::hashp, ch_objects_cache::lru, ch_oc_lru_header::lru_next, ch_oc_lru_header::lru_prev, ch_objects_cache::lru_sem, ch_oc_object::obj_sem, ch_objects_cache::objn, ch_objects_cache::objvp, PORT_NATURAL_ALIGN, ch_objects_cache::readf, and ch_objects_cache::writef.

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◆ chCacheGetObject()

oc_object_t * chCacheGetObject	(	objects_cache_t *	ocp,
		uint32_t	group,
		uint32_t	key
	)

Retrieves an object from the cache.

Note: If the object is not in cache then the returned object is marked as OC_FLAG_NOTSYNC meaning that its data contains garbage and must be initialized.

Parameters

[in]	ocp	pointer to the `objects_cache_t` structure
[in]	group	object group identifier
[in]	key	object identifier within the group

Returns: The pointer to the retrieved object.

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 304 of file chobjcaches.c.

References chDbgAssert, chSysLock, hash_get_s(), and ch_oc_object::obj_flags.

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◆ chCacheReleaseObjectI()

void chCacheReleaseObjectI	(	objects_cache_t *	ocp,
		oc_object_t *	objp
	)

Releases an object into the cache.

Note

This function gives a meaning to the following flags:

OC_FLAG_INLRU must be cleared.
OC_FLAG_INHASH must be set.
OC_FLAG_SHARED must be cleared.
OC_FLAG_NOTSYNC invalidates the object and queues it on the LRU tail.
OC_FLAG_LAZYWRITE is ignored and kept, a write will occur when the object is removed from the LRU list (lazy write).

Parameters

[in]	ocp	pointer to the `objects_cache_t` structure
[in]	objp	pointer to the `oc_object_t` structure

Function Class:: This is an I-Class API, this function can be invoked from within a system lock zone by both threads and interrupt handlers.

Definition at line 379 of file chobjcaches.c.

References chDbgAssert, and ch_oc_object::obj_flags.

Referenced by chCacheReleaseObject().

◆ chCacheReadObject()

bool chCacheReadObject	(	objects_cache_t *	ocp,
		oc_object_t *	objp,
		bool	async
	)

Reads object data from the storage.

Note: In case of asynchronous operation an error condition is not reported by this function.

Parameters

[in]	ocp	pointer to the `objects_cache_t` structure
[in]	objp	pointer to the `oc_object_t` structure
[in]	async	requests an asynchronous operation if supported, the function is then responsible for releasing the object

Returns: The operation status. In case of asynchronous operation false is always returned.

Return values

false	if the operation succeeded.
true	if the synchronous read operation failed.

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 449 of file chobjcaches.c.

References ch_oc_object::obj_flags.

◆ chCacheWriteObject()

bool chCacheWriteObject	(	objects_cache_t *	ocp,
		oc_object_t *	objp,
		bool	async
	)

Writes the object data back to storage.

Note: In case of asynchronous operation an error condition is not reported by this function.

Parameters

[in]	ocp	pointer to the `objects_cache_t` structure
[in]	objp	pointer to the `oc_object_t` structure
[in]	async	requests an asynchronous operation if supported, the function is then responsible for releasing the object

Returns: The operation status. In case of asynchronous operation false is always returned.

Return values

false	if the operation succeeded.
true	if the synchronous write operation failed.

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 478 of file chobjcaches.c.

References ch_oc_object::obj_flags.

◆ chCacheReleaseObject()

static void chCacheReleaseObject	(	objects_cache_t *	ocp,
		oc_object_t *	objp
	)

inlinestatic

Releases an object into the cache.

Note

This function gives a meaning to the following flags:

OC_FLAG_INLRU must be cleared.
OC_FLAG_INHASH must be set.
OC_FLAG_SHARED must be cleared.
OC_FLAG_NOTSYNC invalidates the object and queues it on the LRU tail.
OC_FLAG_LAZYWRITE is ignored and kept, a write will occur when the object is removed from the LRU list (lazy write).

Parameters

[in]	ocp	pointer to the `objects_cache_t` structure
[in]	objp	pointer to the `oc_object_t` structure

Function Class:: Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 291 of file chobjcaches.h.

References chCacheReleaseObjectI(), chSchRescheduleS(), chSysLock, and chSysUnlock.

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Detailed Description

Cached objects flags

Typedefs

Data Structures

Functions

Typedef Documentation

◆ oc_flags_t

◆ oc_hash_header_t

◆ oc_lru_header_t

◆ oc_object_t

◆ objects_cache_t

◆ oc_readf_t

◆ oc_writef_t

Function Documentation

◆ hash_get_s()

◆ lru_get_last_s()

◆ chCacheObjectInit()

◆ chCacheGetObject()

◆ chCacheReleaseObjectI()

◆ chCacheReadObject()

◆ chCacheWriteObject()

◆ chCacheReleaseObject()