D-Bus: Data slots

D-Bus 1.14.10

Functions
Data slots
D-Bus secret internal implementation details

Storing data by ID. More...

## Functions
dbus_bool_t | _dbus_data_slot_allocator_init (DBusDataSlotAllocator *allocator, DBusGlobalLock lock)
| Initializes a data slot allocator object, used to assign integer IDs for data slots.
dbus_bool_t | _dbus_data_slot_allocator_alloc (DBusDataSlotAllocator *allocator, dbus_int32_t *slot_id_p)
| Allocates an integer ID to be used for storing data in a DBusDataSlotList.
void | _dbus_data_slot_allocator_free (DBusDataSlotAllocator *allocator, dbus_int32_t *slot_id_p)
| Deallocates an ID previously allocated with _dbus_data_slot_allocator_alloc().
void | _dbus_data_slot_list_init (DBusDataSlotList *list)
| Initializes a slot list.
dbus_bool_t | _dbus_data_slot_list_set (DBusDataSlotAllocator *allocator, DBusDataSlotList *list, int slot, void *data, DBusFreeFunction free_data_func, DBusFreeFunction *old_free_func, void **old_data)
| Stores a pointer in the data slot list, along with an optional function to be used for freeing the data when the data is set again, or when the slot list is finalized.
void * | _dbus_data_slot_list_get (DBusDataSlotAllocator *allocator, DBusDataSlotList *list, int slot)
| Retrieves data previously set with _dbus_data_slot_list_set_data().
void | _dbus_data_slot_list_clear (DBusDataSlotList *list)
| Frees all data slots contained in the list, calling application-provided free functions if they exist.
void | _dbus_data_slot_list_free (DBusDataSlotList *list)
| Frees the data slot list and all data slots contained in it, calling application-provided free functions if they exist.

## Detailed Description

Storing data by ID.

Types and functions related to storing data by an allocated ID. This is used for dbus_connection_set_data(), dbus_server_set_data(), etc.

## Function Documentation

## ◆ _dbus_data_slot_allocator_alloc()

dbus_bool_t _dbus_data_slot_allocator_alloc | ( | DBusDataSlotAllocator * | allocator,
|  | dbus_int32_t * | slot_id_p
| ) |  |

Allocates an integer ID to be used for storing data in a DBusDataSlotList.

If the value at *slot_id_p is not -1, this function just increments the refcount for the existing slot ID. If the value is -1, a new slot ID is allocated and stored at *slot_id_p.

Parameters

  allocator | the allocator
  slot_id_p | address to fill with the slot ID

Returns
  TRUE on success

Definition at line 70 of file dbus-dataslot.c.

References _dbus_assert, DBusDataSlotAllocator::allocated_slots, dbus_realloc(), FALSE, DBusDataSlotAllocator::lock, DBusDataSlotAllocator::n_allocated_slots, DBusDataSlotAllocator::n_used_slots, NULL, DBusAllocatedSlot::refcount, and DBusAllocatedSlot::slot_id.

Referenced by dbus_connection_allocate_data_slot(), dbus_message_allocate_data_slot(), dbus_pending_call_allocate_data_slot(), and dbus_server_allocate_data_slot().

## ◆ _dbus_data_slot_allocator_free()

void _dbus_data_slot_allocator_free | ( | DBusDataSlotAllocator * | allocator,
|  | dbus_int32_t * | slot_id_p
| ) |  |

Deallocates an ID previously allocated with _dbus_data_slot_allocator_alloc().

Existing data stored on existing DBusDataSlotList objects with this ID will be freed when the data list is finalized, but may not be retrieved (and may only be replaced if someone else reallocates the slot). The slot value is reset to -1 if this is the last unref.

Parameters

  allocator | the allocator
  slot_id_p | address where we store the slot

Definition at line 155 of file dbus-dataslot.c.

References _dbus_assert, _dbus_assert_not_reached, DBusDataSlotAllocator::allocated_slots, dbus_free(), DBusDataSlotAllocator::lock, DBusDataSlotAllocator::n_allocated_slots, DBusDataSlotAllocator::n_used_slots, NULL, DBusAllocatedSlot::refcount, and DBusAllocatedSlot::slot_id.

Referenced by dbus_connection_free_data_slot(), dbus_message_free_data_slot(), dbus_pending_call_free_data_slot(), and dbus_server_free_data_slot().

## ◆ _dbus_data_slot_allocator_init()

dbus_bool_t _dbus_data_slot_allocator_init | ( | DBusDataSlotAllocator * | allocator,
|  | DBusGlobalLock | lock
| ) |  |

Initializes a data slot allocator object, used to assign integer IDs for data slots.

Parameters

  allocator | the allocator to initialize

Definition at line 47 of file dbus-dataslot.c.

References DBusDataSlotAllocator::allocated_slots, DBusDataSlotAllocator::lock, DBusDataSlotAllocator::n_allocated_slots, DBusDataSlotAllocator::n_used_slots, NULL, and TRUE.

## ◆ _dbus_data_slot_list_clear()

void _dbus_data_slot_list_clear | ( | DBusDataSlotList * | list | ) |

Frees all data slots contained in the list, calling application-provided free functions if they exist.

Parameters

  list | the list to clear

Definition at line 318 of file dbus-dataslot.c.

References data, free_data_func, NULL, and DBusDataSlotList::slots.

Referenced by _dbus_data_slot_list_free().

## ◆ _dbus_data_slot_list_free()

void _dbus_data_slot_list_free | ( | DBusDataSlotList * | list | ) |

Frees the data slot list and all data slots contained in it, calling application-provided free functions if they exist.

Parameters

  list | the list to free

Definition at line 341 of file dbus-dataslot.c.

References _dbus_data_slot_list_clear(), dbus_free(), DBusDataSlotList::n_slots, NULL, and DBusDataSlotList::slots.

Referenced by _dbus_server_finalize_base().

## ◆ _dbus_data_slot_list_get()

void * _dbus_data_slot_list_get | ( | DBusDataSlotAllocator * | allocator,
|  | DBusDataSlotList * | list,
|  | int | slot
| ) |  |

Retrieves data previously set with _dbus_data_slot_list_set_data().

The slot must still be allocated (must not have been freed).

Parameters

  allocator | the allocator slot was allocated from
  list | the data slot list
  slot | the slot to get data from

Returns
  the data, or NULL if not found

Definition at line 286 of file dbus-dataslot.c.

References _dbus_assert, _dbus_assert_not_reached, DBusDataSlotAllocator::allocated_slots, data, DBusDataSlotAllocator::lock, DBusDataSlotList::n_slots, NULL, DBusAllocatedSlot::slot_id, and DBusDataSlotList::slots.

Referenced by dbus_connection_get_data(), dbus_message_get_data(), dbus_pending_call_get_data(), and dbus_server_get_data().

## ◆ _dbus_data_slot_list_init()

void _dbus_data_slot_list_init | ( | DBusDataSlotList * | list | ) |

Initializes a slot list.

Parameters

  list | the list to initialize.

Definition at line 198 of file dbus-dataslot.c.

References DBusDataSlotList::n_slots, NULL, and DBusDataSlotList::slots.

Referenced by _dbus_connection_new_for_transport(), _dbus_pending_call_new_unlocked(), and _dbus_server_init_base().

## ◆ _dbus_data_slot_list_set()

dbus_bool_t _dbus_data_slot_list_set | ( | DBusDataSlotAllocator * | allocator,
|  | DBusDataSlotList * | list,
|  | int | slot,
|  | void * | data,
|  | DBusFreeFunction | free_data_func,
|  | DBusFreeFunction * | old_free_func,
|  | void ** | old_data
| ) |  |

Stores a pointer in the data slot list, along with an optional function to be used for freeing the data when the data is set again, or when the slot list is finalized.

The slot number must have been allocated with _dbus_data_slot_allocator_alloc() for the same allocator passed in here. The same allocator has to be used with the slot list every time.

Parameters

  allocator | the allocator to use
  list | the data slot list
  slot | the slot number
  data | the data to store
  free_data_func | finalizer function for the data
  old_free_func | free function for any previously-existing data
  old_data | previously-existing data, should be freed with old_free_func

Returns
  TRUE if there was enough memory to store the data

Definition at line 222 of file dbus-dataslot.c.

References _dbus_assert, _dbus_assert_not_reached, DBusDataSlotAllocator::allocated_slots, data, dbus_realloc(), FALSE, free_data_func, DBusDataSlotAllocator::lock, DBusDataSlotList::n_slots, NULL, DBusAllocatedSlot::slot_id, DBusDataSlotList::slots, and TRUE.

Referenced by _dbus_pending_call_set_data_unlocked(), dbus_connection_set_data(), dbus_message_set_data(), and dbus_server_set_data().