X-Git-Url: http://vcs.maemo.org/git/?a=blobdiff_plain;f=src%2Fdbus%2Fdbus-dataslot.c;fp=src%2Fdbus%2Fdbus-dataslot.c;h=a7ad2e454aa8c88aa9f1795ffe654feca81fb7f1;hb=d00115111c6ab0c3f82117c4e2c3d24663c4f1ce;hp=0000000000000000000000000000000000000000;hpb=19516645fd679ce8c6779722bb831a42d0b3ddfe;p=monky diff --git a/src/dbus/dbus-dataslot.c b/src/dbus/dbus-dataslot.c new file mode 100644 index 0000000..a7ad2e4 --- /dev/null +++ b/src/dbus/dbus-dataslot.c @@ -0,0 +1,477 @@ +/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */ +/* dbus-dataslot.c storing data on objects + * + * Copyright (C) 2003 Red Hat, Inc. + * + * Licensed under the Academic Free License version 2.1 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ +#include "dbus-dataslot.h" +#include "dbus-threads-internal.h" + +/** + * @defgroup DBusDataSlot Data slots + * @ingroup DBusInternals + * @brief 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. + * @{ + */ + +/** + * Initializes a data slot allocator object, used to assign + * integer IDs for data slots. + * + * @param allocator the allocator to initialize + */ +dbus_bool_t +_dbus_data_slot_allocator_init (DBusDataSlotAllocator *allocator) +{ + allocator->allocated_slots = NULL; + allocator->n_allocated_slots = 0; + allocator->n_used_slots = 0; + allocator->lock_loc = NULL; + + return TRUE; +} + +/** + * 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. + * + * @param allocator the allocator + * @param mutex_loc the location lock for this allocator + * @param slot_id_p address to fill with the slot ID + * @returns #TRUE on success + */ +dbus_bool_t +_dbus_data_slot_allocator_alloc (DBusDataSlotAllocator *allocator, + DBusMutex **mutex_loc, + dbus_int32_t *slot_id_p) +{ + dbus_int32_t slot; + + _dbus_mutex_lock (*mutex_loc); + + if (allocator->n_allocated_slots == 0) + { + _dbus_assert (allocator->lock_loc == NULL); + allocator->lock_loc = mutex_loc; + } + else if (allocator->lock_loc != mutex_loc) + { + _dbus_warn_check_failed ("D-Bus threads were initialized after first using the D-Bus library. If your application does not directly initialize threads or use D-Bus, keep in mind that some library or plugin may have used D-Bus or initialized threads behind your back. You can often fix this problem by calling dbus_init_threads() or dbus_g_threads_init() early in your main() method, before D-Bus is used.\n"); + _dbus_assert_not_reached ("exiting"); + } + + if (*slot_id_p >= 0) + { + slot = *slot_id_p; + + _dbus_assert (slot < allocator->n_allocated_slots); + _dbus_assert (allocator->allocated_slots[slot].slot_id == slot); + + allocator->allocated_slots[slot].refcount += 1; + + goto out; + } + + _dbus_assert (*slot_id_p < 0); + + if (allocator->n_used_slots < allocator->n_allocated_slots) + { + slot = 0; + while (slot < allocator->n_allocated_slots) + { + if (allocator->allocated_slots[slot].slot_id < 0) + { + allocator->allocated_slots[slot].slot_id = slot; + allocator->allocated_slots[slot].refcount = 1; + allocator->n_used_slots += 1; + break; + } + ++slot; + } + + _dbus_assert (slot < allocator->n_allocated_slots); + } + else + { + DBusAllocatedSlot *tmp; + + slot = -1; + tmp = dbus_realloc (allocator->allocated_slots, + sizeof (DBusAllocatedSlot) * (allocator->n_allocated_slots + 1)); + if (tmp == NULL) + goto out; + + allocator->allocated_slots = tmp; + slot = allocator->n_allocated_slots; + allocator->n_allocated_slots += 1; + allocator->n_used_slots += 1; + allocator->allocated_slots[slot].slot_id = slot; + allocator->allocated_slots[slot].refcount = 1; + } + + _dbus_assert (slot >= 0); + _dbus_assert (slot < allocator->n_allocated_slots); + _dbus_assert (*slot_id_p < 0); + _dbus_assert (allocator->allocated_slots[slot].slot_id == slot); + _dbus_assert (allocator->allocated_slots[slot].refcount == 1); + + *slot_id_p = slot; + + _dbus_verbose ("Allocated slot %d on allocator %p total %d slots allocated %d used\n", + slot, allocator, allocator->n_allocated_slots, allocator->n_used_slots); + + out: + _dbus_mutex_unlock (*(allocator->lock_loc)); + return slot >= 0; +} + +/** + * 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. + * + * @param allocator the allocator + * @param slot_id_p address where we store the slot + */ +void +_dbus_data_slot_allocator_free (DBusDataSlotAllocator *allocator, + dbus_int32_t *slot_id_p) +{ + _dbus_mutex_lock (*(allocator->lock_loc)); + + _dbus_assert (*slot_id_p < allocator->n_allocated_slots); + _dbus_assert (allocator->allocated_slots[*slot_id_p].slot_id == *slot_id_p); + _dbus_assert (allocator->allocated_slots[*slot_id_p].refcount > 0); + + allocator->allocated_slots[*slot_id_p].refcount -= 1; + + if (allocator->allocated_slots[*slot_id_p].refcount > 0) + { + _dbus_mutex_unlock (*(allocator->lock_loc)); + return; + } + + /* refcount is 0, free the slot */ + _dbus_verbose ("Freeing slot %d on allocator %p total %d allocated %d used\n", + *slot_id_p, allocator, allocator->n_allocated_slots, allocator->n_used_slots); + + allocator->allocated_slots[*slot_id_p].slot_id = -1; + *slot_id_p = -1; + + allocator->n_used_slots -= 1; + + if (allocator->n_used_slots == 0) + { + DBusMutex **mutex_loc = allocator->lock_loc; + + dbus_free (allocator->allocated_slots); + allocator->allocated_slots = NULL; + allocator->n_allocated_slots = 0; + allocator->lock_loc = NULL; + + _dbus_mutex_unlock (*mutex_loc); + } + else + { + _dbus_mutex_unlock (*(allocator->lock_loc)); + } +} + +/** + * Initializes a slot list. + * @param list the list to initialize. + */ +void +_dbus_data_slot_list_init (DBusDataSlotList *list) +{ + list->slots = NULL; + list->n_slots = 0; +} + +/** + * 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. + * + * @param allocator the allocator to use + * @param list the data slot list + * @param slot the slot number + * @param data the data to store + * @param free_data_func finalizer function for the data + * @param old_free_func free function for any previously-existing data + * @param old_data previously-existing data, should be freed with old_free_func + * @returns #TRUE if there was enough memory to store the data + */ +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) +{ +#ifndef DBUS_DISABLE_ASSERT + /* We need to take the allocator lock here, because the allocator could + * be e.g. realloc()ing allocated_slots. We avoid doing this if asserts + * are disabled, since then the asserts are empty. + */ + _dbus_mutex_lock (*(allocator->lock_loc)); + _dbus_assert (slot < allocator->n_allocated_slots); + _dbus_assert (allocator->allocated_slots[slot].slot_id == slot); + _dbus_mutex_unlock (*(allocator->lock_loc)); +#endif + + if (slot >= list->n_slots) + { + DBusDataSlot *tmp; + int i; + + tmp = dbus_realloc (list->slots, + sizeof (DBusDataSlot) * (slot + 1)); + if (tmp == NULL) + return FALSE; + + list->slots = tmp; + i = list->n_slots; + list->n_slots = slot + 1; + while (i < list->n_slots) + { + list->slots[i].data = NULL; + list->slots[i].free_data_func = NULL; + ++i; + } + } + + _dbus_assert (slot < list->n_slots); + + *old_data = list->slots[slot].data; + *old_free_func = list->slots[slot].free_data_func; + + list->slots[slot].data = data; + list->slots[slot].free_data_func = free_data_func; + + return TRUE; +} + +/** + * Retrieves data previously set with _dbus_data_slot_list_set_data(). + * The slot must still be allocated (must not have been freed). + * + * @param allocator the allocator slot was allocated from + * @param list the data slot list + * @param slot the slot to get data from + * @returns the data, or #NULL if not found + */ +void* +_dbus_data_slot_list_get (DBusDataSlotAllocator *allocator, + DBusDataSlotList *list, + int slot) +{ +#ifndef DBUS_DISABLE_ASSERT + /* We need to take the allocator lock here, because the allocator could + * be e.g. realloc()ing allocated_slots. We avoid doing this if asserts + * are disabled, since then the asserts are empty. + */ + _dbus_mutex_lock (*(allocator->lock_loc)); + _dbus_assert (slot >= 0); + _dbus_assert (slot < allocator->n_allocated_slots); + _dbus_assert (allocator->allocated_slots[slot].slot_id == slot); + _dbus_mutex_unlock (*(allocator->lock_loc)); +#endif + + if (slot >= list->n_slots) + return NULL; + else + return list->slots[slot].data; +} + +/** + * Frees all data slots contained in the list, calling + * application-provided free functions if they exist. + * + * @param list the list to clear + */ +void +_dbus_data_slot_list_clear (DBusDataSlotList *list) +{ + int i; + + i = 0; + while (i < list->n_slots) + { + if (list->slots[i].free_data_func) + (* list->slots[i].free_data_func) (list->slots[i].data); + list->slots[i].data = NULL; + list->slots[i].free_data_func = NULL; + ++i; + } +} + +/** + * Frees the data slot list and all data slots contained + * in it, calling application-provided free functions + * if they exist. + * + * @param list the list to free + */ +void +_dbus_data_slot_list_free (DBusDataSlotList *list) +{ + _dbus_data_slot_list_clear (list); + + dbus_free (list->slots); + list->slots = NULL; + list->n_slots = 0; +} + +/** @} */ + +#ifdef DBUS_BUILD_TESTS +#include "dbus-test.h" +#include + +static int free_counter; + +static void +test_free_slot_data_func (void *data) +{ + int i = _DBUS_POINTER_TO_INT (data); + + _dbus_assert (free_counter == i); + ++free_counter; +} + +/** + * Test function for data slots + */ +dbus_bool_t +_dbus_data_slot_test (void) +{ + DBusDataSlotAllocator allocator; + DBusDataSlotList list; + int i; + DBusFreeFunction old_free_func; + void *old_data; + DBusMutex *mutex; + + if (!_dbus_data_slot_allocator_init (&allocator)) + _dbus_assert_not_reached ("no memory for allocator"); + + _dbus_data_slot_list_init (&list); + + _dbus_mutex_new_at_location (&mutex); + if (mutex == NULL) + _dbus_assert_not_reached ("failed to alloc mutex"); + +#define N_SLOTS 100 + + i = 0; + while (i < N_SLOTS) + { + /* we don't really want apps to rely on this ordered + * allocation, but it simplifies things to rely on it + * here. + */ + dbus_int32_t tmp = -1; + + _dbus_data_slot_allocator_alloc (&allocator, &mutex, &tmp); + + if (tmp != i) + _dbus_assert_not_reached ("did not allocate slots in numeric order\n"); + + ++i; + } + + i = 0; + while (i < N_SLOTS) + { + if (!_dbus_data_slot_list_set (&allocator, &list, + i, + _DBUS_INT_TO_POINTER (i), + test_free_slot_data_func, + &old_free_func, &old_data)) + _dbus_assert_not_reached ("no memory to set data"); + + _dbus_assert (old_free_func == NULL); + _dbus_assert (old_data == NULL); + + _dbus_assert (_dbus_data_slot_list_get (&allocator, &list, i) == + _DBUS_INT_TO_POINTER (i)); + + ++i; + } + + free_counter = 0; + i = 0; + while (i < N_SLOTS) + { + if (!_dbus_data_slot_list_set (&allocator, &list, + i, + _DBUS_INT_TO_POINTER (i), + test_free_slot_data_func, + &old_free_func, &old_data)) + _dbus_assert_not_reached ("no memory to set data"); + + _dbus_assert (old_free_func == test_free_slot_data_func); + _dbus_assert (_DBUS_POINTER_TO_INT (old_data) == i); + + (* old_free_func) (old_data); + _dbus_assert (i == (free_counter - 1)); + + _dbus_assert (_dbus_data_slot_list_get (&allocator, &list, i) == + _DBUS_INT_TO_POINTER (i)); + + ++i; + } + + free_counter = 0; + _dbus_data_slot_list_free (&list); + + _dbus_assert (N_SLOTS == free_counter); + + i = 0; + while (i < N_SLOTS) + { + dbus_int32_t tmp = i; + + _dbus_data_slot_allocator_free (&allocator, &tmp); + _dbus_assert (tmp == -1); + ++i; + } + + _dbus_mutex_free_at_location (&mutex); + + return TRUE; +} + +#endif /* DBUS_BUILD_TESTS */