--- /dev/null
+/* -*- 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 <stdio.h>
+
+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 */
projects / monky / blobdiff