2003-01-05 Havoc Pennington <hp@pobox.com>

	* bus/connection.c: implement routines for handling connections,
	first thing is keeping a list of owned services on each connection
	and setting up watches etc.

	* bus/services.c: implement a mapping from service names to lists
	of connections

	* dbus/dbus-hash.c: add DBUS_HASH_POINTER

	* dbus/dbus-threads.c (dbus_static_mutex_lock): add functions
	to use static mutexes for global data

	* dbus/dbus-connection.c (dbus_connection_set_data): add new
	collection of functions to set/get application-specific data
	on the DBusConnection.

6 files changed, 438 insertions, 38 deletions

diff --git a/dbus/dbus-connection.c b/dbus/dbus-connection.c
index 28f1d7f3..66bd0645 100644
--- a/dbus/dbus-connection.c
+++ b/dbus/dbus-connection.c
@@ -29,6 +29,7 @@
 #include "dbus-list.h"
 #include "dbus-hash.h"
 #include "dbus-message-internal.h"
+#include "dbus-threads.h"
 
 /**
  * @defgroup DBusConnection DBusConnection
@@ -57,6 +58,15 @@
  * @{
  */
 
+/** Opaque typedef for DBusDataSlot */
+typedef struct DBusDataSlot DBusDataSlot;
+/** DBusDataSlot is used to store application data on the connection */
+struct DBusDataSlot
+{
+  void *data;                      /**< The application data */
+  DBusFreeFunction free_data_func; /**< Free the application data */
+};
+
 /**
  * Implementation details of DBusConnection. All fields are private.
  */
@@ -80,8 +90,12 @@ struct DBusConnection
   DBusList *filter_list;        /**< List of filters. */
   int filters_serial;           /**< Increments when the list of filters is changed. */
   int handlers_serial;          /**< Increments when the handler table is changed. */
+  DBusDataSlot *data_slots;        /**< Data slots */
+  int           n_slots; /**< Slots allocated so far. */
 };
 
+static void _dbus_connection_free_data_slots (DBusConnection *connection);
+
 /**
  * Adds a message to the incoming message queue, returning #FALSE
  * if there's insufficient memory to queue the message.
@@ -313,6 +327,9 @@ _dbus_connection_new_for_transport (DBusTransport *transport)
   connection->watches = watch_list;
   connection->handler_table = handler_table;
   connection->filter_list = NULL;
+
+  connection->data_slots = NULL;
+  connection->n_slots = 0;
   
   _dbus_transport_ref (transport);
   _dbus_transport_set_connection (transport, connection);
@@ -449,13 +466,15 @@ dbus_connection_unref (DBusConnection *connection)
     {
       DBusHashIter iter;
       DBusList *link;
-
+      
       /* free error data as a side effect */
       dbus_connection_set_error_function (connection,
                                           NULL, NULL, NULL);
 
       _dbus_watch_list_free (connection->watches);
       connection->watches = NULL;
+
+      _dbus_connection_free_data_slots (connection);
       
       _dbus_hash_iter_init (connection->handler_table, &iter);
       while (_dbus_hash_iter_next (&iter))
@@ -1059,4 +1078,193 @@ dbus_connection_unregister_handler (DBusConnection     *connection,
   connection->handlers_serial += 1;
 }
 
+static int *allocated_slots = NULL;
+static int  n_allocated_slots = 0;
+static int  n_used_slots = 0;
+static DBusStaticMutex allocated_slots_lock = DBUS_STATIC_MUTEX_INIT;
+
+/**
+ * Allocates an integer ID to be used for storing application-specific
+ * data on any DBusConnection. The allocated ID may then be used
+ * with dbus_connection_set_data() and dbus_connection_get_data().
+ * If allocation fails, -1 is returned.
+ *
+ * @returns -1 on failure, otherwise the data slot ID
+ */
+int
+dbus_connection_allocate_data_slot (void)
+{
+  int slot;
+  
+  if (!dbus_static_mutex_lock (&allocated_slots_lock))
+    return -1;
+
+  if (n_used_slots < n_allocated_slots)
+    {
+      slot = 0;
+      while (slot < n_allocated_slots)
+        {
+          if (allocated_slots[slot] < 0)
+            {
+              allocated_slots[slot] = slot;
+              n_used_slots += 1;
+              break;
+            }
+          ++slot;
+        }
+
+      _dbus_assert (slot < n_allocated_slots);
+    }
+  else
+    {
+      int *tmp;
+      
+      slot = -1;
+      tmp = dbus_realloc (allocated_slots,
+                          sizeof (int) * (n_allocated_slots + 1));
+      if (tmp == NULL)
+        goto out;
+
+      allocated_slots = tmp;
+      slot = n_allocated_slots;
+      n_allocated_slots += 1;
+      n_used_slots += 1;
+      allocated_slots[slot] = slot;
+    }
+
+  _dbus_assert (slot >= 0);
+  _dbus_assert (slot < n_allocated_slots);
+  
+ out:
+  dbus_static_mutex_unlock (&allocated_slots_lock);
+  return slot;
+}
+
+/**
+ * Deallocates a global ID for connection data slots.
+ * dbus_connection_get_data() and dbus_connection_set_data()
+ * may no longer be used with this slot.
+ * Existing data stored on existing DBusConnection objects
+ * will be freed when the connection is finalized,
+ * but may not be retrieved (and may only be replaced
+ * if someone else reallocates the slot).
+ *
+ * @param slot the slot to deallocate
+ */
+void
+dbus_connection_free_data_slot (int slot)
+{
+  dbus_static_mutex_lock (&allocated_slots_lock);
+
+  _dbus_assert (slot < n_allocated_slots);
+  _dbus_assert (allocated_slots[slot] == slot);
+  
+  allocated_slots[slot] = -1;
+  n_used_slots -= 1;
+
+  if (n_used_slots == 0)
+    {
+      dbus_free (allocated_slots);
+      allocated_slots = NULL;
+      n_allocated_slots = 0;
+    }
+  
+  dbus_static_mutex_unlock (&allocated_slots_lock);
+}
+
+/**
+ * Stores a pointer on a DBusConnection, along
+ * with an optional function to be used for freeing
+ * the data when the data is set again, or when
+ * the connection is finalized. The slot number
+ * must have been allocated with dbus_connection_allocate_data_slot().
+ *
+ * @param connection the connection
+ * @param slot the slot number
+ * @param data the data to store
+ * @param free_data_func finalizer function for the data
+ * @returns #TRUE if there was enough memory to store the data
+ */
+dbus_bool_t
+dbus_connection_set_data (DBusConnection   *connection,
+                          int               slot,
+                          void             *data,
+                          DBusFreeFunction  free_data_func)
+{
+  _dbus_assert (slot < n_allocated_slots);
+  _dbus_assert (allocated_slots[slot] == slot);
+  
+  if (slot >= connection->n_slots)
+    {
+      DBusDataSlot *tmp;
+      int i;
+      
+      tmp = dbus_realloc (connection->data_slots,
+                          sizeof (DBusDataSlot) * (slot + 1));
+      if (tmp == NULL)
+        return FALSE;
+      
+      connection->data_slots = tmp;
+      i = connection->n_slots;
+      connection->n_slots = slot + 1;
+      while (i < connection->n_slots)
+        {
+          connection->data_slots[i].data = NULL;
+          connection->data_slots[i].free_data_func = NULL;
+          ++i;
+        }
+    }
+
+  _dbus_assert (slot < connection->n_slots);
+  
+  if (connection->data_slots[slot].free_data_func)
+    (* connection->data_slots[slot].free_data_func) (connection->data_slots[slot].data);
+
+  connection->data_slots[slot].data = data;
+  connection->data_slots[slot].free_data_func = free_data_func;
+
+  return TRUE;
+}
+
+/**
+ * Retrieves data previously set with dbus_connection_set_data().
+ * The slot must still be allocated (must not have been freed).
+ *
+ * @param connection the connection
+ * @param slot the slot to get data from
+ * @returns the data, or #NULL if not found
+ */
+void*
+dbus_connection_get_data (DBusConnection   *connection,
+                          int               slot)
+{
+  _dbus_assert (slot < n_allocated_slots);
+  _dbus_assert (allocated_slots[slot] == slot);
+
+  if (slot >= connection->n_slots)
+    return NULL;
+
+  return connection->data_slots[slot].data;
+}
+
+static void
+_dbus_connection_free_data_slots (DBusConnection *connection)
+{
+  int i;
+
+  i = 0;
+  while (i < connection->n_slots)
+    {
+      if (connection->data_slots[i].free_data_func)
+        (* connection->data_slots[i].free_data_func) (connection->data_slots[i].data);
+      connection->data_slots[i].data = NULL;
+      connection->data_slots[i].free_data_func = NULL;
+      ++i;
+    }
+
+  dbus_free (connection->data_slots);
+  connection->data_slots = NULL;
+  connection->n_slots = 0;
+}
+
 /** @} */
diff --git a/dbus/dbus-connection.h b/dbus/dbus-connection.h
index 518295b2..c7692905 100644
--- a/dbus/dbus-connection.h
+++ b/dbus/dbus-connection.h
@@ -122,6 +122,16 @@ void        dbus_connection_unregister_handler (DBusConnection      *connection,
                                                 const char         **messages_to_handle,
                                                 int                  n_messages);
 
+
+int         dbus_connection_allocate_data_slot (void);
+void        dbus_connection_free_data_slot     (int               slot);
+dbus_bool_t dbus_connection_set_data           (DBusConnection   *connection,
+                                                int               slot,
+                                                void             *data,
+                                                DBusFreeFunction  free_data_func);
+void*       dbus_connection_get_data           (DBusConnection   *connection,
+                                                int               slot);
+
 DBUS_END_DECLS;
 
 #endif /* DBUS_CONNECTION_H */
diff --git a/dbus/dbus-hash.c b/dbus/dbus-hash.c
index 9cec1c1d..8bac61a8 100644
--- a/dbus/dbus-hash.c
+++ b/dbus/dbus-hash.c
@@ -220,7 +220,7 @@ typedef struct
   int n_entries_on_init;     /**< used to detect table resize since initialization */
 } DBusRealHashIter;
 
-static DBusHashEntry* find_int_function    (DBusHashTable   *table,
+static DBusHashEntry* find_direct_function (DBusHashTable   *table,
                                             void            *key,
                                             dbus_bool_t      create_if_not_found,
                                             DBusHashEntry ***bucket);
@@ -310,7 +310,8 @@ _dbus_hash_table_new (DBusHashType     type,
   switch (table->key_type)
     {
     case DBUS_HASH_INT:
-      table->find_function = find_int_function;
+    case DBUS_HASH_POINTER:
+      table->find_function = find_direct_function;
       break;
     case DBUS_HASH_STRING:
       table->find_function = find_string_function;
@@ -808,10 +809,10 @@ find_string_function (DBusHashTable   *table,
 }
 
 static DBusHashEntry*
-find_int_function (DBusHashTable   *table,
-                   void            *key,
-                   dbus_bool_t      create_if_not_found,
-                   DBusHashEntry ***bucket)
+find_direct_function (DBusHashTable   *table,
+                      void            *key,
+                      dbus_bool_t      create_if_not_found,
+                      DBusHashEntry ***bucket)
 {
   DBusHashEntry *entry;
   unsigned int idx;
@@ -940,6 +941,7 @@ rebuild_table (DBusHashTable *table)
               idx = string_hash (entry->key) & table->mask;
               break;
             case DBUS_HASH_INT:
+            case DBUS_HASH_POINTER:
               idx = RANDOM_INDEX (table, entry->key);
               break;
             default:
@@ -1011,6 +1013,31 @@ _dbus_hash_table_lookup_int (DBusHashTable *table,
 }
 
 /**
+ * Looks up the value for a given integer in a hash table
+ * of type #DBUS_HASH_POINTER. Returns %NULL if the value
+ * is not present. (A not-present entry is indistinguishable
+ * from an entry with a value of %NULL.)
+ * @param table the hash table.
+ * @param key the integer to look up.
+ * @returns the value of the hash entry.
+ */
+void*
+_dbus_hash_table_lookup_pointer (DBusHashTable *table,
+                                 void          *key)
+{
+  DBusHashEntry *entry;
+
+  _dbus_assert (table->key_type == DBUS_HASH_POINTER);
+  
+  entry = (* table->find_function) (table, key, FALSE, NULL);
+
+  if (entry)
+    return entry->value;
+  else
+    return NULL;
+}
+
+/**
  * Removes the hash entry for the given key. If no hash entry
  * for the key exists, does nothing.
  *
@@ -1067,6 +1094,35 @@ _dbus_hash_table_remove_int (DBusHashTable *table,
 }
 
 /**
+ * Removes the hash entry for the given key. If no hash entry
+ * for the key exists, does nothing.
+ *
+ * @param table the hash table.
+ * @param key the hash key.
+ * @returns #TRUE if the entry existed
+ */
+dbus_bool_t
+_dbus_hash_table_remove_pointer (DBusHashTable *table,
+                                 void          *key)
+{
+  DBusHashEntry *entry;
+  DBusHashEntry **bucket;
+  
+  _dbus_assert (table->key_type == DBUS_HASH_POINTER);
+  
+  entry = (* table->find_function) (table, key, FALSE, &bucket);
+  
+  if (entry)
+    {
+      remove_entry (table, bucket, entry);
+      return TRUE;
+    }
+  else
+    return FALSE;
+}
+
+
+/**
  * Creates a hash entry with the given key and value.
  * The key and value are not copied; they are stored
  * in the hash table by reference. If an entry with the
@@ -1149,6 +1205,47 @@ _dbus_hash_table_insert_int (DBusHashTable *table,
 }
 
 /**
+ * Creates a hash entry with the given key and value.
+ * The key and value are not copied; they are stored
+ * in the hash table by reference. If an entry with the
+ * given key already exists, the previous key and value
+ * are overwritten (and freed if the hash table has
+ * a key_free_function and/or value_free_function).
+ *
+ * Returns #FALSE if memory for the new hash entry
+ * can't be allocated.
+ * 
+ * @param table the hash table.
+ * @param key the hash entry key.
+ * @param value the hash entry value.
+ */
+dbus_bool_t
+_dbus_hash_table_insert_pointer (DBusHashTable *table,
+                                 void          *key,
+                                 void          *value)
+{
+  DBusHashEntry *entry;
+
+  _dbus_assert (table->key_type == DBUS_HASH_POINTER);
+  
+  entry = (* table->find_function) (table, key, TRUE, NULL);
+
+  if (entry == NULL)
+    return FALSE; /* no memory */
+
+  if (table->free_key_function && entry->key != key)
+    (* table->free_key_function) (entry->key);
+  
+  if (table->free_value_function && entry->value != value)
+    (* table->free_value_function) (entry->value);
+  
+  entry->key = key;
+  entry->value = value;
+
+  return TRUE;
+}
+
+/**
  * Gets the number of hash entries in a hash table.
  *
  * @param table the hash table.
diff --git a/dbus/dbus-hash.h b/dbus/dbus-hash.h
index 6c753a50..dc60679b 100644
--- a/dbus/dbus-hash.h
+++ b/dbus/dbus-hash.h
@@ -53,7 +53,8 @@ typedef struct DBusHashIter  DBusHashIter;
 typedef enum
 {
   DBUS_HASH_STRING, /**< Hash keys are strings. */
-  DBUS_HASH_INT     /**< Hash keys are integers. */
+  DBUS_HASH_INT,    /**< Hash keys are integers. */
+  DBUS_HASH_POINTER /**< Hash keys are pointers. */
 } DBusHashType;
 
 DBusHashTable* _dbus_hash_table_new   (DBusHashType     type,
@@ -66,33 +67,39 @@ void        _dbus_hash_iter_init (DBusHashTable *table,
                                   DBusHashIter  *iter);
 dbus_bool_t _dbus_hash_iter_next (DBusHashIter  *iter);
 
-void        _dbus_hash_iter_remove_entry   (DBusHashIter *iter);
-void*       _dbus_hash_iter_get_value      (DBusHashIter *iter);
-void        _dbus_hash_iter_set_value      (DBusHashIter *iter,
-                                            void         *value);
-int         _dbus_hash_iter_get_int_key    (DBusHashIter *iter);
-const char* _dbus_hash_iter_get_string_key (DBusHashIter *iter);
+void        _dbus_hash_iter_remove_entry    (DBusHashIter  *iter);
+void*       _dbus_hash_iter_get_value       (DBusHashIter  *iter);
+void        _dbus_hash_iter_set_value       (DBusHashIter  *iter,
+                                             void          *value);
+int         _dbus_hash_iter_get_int_key     (DBusHashIter  *iter);
+const char* _dbus_hash_iter_get_string_key  (DBusHashIter  *iter);
+dbus_bool_t _dbus_hash_iter_lookup          (DBusHashTable *table,
+                                             void          *key,
+                                             dbus_bool_t    create_if_not_found,
+                                             DBusHashIter  *iter);
+void*       _dbus_hash_table_lookup_string  (DBusHashTable *table,
+                                             const char    *key);
+void*       _dbus_hash_table_lookup_int     (DBusHashTable *table,
+                                             int            key);
+void*       _dbus_hash_table_lookup_pointer (DBusHashTable *table,
+                                             void          *key);
+dbus_bool_t _dbus_hash_table_remove_string  (DBusHashTable *table,
+                                             const char    *key);
+dbus_bool_t _dbus_hash_table_remove_int     (DBusHashTable *table,
+                                             int            key);
+dbus_bool_t _dbus_hash_table_remove_pointer (DBusHashTable *table,
+                                             void          *key);
+dbus_bool_t _dbus_hash_table_insert_string  (DBusHashTable *table,
+                                             char          *key,
+                                             void          *value);
+dbus_bool_t _dbus_hash_table_insert_int     (DBusHashTable *table,
+                                             int            key,
+                                             void          *value);
+dbus_bool_t _dbus_hash_table_insert_pointer (DBusHashTable *table,
+                                             void          *key,
+                                             void          *value);
+int         _dbus_hash_table_get_n_entries  (DBusHashTable *table);
 
-dbus_bool_t _dbus_hash_iter_lookup         (DBusHashTable *table,
-                                            void          *key,
-                                            dbus_bool_t    create_if_not_found,
-                                            DBusHashIter  *iter);
-
-void*       _dbus_hash_table_lookup_string (DBusHashTable *table,
-                                            const char    *key);
-void*       _dbus_hash_table_lookup_int    (DBusHashTable *table,
-                                            int            key);
-dbus_bool_t _dbus_hash_table_remove_string (DBusHashTable *table,
-                                            const char    *key);
-dbus_bool_t _dbus_hash_table_remove_int    (DBusHashTable *table,
-                                            int            key);
-dbus_bool_t _dbus_hash_table_insert_string (DBusHashTable *table,
-                                            char          *key,
-                                            void          *value);
-dbus_bool_t _dbus_hash_table_insert_int    (DBusHashTable *table,
-                                            int            key,
-                                            void          *value);
-int         _dbus_hash_table_get_n_entries (DBusHashTable *table);
 
 DBUS_END_DECLS;
 
diff --git a/dbus/dbus-threads.c b/dbus/dbus-threads.c
index 4a1b0214..434148b8 100644
--- a/dbus/dbus-threads.c
+++ b/dbus/dbus-threads.c
@@ -32,6 +32,11 @@ static DBusThreadFunctions thread_functions =
   NULL, NULL, NULL, NULL
 };
 
+static DBusMutex *static_mutex_init_lock = NULL;
+
+/** This is used for the no-op default mutex pointer, just to be distinct from #NULL */
+#define _DBUS_DUMMY_MUTEX ((void*)0xABCDEF)
+
 /**
  * @defgroup DBusThreads Thread functions
  * @ingroup  DBus
@@ -56,7 +61,7 @@ dbus_mutex_new (void)
   if (thread_functions.mutex_new)
     return (* thread_functions.mutex_new) ();
   else
-    return NULL;
+    return _DBUS_DUMMY_MUTEX;
 }
 
 /**
@@ -106,9 +111,13 @@ dbus_mutex_unlock (DBusMutex *mutex)
  * in efficiency. Note that this function must be called
  * BEFORE using any other D-BUS functions.
  *
+ * @todo right now this function can only be called once,
+ * maybe we should instead silently ignore multiple calls.
+ *
  * @param functions functions for using threads
+ * @returns #TRUE on success, #FALSE if no memory
  */
-void
+dbus_bool_t
 dbus_threads_init (const DBusThreadFunctions *functions)
 {
   _dbus_assert (functions != NULL);
@@ -134,7 +143,7 @@ dbus_threads_init (const DBusThreadFunctions *functions)
   if (thread_functions.mask != 0)
     {
       _dbus_warn ("dbus_threads_init() may only be called one time\n");
-      return;
+      return FALSE;
     }
   
   thread_functions.mutex_new = functions->mutex_new;
@@ -143,6 +152,60 @@ dbus_threads_init (const DBusThreadFunctions *functions)
   thread_functions.mutex_unlock = functions->mutex_unlock;
   
   thread_functions.mask = functions->mask;
+
+  static_mutex_init_lock = dbus_mutex_new ();
+
+  if (static_mutex_init_lock == NULL)
+    {
+      thread_functions.mask = 0;
+      return FALSE;
+    }
+
+  return TRUE;
+}
+
+/** Accesses the field of DBusStaticMutex that
+ * stores the DBusMutex used to implement.
+ */
+#define _DBUS_STATIC_MUTEX_IMPL(mutex) ((mutex)->pad1)
+
+/**
+ * Lock a static mutex
+ *
+ * @param mutex the mutex to lock
+ * @returns #TRUE on success
+ */
+dbus_bool_t
+dbus_static_mutex_lock (DBusStaticMutex *mutex)
+{
+  if (_DBUS_STATIC_MUTEX_IMPL (mutex))
+    return dbus_mutex_lock (_DBUS_STATIC_MUTEX_IMPL (mutex));
+
+  if (!dbus_mutex_lock (static_mutex_init_lock))
+    return FALSE;
+
+  if (_DBUS_STATIC_MUTEX_IMPL (mutex) == NULL)
+    _DBUS_STATIC_MUTEX_IMPL (mutex) = dbus_mutex_new ();
+  
+  dbus_mutex_unlock (static_mutex_init_lock);
+
+  if (_DBUS_STATIC_MUTEX_IMPL (mutex))
+    return dbus_mutex_lock (_DBUS_STATIC_MUTEX_IMPL (mutex));
+  else
+    return FALSE;
+}
+
+/**
+ * Unlock a static mutex
+ * @param mutex the mutex to lock
+ * @returns #TRUE on success
+ */
+dbus_bool_t
+dbus_static_mutex_unlock (DBusStaticMutex *mutex)
+{
+  _dbus_assert (_DBUS_STATIC_MUTEX_IMPL (mutex) != NULL);
+  
+  return dbus_mutex_unlock (_DBUS_STATIC_MUTEX_IMPL (mutex));
 }
 
 /** @} */
diff --git a/dbus/dbus-threads.h b/dbus/dbus-threads.h
index 956fac61..ddc270bb 100644
--- a/dbus/dbus-threads.h
+++ b/dbus/dbus-threads.h
@@ -75,7 +75,22 @@ void        dbus_mutex_free   (DBusMutex *mutex);
 dbus_bool_t dbus_mutex_lock   (DBusMutex *mutex);
 dbus_bool_t dbus_mutex_unlock (DBusMutex *mutex);
 
-void dbus_threads_init (const DBusThreadFunctions *functions);
+dbus_bool_t dbus_threads_init (const DBusThreadFunctions *functions);
+
+typedef struct DBusStaticMutex DBusStaticMutex;
+
+struct DBusStaticMutex
+{
+  void *pad1;
+  void *pad2;
+  void *pad3;
+  void *pad4;
+};
+
+#define DBUS_STATIC_MUTEX_INIT { NULL, NULL, NULL, NULL }
+
+dbus_bool_t dbus_static_mutex_lock   (DBusStaticMutex *mutex);
+dbus_bool_t dbus_static_mutex_unlock (DBusStaticMutex *mutex);
 
 DBUS_END_DECLS;