1 files changed, 120 insertions, 0 deletions

diff --git a/ipc/ipc_space.h b/ipc/ipc_space.h
index 20b9d57d..58fe47c4 100644
--- a/ipc/ipc_space.h
+++ b/ipc/ipc_space.h
@@ -137,6 +137,126 @@ kern_return_t	ipc_space_create(ipc_table_size_t, ipc_space_t *);
 kern_return_t	ipc_space_create_special(struct ipc_space **);
 void		ipc_space_destroy(struct ipc_space *);
 
+/* IPC entry lookups.  */
+
+/*
+ *	Routine:	ipc_entry_lookup
+ *	Purpose:
+ *		Searches for an entry, given its name.
+ *	Conditions:
+ *		The space must be read or write locked throughout.
+ *		The space must be active.
+ */
+
+static inline ipc_entry_t
+ipc_entry_lookup(
+	ipc_space_t space,
+	mach_port_t name)
+{
+	ipc_entry_t entry;
+
+	assert(space->is_active);
+	entry = rdxtree_lookup(&space->is_map, (rdxtree_key_t) name);
+	if (entry != IE_NULL
+	    && IE_BITS_TYPE(entry->ie_bits) == MACH_PORT_TYPE_NONE)
+		entry = NULL;
+	assert((entry == IE_NULL) || IE_BITS_TYPE(entry->ie_bits));
+	return entry;
+}
+
+/*
+ *	Routine:	ipc_entry_get
+ *	Purpose:
+ *		Tries to allocate an entry out of the space.
+ *	Conditions:
+ *		The space is write-locked and active throughout.
+ *		An object may be locked.  Will not allocate memory.
+ *	Returns:
+ *		KERN_SUCCESS		A free entry was found.
+ *		KERN_NO_SPACE		No entry allocated.
+ */
+
+static inline kern_return_t
+ipc_entry_get(
+	ipc_space_t space,
+	mach_port_t *namep,
+	ipc_entry_t *entryp)
+{
+	mach_port_t new_name;
+	ipc_entry_t free_entry;
+
+	assert(space->is_active);
+
+	/* Get entry from the free list.  */
+	free_entry = space->is_free_list;
+	if (free_entry == IE_NULL)
+		return KERN_NO_SPACE;
+
+	space->is_free_list = free_entry->ie_next_free;
+	space->is_free_list_size -= 1;
+
+	/*
+	 *	Initialize the new entry.  We need only
+	 *	increment the generation number and clear ie_request.
+	 */
+
+    {
+	mach_port_gen_t gen;
+
+	assert((free_entry->ie_bits &~ IE_BITS_GEN_MASK) == 0);
+	gen = free_entry->ie_bits + IE_BITS_GEN_ONE;
+	free_entry->ie_bits = gen;
+	free_entry->ie_request = 0;
+	new_name = MACH_PORT_MAKE(free_entry->ie_name, gen);
+    }
+
+	/*
+	 *	The new name can't be MACH_PORT_NULL because index
+	 *	is non-zero.  It can't be MACH_PORT_DEAD because
+	 *	the table isn't allowed to grow big enough.
+	 *	(See comment in ipc/ipc_table.h.)
+	 */
+
+	assert(MACH_PORT_VALID(new_name));
+	assert(free_entry->ie_object == IO_NULL);
+
+	space->is_size += 1;
+	*namep = new_name;
+	*entryp = free_entry;
+	return KERN_SUCCESS;
+}
+
+/*
+ *	Routine:	ipc_entry_dealloc
+ *	Purpose:
+ *		Deallocates an entry from a space.
+ *	Conditions:
+ *		The space must be write-locked throughout.
+ *		The space must be active.
+ */
+
+static inline void
+ipc_entry_dealloc(
+	ipc_space_t	space,
+	mach_port_t	name,
+	ipc_entry_t	entry)
+{
+	assert(space->is_active);
+	assert(entry->ie_object == IO_NULL);
+	assert(entry->ie_request == 0);
+
+	if (space->is_free_list_size < IS_FREE_LIST_SIZE_LIMIT) {
+		space->is_free_list_size += 1;
+		entry->ie_bits &= IE_BITS_GEN_MASK;
+		entry->ie_next_free = space->is_free_list;
+		space->is_free_list = entry;
+	} else {
+		rdxtree_remove(&space->is_map, (rdxtree_key_t) name);
+		ie_free(entry);
+	}
+	space->is_size -= 1;
+}
+
 /* Reverse lookups.  */
 
 /* Cast a pointer to a suitable key.  */