assert(is_active(space));
-
index = MACH_PORT_INDEX(name);
if (index < space->is_table_size) {
entry = &space->is_table[index];
return entry;
}
+
/*
- * Routine: ipc_entry_get
+ * Routine: ipc_entries_hold
* Purpose:
- * Tries to allocate an entry out of the space.
+ * Verifies that there are at least 'entries_needed'
+ * free list members
* 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_SUCCESS Free entries were found.
* KERN_NO_SPACE No entry allocated.
*/
kern_return_t
-ipc_entry_get(
+ipc_entries_hold(
+ ipc_space_t space,
+ uint32_t entries_needed)
+{
+
+ ipc_entry_t table;
+ mach_port_index_t next_free = 0;
+ uint32_t i;
+
+ assert(is_active(space));
+
+ table = &space->is_table[0];
+
+ for (i = 0; i < entries_needed; i++) {
+ next_free = table[next_free].ie_next;
+ if (next_free == 0) {
+ return KERN_NO_SPACE;
+ }
+ assert(next_free < space->is_table_size);
+ assert(table[next_free].ie_object == IO_NULL);
+ }
+ return KERN_SUCCESS;
+}
+
+/*
+ * Routine: ipc_entry_claim
+ * Purpose:
+ * Take formal ownership of a held entry.
+ * Conditions:
+ * The space is write-locked and active throughout.
+ * An object may be locked. Will not allocate memory.
+ *
+ * Note: The returned entry must be marked as modified before
+ * releasing the space lock
+ */
+
+kern_return_t
+ipc_entry_claim(
ipc_space_t space,
mach_port_name_t *namep,
ipc_entry_t *entryp)
{
+ ipc_entry_t entry;
ipc_entry_t table;
mach_port_index_t first_free;
- ipc_entry_t free_entry;
+ mach_port_gen_t gen;
+ mach_port_name_t new_name;
- assert(is_active(space));
+ table = &space->is_table[0];
- {
- table = space->is_table;
- first_free = table->ie_next;
+ first_free = table->ie_next;
+ assert(first_free != 0);
- if (first_free == 0)
- return KERN_NO_SPACE;
+ entry = &table[first_free];
+ table->ie_next = entry->ie_next;
+ space->is_table_free--;
- assert(first_free < space->is_table_size);
- free_entry = &table[first_free];
- table->ie_next = free_entry->ie_next;
- }
+ assert(table->ie_next < space->is_table_size);
/*
* Initialize the new entry. We need only
* increment the generation number and clear ie_request.
*/
- {
- mach_port_name_t new_name;
- mach_port_gen_t gen;
+ gen = IE_BITS_NEW_GEN(entry->ie_bits);
+ entry->ie_bits = gen;
+ entry->ie_request = IE_REQ_NONE;
- gen = IE_BITS_NEW_GEN(free_entry->ie_bits);
- free_entry->ie_bits = gen;
- free_entry->ie_request = IE_REQ_NONE;
+ /*
+ * 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.)
+ */
+ new_name = MACH_PORT_MAKE(first_free, gen);
+ assert(MACH_PORT_VALID(new_name));
+ *namep = new_name;
+ *entryp = entry;
- /*
- * 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.)
- */
- new_name = MACH_PORT_MAKE(first_free, gen);
- assert(MACH_PORT_VALID(new_name));
- *namep = new_name;
- }
+ return KERN_SUCCESS;
+}
- assert(free_entry->ie_object == IO_NULL);
+/*
+ * 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.
+ */
- *entryp = free_entry;
- return KERN_SUCCESS;
+kern_return_t
+ipc_entry_get(
+ ipc_space_t space,
+ mach_port_name_t *namep,
+ ipc_entry_t *entryp)
+{
+ kern_return_t kr;
+
+ kr = ipc_entries_hold(space, 1);
+ if (KERN_SUCCESS != kr)
+ return kr;
+
+ return ipc_entry_claim(space, namep, entryp);
}
/*
table[free_index].ie_next =
table[next_index].ie_next;
-
+ space->is_table_free--;
+
/* mark the previous entry modified - reconstructing the name */
ipc_entry_modified(space,
MACH_PORT_MAKE(free_index,
entry->ie_bits &= IE_BITS_GEN_MASK;
entry->ie_next = table->ie_next;
table->ie_next = index;
+ space->is_table_free++;
} else {
/*
* Nothing to do. The entry does not match
space->is_table = table;
space->is_table_size = size;
space->is_table_next = nits;
+ space->is_table_free += size - osize;
is_done_growing(space);
is_write_unlock(space);
projects / apple / xnu.git / blobdiff