Changeset 957cfa58 in mainline for uspace/srv/devman/devman.c

Timestamp:

2010-05-26T20:25:43Z (14 years ago)

Author:

Lenka Trochtova <trochtova.lenka@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

c9f3b45c

Parents:

d51ee2b

Message:

devman - use hash table to lookup device according to its handle.

File:

• uspace/srv/devman/devman.c (modified) (10 diffs)

uspace/srv/devman/devman.c

@@ -39 +39 @@
 #include "devman.h"
 
+// hash table operations
+
+static hash_index_t devices_hash(unsigned long key[])
+{
+        return key[0] % DEVICE_BUCKETS;
+}
+
+static int devman_devices_compare(unsigned long key[], hash_count_t keys, link_t *item)
+{
+        node_t *dev = hash_table_get_instance(item, node_t, devman_link);
+        return (dev->handle == (device_handle_t) key[0]);
+}
+
+static int devmap_devices_compare(unsigned long key[], hash_count_t keys, link_t *item)
+{
+        node_t *dev = hash_table_get_instance(item, node_t, devmap_link);
+        return (dev->devmap_handle == (dev_handle_t) key[0]);
+}
+
+static void devices_remove_callback(link_t *item)
+{
+}
+
+static hash_table_operations_t devman_devices_ops = {
+        .hash = devices_hash,
+        .compare = devman_devices_compare,
+        .remove_callback = devices_remove_callback
+};
+
+static hash_table_operations_t devmap_devices_ops = {
+        .hash = devices_hash,
+        .compare = devmap_devices_compare,
+        .remove_callback = devices_remove_callback
+};
+
 /** Allocate and initialize a new driver structure.
  * 
@@ -584 +619 @@
         printf(NAME ": init_device_tree.\n");
         
-        memset(tree->node_map, 0, MAX_DEV * sizeof(node_t *));
-        
-        atomic_set(&tree->current_handle, 0);
+        tree->current_handle = 0;
+        
+        hash_table_create(&tree->devman_devices, DEVICE_BUCKETS, 1, &devman_devices_ops);
+        hash_table_create(&tree->devmap_devices, DEVICE_BUCKETS, 1, &devmap_devices_ops);
+        
+        fibril_rwlock_initialize(&tree->rwlock);
         
         // create root node and add it to the device tree
@@ -630 +668 @@
 /** Insert new device into device tree.
  * 
+ * The device tree's rwlock should be already held exclusively when calling this function.
+ * 
  * @param tree the device tree.
  * @param node the newly added device node. 
@@ -644 +684 @@
         node->name = dev_name;
         if (!set_dev_path(node, parent)) {
+                fibril_rwlock_write_unlock(&tree->rwlock);
                 return false;           
         }
         
         // add the node to the handle-to-node map
-        node->handle = atomic_postinc(&tree->current_handle);
-        if (node->handle >= MAX_DEV) {
-                printf(NAME ": failed to add device to device tree, because maximum number of devices was reached.\n");
-                free(node->pathname);
-                node->pathname = NULL;
-                atomic_postdec(&tree->current_handle);
-                return false;
-        }
-        tree->node_map[node->handle] = node;
+        node->handle = ++tree->current_handle;
+        unsigned long key = node->handle;
+        hash_table_insert(&tree->devman_devices, &key, &node->devman_link);
 
         // add the node to the list of its parent's children
         node->parent = parent;
         if (NULL != parent) {
-                fibril_mutex_lock(&parent->children_mutex);
-                list_append(&node->sibling, &parent->children);
-                fibril_mutex_unlock(&parent->children_mutex);
-        }       
+                list_append(&node->sibling, &parent->children);         
+        }
         return true;
 }
@@ -678 +711 @@
 node_t * find_dev_node_by_path(dev_tree_t *tree, char *path)
 {
+        fibril_rwlock_read_lock(&tree->rwlock);
+        
         node_t *dev = tree->root_node;
         // relative path to the device from its parent (but with '/' at the beginning)
@@ -702 +737 @@
         }
         
+        fibril_rwlock_read_unlock(&tree->rwlock);
+        
         return dev;
 }
@@ -708 +745 @@
  * Find child device node with a specified name.
  * 
+ * Device tree rwlock should be held at least for reading. 
+ * 
  * @param parent the parent device node.
  * @param name the name of the child device node.
@@ -717 +756 @@
         node_t *dev;
         link_t *link;
-        
-        fibril_mutex_lock(&parent->children_mutex);             
+                        
         link = parent->children.next;
         
@@ -725 +763 @@
                 
                 if (0 == str_cmp(name, dev->name)) {
-                        fibril_mutex_unlock(&parent->children_mutex);
                         return dev;                     
                 }
@@ -731 +768 @@
                 link = link->next;
         }       
-        
-        fibril_mutex_unlock(&parent->children_mutex);   
+                
         return NULL;
 }