Changeset 853802e in mainline

Timestamp:

2017-08-22T20:11:47Z (7 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

58e8646

Parents:

1d81eb6

Message:

Include task ID in connection hash table operations

The task ID must be included in the hash computation because a phone hash alone
might not be unique while the server is still tracking connections for killed
tasks due to kernel's recycling of phone structures.

File:

• uspace/lib/c/generic/async.c (modified) (6 diffs)

uspace/lib/c/generic/async.c

@@ -106 +106 @@
 #include <fibril.h>
 #include <adt/hash_table.h>
+#include <adt/hash.h>
 #include <adt/list.h>
 #include <assert.h>
@@ -587 +588 @@
 };
 
-/** Compute hash into the connection hash table based on the source phone hash.
- *
- * @param key Pointer to source phone hash.
+typedef struct {
+        task_id_t task_id;
+        sysarg_t phone_hash;
+} conn_key_t;
+
+/** Compute hash into the connection hash table
+ *
+ * The hash is based on the source task ID and the source phone hash. The task
+ * ID is included in the hash because a phone hash alone might not be unique
+ * while we still track connections for killed tasks due to kernel's recycling
+ * of phone structures.
+ *
+ * @param key Pointer to the connection key structure.
  *
  * @return Index into the connection hash table.
@@ -596 +607 @@
 static size_t conn_key_hash(void *key)
 {
-        sysarg_t in_phone_hash = *(sysarg_t *) key;
-        return in_phone_hash;
+        conn_key_t *ck = (conn_key_t *) key;
+
+        size_t hash = 0;
+        hash = hash_combine(hash, LOWER32(ck->task_id));
+        hash = hash_combine(hash, UPPER32(ck->task_id));
+        hash = hash_combine(hash, ck->phone_hash);
+        return hash;
 }
 
@@ -603 +619 @@
 {
         connection_t *conn = hash_table_get_inst(item, connection_t, link);
-        return conn_key_hash(&conn->in_phone_hash);
+        return conn_key_hash(&(conn_key_t){
+                .task_id = conn->in_task_id,
+                .phone_hash = conn->in_phone_hash
+        });
 }
 
 static bool conn_key_equal(void *key, const ht_link_t *item)
 {
-        sysarg_t in_phone_hash = *(sysarg_t *) key;
+        conn_key_t *ck = (conn_key_t *) key;
         connection_t *conn = hash_table_get_inst(item, connection_t, link);
-        return (in_phone_hash == conn->in_phone_hash);
+        return ((ck->task_id == conn->in_task_id) &&
+            (ck->phone_hash == conn->in_phone_hash));
 }
 
@@ -716 +736 @@
          */
         futex_down(&async_futex);
-        hash_table_remove(&conn_hash_table, &fibril_connection->in_phone_hash);
+        hash_table_remove(&conn_hash_table, &(conn_key_t){
+                .task_id = fibril_connection->in_task_id,
+                .phone_hash = fibril_connection->in_phone_hash
+        });
         futex_up(&async_futex);
         
@@ -951 +974 @@
         futex_down(&async_futex);
         
-        ht_link_t *link = hash_table_find(&conn_hash_table, &call->in_phone_hash);
+        ht_link_t *link = hash_table_find(&conn_hash_table, &(conn_key_t){
+                .task_id = call->in_task_id,
+                .phone_hash = call->in_phone_hash
+        });
         if (!link) {
                 futex_up(&async_futex);