Changeset 5c76cc61 in mainline

Timestamp:

2018-06-19T19:46:03Z (6 years ago)

Author:

Jiří Zárevúcky <jiri.zarevucky@…>

Branches:

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

Children:

3bd1d7d4

Parents:

9f272d9

git-author:

Jiří Zárevúcky <jiri.zarevucky@…> (2018-05-31 16:37:35)

git-committer:

Jiří Zárevúcky <jiri.zarevucky@…> (2018-06-19 19:46:03)

Message:

async: Lock interface hash table with a dedicated interface_futex, and remove redundant per-interface futexes.

File:

• uspace/lib/c/generic/async/ports.c (modified) (11 diffs)

uspace/lib/c/generic/async/ports.c

@@ -60 +60 @@
         iface_t iface;
 
-        /** Futex protecting the hash table */
-        futex_t futex;
-
         /** Interface ports */
         hash_table_t port_hash_table;
@@ -104 +101 @@
 static void *fallback_port_data = NULL;
 
+/** Futex guarding the interface hash table. */
+static futex_t interface_futex = FUTEX_INITIALIZER;
 static hash_table_t interface_hash_table;
 
@@ -177 +176 @@
 
         interface->iface = iface;
-        futex_initialize(&interface->futex, 1);
         interface->port_id_avail = 0;
 
@@ -188 +186 @@
     async_port_handler_t handler, void *data)
 {
+        // TODO: Move the malloc out of critical section.
         port_t *port = (port_t *) malloc(sizeof(port_t));
         if (!port)
                 return NULL;
 
-        futex_down(&interface->futex);
-
         port_id_t id = interface->port_id_avail;
         interface->port_id_avail++;
@@ -203 +200 @@
         hash_table_insert(&interface->port_hash_table, &port->link);
 
-        futex_up(&interface->futex);
-
         return port;
 }
@@ -213 +208 @@
         interface_t *interface;
 
-        futex_down(&async_futex);
+        futex_lock(&interface_futex);
 
         ht_link_t *link = hash_table_find(&interface_hash_table, &iface);
@@ -222 +217 @@
 
         if (!interface) {
-                futex_up(&async_futex);
+                futex_unlock(&interface_futex);
                 return ENOMEM;
         }
@@ -228 +223 @@
         port_t *port = async_new_port(interface, handler, data);
         if (!port) {
-                futex_up(&async_futex);
+                futex_unlock(&interface_futex);
                 return ENOMEM;
         }
@@ -234 +229 @@
         *port_id = port->id;
 
-        futex_up(&async_futex);
+        futex_unlock(&interface_futex);
 
         return EOK;
@@ -260 +255 @@
         port_t *port = NULL;
 
-        futex_down(&async_futex);
+        futex_lock(&interface_futex);
 
         ht_link_t *link = hash_table_find(&interface_hash_table, &iface);
@@ -272 +267 @@
         }
 
-        futex_up(&async_futex);
+        futex_unlock(&interface_futex);
 
         return port;