Changeset 8b5c8ae in mainline

Timestamp:

2011-01-09T20:44:24Z (13 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

622dea8

Parents:

80bffdb0

Message:

If there are no available phones to be used by the async sessions
framework, sleep on a condition variable until a phone becomes
available.

File:

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

uspace/lib/c/generic/async_sess.c

@@ -110 +110 @@
 typedef struct {
         link_t sess_link;       /**< Link for the session list of inactive connections. */
-        link_t global_link;     /**< Link for the global list of inactive connectinos. */
+        link_t global_link;     /**< Link for the global list of inactive connections. */
         int data_phone;         /**< Connected data phone. */
 } conn_node_t;
 
 /**
- * Mutex protecting the inactive_conn_head list and the session list.
+ * Mutex protecting the inactive_conn_head list, the session list and the
+ * avail_phone condition variable.
  */
 static fibril_mutex_t async_sess_mutex;
@@ -128 +129 @@
  */
 static LIST_INITIALIZE(session_list_head);
+
+/**
+ * Condition variable used to wait for a phone to become available.
+ */
+static FIBRIL_CONDVAR_INITIALIZE(avail_phone_cv);
 
 /** Initialize the async_sess subsystem.
@@ -197 +203 @@
                 free(conn);
         }
+        
+        fibril_condvar_broadcast(&avail_phone_cv);
 }
 
@@ -256 +264 @@
                 } else {
                         /*
-                         * This is unfortunate. We failed both to find a cached
-                         * connection or to create a new one even after cleaning up
-                         * the cache. This is most likely due to too many
-                         * open sessions (connected session phones).
+                         * Wait for a phone to become available.
                          */
-                        data_phone = ELIMIT;
+                        fibril_condvar_wait(&avail_phone_cv, &async_sess_mutex);
+                        goto retry;
                 }
         }
@@ -279 +285 @@
 
         fibril_mutex_lock(&async_sess_mutex);
+        fibril_condvar_signal(&avail_phone_cv);
         conn = (conn_node_t *) malloc(sizeof(conn_node_t));
         if (!conn) {
@@ -285 +292 @@
                  * means that we simply hang up.
                  */
+                ipc_hangup(data_phone);
                 fibril_mutex_unlock(&async_sess_mutex);
-                ipc_hangup(data_phone);
                 return;
         }