Changeset 01ff41c in mainline for libc/generic/async.c

Timestamp:

2006-05-27T22:28:25Z (19 years ago)

Author:

Ondrej Palkovsky <ondrap@…>

Branches:

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

Children:

7f5b37a

Parents:

7f9cd77

Message:

Added functions to async framework for reasonable sending asynchronous
messages.

File:

• libc/generic/async.c (modified) (14 diffs)

libc/generic/async.c

@@ -92 +92 @@
 #include <errno.h>
 
-static atomic_t conn_futex = FUTEX_INITIALIZER;
+static atomic_t async_futex = FUTEX_INITIALIZER;
 static hash_table_t conn_hash_table;
+
+typedef struct {
+        pstid_t ptid;                /**< Thread waiting for this message */
+        int active;                  /**< If this thread is currently active */
+        int done;                    /**< If reply was received */
+        ipc_call_t *dataptr;         /**< Pointer where the answer data
+                                      *   should be stored */
+        ipcarg_t retval;
+} amsg_t;
 
 typedef struct {
@@ -116 +125 @@
 
 /* Hash table functions */
-
 #define CONN_HASH_TABLE_CHAINS  32
 
@@ -147 +155 @@
 };
 
+/*************************************************/
+
 /** Try to route a call to an appropriate connection thread
  *
@@ -157 +167 @@
         unsigned long key;
 
-        futex_down(&conn_futex);
+        futex_down(&async_futex);
 
         key = call->in_phone_hash;
         hlp = hash_table_find(&conn_hash_table, &key);
         if (!hlp) {
-                futex_up(&conn_futex);
+                futex_up(&async_futex);
                 return 0;
         }
@@ -177 +187 @@
         }
 
-        futex_up(&conn_futex);
+        futex_up(&async_futex);
 
         return 1;
@@ -189 +199 @@
         connection_t *conn;
         
-        futex_down(&conn_futex);
+        futex_down(&async_futex);
 
         conn = PS_connection;
@@ -204 +214 @@
         free(msg);
         
-        futex_up(&conn_futex);
+        futex_up(&async_futex);
         return callid;
 }
@@ -237 +247 @@
 
         /* Remove myself from connection hash table */
-        futex_down(&conn_futex);
+        futex_down(&async_futex);
         key = conn->in_phone_hash;
         hash_table_remove(&conn_hash_table, &key, 1);
-        futex_up(&conn_futex);
+        futex_up(&async_futex);
         /* Answer all remaining messages with ehangup */
         while (!list_empty(&conn->msg_queue)) {
@@ -289 +299 @@
         }
         key = conn->in_phone_hash;
-        futex_down(&conn_futex);
+        futex_down(&async_futex);
         /* Add connection to hash table */
         hash_table_insert(&conn_hash_table, &key, &conn->link);
-        futex_up(&conn_futex);
+        futex_up(&async_futex);
 
         psthread_add_ready(conn->ptid);
@@ -299 +309 @@
 }
 
-/** Handle call to a task */
+/** Handle call that was received */
 static void handle_call(ipc_callid_t callid, ipc_call_t *call)
 {
@@ -325 +335 @@
         while (1) {
                 if (psthread_schedule_next_adv(PS_FROM_MANAGER)) {
-                        futex_up(&conn_futex); /* conn_futex is always held
+                        futex_up(&async_futex); /* async_futex is always held
                                                 * when entering manager thread
                                                 */
@@ -334 +344 @@
                 if (callid & IPC_CALLID_ANSWERED)
                         continue;
+
                 handle_call(callid, &call);
         }
@@ -347 +358 @@
 static int async_manager_thread(void *arg)
 {
-        futex_up(&conn_futex); /* conn_futex is always locked when entering
+        futex_up(&async_futex); /* async_futex is always locked when entering
                                 * manager */
         async_manager();
@@ -376 +387 @@
         
 }
+
+/** IPC handler for messages in async framework
+ *
+ * Notify thread that is waiting for this message, that it arrived
+ */
+static void reply_received(void *private, int retval,
+                           ipc_call_t *data)
+{
+        amsg_t *msg = (amsg_t *) private;
+
+        msg->retval = retval;
+
+        futex_down(&async_futex);
+        /* Copy data after futex_down, just in case the
+         * call was detached 
+         */
+        if (msg->dataptr)
+                *msg->dataptr = *data; 
+        
+        msg->done = 1;
+        if (! msg->active) {
+                msg->active = 1;
+                psthread_add_ready(msg->ptid);
+        }
+        futex_up(&async_futex);
+}
+
+/** Send message and return id of the sent message
+ *
+ * The return value can be used as input for async_wait() to wait
+ * for completion.
+ */
+aid_t async_send_2(int phoneid, ipcarg_t method, ipcarg_t arg1, ipcarg_t arg2,
+                   ipc_call_t *dataptr)
+{
+        amsg_t *msg;
+
+        msg = malloc(sizeof(*msg));
+        msg->active = 1;
+        msg->done = 0;
+        msg->dataptr = dataptr;
+        ipc_call_async_2(phoneid,method,arg1,arg2,msg,reply_received);
+
+        return (aid_t) msg;
+}
+
+/** Wait for a message sent by async framework
+ *
+ * @param amsgid Message ID to wait for
+ * @param retval Pointer to variable where will be stored retval
+ *               of the answered message. If NULL, it is ignored.
+ *
+ */
+void async_wait_for(aid_t amsgid, ipcarg_t *retval)
+{
+        amsg_t *msg = (amsg_t *) amsgid;
+        connection_t *conn;
+
+        futex_down(&async_futex);
+        if (msg->done) {
+                futex_up(&async_futex);
+                goto done;
+        }
+
+        msg->ptid = psthread_get_id();
+        msg->active = 0;
+        /* Leave locked async_futex when entering this function */
+        psthread_schedule_next_adv(PS_TO_MANAGER);
+        /* futex is up automatically after psthread_schedule_next...*/
+done:
+        if (retval)
+                *retval = msg->retval;
+        free(msg);
+}