Changeset ab6edb6 in mainline for uspace/lib/c/generic/async

Timestamp:

2018-06-26T17:34:48Z (7 years ago)

Author:

Jiří Zárevúcky <jiri.zarevucky@…>

Branches:

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

Children:

e768aea

Parents:

b59318e

git-author:

Jiří Zárevúcky <jiri.zarevucky@…> (2018-06-25 19:28:19)

git-committer:

Jiří Zárevúcky <jiri.zarevucky@…> (2018-06-26 17:34:48)

Message:

Simplify the interaction between async_futex and fibril_switch().

Location:

uspace/lib/c/generic/async

Files:

• client.c (modified) (3 diffs)
• server.c (modified) (3 diffs)

uspace/lib/c/generic/async/client.c

@@ -372 +372 @@
 
         /* Leave the async_futex locked when entering this function */
-        fibril_switch(FIBRIL_TO_MANAGER);
-
-        /* Futex is up automatically after fibril_switch */
+        fibril_switch(FIBRIL_FROM_BLOCKED);
+        futex_unlock(&async_futex);
 
 done:
@@ -445 +444 @@
 
         /* Leave the async_futex locked when entering this function */
-        fibril_switch(FIBRIL_TO_MANAGER);
-
-        /* Futex is up automatically after fibril_switch */
+        fibril_switch(FIBRIL_FROM_BLOCKED);
+        futex_unlock(&async_futex);
 
         if (!msg->done)
@@ -511 +509 @@
 
         /* Leave the async_futex locked when entering this function */
-        fibril_switch(FIBRIL_TO_MANAGER);
-
-        /* Futex is up automatically after fibril_switch() */
+        fibril_switch(FIBRIL_FROM_BLOCKED);
+        futex_unlock(&async_futex);
 }
 

uspace/lib/c/generic/async/server.c

@@ -997 +997 @@
                  * case, route_call() will perform the wakeup.
                  */
-                fibril_switch(FIBRIL_TO_MANAGER);
-
-                /*
-                 * Futex is up after getting back from async_manager.
-                 * Get it again.
-                 */
-                futex_lock(&async_futex);
+                fibril_switch(FIBRIL_FROM_BLOCKED);
+
                 if ((usecs) && (conn->wdata.to_event.occurred) &&
                     (list_empty(&conn->msg_queue))) {
@@ -1143 +1138 @@
 {
         while (true) {
-                if (fibril_switch(FIBRIL_FROM_MANAGER)) {
-                        futex_unlock(&async_futex);
-                        /*
-                         * async_futex is always held when entering a manager
-                         * fibril.
-                         */
-                        continue;
-                }
-
                 futex_lock(&async_futex);
+                fibril_switch(FIBRIL_FROM_MANAGER);
+
+                /*
+                 * The switch only returns when there is no non-manager fibril
+                 * it can run.
+                 */
 
                 suseconds_t timeout;
@@ -1226 +1218 @@
 static errno_t async_manager_fibril(void *arg)
 {
-        futex_unlock(&async_futex);
-
-        /*
-         * async_futex is always locked when entering manager
-         */
         async_manager_worker();
-
         return 0;
 }