Changes in libcfa/src/concurrency/channel.hfa [6f774be:70a4ed5]

File:

• libcfa/src/concurrency/channel.hfa (modified) (7 diffs)

libcfa/src/concurrency/channel.hfa

@@ -341 +341 @@
 }
 
-// special case of __handle_waituntil_OR, that does some work to avoid starvation/deadlock case
-static inline bool __handle_pending( dlist( select_node ) & queue, select_node & mine ) {
-    while ( !queue`isEmpty ) {
-        // if node not a special OR case or if we win the special OR case race break
-        if ( !queue`first.clause_status || queue`first.park_counter || __pending_set_other( queue`first, mine, ((unsigned long int)(&(queue`first))) ) )
-            return true;
-        
-        // our node lost the race when toggling in __pending_set_other
-        if ( *mine.clause_status != __SELECT_PENDING ) 
-            return false;
-
-        // otherwise we lost the special OR race so discard node
-        try_pop_front( queue );
-    }
-    return false;
-}
-
 // type used by select statement to capture a chan read as the selected operation
 struct chan_read {
@@ -391 +374 @@
                 return false;
             }
-
-            if ( __handle_pending( prods, node ) ) {
+            
+            if ( __handle_waituntil_OR( prods ) ) {
                 __prods_handoff( chan, ret );
                 __make_select_node_sat( node ); // need to to mark SAT now that we know operation is done or else threads could get stuck in __mark_select_node
@@ -398 +381 @@
                 return true;
             }
-            if ( *node.clause_status == __SELECT_PENDING )
-                __make_select_node_unsat( node );
+            __make_select_node_unsat( node );
         }
         // check if we can complete operation. If so race to establish winner in special OR case
@@ -441 +423 @@
 }
 static inline bool unregister_select( chan_read(T) & this, select_node & node ) { return unregister_chan( this.chan, node ); }
-static inline bool on_selected( chan_read(T) & this, select_node & node ) with(this) {
+static inline void on_selected( chan_read(T) & this, select_node & node ) with(this) {
     if ( node.extra == 0p ) // check if woken up due to closed channel
         __closed_remove( chan, ret );
     // This is only reachable if not closed or closed exception was handled
-    return true;
 }
 
@@ -482 +463 @@
                 return false;
             }
-
-            if ( __handle_pending( cons, node ) ) {
+            
+            if ( __handle_waituntil_OR( cons ) ) {
                 __cons_handoff( chan, elem );
                 __make_select_node_sat( node ); // need to to mark SAT now that we know operation is done or else threads could get stuck in __mark_select_node
@@ -489 +470 @@
                 return true;
             }
-            if ( *node.clause_status == __SELECT_PENDING )
-                __make_select_node_unsat( node );
+            __make_select_node_unsat( node );
         }
         // check if we can complete operation. If so race to establish winner in special OR case
@@ -534 +514 @@
 static inline bool unregister_select( chan_write(T) & this, select_node & node ) { return unregister_chan( this.chan, node ); }
 
-static inline bool on_selected( chan_write(T) & this, select_node & node ) with(this) { 
+static inline void on_selected( chan_write(T) & this, select_node & node ) with(this) { 
     if ( node.extra == 0p ) // check if woken up due to closed channel
         __closed_insert( chan, elem );
 
     // This is only reachable if not closed or closed exception was handled
-    return true;
 }