Changes in libcfa/src/containers/lockfree.hfa [0658672:b2f3880]

File:

• libcfa/src/containers/lockfree.hfa (modified) (4 diffs)

libcfa/src/containers/lockfree.hfa

@@ -199 +199 @@
 
 forall( T & )
-struct LinkData {
-        T * volatile top;                                                               // pointer to stack top
-        uintptr_t count;                                                                // count each push
-};
-
-forall( T & )
 union Link {
-        LinkData(T) data;
+        struct {                                                                                        // 32/64-bit x 2
+                T * volatile top;                                                               // pointer to stack top
+                uintptr_t count;                                                                // count each push
+        };
         #if __SIZEOF_INT128__ == 16
         __int128                                                                                        // gcc, 128-bit integer
@@ -223 +220 @@
                 void ?{}( StackLF(T) & this ) with(this) { stack.atom = 0; }
 
-                T * top( StackLF(T) & this ) with(this) { return stack.data.top; }
+                T * top( StackLF(T) & this ) with(this) { return stack.top; }
 
                 void push( StackLF(T) & this, T & n ) with(this) {
                         *( &n )`next = stack;                                           // atomic assignment unnecessary, or use CAA
                         for () {                                                                        // busy wait
-                                if ( __atomic_compare_exchange_n( &stack.atom, &( &n )`next->atom, (Link(T))@{ (LinkData(T))@{ &n, ( &n )`next->data.count + 1} }.atom, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST ) ) break; // attempt to update top node
+                          if ( __atomic_compare_exchange_n( &stack.atom, &( &n )`next->atom, (Link(T))@{ {&n, ( &n )`next->count + 1} }.atom, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST ) ) break; // attempt to update top node
                         } // for
                 } // push
@@ -235 +232 @@
                         Link(T) t @= stack;                                                     // atomic assignment unnecessary, or use CAA
                         for () {                                                                        // busy wait
-                                if ( t.data.top == 0p ) return 0p;                              // empty stack ?
-                                Link(T) * next = ( t.data.top )`next;
-                                if ( __atomic_compare_exchange_n( &stack.atom, &t.atom, (Link(T))@{ (LinkData(T))@{ next->data.top, t.data.count } }.atom, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST ) ) return t.data.top; // attempt to update top node
+                          if ( t.top == 0p ) return 0p;                         // empty stack ?
+                          if ( __atomic_compare_exchange_n( &stack.atom, &t.atom, (Link(T))@{ {( t.top )`next->top, t.count} }.atom, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST ) ) return t.top; // attempt to update top node
                         } // for
                 } // pop
@@ -243 +239 @@
                 bool unsafe_remove( StackLF(T) & this, T * node ) with(this) {
                         Link(T) * link = &stack;
-                        for () {
-                                // TODO: Avoiding some problems with double fields access.
-                                LinkData(T) * data = &link->data;
-                                T * next = (T *)&(*data).top;
-                                if ( next == node ) {
-                                        data->top = ( node )`next->data.top;
+                        for() {
+                                T * next = link->top;
+                                if( next == node ) {
+                                        link->top = ( node )`next->top;
                                         return true;
                                 }
-                                if ( next == 0p ) return false;
+                                if( next == 0p ) return false;
                                 link = ( next )`next;
                         }