weak_set iterator

p2pApp/weakset.h

@@ -195,6 +195,27 @@ public:
         return m_data->mutex;
     }
 
+    //! an iterator-ish object which also locks the set during iteration
+    struct XIterator {
+        weak_set& set;
+        epicsGuard<epicsMutex> guard;
+        typename store_t::iterator it, end;
+        XIterator(weak_set& S) :set(S), guard(S.mutex()), it(S.m_data->store.begin()), end(S.m_data->store.end()) {}
+        //! yield the next live entry
+        value_pointer next() {
+            value_pointer ret;
+            while(it!=end) {
+                ret = (it++)->lock();
+                if(ret) break;
+            }
+            return ret;
+        }
+    private:
+        XIterator(const XIterator&);
+        XIterator& operator=(const XIterator&);
+    };
+
+    typedef XIterator iterator;
 };
 
 template<typename T>

testApp/testweak.cpp

@@ -165,16 +165,49 @@ void testWeakLock()
     }
 }
 
+static
+void testWeakIterate()
+{
+    typedef weak_set<int> set_type;
+    set_type::value_pointer A, B;
+    set_type set;
+
+    testDiag("Test weak_set locked iteration");
+
+    A.reset(new int(42));
+    set.insert(A);
+    A.reset(new int(43));
+    // ref. to 42 is dropped
+    set.insert(A);
+    B.reset(new int(44));
+    set.insert(B);
+
+    testOk1(set.size()==2);
+
+    {
+        set_type::iterator it(set);
+        set_type::value_pointer V;
+
+        V = it.next();
+        testOk1(V && (*V==43 || *V==44));
+        V = it.next();
+        testOk1(V && (*V==43 || *V==44));
+        V = it.next();
+        testOk1(!V);
+    }
+}
+
 } // namespace
 
 MAIN(testweak)
 {
-    testPlan(33);
+    testPlan(37);
     testWeakSet1();
     testWeakSet2();
     testWeakSetInvalid();
     testWeakMap1();
     testWeakMap2();
     testWeakLock();
+    testWeakIterate();
     return testDone();
 }