AtomicBoolean for _closed flag

pvAccessApp/remote/blockingTCP.h

@@ -39,29 +39,6 @@ using epics::pvData::int64;
 namespace epics {
     namespace pvAccess {
 
-struct null_deleter
-{
-    void operator()(void const *) const {}
-};
-
-// standard performance on set/clear, use of tr1::shared_ptr lock-free counter for get
-// alternative is to use boost::atomic
-class AtomicBoolean
-{
-    public:
-        AtomicBoolean() : counter(static_cast<void*>(0), null_deleter()) {};
-
-        void set() { mutex.lock(); setp = counter; mutex.unlock(); }
-        void clear() { mutex.lock(); setp.reset(); mutex.unlock(); }
-
-        bool get() const { return counter.use_count() == 2; }
-    private:
-        std::tr1::shared_ptr<void> counter;
-        std::tr1::shared_ptr<void> setp;
-        epics::pvData::Mutex mutex;
-};
-
-
         //class MonitorSender;
 
         enum ReceiveStage {

pvAccessApp/remote/blockingUDP.h

@@ -54,8 +54,7 @@ namespace epics {
             virtual ~BlockingUDPTransport();
 
             virtual bool isClosed() {
-                epics::pvData::Lock guard(_mutex);
-                return _closed;
+                return _closed.get();
             }
 
             virtual const osiSockAddr* getRemoteAddress() const {
@@ -210,7 +209,7 @@ namespace epics {
             }
 
         protected:
-            bool _closed;
+            AtomicBoolean _closed;
 
             /**
              * Response handler.

pvAccessApp/remote/blockingUDPTransport.cpp

@@ -44,7 +44,7 @@ namespace epics {
                 auto_ptr<ResponseHandler>& responseHandler, SOCKET channel,
                 osiSockAddr& bindAddress,
                 short remoteTransportRevision) :
-                    _closed(false),
+                    _closed(),
                     _responseHandler(responseHandler),
                     _channel(channel),
                     _bindAddress(bindAddress),
@@ -108,8 +108,8 @@ namespace epics {
         void BlockingUDPTransport::close(bool forced, bool waitForThreadToComplete) {
             {
                 Lock guard(_mutex);
-                if(_closed) return;
-                _closed = true;
+                if(_closed.get()) return;
+                _closed.set();
     
                 LOG(logLevelDebug,
                     "UDP socket %s closed.",
@@ -178,14 +178,8 @@ namespace epics {
 
             try {
 
-                while(true)
+                while(!_closed.get())
                 {
-                    _mutex.lock();
-                    bool closed = _closed;
-                    _mutex.unlock();
-                    if (unlikely(closed))
-                        break;
-                        
                     // we poll to prevent blocking indefinitely
 
                     // data ready to be read
@@ -237,10 +231,7 @@ namespace epics {
                             continue;
                                                     
                         // log a 'recvfrom' error
-                        _mutex.lock();
-                        closed = _closed;
-                        _mutex.unlock();
-                        if(!closed)
+                        if(!_closed.get())
                         {
                             char errStr[64];
                             epicsSocketConvertErrnoToString(errStr, sizeof(errStr));

pvAccessApp/remote/remote.h

@@ -596,6 +596,28 @@ namespace epics {
         };
 
 
+        struct AtomicBoolean_null_deleter
+        {
+            void operator()(void const *) const {}
+        };
+        
+        // standard performance on set/clear, use of tr1::shared_ptr lock-free counter for get
+        // alternative is to use boost::atomic
+        class AtomicBoolean
+        {
+            public:
+                AtomicBoolean() : counter(static_cast<void*>(0), AtomicBoolean_null_deleter()) {};
+        
+                void set() { mutex.lock(); setp = counter; mutex.unlock(); }
+                void clear() { mutex.lock(); setp.reset(); mutex.unlock(); }
+        
+                bool get() const { return counter.use_count() == 2; }
+            private:
+                std::tr1::shared_ptr<void> counter;
+                std::tr1::shared_ptr<void> setp;
+                epics::pvData::Mutex mutex;
+        };
+
     }
 }
 

testApp/utils/Makefile

@@ -7,6 +7,7 @@ PROD_HOST += testUtils
 testUtils_SRCS += hexDumpTest.cpp
 testUtils_SRCS += wildcharMatcherTest.cpp
 testUtils_SRCS += inetAddressUtilsTest.cpp
+testUtils_SRCS += atomicBooleanTest.cpp
 testUtils_LIBS += pvAccess pvData Com gtest_main
 endif
 

testApp/utils/atomicBooleanTest.cpp

@@ -0,0 +1,16 @@
+#include <gtest/gtest.h>
+
+#include <remote.h>
+
+using namespace epics::pvAccess;
+
+TEST(atomicBooleanTest, atomicBoolean)
+{
+    AtomicBoolean ab;
+
+    EXPECT_FALSE(ab.get());
+    ab.set();
+    EXPECT_TRUE(ab.get());
+    ab.clear();
+    EXPECT_FALSE(ab.get());
+}