localStaticLock - static local thread-safety

pvDataApp/Makefile

@@ -23,6 +23,7 @@ INC += messageQueue.h
 INC += destroyable.h
 INC += status.h
 INC += sharedPtr.h
+INC += localStaticLock.h
 
 LIBSRCS += byteBuffer.cpp
 LIBSRCS += bitSet.cpp
@@ -35,6 +36,7 @@ LIBSRCS += timeFunction.cpp
 LIBSRCS += timer.cpp
 LIBSRCS += status.cpp
 LIBSRCS += messageQueue.cpp
+LIBSRCS += localStaticLock.cpp
 
 SRC_DIRS += $(PVDATA)/pv
 

pvDataApp/factory/FieldCreateFactory.cpp

@@ -528,10 +528,11 @@ FieldConstPtr FieldCreate::deserialize(ByteBuffer* buffer, DeserializableControl
 
 FieldCreatePtr FieldCreate::getFieldCreate()
 {
-    static FieldCreatePtr fieldCreate;
-    static Mutex mutex;
-    Lock xx(mutex);
+	LOCAL_STATIC_LOCK;
+	static FieldCreatePtr fieldCreate;
+	static Mutex mutex;
 
+	Lock xx(mutex);
     if(fieldCreate.get()==0) fieldCreate = FieldCreatePtr(new FieldCreate());
     return fieldCreate;
 }

pvDataApp/misc/localStaticLock.cpp

@@ -0,0 +1,39 @@
+/* localStaticLock.cpp */
+/**
+ * Copyright - See the COPYRIGHT that is included with this distribution.
+ * EPICS pvData is distributed subject to a Software License Agreement found
+ * in file LICENSE that is included with this distribution.
+ */
+/**
+ *  @author mse
+ */
+
+#include <pv/localStaticLock.h>
+
+static int nifty_counter;
+static epics::pvData::Mutex* g_localStaticInitMutex;
+
+epics::pvData::Mutex& getLocalStaticInitMutex()
+{
+    return *g_localStaticInitMutex;
+}
+
+
+// The counter is initialized at load-time, i.e., before any of the static objects are initialized.
+MutexInitializer::MutexInitializer ()
+{
+    if (0 == nifty_counter++)
+    {
+        // Initialize static members.
+        g_localStaticInitMutex = new epics::pvData::Mutex();
+    }
+}
+
+MutexInitializer::~MutexInitializer ()
+{
+    if (0 == --nifty_counter)
+    {
+        // Clean-up.
+        delete g_localStaticInitMutex;
+    }
+}

pvDataApp/misc/localStaticLock.h

@@ -0,0 +1,31 @@
+/* localStaticLock.h */
+/**
+ * Copyright - See the COPYRIGHT that is included with this distribution.
+ * EPICS pvData is distributed subject to a Software License Agreement found
+ * in file LICENSE that is included with this distribution.
+ */
+/**
+ *  @author mse
+ */
+#ifndef LOCALSTATICLOCK_H
+#define LOCALSTATICLOCK_H
+
+#include <pv/lock.h>
+
+extern epics::pvData::Mutex& getLocalStaticInitMutex();
+
+#if defined(__GNUC__) && __GNUC__ >= 4
+// noop
+#define LOCAL_STATIC_LOCK
+#else
+#define LOCAL_STATIC_LOCK epics::pvData::Lock localStaticInitMutexLock(getLocalStaticInitMutex());
+#endif
+
+static class MutexInitializer {
+  public:
+    MutexInitializer ();
+    ~MutexInitializer ();
+} localStaticMutexInitializer; // Note object here in the header.
+
+
+#endif  /* LOCALSTATICLOCK_H */

pvDataApp/pv/pvType.h

@@ -27,6 +27,7 @@ typedef unsigned int uintptr_t;
 #endif
 
 #include <pv/sharedPtr.h>
+#include <pv/localStaticLock.h>
 
 namespace epics { namespace pvData {