Fix PluginManager teardown.

src/DynamicLibrary.cpp

@@ -43,7 +43,7 @@
   #include <dlfcn.h>
 #endif
 
-#include "DynamicLibrary.h"
+#include "DynamicLibrary.hpp"
 #include <sstream>
 #include <iostream>
 
@@ -62,6 +62,13 @@ DynamicLibrary::~DynamicLibrary()
     }
 }
 
+
+void DynamicLibrary::clear()
+{
+    m_handle = NULL;
+}
+
+
 DynamicLibrary *DynamicLibrary::load(const std::string &name, 
     std::string &errorString)
 {

src/DynamicLibrary.h → src/DynamicLibrary.hpp

@@ -52,6 +52,7 @@ class DynamicLibrary
 
     ~DynamicLibrary();
     void *getSymbol(const std::string& name);
+    void clear();
 
 private:
     DynamicLibrary(void *handle) : m_handle(handle)

src/PluginManager.cpp

@@ -47,7 +47,7 @@
 #include <pdal/util/Utils.hpp>
 #include <pdal/Log.hpp>
 
-#include "DynamicLibrary.h"
+#include "DynamicLibrary.hpp"
 
 #include <memory>
 #include <sstream>
@@ -253,6 +253,17 @@ bool PluginManager::shutdown()
         }
     }
 
+    // This clears the handles on the dynamic libraries so that they won't
+    // be closed with dlclose().  Depending on the order of dll unloading,
+    // it's possible for a plugin library to be unloaded before this function
+    // (which is usually in a dll) is called, which can raise an error on
+    // some systems when dlclose() is called on a library for which the
+    // reference count is already 0.  Since we're exiting anyway and all the
+    // dlls will be closed, there is no need to call dlclose() on them
+    // explicitly.
+    for (auto l : m_dynamicLibraryMap)
+        l.second->clear();
+
     m_dynamicLibraryMap.clear();
     m_plugins.clear();
     m_exitFuncVec.clear();

test/unit/CMakeLists.txt

@@ -67,7 +67,7 @@ PDAL_ADD_TEST(pdal_pipeline_manager_test FILES PipelineManagerTest.cpp)
 PDAL_ADD_TEST(pdal_point_view_test FILES PointViewTest.cpp)
 PDAL_ADD_TEST(pdal_point_table_test FILES PointTableTest.cpp)
 PDAL_ADD_TEST(pdal_spatial_reference_test FILES SpatialReferenceTest.cpp)
-#PDAL_ADD_TEST(pdal_stage_factory_test FILES StageFactoryTest.cpp)
+PDAL_ADD_TEST(pdal_stage_factory_test FILES StageFactoryTest.cpp)
 PDAL_ADD_TEST(pdal_streaming_test FILES StreamingTest.cpp)
 PDAL_ADD_TEST(pdal_support_test FILES SupportTest.cpp)
 PDAL_ADD_TEST(pdal_user_callback_test FILES UserCallbackTest.cpp)