Add a helper class for symbol binding to dynamic libraries.

source/adios2/CMakeLists.txt

@@ -18,6 +18,7 @@ add_library(adios2
   core/VariableCompound.cpp core/VariableCompound.tcc
   
 #helper
+  helper/adiosDynamicBinder.h  helper/adiosDynamicBinder.cpp
   helper/adiosMath.cpp
   helper/adiosMPIFunctions.cpp
   helper/adiosString.cpp

source/adios2/helper/adiosDynamicBinder.cpp

+/*
+ * Distributed under the OSI-approved Apache License, Version 2.0.  See
+ * accompanying file Copyright.txt for details.
+ *
+ * DynamicBinder.cpp
+ *
+ * Created on: Jul 21, 2017
+ *     Author: Chuck Atkins
+ */
+
+#include "adiosDynamicBinder.h"
+
+#include <algorithm>                    // for copy
+#include <iostream>                     // for operator<<, stringstream, bas...
+#include <iterator>                     // for ostream_iterator
+#include <sstream>                      // for stringstream
+#include <stdexcept>                    // for runtime_error
+#include <vector>                       // for vector
+
+#include <adios2sys/DynamicLoader.hxx>
+
+namespace adios2
+{
+
+struct DynamicBinder::Impl
+{
+    adios2sys::DynamicLoader::LibraryHandle m_LibraryHandle;
+};
+
+DynamicBinder::DynamicBinder(std::string libName)
+{
+    std::vector<std::string> libPrefixes;
+    libPrefixes.emplace_back("");
+    libPrefixes.emplace_back("lib");
+#ifdef __CYGWIN__
+    libPrefixes.emplace_back("cyg");
+#endif
+
+    std::vector<std::string> libSuffixes;
+#ifdef __APPLE__
+    libSuffixes.emplace_back(".dylib");
+    libSuffixes.emplace_back(".so");
+#endif
+#ifdef __hpux
+    libSuffixes.emplace_back(".sl");
+#endif
+#ifdef __unix__
+    libSuffixes.emplace_back(".so");
+#endif
+#ifdef _WIN32
+    libSuffixes.emplace_back(".dll");
+#endif
+
+    std::vector<std::string> searchedLibs;
+    std::string fileName;
+
+    // Test the various combinations of library names
+    for (const std::string &prefix : libPrefixes)
+    {
+        for (const std::string &suffix : libSuffixes)
+        {
+            fileName = prefix + libName + suffix;
+            m_Impl->m_LibraryHandle =
+                adios2sys::DynamicLoader::OpenLibrary(fileName);
+            searchedLibs.push_back(fileName);
+            if (m_Impl->m_LibraryHandle)
+            {
+                break;
+            }
+        }
+        if (m_Impl->m_LibraryHandle)
+        {
+            break;
+        }
+    }
+    if (!m_Impl->m_LibraryHandle)
+    {
+        std::stringstream errString;
+        errString << "Unable to locate the " << libName
+                  << " library; searched for ";
+        std::copy(searchedLibs.begin(), searchedLibs.end(),
+                  std::ostream_iterator<std::string>(errString, " "));
+
+        throw std::runtime_error(errString.str());
+    }
+}
+
+DynamicBinder::~DynamicBinder()
+{
+    adios2sys::DynamicLoader::CloseLibrary(m_Impl->m_LibraryHandle);
+}
+
+DynamicBinder::VoidSymbolPointer
+DynamicBinder::GetSymbol(std::string symbolName)
+{
+    return adios2sys::DynamicLoader::GetSymbolAddress(m_Impl->m_LibraryHandle,
+                                                      symbolName);
+}
+};

source/adios2/helper/adiosDynamicBinder.h

+/*
+ * Distributed under the OSI-approved Apache License, Version 2.0.  See
+ * accompanying file Copyright.txt for details.
+ *
+ * DynamicBinder.h
+ *
+ * Created on: Jul 21, 2017
+ *     Author: Chuck Atkins
+ */
+
+#ifndef ADIOS2_HELPER_DYNAMICBINDER_H_
+#define ADIOS2_HELPER_DYNAMICBINDER_H_
+
+#include <memory>
+#include <string>
+#include <type_traits>
+
+namespace adios2
+{
+
+class DynamicBinder
+{
+public:
+    using VoidSymbolPointer = std::add_pointer<void()>::type;
+
+public:
+    DynamicBinder(std::string libName);
+    ~DynamicBinder();
+
+    VoidSymbolPointer GetSymbol(std::string symbolName);
+
+private:
+    struct Impl;
+    std::unique_ptr<Impl> m_Impl;
+};
+}
+
+#endif // ADIOS2_HELPER_DYNAMICBINDER_H_