More juggling

git-svn-id: http://svn.drobilla.net/lad/grauph@15 a436a847-0d15-0410-975c-d299462d15a1

1 files changed, 100 insertions, 0 deletions

diff --git a/src/libs/engine/PluginLibrary.h b/src/libs/engine/PluginLibrary.h
new file mode 100644
index 00000000..53279d8a
--- /dev/null
+++ b/src/libs/engine/PluginLibrary.h
@@ -0,0 +1,100 @@
+/* This file is part of Om.  Copyright (C) 2006 Dave Robillard.
+ * 
+ * Om is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation; either version 2 of the License, or (at your option) any later
+ * version.
+ * 
+ * Om is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for details.
+ * 
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+
+#ifndef PLUGINLIBRARY_H
+#define PLUGINLIBRARY_H
+
+#include <dlfcn.h>
+#include <string>
+#include <iostream>
+using std::string;
+using std::cerr; using std::endl;
+
+
+namespace Om {
+
+
+/** Representation of a shared library containing at least one Plugin.
+ *
+ * In the NodeFactory, this represents one loaded shared library instance,
+ * which is what handle() returns.
+ */
+class PluginLibrary
+{
+public:
+	/** Construct a new PluginLibrary.
+	 *
+	 * Path is assumed to be the path of a valid shared library that can be
+	 * successfully dlopen'ed.
+	 */
+	PluginLibrary(const string& path)
+	: m_path(path), m_handle(NULL)
+	{}
+	
+	~PluginLibrary()
+	{
+		close();
+	}
+	
+	/** Load and resolve all symbols in this shared library
+	 * (dlopen with RTLD_NOW).
+	 *
+	 * It is okay to call this many times, the library will only be opened
+	 * once.
+	 */
+	void open()
+	{
+		if (m_handle == NULL) {
+			dlerror();
+			m_handle = dlopen(m_path.c_str(), RTLD_NOW);
+			if (m_handle == NULL)
+				cerr << "[PluginLibrary] Warning:  Error opening shared library "
+					<< m_path << "(" << dlerror() << ")" << endl;
+		}
+	}
+	
+	/** Close the dynamic library.
+	 *
+	 * This can be called on an already closed PluginLibrary without problems.
+	 */
+	void close()
+	{
+		if (m_handle != NULL) {
+			dlerror();
+			if (dlclose(m_handle))
+				cerr << "[PluginLibrary] Error closing shared library " << m_path
+					<< "(" << dlerror() << ")" << endl;
+		}
+		m_handle = NULL;
+	}
+
+	void* handle() const { return m_handle; }
+
+private:
+	// Disallow copies (undefined)
+	PluginLibrary(const PluginLibrary&);
+	PluginLibrary& operator=(const PluginLibrary&);
+	
+	string m_path;
+	void*  m_handle;
+};
+
+
+} // namespace Om
+
+#endif // PLUGINLIBRARY_H
+