From ca3a7cd64822e874076bd23e9981af077eb47b03 Mon Sep 17 00:00:00 2001
From: Alan Conway <aconway@apache.org>
Date: Fri, 13 Apr 2007 20:58:27 +0000
Subject: Moved src/ source code to src/qpid directory:  - allows rhm package
 to build consistently against checked-out or installed qpid.  - consistent
 correspondence between source paths and C++ namespaces.  - consistent use of
 #include <qpid/foo> in source and by users.  - allows header files to split
 over multiple directories,    e.g. separating generated code, separating
 public API from private files.

git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk/qpid@528668 13f79535-47bb-0310-9956-ffa450edef68
---
 cpp/src/qpid/sys/Module.h | 161 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 161 insertions(+)
 create mode 100644 cpp/src/qpid/sys/Module.h

(limited to 'cpp/src/qpid/sys/Module.h')

diff --git a/cpp/src/qpid/sys/Module.h b/cpp/src/qpid/sys/Module.h
new file mode 100644
index 0000000000..cb31018fdc
--- /dev/null
+++ b/cpp/src/qpid/sys/Module.h
@@ -0,0 +1,161 @@
+#ifndef _sys_Module_h
+#define _sys_Module_h
+
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+#include <boost/noncopyable.hpp>
+#include <iostream>
+#include "qpid/QpidError.h"
+
+namespace qpid {
+namespace sys {
+#if USE_APR
+#include <apr_dso.h>
+    typedef apr_dso_handle_t* dso_handle_t;
+#else 
+    typedef void* dso_handle_t;
+#endif
+
+    template <class T> class Module : private boost::noncopyable
+    {
+        typedef T* create_t();
+        typedef void destroy_t(T*);
+        
+        dso_handle_t handle;
+        destroy_t* destroy;
+        T* ptr;
+
+        void load(const std::string& name);
+        void unload();
+        void* getSymbol(const std::string& name);
+
+    public:
+        Module(const std::string& name);
+        T* operator->(); 
+        T* get(); 
+        ~Module() throw();
+    };
+
+}
+}
+
+using namespace qpid::sys;
+
+template <class T> Module<T>::Module(const std::string& module) : destroy(0), ptr(0) 
+{
+    load(module);
+    //TODO: need a better strategy for symbol names to allow multiple
+    //modules to be loaded without clashes...
+
+    //Note: need the double cast to avoid errors in casting from void* to function pointer with -pedantic
+    create_t* create = reinterpret_cast<create_t*>(reinterpret_cast<intptr_t>(getSymbol("create")));
+    destroy = reinterpret_cast<destroy_t*>(reinterpret_cast<intptr_t>(getSymbol("destroy")));
+    ptr = create();
+}
+
+template <class T> T* Module<T>::operator->() 
+{ 
+    return ptr; 
+}
+
+template <class T> T* Module<T>::get() 
+{ 
+    return ptr; 
+}
+
+template <class T> Module<T>::~Module() throw()
+{
+    try {
+        if (handle && ptr) {
+            destroy(ptr);
+        }
+        if (handle) unload();
+    } catch (std::exception& e) {
+        std::cout << "Error while destroying module: " << e.what() << std::endl;
+    }
+    destroy = 0;
+    handle = 0;
+    ptr = 0;
+}
+
+// APR ================================================================
+#if USE_APR
+
+#include "apr/APRBase.h"
+#include "apr/APRPool.h"
+
+template <class T> void Module<T>::load(const std::string& name)
+{
+    CHECK_APR_SUCCESS(apr_dso_load(&handle, name.c_str(), APRPool::get()));
+}
+
+template <class T> void Module<T>::unload()
+{
+    CHECK_APR_SUCCESS(apr_dso_unload(handle));
+}
+
+template <class T> void* Module<T>::getSymbol(const std::string& name)
+{
+    apr_dso_handle_sym_t symbol;
+    CHECK_APR_SUCCESS(apr_dso_sym(&symbol, handle, name.c_str()));
+    return (void*) symbol;
+}
+
+// POSIX================================================================
+#else 
+
+#include <dlfcn.h>
+
+template <class T> void Module<T>::load(const std::string& name)
+{
+    dlerror();
+    handle = dlopen(name.c_str(), RTLD_NOW);
+    const char* error = dlerror();
+    if (error) {
+        THROW_QPID_ERROR(INTERNAL_ERROR, error);
+    }
+}
+
+template <class T> void Module<T>::unload()
+{
+    dlerror();
+    dlclose(handle);
+    const char* error = dlerror();
+    if (error) {
+        THROW_QPID_ERROR(INTERNAL_ERROR, error);
+    }
+}
+
+template <class T> void* Module<T>::getSymbol(const std::string& name)
+{
+    dlerror();
+    void* sym = dlsym(handle, name.c_str());
+    const char* error = dlerror();
+    if (error) {
+        THROW_QPID_ERROR(INTERNAL_ERROR, error);
+    }
+    return sym;
+}
+
+#endif //if USE_APR
+
+#endif //ifndef _sys_Module_h
+
-- 
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