Add some options to control the shutdown sequence

jpype/_core.py

@@ -96,6 +96,10 @@ def decorate(func):
 
 
 def isJVMStarted():
+    """ This method is horribly named.  It should be named isJVMRunning as
+    isJVMStarted would seem to imply that the JVM was started at some 
+    point without regard to whether it has been shutdown.
+    """
     return _jpype.isStarted()
 
 
@@ -327,17 +331,25 @@ def shutdownJVM():
     restart the JVM after being terminated.
     """
     import threading
+    import jpype.config
     if threading.current_thread() is not threading.main_thread():
         raise RuntimeError("Shutdown must be called from main thread")
-    _jpype.shutdown()
+    if _jpype.isStarted():
+        _jpype.JPypeContext.freeResources = jpype.config.free_resources
+    _jpype.shutdown(jpype.config.destroy_jvm, jpype.config.free_jvm)
 
 
 # In order to shutdown cleanly we need the reference queue stopped
 # otherwise, we can experience a crash if a Java thread is waiting
 # for the GIL.
 def _JTerminate():
     try:
-        _jpype.shutdown()
+        import jpype.config
+        # We are exiting anyway so no need to free resources
+        if _jpype.isStarted():
+            _jpype.JPypeContext.freeResources = False
+        if jpype.config.onexit:
+            _jpype.shutdown(jpype.config.destroy_jvm, False)
     except RuntimeError:
         pass
 

jpype/config.py

@@ -0,0 +1,44 @@
+# *****************************************************************************
+#
+#   Licensed 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.
+#
+#   See NOTICE file for details.
+#
+# *****************************************************************************
+
+# This files holds hints used to control behavior of the JVM
+# It is global variables rather than options to a function so that
+# they can be set a module at any time rather than requiring arguments
+# for a function.
+#
+# These options are to be treated as hints which may or may not be supported
+# in future versions.  Setting an unsupported option shall have no effect.
+# Variables shall not be removed even if deprecated so that conditions
+# based on these will be valid in all future versions.
+#
+
+onexit = True
+"""If this is False, the JVM not will be notified of Python exit.  Java will not execute any
+resource cleanup routines."""
+
+destroy_jvm = True
+""" If this is False, the JVM will not execute any cleanup routines and memory will
+not be freed."""
+
+free_resources = True
+""" If this is False, the resources will be allowed to leak after the shutdown call.
+"""
+
+free_jvm = True
+""" If this is False, the shared library will not be unloaded which leaks memory.
+"""

native/common/include/jp_context.h

@@ -127,7 +127,7 @@ class JPContext
 			bool ignoreUnrecognized, bool convertStrings, bool interrupt);
 	void attachJVM(JNIEnv* env);
 	void initializeResources(JNIEnv* env, bool interrupt);
-	void shutdownJVM();
+	void shutdownJVM(bool destroyJVM, bool freeJVM);
 	void attachCurrentThread();
 	void attachCurrentThreadAsDaemon();
 	bool isThreadAttached();

native/common/jp_context.cpp

@@ -374,7 +374,7 @@ void JPContext::onShutdown()
 	m_Running = false;
 }
 
-void JPContext::shutdownJVM()
+void JPContext::shutdownJVM(bool destroyJVM, bool freeJVM)
 {
 	JP_TRACE_IN("JPContext::shutdown");
 	if (m_JavaVM == NULL)
@@ -383,12 +383,21 @@ void JPContext::shutdownJVM()
 	//		JP_RAISE(PyExc_RuntimeError, "Cannot shutdown from embedded Python");
 
 	// Wait for all non-demon threads to terminate
-	JP_TRACE("Destroy JVM");
+	if (destroyJVM)
 	{
+		JP_TRACE("Destroy JVM");
 		JPPyCallRelease call;
 		m_JavaVM->DestroyJavaVM();
 	}
 
+	// unload the jvm library
+	if (freeJVM)
+	{
+		JP_TRACE("Unload JVM");
+		m_JavaVM = NULL;
+		JPPlatformAdapter::getAdapter()->unloadLibrary();
+	}
+
 	JP_TRACE("Delete resources");
 	for (std::list<JPResource*>::iterator iter = m_Resources.begin();
 			iter != m_Resources.end(); ++iter)
@@ -397,10 +406,6 @@ void JPContext::shutdownJVM()
 	}
 	m_Resources.clear();
 
-	// unload the jvm library
-	JP_TRACE("Unload JVM");
-	m_JavaVM = NULL;
-	JPPlatformAdapter::getAdapter()->unloadLibrary();
 	JP_TRACE_OUT;
 }
 

native/java/org/jpype/JPypeContext.java

@@ -84,6 +84,7 @@ public class JPypeContext
   private final AtomicInteger shutdownFlag = new AtomicInteger();
   private final List<Thread> shutdownHooks = new ArrayList<>();
   private final List<Runnable> postHooks = new ArrayList<>();
+  public static boolean freeResources = true;
 
   static public JPypeContext getInstance()
   {
@@ -241,20 +242,23 @@ private void shutdown()
     {
     }
 
-    // Release all Python references
-    try
-    {
-      JPypeReferenceQueue.getInstance().stop();
-    } catch (Throwable th)
-    {
-    }
-
-    // Release any C++ resources
-    try
-    {
-      this.typeManager.shutdown();
-    } catch (Throwable th)
+    if (freeResources)
     {
+       // Release all Python references
+       try
+       {
+         JPypeReferenceQueue.getInstance().stop();
+       } catch (Throwable th)
+       {
+       }
+
+       // Release any C++ resources
+       try
+       {
+         this.typeManager.shutdown();
+       } catch (Throwable th)
+       {
+       }
     }
 
     // Execute post hooks

native/python/pyjp_module.cpp

@@ -277,10 +277,16 @@ static PyObject* PyJPModule_startup(PyObject* module, PyObject* pyargs)
 	JP_PY_CATCH(NULL);
 }
 
-static PyObject* PyJPModule_shutdown(PyObject* obj)
+static PyObject* PyJPModule_shutdown(PyObject* obj, PyObject* pyargs, PyObject* kwargs)
 {
 	JP_PY_TRY("PyJPModule_shutdown");
-	JPContext_global->shutdownJVM();
+	char destroyJVM = true;
+	char freeJVM = true;
+
+	if (!PyArg_ParseTuple(pyargs, "bb", &destroyJVM, &freeJVM))
+		return NULL;
+
+	JPContext_global->shutdownJVM(destroyJVM, freeJVM);
 	Py_RETURN_NONE;
 	JP_PY_CATCH(NULL);
 }
@@ -660,7 +666,7 @@ static PyMethodDef moduleMethods[] = {
 #else
 	{"startup", (PyCFunction) PyJPModule_startup, METH_VARARGS, ""},
 	//	{"attach", (PyCFunction) (&PyJPModule_attach), METH_VARARGS, ""},
-	{"shutdown", (PyCFunction) PyJPModule_shutdown, METH_NOARGS, ""},
+	{"shutdown", (PyCFunction) PyJPModule_shutdown, METH_VARARGS, ""},
 #endif
 	{"_getClass", (PyCFunction) PyJPModule_getClass, METH_O, ""},
 	{"_hasClass", (PyCFunction) PyJPModule_hasClass, METH_O, ""},