[Jogl|Nativewindow|Newt]Common: Align all *Common_GetJNIEnv()/_ReleaseJNIEnv() Methods and Usage / Check arguments ..

Since we still don't use inter-module native code sharing, align the JNIEnv get/release methods and usage.

Most beneficary here is OSX and the GLDebugMessageHandle,
both managed the JVM handle on their own - removed now.

Also ensuring that *Common_init(..) is called for all modules on all platforms.

17 files changed, 431 insertions, 458 deletions

diff --git a/src/jogl/native/GLContext.c b/src/jogl/native/GLContext.c
index f10d0e421..9be9f82af 100644
--- a/src/jogl/native/GLContext.c
+++ b/src/jogl/native/GLContext.c
@@ -19,7 +19,7 @@ Java_jogamp_opengl_GLContextImpl_glGetStringInt(JNIEnv *env, jclass _unused, jin
   assert(ptr_glGetString != NULL);
   _res = (* ptr_glGetString) ((unsigned int) name);
   if (NULL == _res) return NULL;
-  return (*env)->NewStringUTF(env, _res);
+  return (*env)->NewStringUTF(env, (const char *)_res);
 }
 
 /*
diff --git a/src/jogl/native/GLDebugMessageHandler.c b/src/jogl/native/GLDebugMessageHandler.c
index 2e9d6033a..0aa7a01e7 100644
--- a/src/jogl/native/GLDebugMessageHandler.c
+++ b/src/jogl/native/GLDebugMessageHandler.c
@@ -49,8 +49,6 @@ JNIEXPORT jboolean JNICALL Java_jogamp_opengl_GLDebugMessageHandler_initIDs0
 }
 
 typedef struct {
-    JavaVM *vm;
-    int version;
     jobject obj;
     int extType;
 } DebugHandlerType;
@@ -60,39 +58,21 @@ typedef struct {
 static void GLDebugMessageARBCallback(GLenum source, GLenum type, GLuint id, GLenum severity, 
                                       GLsizei length, const GLchar *message, GLvoid *userParam) {
     DebugHandlerType * handle = (DebugHandlerType*) (intptr_t) userParam;
-    JavaVM *vm = handle->vm;
-    int version = handle->version;
     jobject obj = handle->obj;
-    JNIEnv *curEnv = NULL;
-    JNIEnv *newEnv = NULL;
-    int envRes ;
-    DBG_PRINT("GLDebugMessageARBCallback: 00 - %s, vm %p, version 0x%X, jobject %p, extType %d\n", 
-        message, handle->vm, handle->version, (void*)handle->obj, handle->extType);
-
-    // retrieve this thread's JNIEnv curEnv - or detect it's detached
-    envRes = (*vm)->GetEnv(vm, (void **) &curEnv, version) ;
-    DBG_PRINT("GLDebugMessageARBCallback: 01 - JVM Env: curEnv %p, res 0x%X\n", curEnv, envRes);
-    if( JNI_EDETACHED == envRes ) {
-        // detached thread - attach to JVM
-        if( JNI_OK != ( envRes = (*vm)->AttachCurrentThread(vm, (void**) &newEnv, NULL) ) ) {
-            fprintf(stderr, "GLDebugMessageARBCallback: can't attach thread: %d\n", envRes);
-            return;
-        }
-        curEnv = newEnv;
-        DBG_PRINT("GLDebugMessageARBCallback: 02 - attached .. \n");
-    } else if( JNI_OK != envRes ) {
-        // oops ..
-        fprintf(stderr, "GLDebugMessageARBCallback: can't GetEnv: %d\n", envRes);
+    JNIEnv *env = NULL;
+    int shallBeDetached ;
+    DBG_PRINT("GLDebugMessageARBCallback: 00 - %s, jobject %p, extType %d\n", message, (void*)handle->obj, handle->extType);
+
+    env = JoglCommon_GetJNIEnv (1 /* asDaemon */, &shallBeDetached);
+    if( NULL == env ) {
+        DBG_PRINT("GLDebugMessageARBCallback: Null JNIEnv\n");
         return;
     }
-    (*curEnv)->CallVoidMethod(curEnv, obj, glDebugMessageARB, 
+    (*env)->CallVoidMethod(env, obj, glDebugMessageARB, 
                               (jint) source, (jint) type, (jint) id, (jint) severity, 
-                              (*curEnv)->NewStringUTF(curEnv, message));
-    if( NULL != newEnv ) {
-        // detached attached thread
-        (*vm)->DetachCurrentThread(vm);
-        DBG_PRINT("GLDebugMessageARBCallback: 04 - detached .. \n");
-    }
+                              (*env)->NewStringUTF(env, message));
+    // detaching thread not required - daemon
+    // JoglCommon_ReleaseJNIEnv(shallBeDetached);
     DBG_PRINT("GLDebugMessageARBCallback: 0X\n");
     /**
      * On Java 32bit on 64bit Windows and w/ GL_DEBUG_OUTPUT_SYNCHRONOUS_ARB disables,
@@ -104,39 +84,21 @@ static void GLDebugMessageARBCallback(GLenum source, GLenum type, GLuint id, GLe
 static void GLDebugMessageAMDCallback(GLuint id, GLenum category, GLenum severity, 
                                       GLsizei length, const GLchar *message, GLvoid *userParam) {
     DebugHandlerType * handle = (DebugHandlerType*) (intptr_t) userParam;
-    JavaVM *vm = handle->vm;
-    int version = handle->version;
     jobject obj = handle->obj;
-    JNIEnv *curEnv = NULL;
-    JNIEnv *newEnv = NULL;
-    int envRes ;
-    DBG_PRINT("GLDebugMessageAMDCallback: 00 - %s, vm %p, version 0x%X, jobject %p, extType %d\n", 
-        message, handle->vm, handle->version, (void*)handle->obj, handle->extType);
-
-    // retrieve this thread's JNIEnv curEnv - or detect it's detached
-    envRes = (*vm)->GetEnv(vm, (void **) &curEnv, version) ;
-    DBG_PRINT("GLDebugMessageAMDCallback: 01 - JVM Env: curEnv %p, res 0x%X\n", curEnv, envRes);
-    if( JNI_EDETACHED == envRes ) {
-        // detached thread - attach to JVM
-        if( JNI_OK != ( envRes = (*vm)->AttachCurrentThread(vm, (void**) &newEnv, NULL) ) ) {
-            fprintf(stderr, "GLDebugMessageAMDCallback: can't attach thread: %d\n", envRes);
-            return;
-        }
-        curEnv = newEnv;
-        DBG_PRINT("GLDebugMessageAMDCallback: 02 - attached .. \n");
-    } else if( JNI_OK != envRes ) {
-        // oops ..
-        fprintf(stderr, "GLDebugMessageAMDCallback: can't GetEnv: %d\n", envRes);
+    JNIEnv *env = NULL;
+    int shallBeDetached ;
+    DBG_PRINT("GLDebugMessageAMDCallback: 00 - %s, jobject %p, extType %d\n", message, (void*)handle->obj, handle->extType);
+
+    env = JoglCommon_GetJNIEnv (1 /* asDaemon */, &shallBeDetached);
+    if( NULL == env ) {
+        DBG_PRINT("GLDebugMessageARBCallback: Null JNIEnv\n");
         return;
     }
-    (*curEnv)->CallVoidMethod(curEnv, obj, glDebugMessageAMD, 
+    (*env)->CallVoidMethod(env, obj, glDebugMessageAMD, 
                               (jint) id, (jint) category, (jint) severity, 
-                              (*curEnv)->NewStringUTF(curEnv, message));
-    if( NULL != newEnv ) {
-        // detached attached thread
-        (*vm)->DetachCurrentThread(vm);
-        DBG_PRINT("GLDebugMessageAMDCallback: 04 - detached .. \n");
-    }
+                              (*env)->NewStringUTF(env, message));
+    // detached attached thread not required - daemon
+    // JoglCommon_ReleaseJNIEnv(shallBeDetached);
     DBG_PRINT("GLDebugMessageAMDCallback: 0X\n");
     /**
      * On Java 32bit on 64bit Windows,
@@ -153,18 +115,10 @@ static void GLDebugMessageAMDCallback(GLuint id, GLenum category, GLenum severit
 JNIEXPORT jlong JNICALL Java_jogamp_opengl_GLDebugMessageHandler_register0
   (JNIEnv *env, jobject obj, jlong procAddress, jint extType)
 {
-    JavaVM *vm;
     DebugHandlerType * handle = malloc(sizeof(DebugHandlerType));
-    if(0 != (*env)->GetJavaVM(env, &vm)) {
-        vm = NULL;
-        JoglCommon_throwNewRuntimeException(env, "GetJavaVM failed");
-    }
-    handle->vm = vm;
-    handle->version = (*env)->GetVersion(env);
     handle->obj = (*env)->NewGlobalRef(env, obj);
     handle->extType = extType;
-    DBG_PRINT("GLDebugMessageHandler.register0: vm %p, version 0x%X, jobject %p, extType %d\n", 
-        handle->vm, handle->version, (void*)handle->obj, handle->extType);
+    DBG_PRINT("GLDebugMessageHandler.register0: jobject %p, extType %d\n", (void*)handle->obj, handle->extType);
 
     if(jogamp_opengl_GLDebugMessageHandler_EXT_ARB == extType) {
         _local_PFNGLDEBUGMESSAGECALLBACKARBPROC ptr_glDebugMessageCallbackARB;
@@ -191,8 +145,7 @@ JNIEXPORT void JNICALL Java_jogamp_opengl_GLDebugMessageHandler_unregister0
 {
     DebugHandlerType * handle = (DebugHandlerType*) (intptr_t) jhandle;
 
-    DBG_PRINT("GLDebugMessageHandler.unregister0: vm %p, version 0x%X, jobject %p, extType %d\n", 
-        handle->vm, handle->version, (void*)handle->obj, handle->extType);
+    DBG_PRINT("GLDebugMessageHandler.unregister0: jobject %p, extType %d\n", (void*)handle->obj, handle->extType);
 
     if(JNI_FALSE == (*env)->IsSameObject(env, obj, handle->obj)) {
         JoglCommon_throwNewRuntimeException(env, "wrong handle (obj doesn't match)");
diff --git a/src/jogl/native/JoglCommon.c b/src/jogl/native/JoglCommon.c
index 4170b13ec..e9984ada2 100644
--- a/src/jogl/native/JoglCommon.c
+++ b/src/jogl/native/JoglCommon.c
@@ -11,42 +11,38 @@ static JavaVM *_jvmHandle = NULL;
 static int _jvmVersion = 0;
 
 void JoglCommon_init(JNIEnv *env) {
-    if(NULL==runtimeExceptionClz) {
+    if(NULL==_jvmHandle) {
+        if(0 != (*env)->GetJavaVM(env, &_jvmHandle)) {
+            JoglCommon_FatalError(env, "JOGL: Can't fetch JavaVM handle");
+        } else {
+            _jvmVersion = (*env)->GetVersion(env);
+        }
         jclass c = (*env)->FindClass(env, ClazzNameRuntimeException);
         if(NULL==c) {
-            JoglCommon_FatalError(env, "JOGL: can't find %s", ClazzNameRuntimeException);
+            JoglCommon_FatalError(env, "JOGL: Can't find %s", ClazzNameRuntimeException);
         }
         runtimeExceptionClz = (jclass)(*env)->NewGlobalRef(env, c);
         (*env)->DeleteLocalRef(env, c);
         if(NULL==runtimeExceptionClz) {
-            JoglCommon_FatalError(env, "JOGL: can't use %s", ClazzNameRuntimeException);
+            JoglCommon_FatalError(env, "JOGL: Can't use %s", ClazzNameRuntimeException);
         }
     }
-    if(0 != (*env)->GetJavaVM(env, &_jvmHandle)) {
-        JoglCommon_FatalError(env, "JOGL: can't fetch JavaVM handle");
-    } else {
-        _jvmVersion = (*env)->GetVersion(env);
-    }
 }
 
 void JoglCommon_FatalError(JNIEnv *env, const char* msg, ...)
 {
     char buffer[512];
     va_list ap;
-    int shallBeDetached = 0;
-
-    if(NULL == env) {
-        env = JoglCommon_GetJNIEnv (&shallBeDetached);
-    }
 
-    va_start(ap, msg);
-    vsnprintf(buffer, sizeof(buffer), msg, ap);
-    va_end(ap);
+    if( NULL != msg ) {
+        va_start(ap, msg);
+        vsnprintf(buffer, sizeof(buffer), msg, ap);
+        va_end(ap);
 
-    fprintf(stderr, "%s\n", buffer);
-    if(NULL != env) {
-        (*env)->FatalError(env, buffer);
-        JoglCommon_ReleaseJNIEnv (shallBeDetached);
+        fprintf(stderr, "%s\n", buffer);
+        if(NULL != env) {
+            (*env)->FatalError(env, buffer);
+        }
     }
 }
 
@@ -54,48 +50,42 @@ void JoglCommon_throwNewRuntimeException(JNIEnv *env, const char* msg, ...)
 {
     char buffer[512];
     va_list ap;
-    int shallBeDetached = 0;
 
-    if(NULL == env) {
-        env = JoglCommon_GetJNIEnv (&shallBeDetached);
+    if(NULL==_jvmHandle) {
+        JoglCommon_FatalError(env, "JOGL: NULL JVM handle, call JoglCommon_init 1st\n");
+        return;
     }
 
-    va_start(ap, msg);
-    vsnprintf(buffer, sizeof(buffer), msg, ap);
-    va_end(ap);
+    if( NULL != msg ) {
+        va_start(ap, msg);
+        vsnprintf(buffer, sizeof(buffer), msg, ap);
+        va_end(ap);
 
-    if(NULL != env) {
-        (*env)->ThrowNew(env, runtimeExceptionClz, buffer);
-        JoglCommon_ReleaseJNIEnv (shallBeDetached);
+        if(NULL != env) {
+            (*env)->ThrowNew(env, runtimeExceptionClz, buffer);
+        }
     }
 }
 
-JavaVM *JoglCommon_GetJVMHandle() {
-    return _jvmHandle;
-}
-
-int JoglCommon_GetJVMVersion() {
-    return _jvmVersion;
-}
-
 jchar* JoglCommon_GetNullTerminatedStringChars(JNIEnv* env, jstring str)
 {
     jchar* strChars = NULL;
-    strChars = calloc((*env)->GetStringLength(env, str) + 1, sizeof(jchar));
-    if (strChars != NULL) {
-        (*env)->GetStringRegion(env, str, 0, (*env)->GetStringLength(env, str), strChars);
+    if( NULL != env && 0 != str ) {
+        strChars = calloc((*env)->GetStringLength(env, str) + 1, sizeof(jchar));
+        if (strChars != NULL) {
+            (*env)->GetStringRegion(env, str, 0, (*env)->GetStringLength(env, str), strChars);
+        }
     }
     return strChars;
 }
 
-JNIEnv* JoglCommon_GetJNIEnv (int * shallBeDetached)
-{
+JNIEnv* JoglCommon_GetJNIEnv (int asDaemon, int * shallBeDetached) {
     JNIEnv* curEnv = NULL;
     JNIEnv* newEnv = NULL;
     int envRes;
 
-    if(NULL == _jvmHandle) {
-        fprintf(stderr, "JOGL: No JavaVM handle registered, call JoglCommon_init(..) 1st");
+    if(NULL==_jvmHandle) {
+        fprintf(stderr, "JOGL GetJNIEnv: NULL JVM handle, call JoglCommon_init 1st\n");
         return NULL;
     }
 
@@ -103,18 +93,23 @@ JNIEnv* JoglCommon_GetJNIEnv (int * shallBeDetached)
     envRes = (*_jvmHandle)->GetEnv(_jvmHandle, (void **) &curEnv, _jvmVersion) ;
     if( JNI_EDETACHED == envRes ) {
         // detached thread - attach to JVM
-        if( JNI_OK != ( envRes = (*_jvmHandle)->AttachCurrentThread(_jvmHandle, (void**) &newEnv, NULL) ) ) {
-            fprintf(stderr, "JNIEnv: can't attach thread: %d\n", envRes);
+        if( asDaemon ) {
+            envRes = (*_jvmHandle)->AttachCurrentThreadAsDaemon(_jvmHandle, (void**) &newEnv, NULL);
+        } else {
+            envRes = (*_jvmHandle)->AttachCurrentThread(_jvmHandle, (void**) &newEnv, NULL);
+        }
+        if( JNI_OK != envRes ) {
+            fprintf(stderr, "JOGL GetJNIEnv: Can't attach thread: %d\n", envRes);
             return NULL;
         }
         curEnv = newEnv;
     } else if( JNI_OK != envRes ) {
         // oops ..
-        fprintf(stderr, "can't GetEnv: %d\n", envRes);
+        fprintf(stderr, "JOGL GetJNIEnv: Can't GetEnv: %d\n", envRes);
         return NULL;
     }
     if (curEnv==NULL) {
-        fprintf(stderr, "env is NULL\n");
+        fprintf(stderr, "JOGL GetJNIEnv: env is NULL\n");
         return NULL;
     }
     *shallBeDetached = NULL != newEnv;
@@ -123,10 +118,8 @@ JNIEnv* JoglCommon_GetJNIEnv (int * shallBeDetached)
 
 void JoglCommon_ReleaseJNIEnv (int shallBeDetached) {
     if(NULL == _jvmHandle) {
-        fprintf(stderr, "JOGL: No JavaVM handle registered, call JoglCommon_init(..) 1st");
-    }
-
-    if(shallBeDetached) {
+        fprintf(stderr, "JOGL ReleaseJNIEnv: No JavaVM handle registered, call JoglCommon_init(..) 1st");
+    } else if(shallBeDetached) {
         (*_jvmHandle)->DetachCurrentThread(_jvmHandle);
     }
 }
diff --git a/src/jogl/native/JoglCommon.h b/src/jogl/native/JoglCommon.h
index 023b4be03..2aeaf7d1d 100644
--- a/src/jogl/native/JoglCommon.h
+++ b/src/jogl/native/JoglCommon.h
@@ -1,3 +1,30 @@
+/**
+ * Copyright 2011 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ * 
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ * 
+ *    2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *       of conditions and the following disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
+ */
 
 #ifndef JOGL_COMMON_H
 #define JOGL_COMMON_H 1
@@ -7,29 +34,25 @@
 
 void JoglCommon_init(JNIEnv *env);
 
-/** Set by JoglCommon_init */
-JavaVM *JoglCommon_GetJVMHandle();
-
-/** Set by JoglCommon_init */
-int JoglCommon_GetJVMVersion();
-
 jchar* JoglCommon_GetNullTerminatedStringChars(JNIEnv* env, jstring str);
 
-/** env may be NULL, in which case JoglCommon_GetJNIEnv() is being used. */
 void JoglCommon_FatalError(JNIEnv *env, const char* msg, ...);
-
-/** env may be NULL, in which case JoglCommon_GetJNIEnv() is being used. */
 void JoglCommon_throwNewRuntimeException(JNIEnv *env, const char* msg, ...);
 
 /**
  *
- * 1) Store jvmHandle and jvmVersion is done by 'JoglCommon_init(JNIEnv*)'
- *    and internally used by 'JoglCommon_GetJNIEnv(..)' and 'JoglCommon_ReleaseJNIEnv(..)'.
+ * 1) Init static jvmHandle, jvmVersion and clazz references
+ *    from an early initialization call w/ valid 'JNIEnv * env'
+
+    JoglCommon_init(env);
+
  *
  * 2) Use current thread JNIEnv or attach current thread to JVM, generating new JNIEnv
  *
+
+    int asDaemon = 0;
     int shallBeDetached = 0;
-    JNIEnv* env = NewtCommon_GetJNIEnv(&shallBeDetached);
+    JNIEnv* env = JoglCommon_GetJNIEnv(asDaemon, &shallBeDetached);
     if(NULL==env) {
         DBG_PRINT("drawRect: null JNIEnv\n");
         return;
@@ -41,11 +64,13 @@ void JoglCommon_throwNewRuntimeException(JNIEnv *env, const char* msg, ...);
     .. your JNIEnv code here ..
 
  *
- * 4) Detach thread from JVM, if required
+ * 4) Detach thread from JVM if required, i.e. not attached as daemon!
+ *    Not recommended for recurring _daemon_ threads (performance)
  *
-    JoglCommon_ReleaseJNIEnv (shallBeDetached);
+    JoglCommon_ReleaseJNIEnv(shallBeDetached);
  */
-JNIEnv* JoglCommon_GetJNIEnv (int * shallBeDetached);
+JNIEnv* JoglCommon_GetJNIEnv (int asDaemon, int * shallBeDetached);
+
 void JoglCommon_ReleaseJNIEnv (int shallBeDetached);
 
 #endif
diff --git a/src/jogl/native/libav/ffmpeg_impl_template.c b/src/jogl/native/libav/ffmpeg_impl_template.c
index 44acfe46a..e86b2a542 100644
--- a/src/jogl/native/libav/ffmpeg_impl_template.c
+++ b/src/jogl/native/libav/ffmpeg_impl_template.c
@@ -1499,7 +1499,7 @@ JNIEXPORT jint JNICALL FF_FUNC(seek0)
     int64_t pts1 = (int64_t) (pos1 * (int64_t) time_base.den)
                            / (1000 * (int64_t) time_base.num);
     if(pAV->verbose) {
-        fprintf(stderr, "SEEK: vid %d, aid %d, pos0 %d, pos1 %d, pts: %"PRId64" -> %"PRId64"\n", pAV->vid, pAV->aid, pos0, pos1, pts0, pts1);
+        fprintf(stderr, "SEEK: vid %d, aid %d, pos0 %"PRId64", pos1 %d, pts: %"PRId64" -> %"PRId64"\n", pAV->vid, pAV->aid, pos0, pos1, pts0, pts1);
     }
     int flags = 0;
     if(pos1 < pos0) {
@@ -1508,7 +1508,7 @@ JNIEXPORT jint JNICALL FF_FUNC(seek0)
     int res = -2;
     if(HAS_FUNC(sp_av_seek_frame)) {
         if(pAV->verbose) {
-            fprintf(stderr, "SEEK.0: pre  : s %d / %"PRId64" -> t %d / %"PRId64"\n", pos0, pts0, pos1, pts1);
+            fprintf(stderr, "SEEK.0: pre  : s %"PRId64" / %"PRId64" -> t %d / %"PRId64"\n", pos0, pts0, pos1, pts1);
         }
         sp_av_seek_frame(pAV->pFormatCtx, streamID, pts1, flags);
     } else if(HAS_FUNC(sp_avformat_seek_file)) {
diff --git a/src/jogl/native/macosx/MacOSXWindowSystemInterface-calayer.m b/src/jogl/native/macosx/MacOSXWindowSystemInterface-calayer.m
index 75917d2dc..7ce8c58cf 100644
--- a/src/jogl/native/macosx/MacOSXWindowSystemInterface-calayer.m
+++ b/src/jogl/native/macosx/MacOSXWindowSystemInterface-calayer.m
@@ -578,6 +578,7 @@ static const GLfloat gl_verts[] = {
         quirks, dedicatedFramePosSet, dedicatedFrameSizeSet, dedicatedLayoutSet, self, texWidth, texHeight,
         lRect.origin.x, lRect.origin.y, lRect.size.width, lRect.size.height,
         dFrame.origin.x, dFrame.origin.y, dFrame.size.width, dFrame.size.height);
+    (void)lRect; // silence
     
     if( dedicatedFrameSet ) {
         [super setFrame: dedicatedFrame];
diff --git a/src/jogl/native/openmax/jogamp_opengl_util_av_impl_OMXGLMediaPlayer.c b/src/jogl/native/openmax/jogamp_opengl_util_av_impl_OMXGLMediaPlayer.c
index ec68a24aa..3166306ba 100644
--- a/src/jogl/native/openmax/jogamp_opengl_util_av_impl_OMXGLMediaPlayer.c
+++ b/src/jogl/native/openmax/jogamp_opengl_util_av_impl_OMXGLMediaPlayer.c
@@ -67,7 +67,7 @@ void OMXInstance_UpdateJavaAttributes(OMXToolBasicAV_t *pAV)
         return;
     }
     int shallBeDetached = 0;
-    JNIEnv  * env = JoglCommon_GetJNIEnv (&shallBeDetached); 
+    JNIEnv  * env = JoglCommon_GetJNIEnv (1 /* daemon */, &shallBeDetached); 
     if(NULL!=env) {
         (*env)->CallVoidMethod(env, (jobject)pAV->jni_instance, jni_mid_updateAttributes,
                                pAV->width, pAV->height, 
@@ -75,7 +75,8 @@ void OMXInstance_UpdateJavaAttributes(OMXToolBasicAV_t *pAV)
                                pAV->framerate, (uint32_t)(pAV->length*pAV->framerate), pAV->length,
                                (*env)->NewStringUTF(env, pAV->videoCodec),
                                (*env)->NewStringUTF(env, pAV->audioCodec) );
-        JoglCommon_ReleaseJNIEnv (shallBeDetached);
+        // detaching thread not required - daemon
+        // JoglCommon_ReleaseJNIEnv(shallBeDetached);
     }
 }
 
diff --git a/src/nativewindow/native/NativewindowCommon.c b/src/nativewindow/native/NativewindowCommon.c
index ec7ee7728..e65f87272 100644
--- a/src/nativewindow/native/NativewindowCommon.c
+++ b/src/nativewindow/native/NativewindowCommon.c
@@ -8,41 +8,24 @@
 static const char * const ClazzNameRuntimeException = "java/lang/RuntimeException";
 static jclass    runtimeExceptionClz=NULL;
 
-void NativewindowCommon_FatalError(JNIEnv *env, const char* msg, ...)
-{
-    char buffer[512];
-    va_list ap;
-
-    va_start(ap, msg);
-    vsnprintf(buffer, sizeof(buffer), msg, ap);
-    va_end(ap);
-
-    fprintf(stderr, "%s\n", buffer);
-    (*env)->FatalError(env, buffer);
-}
-
-void NativewindowCommon_throwNewRuntimeException(JNIEnv *env, const char* msg, ...)
-{
-    char buffer[512];
-    va_list ap;
-
-    va_start(ap, msg);
-    vsnprintf(buffer, sizeof(buffer), msg, ap);
-    va_end(ap);
-
-    (*env)->ThrowNew(env, runtimeExceptionClz, buffer);
-}
+static JavaVM *_jvmHandle = NULL;
+static int _jvmVersion = 0;
 
 int NativewindowCommon_init(JNIEnv *env) {
-    if(NULL==runtimeExceptionClz) {
+    if(NULL==_jvmHandle) {
+        if(0 != (*env)->GetJavaVM(env, &_jvmHandle)) {
+            NativewindowCommon_FatalError(env, "Nativewindow: Can't fetch JavaVM handle");
+        } else {
+            _jvmVersion = (*env)->GetVersion(env);
+        }
         jclass c = (*env)->FindClass(env, ClazzNameRuntimeException);
         if(NULL==c) {
-            NativewindowCommon_FatalError(env, "Nativewindow: can't find %s", ClazzNameRuntimeException);
+            NativewindowCommon_FatalError(env, "Nativewindow: Can't find %s", ClazzNameRuntimeException);
         }
         runtimeExceptionClz = (jclass)(*env)->NewGlobalRef(env, c);
         (*env)->DeleteLocalRef(env, c);
         if(NULL==runtimeExceptionClz) {
-            NativewindowCommon_FatalError(env, "Nativewindow: can't use %s", ClazzNameRuntimeException);
+            NativewindowCommon_FatalError(env, "Nativewindow: Can't use %s", ClazzNameRuntimeException);
         }
         #ifdef STDERR_TO_FILE
             FILE * old_stderr = stderr; 
@@ -54,6 +37,44 @@ int NativewindowCommon_init(JNIEnv *env) {
     return 0;
 }
 
+void NativewindowCommon_FatalError(JNIEnv *env, const char* msg, ...)
+{
+    char buffer[512];
+    va_list ap;
+
+    if( NULL != msg ) {
+        va_start(ap, msg);
+        vsnprintf(buffer, sizeof(buffer), msg, ap);
+        va_end(ap);
+
+        fprintf(stderr, "%s\n", buffer);
+        if(NULL != env) {
+            (*env)->FatalError(env, buffer);
+        }
+    }
+}
+
+void NativewindowCommon_throwNewRuntimeException(JNIEnv *env, const char* msg, ...)
+{
+    char buffer[512];
+    va_list ap;
+
+    if(NULL==_jvmHandle) {
+        NativewindowCommon_FatalError(env, "Nativewindow: NULL JVM handle, call NativewindowCommon_init 1st\n");
+        return;
+    }
+
+    if( NULL != msg ) {
+        va_start(ap, msg);
+        vsnprintf(buffer, sizeof(buffer), msg, ap);
+        va_end(ap);
+
+        if(NULL != env) {
+            (*env)->ThrowNew(env, runtimeExceptionClz, buffer);
+        }
+    }
+}
+
 const char * NativewindowCommon_GetStaticStringMethod(JNIEnv *jniEnv, jclass clazz, jmethodID jGetStrID, char *dest, int destSize, const char *altText) {
     if(NULL != jniEnv && NULL != clazz && NULL != jGetStrID) {
         jstring jstr = (jstring) (*jniEnv)->CallStaticObjectMethod(jniEnv, clazz, jGetStrID);
@@ -75,45 +96,60 @@ const char * NativewindowCommon_GetStaticStringMethod(JNIEnv *jniEnv, jclass cla
 jchar* NativewindowCommon_GetNullTerminatedStringChars(JNIEnv* env, jstring str)
 {
     jchar* strChars = NULL;
-    strChars = calloc((*env)->GetStringLength(env, str) + 1, sizeof(jchar));
-    if (strChars != NULL) {
-        (*env)->GetStringRegion(env, str, 0, (*env)->GetStringLength(env, str), strChars);
+    if( NULL != env && 0 != str ) {
+        strChars = calloc((*env)->GetStringLength(env, str) + 1, sizeof(jchar));
+        if (strChars != NULL) {
+            (*env)->GetStringRegion(env, str, 0, (*env)->GetStringLength(env, str), strChars);
+        }
     }
     return strChars;
 }
 
-JNIEnv* NativewindowCommon_GetJNIEnv (JavaVM * jvmHandle, int jvmVersion, int asDaemon, int * shallBeDetached) {
+JNIEnv* NativewindowCommon_GetJNIEnv (int asDaemon, int * shallBeDetached) {
     JNIEnv* curEnv = NULL;
     JNIEnv* newEnv = NULL;
     int envRes;
 
+    if(NULL==_jvmHandle) {
+        fprintf(stderr, "Nativewindow GetJNIEnv: NULL JVM handle, call NativewindowCommon_init 1st\n");
+        return NULL;
+    }
+
     // retrieve this thread's JNIEnv curEnv - or detect it's detached
-    envRes = (*jvmHandle)->GetEnv(jvmHandle, (void **) &curEnv, jvmVersion) ;
+    envRes = (*_jvmHandle)->GetEnv(_jvmHandle, (void **) &curEnv, _jvmVersion) ;
     if( JNI_EDETACHED == envRes ) {
         // detached thread - attach to JVM
         if( asDaemon ) {
-            envRes = (*jvmHandle)->AttachCurrentThreadAsDaemon(jvmHandle, (void**) &newEnv, NULL);
+            envRes = (*_jvmHandle)->AttachCurrentThreadAsDaemon(_jvmHandle, (void**) &newEnv, NULL);
         } else {
-            envRes = (*jvmHandle)->AttachCurrentThread(jvmHandle, (void**) &newEnv, NULL);
+            envRes = (*_jvmHandle)->AttachCurrentThread(_jvmHandle, (void**) &newEnv, NULL);
         }
         if( JNI_OK != envRes ) {
-            fprintf(stderr, "JNIEnv: can't attach thread: %d\n", envRes);
+            fprintf(stderr, "Nativewindow GetJNIEnv: Can't attach thread: %d\n", envRes);
             return NULL;
         }
         curEnv = newEnv;
     } else if( JNI_OK != envRes ) {
         // oops ..
-        fprintf(stderr, "can't GetEnv: %d\n", envRes);
+        fprintf(stderr, "Nativewindow GetJNIEnv: Can't GetEnv: %d\n", envRes);
         return NULL;
     }
     if (curEnv==NULL) {
-        fprintf(stderr, "env is NULL\n");
+        fprintf(stderr, "Nativewindow GetJNIEnv: env is NULL\n");
         return NULL;
     }
     *shallBeDetached = NULL != newEnv;
     return curEnv;
 }
 
+void NativewindowCommon_ReleaseJNIEnv (int shallBeDetached) {
+    if(NULL == _jvmHandle) {
+        fprintf(stderr, "Nativewindow ReleaseJNIEnv: No JavaVM handle registered, call NativewindowCommon_init(..) 1st");
+    } else if(shallBeDetached) {
+        (*_jvmHandle)->DetachCurrentThread(_jvmHandle);
+    }
+}
+
 int64_t NativewindowCommon_CurrentTimeMillis() {
     struct timeval tv;
     gettimeofday(&tv,NULL);
diff --git a/src/nativewindow/native/NativewindowCommon.h b/src/nativewindow/native/NativewindowCommon.h
index a23fad9fd..f19552e33 100644
--- a/src/nativewindow/native/NativewindowCommon.h
+++ b/src/nativewindow/native/NativewindowCommon.h
@@ -1,3 +1,30 @@
+/**
+ * Copyright 2011 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ * 
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ * 
+ *    2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *       of conditions and the following disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ * 
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
+ */
 
 #ifndef NATIVEWINDOW_COMMON_H
 #define NATIVEWINDOW_COMMON_H 1
@@ -14,7 +41,39 @@ jchar* NativewindowCommon_GetNullTerminatedStringChars(JNIEnv* env, jstring str)
 void NativewindowCommon_FatalError(JNIEnv *env, const char* msg, ...);
 void NativewindowCommon_throwNewRuntimeException(JNIEnv *env, const char* msg, ...);
 
-JNIEnv* NativewindowCommon_GetJNIEnv (JavaVM * jvmHandle, int jvmVersion, int asDaemon, int * shallBeDetached);
+/**
+ *
+ * 1) Init static jvmHandle, jvmVersion and clazz references
+ *    from an early initialization call w/ valid 'JNIEnv * env'
+
+    NativewindowCommon_init(env);
+
+ *
+ * 2) Use current thread JNIEnv or attach current thread to JVM, generating new JNIEnv
+ *
+
+    int asDaemon = 0;
+    int shallBeDetached = 0;
+    JNIEnv* env = NewtCommon_GetJNIEnv(asDaemon, &shallBeDetached);
+    if(NULL==env) {
+        DBG_PRINT("drawRect: null JNIEnv\n");
+        return;
+    }
+    
+ *
+ * 3) Use JNIEnv ..
+ *
+    .. your JNIEnv code here ..
+
+ *
+ * 4) Detach thread from JVM if required, i.e. not attached as daemon!
+ *    Not recommended for recurring _daemon_ threads (performance)
+ *
+    NewtCommon_ReleaseJNIEnv(shallBeDetached);
+ */
+JNIEnv* NativewindowCommon_GetJNIEnv (int asDaemon, int * shallBeDetached);
+
+void NativewindowCommon_ReleaseJNIEnv (int shallBeDetached);
 
 int64_t NativewindowCommon_CurrentTimeMillis();
 
diff --git a/src/nativewindow/native/macosx/OSXmisc.m b/src/nativewindow/native/macosx/OSXmisc.m
index 6a7952eaf..4887cc3cf 100644
--- a/src/nativewindow/native/macosx/OSXmisc.m
+++ b/src/nativewindow/native/macosx/OSXmisc.m
@@ -75,11 +75,9 @@ static const char * const ClazzNameInsetsCstrSignature = "(IIII)V";
 static jclass insetsClz = NULL;
 static jmethodID insetsCstr = NULL;
 
-static int _initialized=0;
-
 JNIEXPORT jboolean JNICALL 
 Java_jogamp_nativewindow_macosx_OSXUtil_initIDs0(JNIEnv *env, jclass _unused) {
-    if(0==_initialized) {
+    if( NativewindowCommon_init(env) ) {
         jclass c;
         c = (*env)->FindClass(env, ClazzNamePoint);
         if(NULL==c) {
@@ -119,7 +117,6 @@ Java_jogamp_nativewindow_macosx_OSXUtil_initIDs0(JNIEnv *env, jclass _unused) {
         if(NULL==runnableRunID) {
             NativewindowCommon_FatalError(env, "FatalError Java_jogamp_newt_driver_macosx_MacWindow_initIDs0: can't fetch %s.run()V", ClazzNameRunnable);
         }
-        _initialized=1;
     }
     return JNI_TRUE;
 }
@@ -775,12 +772,10 @@ JNIEXPORT void JNICALL Java_jogamp_nativewindow_jawt_macosx_MacOSXJAWTWindow_Uns
 @interface MainRunnable : NSObject
 
 {
-    JavaVM *jvmHandle;
-    int jvmVersion;
     jobject runnableObj;
 }
 
-- (id) initWithRunnable: (jobject)runnable jvmHandle: (JavaVM*)jvm jvmVersion: (int)jvmVers;
+- (id) initWithRunnable: (jobject)runnable;
 - (void) jRun;
 
 #ifdef DBG_LIFECYCLE
@@ -794,10 +789,8 @@ JNIEXPORT void JNICALL Java_jogamp_nativewindow_jawt_macosx_MacOSXJAWTWindow_Uns
 
 @implementation MainRunnable
 
-- (id) initWithRunnable: (jobject)runnable jvmHandle: (JavaVM*)jvm jvmVersion: (int)jvmVers
+- (id) initWithRunnable: (jobject)runnable
 {
-    jvmHandle = jvm;
-    jvmVersion = jvmVers;
     runnableObj = runnable;
     return [super init];
 }
@@ -805,7 +798,7 @@ JNIEXPORT void JNICALL Java_jogamp_nativewindow_jawt_macosx_MacOSXJAWTWindow_Uns
 - (void) jRun
 {
     int shallBeDetached = 0;
-    JNIEnv* env = NativewindowCommon_GetJNIEnv(jvmHandle, jvmVersion, 1 /* asDaemon */, &shallBeDetached);
+    JNIEnv* env = NativewindowCommon_GetJNIEnv(1 /* asDaemon */, &shallBeDetached);
     DBG_PRINT2("MainRunnable.1 env: %d\n", (int)(NULL!=env));
     if(NULL!=env) {
         DBG_PRINT2("MainRunnable.1.0\n");
@@ -813,11 +806,9 @@ JNIEXPORT void JNICALL Java_jogamp_nativewindow_jawt_macosx_MacOSXJAWTWindow_Uns
         DBG_PRINT2("MainRunnable.1.1\n");
         (*env)->DeleteGlobalRef(env, runnableObj);
 
-        if (shallBeDetached) {
-            DBG_PRINT2("MainRunnable.1.3\n");
-            // Keep attached on main thread !
-            // (*jvmHandle)->DetachCurrentThread(jvmHandle);
-        }
+        DBG_PRINT2("MainRunnable.1.3\n");
+        // detaching thread not required - daemon
+        // NativewindowCommon_ReleaseJNIEnv(shallBeDetached);
     }
     DBG_PRINT2("MainRunnable.X\n");
 }
@@ -861,17 +852,8 @@ static void RunOnThread (JNIEnv *env, jobject runnable, BOOL onMain, jint delayI
     if ( forkOnMain ) {
         jobject runnableObj = (*env)->NewGlobalRef(env, runnable);
 
-        JavaVM *jvmHandle = NULL;
-        int jvmVersion = 0;
-
-        if(0 != (*env)->GetJavaVM(env, &jvmHandle)) {
-            jvmHandle = NULL;
-        } else {
-            jvmVersion = (*env)->GetVersion(env);
-        }
-
         DBG_PRINT2( "RunOnThread.1.0\n");
-        MainRunnable * mr = [[MainRunnable alloc] initWithRunnable: runnableObj jvmHandle: jvmHandle jvmVersion: jvmVersion];
+        MainRunnable * mr = [[MainRunnable alloc] initWithRunnable: runnableObj];
 
         if( onMain ) {
             [mr performSelectorOnMainThread:@selector(jRun) withObject:nil waitUntilDone:NO];
diff --git a/src/nativewindow/native/win32/GDImisc.c b/src/nativewindow/native/win32/GDImisc.c
index e28f68e7d..bec1d4922 100644
--- a/src/nativewindow/native/win32/GDImisc.c
+++ b/src/nativewindow/native/win32/GDImisc.c
@@ -487,7 +487,7 @@ JNIEXPORT jboolean JNICALL Java_jogamp_nativewindow_windows_GDIUtil_DestroyWindo
 JNIEXPORT jboolean JNICALL Java_jogamp_nativewindow_windows_GDIUtil_initIDs0
   (JNIEnv *env, jclass gdiClazz)
 {
-    if(NativewindowCommon_init(env)) {
+    if( NativewindowCommon_init(env) ) {
         jclass c = (*env)->FindClass(env, ClazzNamePoint);
         if(NULL==c) {
             NativewindowCommon_FatalError(env, "FatalError jogamp_nativewindow_windows_GDIUtil: can't find %s", ClazzNamePoint);
diff --git a/src/nativewindow/native/x11/Xmisc.c b/src/nativewindow/native/x11/Xmisc.c
index 5e6909f6e..247dc1311 100644
--- a/src/nativewindow/native/x11/Xmisc.c
+++ b/src/nativewindow/native/x11/Xmisc.c
@@ -113,68 +113,56 @@ static jmethodID pointCstr = NULL;
 static void _initClazzAccess(JNIEnv *env) {
     jclass c;
 
-    if(!NativewindowCommon_init(env)) return;
-
-    getCurrentThreadNameID = (*env)->GetStaticMethodID(env, X11UtilClazz, "getCurrentThreadName", "()Ljava/lang/String;");
-    if(NULL==getCurrentThreadNameID) {
-        NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't get method getCurrentThreadName");
-    }
-    dumpStackID = (*env)->GetStaticMethodID(env, X11UtilClazz, "dumpStack", "()V");
-    if(NULL==dumpStackID) {
-        NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't get method dumpStack");
-    }
-
-    c = (*env)->FindClass(env, ClazzNameBuffers);
-    if(NULL==c) {
-        NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't find %s", ClazzNameBuffers);
-    }
-    clazzBuffers = (jclass)(*env)->NewGlobalRef(env, c);
-    (*env)->DeleteLocalRef(env, c);
-    if(NULL==clazzBuffers) {
-        NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't use %s", ClazzNameBuffers);
-    }
-    c = (*env)->FindClass(env, ClazzNameByteBuffer);
-    if(NULL==c) {
-        NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't find %s", ClazzNameByteBuffer);
-    }
-    clazzByteBuffer = (jclass)(*env)->NewGlobalRef(env, c);
-    (*env)->DeleteLocalRef(env, c);
-    if(NULL==c) {
-        NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't use %s", ClazzNameByteBuffer);
-    }
-
-    cstrBuffers = (*env)->GetStaticMethodID(env, clazzBuffers, 
-                            ClazzNameBuffersStaticCstrName, ClazzNameBuffersStaticCstrSignature);
-    if(NULL==cstrBuffers) {
-        NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't create %s.%s %s",
-            ClazzNameBuffers, ClazzNameBuffersStaticCstrName, ClazzNameBuffersStaticCstrSignature);
-    }
+    if( NativewindowCommon_init(env) ) {
+        getCurrentThreadNameID = (*env)->GetStaticMethodID(env, X11UtilClazz, "getCurrentThreadName", "()Ljava/lang/String;");
+        if(NULL==getCurrentThreadNameID) {
+            NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't get method getCurrentThreadName");
+        }
+        dumpStackID = (*env)->GetStaticMethodID(env, X11UtilClazz, "dumpStack", "()V");
+        if(NULL==dumpStackID) {
+            NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't get method dumpStack");
+        }
 
-    c = (*env)->FindClass(env, ClazzNamePoint);
-    if(NULL==c) {
-        NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't find %s", ClazzNamePoint);
-    }
-    pointClz = (jclass)(*env)->NewGlobalRef(env, c);
-    (*env)->DeleteLocalRef(env, c);
-    if(NULL==pointClz) {
-        NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't use %s", ClazzNamePoint);
-    }
-    pointCstr = (*env)->GetMethodID(env, pointClz, ClazzAnyCstrName, ClazzNamePointCstrSignature);
-    if(NULL==pointCstr) {
-        NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't fetch %s.%s %s",
-            ClazzNamePoint, ClazzAnyCstrName, ClazzNamePointCstrSignature);
-    }
-}
+        c = (*env)->FindClass(env, ClazzNameBuffers);
+        if(NULL==c) {
+            NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't find %s", ClazzNameBuffers);
+        }
+        clazzBuffers = (jclass)(*env)->NewGlobalRef(env, c);
+        (*env)->DeleteLocalRef(env, c);
+        if(NULL==clazzBuffers) {
+            NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't use %s", ClazzNameBuffers);
+        }
+        c = (*env)->FindClass(env, ClazzNameByteBuffer);
+        if(NULL==c) {
+            NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't find %s", ClazzNameByteBuffer);
+        }
+        clazzByteBuffer = (jclass)(*env)->NewGlobalRef(env, c);
+        (*env)->DeleteLocalRef(env, c);
+        if(NULL==c) {
+            NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't use %s", ClazzNameByteBuffer);
+        }
 
-static JavaVM *jvmHandle = NULL;
-static int jvmVersion = 0;
+        cstrBuffers = (*env)->GetStaticMethodID(env, clazzBuffers, 
+                                ClazzNameBuffersStaticCstrName, ClazzNameBuffersStaticCstrSignature);
+        if(NULL==cstrBuffers) {
+            NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't create %s.%s %s",
+                ClazzNameBuffers, ClazzNameBuffersStaticCstrName, ClazzNameBuffersStaticCstrSignature);
+        }
 
-static void setupJVMVars(JNIEnv * env) {
-    if( NULL != env && NULL == jvmHandle ) {
-        if(0 != (*env)->GetJavaVM(env, &jvmHandle)) {
-            jvmHandle = NULL;
+        c = (*env)->FindClass(env, ClazzNamePoint);
+        if(NULL==c) {
+            NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't find %s", ClazzNamePoint);
+        }
+        pointClz = (jclass)(*env)->NewGlobalRef(env, c);
+        (*env)->DeleteLocalRef(env, c);
+        if(NULL==pointClz) {
+            NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't use %s", ClazzNamePoint);
+        }
+        pointCstr = (*env)->GetMethodID(env, pointClz, ClazzAnyCstrName, ClazzNamePointCstrSignature);
+        if(NULL==pointCstr) {
+            NativewindowCommon_FatalError(env, "FatalError Java_jogamp_nativewindow_x11_X11Lib: can't fetch %s.%s %s",
+                ClazzNamePoint, ClazzAnyCstrName, ClazzNamePointCstrSignature);
         }
-        jvmVersion = (*env)->GetVersion(env);
     }
 }
 
@@ -201,8 +189,8 @@ static int x11ErrorHandler(Display *dpy, XErrorEvent *e)
             (int)e->request_code, (int)e->minor_code, reqCodeStr);
         fflush(stderr);
 
-        if( NULL != jvmHandle && ( errorHandlerDebug || errorHandlerThrowException ) ) {
-            jniEnv = NativewindowCommon_GetJNIEnv(jvmHandle, jvmVersion, 0 /* asDaemon */, &shallBeDetached);
+        if( errorHandlerDebug || errorHandlerThrowException ) {
+            jniEnv = NativewindowCommon_GetJNIEnv(0 /* asDaemon */, &shallBeDetached);
             if(NULL == jniEnv) {
                 fprintf(stderr, "Nativewindow X11 Error: null JNIEnv");
                 fflush(stderr);
@@ -219,9 +207,7 @@ static int x11ErrorHandler(Display *dpy, XErrorEvent *e)
                                                             e->error_code, errCodeStr, e->display, (int)e->resourceid, (int)e->serial,
                                                             (int)e->request_code, (int)e->minor_code, reqCodeStr);
             }
-            if (shallBeDetached) {
-                (*jvmHandle)->DetachCurrentThread(jvmHandle);
-            }
+            NativewindowCommon_ReleaseJNIEnv(shallBeDetached);
         }
     }
 
@@ -233,7 +219,6 @@ static void NativewindowCommon_x11ErrorHandlerEnable(JNIEnv * env, Display *dpy,
     if(onoff) {
         if(force || NULL==origErrorHandler) {
             XErrorHandler prevErrorHandler;
-            setupJVMVars(env);
             prevErrorHandler = XSetErrorHandler(x11ErrorHandler);
             if(x11ErrorHandler != prevErrorHandler) { // if forced don't overwrite w/ orig w/ our handler
                 origErrorHandler = prevErrorHandler;
@@ -265,14 +250,10 @@ static int x11IOErrorHandler(Display *dpy)
     fprintf(stderr, "Nativewindow X11 IOError: Display %p (%s): %s\n", dpy, dpyName, errnoStr);
     fflush(stderr);
 
-    if( NULL != jvmHandle ) {
-        jniEnv = NativewindowCommon_GetJNIEnv(jvmHandle, jvmVersion, 0 /* asDaemon */, &shallBeDetached);
-        if (NULL != jniEnv) {
-            NativewindowCommon_FatalError(jniEnv, "Nativewindow X11 IOError: Display %p (%s): %s", dpy, dpyName, errnoStr);
-            if (shallBeDetached) {
-                (*jvmHandle)->DetachCurrentThread(jvmHandle);
-            }
-        }
+    jniEnv = NativewindowCommon_GetJNIEnv(0 /* asDaemon */, &shallBeDetached);
+    if (NULL != jniEnv) {
+        NativewindowCommon_FatalError(jniEnv, "Nativewindow X11 IOError: Display %p (%s): %s", dpy, dpyName, errnoStr);
+        NativewindowCommon_ReleaseJNIEnv(shallBeDetached);
     }
     if(NULL!=origIOErrorHandler) {
         origIOErrorHandler(dpy);
@@ -283,7 +264,6 @@ static int x11IOErrorHandler(Display *dpy)
 static void x11IOErrorHandlerEnable(int onoff, JNIEnv * env) {
     if(onoff) {
         if(NULL==origIOErrorHandler) {
-            setupJVMVars(env);
             origIOErrorHandler = XSetIOErrorHandler(x11IOErrorHandler);
         }
     } else {
diff --git a/src/newt/native/MacWindow.m b/src/newt/native/MacWindow.m
index c6fd805a5..130b2e3e3 100644
--- a/src/newt/native/MacWindow.m
+++ b/src/newt/native/MacWindow.m
@@ -113,18 +113,6 @@ static void setJavaWindowObject(JNIEnv *env, jobject newJavaWindowObject, NewtVi
         DBG_PRINT( "setJavaWindowObject.2: View %p - Set new javaWindowObject %p\n", view, newJavaWindowObject);
         jobject globJavaWindowObject = (*env)->NewGlobalRef(env, newJavaWindowObject);
         [view setJavaWindowObject: globJavaWindowObject];
-        {
-            JavaVM *jvmHandle = NULL;
-            int jvmVersion = 0;
-
-            if(0 != (*env)->GetJavaVM(env, &jvmHandle)) {
-                jvmHandle = NULL;
-            } else {
-                jvmVersion = (*env)->GetVersion(env);
-            }
-            [view setJVMHandle: jvmHandle];
-            [view setJVMVersion: jvmVersion];
-        }
     }
     DBG_PRINT( "setJavaWindowObject.X: View %p\n", view);
 }
@@ -979,6 +967,7 @@ JNIEXPORT void JNICALL Java_jogamp_newt_driver_macosx_WindowDriver_close0
     BOOL isNewtWin = [mWin isKindOfClass:[NewtMacWindow class]];
     NSWindow *pWin = [mWin parentWindow];
     DBG_PRINT( "windowClose.0 - %p [isNSWindow %d, isNewtWin %d], parent %p\n", mWin, isNSWin, isNewtWin, pWin);
+    (void)isNSWin; // silence
     if( !isNewtWin ) {
         NewtCommon_throwNewRuntimeException(env, "Not a NewtMacWindow %p", mWin);
         return;
diff --git a/src/newt/native/NewtCommon.c b/src/newt/native/NewtCommon.c
index c294b6e0b..231d6182f 100644
--- a/src/newt/native/NewtCommon.c
+++ b/src/newt/native/NewtCommon.c
@@ -5,17 +5,43 @@
 static const char * const ClazzNameRuntimeException = "java/lang/RuntimeException";
 static jclass    runtimeExceptionClz=NULL;
 
+static JavaVM *_jvmHandle = NULL;
+static int _jvmVersion = 0;
+
+void NewtCommon_init(JNIEnv *env) {
+    if(NULL==_jvmHandle) {
+        if(0 != (*env)->GetJavaVM(env, &_jvmHandle)) {
+            NewtCommon_FatalError(env, "NEWT: Can't fetch JavaVM handle");
+        } else {
+            _jvmVersion = (*env)->GetVersion(env);
+        }
+        jclass c = (*env)->FindClass(env, ClazzNameRuntimeException);
+        if(NULL==c) {
+            NewtCommon_FatalError(env, "NEWT: Can't find %s", ClazzNameRuntimeException);
+        }
+        runtimeExceptionClz = (jclass)(*env)->NewGlobalRef(env, c);
+        (*env)->DeleteLocalRef(env, c);
+        if(NULL==runtimeExceptionClz) {
+            NewtCommon_FatalError(env, "NEWT: Can't use %s", ClazzNameRuntimeException);
+        }
+    }
+}
+
 void NewtCommon_FatalError(JNIEnv *env, const char* msg, ...)
 {
     char buffer[512];
     va_list ap;
 
-    va_start(ap, msg);
-    vsnprintf(buffer, sizeof(buffer), msg, ap);
-    va_end(ap);
+    if( NULL != msg ) {
+        va_start(ap, msg);
+        vsnprintf(buffer, sizeof(buffer), msg, ap);
+        va_end(ap);
 
-    fprintf(stderr, "%s\n", buffer);
-    (*env)->FatalError(env, buffer);
+        fprintf(stderr, "%s\n", buffer);
+        if(NULL != env) {
+            (*env)->FatalError(env, buffer);
+        }
+    }
 }
 
 void NewtCommon_throwNewRuntimeException(JNIEnv *env, const char* msg, ...)
@@ -23,23 +49,18 @@ void NewtCommon_throwNewRuntimeException(JNIEnv *env, const char* msg, ...)
     char buffer[512];
     va_list ap;
 
-    va_start(ap, msg);
-    vsnprintf(buffer, sizeof(buffer), msg, ap);
-    va_end(ap);
+    if(NULL==_jvmHandle) {
+        NewtCommon_FatalError(env, "NEWT: NULL JVM handle, call NewtCommon_init 1st\n");
+        return;
+    }
 
-    (*env)->ThrowNew(env, runtimeExceptionClz, buffer);
-}
+    if( NULL != msg ) {
+        va_start(ap, msg);
+        vsnprintf(buffer, sizeof(buffer), msg, ap);
+        va_end(ap);
 
-void NewtCommon_init(JNIEnv *env) {
-    if(NULL==runtimeExceptionClz) {
-        jclass c = (*env)->FindClass(env, ClazzNameRuntimeException);
-        if(NULL==c) {
-            NewtCommon_FatalError(env, "NEWT: can't find %s", ClazzNameRuntimeException);
-        }
-        runtimeExceptionClz = (jclass)(*env)->NewGlobalRef(env, c);
-        (*env)->DeleteLocalRef(env, c);
-        if(NULL==runtimeExceptionClz) {
-            NewtCommon_FatalError(env, "NEWT: can't use %s", ClazzNameRuntimeException);
+        if(NULL != env) {
+            (*env)->ThrowNew(env, runtimeExceptionClz, buffer);
         }
     }
 }
@@ -65,42 +86,57 @@ const char * NewtCommon_GetStaticStringMethod(JNIEnv *jniEnv, jclass clazz, jmet
 jchar* NewtCommon_GetNullTerminatedStringChars(JNIEnv* env, jstring str)
 {
     jchar* strChars = NULL;
-    strChars = calloc((*env)->GetStringLength(env, str) + 1, sizeof(jchar));
-    if (strChars != NULL) {
-        (*env)->GetStringRegion(env, str, 0, (*env)->GetStringLength(env, str), strChars);
+    if( NULL != env && 0 != str ) {
+        strChars = calloc((*env)->GetStringLength(env, str) + 1, sizeof(jchar));
+        if (strChars != NULL) {
+            (*env)->GetStringRegion(env, str, 0, (*env)->GetStringLength(env, str), strChars);
+        }
     }
     return strChars;
 }
 
-JNIEnv* NewtCommon_GetJNIEnv(JavaVM * jvmHandle, int jvmVersion, int asDaemon, int * shallBeDetached) {
+JNIEnv* NewtCommon_GetJNIEnv(int asDaemon, int * shallBeDetached) {
     JNIEnv* curEnv = NULL;
     JNIEnv* newEnv = NULL;
     int envRes;
 
+    if(NULL==_jvmHandle) {
+        fprintf(stderr, "NEWT GetJNIEnv: NULL JVM handle, call NewtCommon_init 1st\n");
+        return NULL;
+    }
+
     // retrieve this thread's JNIEnv curEnv - or detect it's detached
-    envRes = (*jvmHandle)->GetEnv(jvmHandle, (void **) &curEnv, jvmVersion) ;
+    envRes = (*_jvmHandle)->GetEnv(_jvmHandle, (void **) &curEnv, _jvmVersion) ;
     if( JNI_EDETACHED == envRes ) {
         // detached thread - attach to JVM
         if( asDaemon ) {
-            envRes = (*jvmHandle)->AttachCurrentThreadAsDaemon(jvmHandle, (void**) &newEnv, NULL);
+            envRes = (*_jvmHandle)->AttachCurrentThreadAsDaemon(_jvmHandle, (void**) &newEnv, NULL);
         } else {
-            envRes = (*jvmHandle)->AttachCurrentThread(jvmHandle, (void**) &newEnv, NULL);
+            envRes = (*_jvmHandle)->AttachCurrentThread(_jvmHandle, (void**) &newEnv, NULL);
         }
         if( JNI_OK != envRes ) {
-            fprintf(stderr, "JNIEnv: can't attach thread: %d\n", envRes);
+            fprintf(stderr, "NEWT GetJNIEnv: Can't attach thread: %d\n", envRes);
             return NULL;
         }
         curEnv = newEnv;
     } else if( JNI_OK != envRes ) {
         // oops ..
-        fprintf(stderr, "can't GetEnv: %d\n", envRes);
+        fprintf(stderr, "NEWT GetJNIEnv: Can't GetEnv: %d\n", envRes);
         return NULL;
     }
     if (curEnv==NULL) {
-        fprintf(stderr, "env is NULL\n");
+        fprintf(stderr, "NEWT GetJNIEnv: env is NULL\n");
         return NULL;
     }
     *shallBeDetached = NULL != newEnv;
     return curEnv;
 }
 
+void NewtCommon_ReleaseJNIEnv (int shallBeDetached) {
+    if(NULL == _jvmHandle) {
+        fprintf(stderr, "NEWT ReleaseJNIEnv: No JavaVM handle registered, call NewtCommon_init(..) 1st");
+    } else if(shallBeDetached) {
+        (*_jvmHandle)->DetachCurrentThread(_jvmHandle);
+    }
+}
+
diff --git a/src/newt/native/NewtCommon.h b/src/newt/native/NewtCommon.h
index 9cc9e93a6..43db72b5b 100644
--- a/src/newt/native/NewtCommon.h
+++ b/src/newt/native/NewtCommon.h
@@ -42,23 +42,18 @@ void NewtCommon_throwNewRuntimeException(JNIEnv *env, const char* msg, ...);
 
 /**
  *
- * 1) Store jvmHandle and jvmVersion
+ * 1) Init static jvmHandle, jvmVersion and clazz references
+ *    from an early initialization call w/ valid 'JNIEnv * env'
 
-    JavaVM *jvmHandle = NULL;
-    int jvmVersion = 0;
-
-    if(0 != (*env)->GetJavaVM(env, &jvmHandle)) {
-        jvmHandle = NULL;
-    } else {
-        jvmVersion = (*env)->GetVersion(env);
-    }
+    NewtCommon_init(env);
 
  *
  * 2) Use current thread JNIEnv or attach current thread to JVM, generating new JNIEnv
  *
 
+    int asDaemon = 0;
     int shallBeDetached = 0;
-    JNIEnv* env = NewtCommon_GetJNIEnv(jvmHandle, jvmVersion, &shallBeDetached);
+    JNIEnv* env = NewtCommon_GetJNIEnv(asDaemon, &shallBeDetached);
     if(NULL==env) {
         DBG_PRINT("drawRect: null JNIEnv\n");
         return;
@@ -70,12 +65,13 @@ void NewtCommon_throwNewRuntimeException(JNIEnv *env, const char* msg, ...);
     .. your JNIEnv code here ..
 
  *
- * 4) Detach thread from JVM, if required
+ * 4) Detach thread from JVM if required, i.e. not attached as daemon!
+ *    Not recommended for recurring _daemon_ threads (performance)
  *
-    if (shallBeDetached) {
-        (*jvmHandle)->DetachCurrentThread(jvmHandle);
-    }
+    NativewindowCommon_ReleaseJNIEnv(shallBeDetached);
  */
-JNIEnv* NewtCommon_GetJNIEnv (JavaVM * jvmHandle, int jvmVersion, int asDaemon, int * shallBeDetached);
+JNIEnv* NewtCommon_GetJNIEnv (int asDaemon, int * shallBeDetached);
+
+void NewtCommon_ReleaseJNIEnv (int shallBeDetached);
 
 #endif
diff --git a/src/newt/native/NewtMacWindow.h b/src/newt/native/NewtMacWindow.h
index daf75bec7..8f6362ac2 100644
--- a/src/newt/native/NewtMacWindow.h
+++ b/src/newt/native/NewtMacWindow.h
@@ -53,10 +53,6 @@
 {
     jobject javaWindowObject;
 
-    // This is set while messages are being dispatched and cleared afterward
-    JavaVM *jvmHandle;
-    int jvmVersion;
-
     volatile BOOL destroyNotifySent;
     volatile int softLockCount;
     pthread_mutex_t softLockSync;
@@ -80,12 +76,6 @@
 #endif
 - (void) dealloc;
 
-/* Set during event dispatching cycle */
-- (void) setJVMHandle: (JavaVM*) vm;
-- (JavaVM*) getJVMHandle;
-- (void) setJVMVersion: (int) ver;
-- (int) getJVMVersion;
-
 /* Register or deregister (NULL) the java Window object, 
    ie, if NULL, no events are send */
 - (void) setJavaWindowObject: (jobject) javaWindowObj;
diff --git a/src/newt/native/NewtMacWindow.m b/src/newt/native/NewtMacWindow.m
index 5ccd9c658..b4133ac7e 100644
--- a/src/newt/native/NewtMacWindow.m
+++ b/src/newt/native/NewtMacWindow.m
@@ -193,8 +193,6 @@ static jmethodID windowRepaintID = NULL;
     id res = [super initWithFrame:frameRect];
     javaWindowObject = NULL;
 
-    jvmHandle = NULL;
-    jvmVersion = 0;
     destroyNotifySent = NO;
     softLockCount = 0;
 
@@ -244,25 +242,6 @@ static jmethodID windowRepaintID = NULL;
     [super dealloc];
 }
 
-- (void) setJVMHandle: (JavaVM*) vm
-{
-    jvmHandle = vm;
-}
-- (JavaVM*) getJVMHandle
-{
-    return jvmHandle;
-}
-
-- (void) setJVMVersion: (int) ver
-{
-    jvmVersion = ver;
-}
-
-- (int) getJVMVersion
-{
-    return jvmVersion;
-}
-
 - (void) setJavaWindowObject: (jobject) javaWindowObj
 {
     javaWindowObject = javaWindowObj;
@@ -342,7 +321,7 @@ static jmethodID windowRepaintID = NULL;
         return;
     }
     int shallBeDetached = 0;
-    JNIEnv* env = NewtCommon_GetJNIEnv(jvmHandle, jvmVersion, 1 /* asDaemon */, &shallBeDetached);
+    JNIEnv* env = NewtCommon_GetJNIEnv(1 /* asDaemon */, &shallBeDetached);
     if(NULL==env) {
         DBG_PRINT("drawRect: null JNIEnv\n");
         return;
@@ -354,9 +333,8 @@ static jmethodID windowRepaintID = NULL;
         dirtyRect.origin.x, viewFrame.size.height - dirtyRect.origin.y, 
         dirtyRect.size.width, dirtyRect.size.height);
 
-    /* if (shallBeDetached) {
-        (*jvmHandle)->DetachCurrentThread(jvmHandle);
-    } */
+    // detaching thread not required - daemon
+    // NewtCommon_ReleaseJNIEnv(shallBeDetached);
 }
 
 - (void) viewDidHide
@@ -366,7 +344,7 @@ static jmethodID windowRepaintID = NULL;
         return;
     }
     int shallBeDetached = 0;
-    JNIEnv* env = NewtCommon_GetJNIEnv(jvmHandle, jvmVersion, 1 /* asDaemon */, &shallBeDetached);
+    JNIEnv* env = NewtCommon_GetJNIEnv(1 /* asDaemon */, &shallBeDetached);
     if(NULL==env) {
         DBG_PRINT("viewDidHide: null JNIEnv\n");
         return;
@@ -374,9 +352,8 @@ static jmethodID windowRepaintID = NULL;
 
     (*env)->CallVoidMethod(env, javaWindowObject, visibleChangedID, JNI_FALSE, JNI_FALSE);
 
-    /* if (shallBeDetached) {
-        (*jvmHandle)->DetachCurrentThread(jvmHandle);
-    } */
+    // detaching thread not required - daemon
+    // NewtCommon_ReleaseJNIEnv(shallBeDetached);
 
     [super viewDidHide];
 }
@@ -388,7 +365,7 @@ static jmethodID windowRepaintID = NULL;
         return;
     }
     int shallBeDetached = 0;
-    JNIEnv* env = NewtCommon_GetJNIEnv(jvmHandle, jvmVersion, 1 /* asDaemon */, &shallBeDetached);
+    JNIEnv* env = NewtCommon_GetJNIEnv(1 /* asDaemon */, &shallBeDetached);
     if(NULL==env) {
         DBG_PRINT("viewDidUnhide: null JNIEnv\n");
         return;
@@ -396,9 +373,8 @@ static jmethodID windowRepaintID = NULL;
 
     (*env)->CallVoidMethod(env, javaWindowObject, visibleChangedID, JNI_FALSE, JNI_TRUE);
 
-    /* if (shallBeDetached) {
-        (*jvmHandle)->DetachCurrentThread(jvmHandle);
-    } */
+    // detaching thread not required - daemon
+    // NewtCommon_ReleaseJNIEnv(shallBeDetached);
 
     [super viewDidUnhide];
 }
@@ -645,14 +621,9 @@ static jmethodID windowRepaintID = NULL;
         return;
     }
     int shallBeDetached = 0;
-    JNIEnv* env;
-    if( NULL != jvmHandle ) {
-        env = NewtCommon_GetJNIEnv(jvmHandle, [self getJVMVersion], 1 /* asDaemon */, &shallBeDetached);
-    } else {
-        env = NULL;
-    }
+    JNIEnv* env = NewtCommon_GetJNIEnv(1 /* asDaemon */, &shallBeDetached);
     if(NULL==env) {
-        DBG_PRINT("sendMouseEvent: JVM %p JNIEnv %p\n", jvmHandle, env);
+        DBG_PRINT("sendMouseEvent: null JNIEnv\n");
         return;
     }
     jint javaMods[] = { 0 } ;
@@ -700,9 +671,8 @@ static jmethodID windowRepaintID = NULL;
                            (jint) location.x, (jint) location.y,
                            javaButtonNum, scrollDeltaY);
 
-    /* if (shallBeDetached) {
-        (*jvmHandle)->DetachCurrentThread(jvmHandle);
-    } */
+    // detaching thread not required - daemon
+    // NewtCommon_ReleaseJNIEnv(shallBeDetached);
 }
 
 - (NSPoint) screenPos2NewtClientWinPos: (NSPoint) p
@@ -754,14 +724,9 @@ static jmethodID windowRepaintID = NULL;
         return;
     }
     int shallBeDetached = 0;
-    JNIEnv* env;
-    if( NULL != jvmHandle ) {
-        env = NewtCommon_GetJNIEnv(jvmHandle, [self getJVMVersion], 1 /* asDaemon */, &shallBeDetached);
-    } else {
-        env = NULL;
-    }
+    JNIEnv* env = NewtCommon_GetJNIEnv(1 /* asDaemon */, &shallBeDetached);
     if(NULL==env) {
-        DBG_PRINT("sendKeyEvent: JVM %p JNIEnv %p\n", jvmHandle, env);
+        DBG_PRINT("sendKeyEvent: null JNIEnv\n");
         return;
     }
 
@@ -792,9 +757,8 @@ static jmethodID windowRepaintID = NULL;
                                evType, javaMods, keyCode, keyChar, keyChar);
     }
 
-    /* if (shallBeDetached) {
-        (*jvmHandle)->DetachCurrentThread(jvmHandle);
-    } */
+    // detaching thread not required - daemon
+    // NewtCommon_ReleaseJNIEnv(shallBeDetached);
 }
 
 @end
@@ -1038,23 +1002,16 @@ static jmethodID windowRepaintID = NULL;
         return;
     }
     int shallBeDetached = 0;
-    JavaVM *jvmHandle = [newtView getJVMHandle];
-    JNIEnv* env;
-    if( NULL != jvmHandle ) {
-        env = NewtCommon_GetJNIEnv(jvmHandle, [newtView getJVMVersion], 1 /* asDaemon */, &shallBeDetached);
-    } else {
-        env = NULL;
-    }
+    JNIEnv* env = NewtCommon_GetJNIEnv(1 /* asDaemon */, &shallBeDetached);
     if(NULL==env) {
-        DBG_PRINT("focusChanged: JVM %p JNIEnv %p\n", jvmHandle, env);
+        DBG_PRINT("focusChanged: null JNIEnv\n");
         return;
     }
 
     (*env)->CallVoidMethod(env, javaWindowObject, focusChangedID, JNI_FALSE, (gained == YES) ? JNI_TRUE : JNI_FALSE);
 
-    /* if (shallBeDetached) {
-        (*jvmHandle)->DetachCurrentThread(jvmHandle);
-    } */
+    // detaching thread not required - daemon
+    // NewtCommon_ReleaseJNIEnv(shallBeDetached);
 }
 
 - (void) keyDown: (NSEvent*) theEvent
@@ -1147,37 +1104,31 @@ static jmethodID windowRepaintID = NULL;
 
 - (void)windowDidResize: (NSNotification*) notification
 {
-    JNIEnv* env = NULL;
     jobject javaWindowObject = NULL;
     int shallBeDetached = 0;
-    JavaVM *jvmHandle = NULL;
+    JNIEnv* env = NewtCommon_GetJNIEnv(1 /* asDaemon */, &shallBeDetached);
 
+    if( NULL == env ) {
+        DBG_PRINT("windowDidResize: null JNIEnv\n");
+        return;
+    }
     NewtView* newtView = (NewtView *) [self contentView];
     if( [newtView isKindOfClass:[NewtView class]] ) {
         javaWindowObject = [newtView getJavaWindowObject];
-        if (javaWindowObject != NULL) {
-            jvmHandle = [newtView getJVMHandle];
-            if( NULL != jvmHandle ) {
-                env = NewtCommon_GetJNIEnv(jvmHandle, [newtView getJVMVersion], 1 /* asDaemon */, &shallBeDetached);
-            }
-        }
     }
+    if( NULL != javaWindowObject ) {
+        // update insets on every window resize for lack of better hook place
+        [self updateInsets: env jwin:javaWindowObject];
 
-    // update insets on every window resize for lack of better hook place
-    [self updateInsets: env jwin:javaWindowObject];
-
-    if( NULL != env && NULL != javaWindowObject ) {
         NSRect frameRect = [self frame];
         NSRect contentRect = [self contentRectForFrameRect: frameRect];
 
         (*env)->CallVoidMethod(env, javaWindowObject, sizeChangedID, JNI_FALSE,
                                (jint) contentRect.size.width,
                                (jint) contentRect.size.height, JNI_FALSE);
-
-        /* if (shallBeDetached) {
-            (*jvmHandle)->DetachCurrentThread(jvmHandle);
-        } */
     }
+    // detaching thread not required - daemon
+    // NewtCommon_ReleaseJNIEnv(shallBeDetached);
 }
 
 - (void)windowDidMove: (NSNotification*) notification
@@ -1192,15 +1143,9 @@ static jmethodID windowRepaintID = NULL;
         return;
     }
     int shallBeDetached = 0;
-    JavaVM *jvmHandle = [newtView getJVMHandle];
-    JNIEnv* env;
-    if( NULL != jvmHandle ) {
-        env = NewtCommon_GetJNIEnv(jvmHandle, [newtView getJVMVersion], 1 /* asDaemon */, &shallBeDetached);
-    } else {
-        env = NULL;
-    }
+    JNIEnv* env = NewtCommon_GetJNIEnv(1 /* asDaemon */, &shallBeDetached);
     if(NULL==env) {
-        DBG_PRINT("windowDidMove: JVM %p JNIEnv %p\n", jvmHandle, env);
+        DBG_PRINT("windowDidMove: null JNIEnv\n");
         return;
     }
 
@@ -1208,9 +1153,8 @@ static jmethodID windowRepaintID = NULL;
     p0 = [self getLocationOnScreen: p0];
     (*env)->CallVoidMethod(env, javaWindowObject, positionChangedID, JNI_FALSE, (jint) p0.x, (jint) p0.y);
 
-    /* if (shallBeDetached) {
-        (*jvmHandle)->DetachCurrentThread(jvmHandle);
-    } */
+    // detaching thread not required - daemon
+    // NewtCommon_ReleaseJNIEnv(shallBeDetached);
 }
 
 - (BOOL)windowShouldClose: (id) sender
@@ -1226,13 +1170,12 @@ static jmethodID windowRepaintID = NULL;
 - (BOOL) windowClosingImpl: (BOOL) force
 {
     jboolean closed = JNI_FALSE;
-    NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
 
     NewtView* newtView = (NewtView *) [self contentView];
     if( ! [newtView isKindOfClass:[NewtView class]] ) {
         return NO;
     }
-
+    NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
     [newtView cursorHide: NO enter: -1];
 
     if( false == [newtView getDestroyNotifySent] ) {
@@ -1240,26 +1183,16 @@ static jmethodID windowRepaintID = NULL;
         DBG_PRINT( "*************** windowWillClose.0: %p\n", (void *)(intptr_t)javaWindowObject);
         if (javaWindowObject == NULL) {
             DBG_PRINT("windowWillClose: null javaWindowObject\n");
+            [pool release];
             return NO;
         }
         int shallBeDetached = 0;
-        JavaVM *jvmHandle = [newtView getJVMHandle];
-        JNIEnv* env = NULL;
-NS_DURING
-        if( NULL != jvmHandle ) {
-            env = NewtCommon_GetJNIEnv(jvmHandle, [newtView getJVMVersion], 1 /* asDaemon */, &shallBeDetached);
-        }
-NS_HANDLER
-        jvmHandle = NULL;
-        env = NULL;
-        [newtView setJVMHandle: NULL];
-        DBG_PRINT("windowWillClose: JVMHandler Exception\n");
-NS_ENDHANDLER
-        DBG_PRINT("windowWillClose: JVM %p JNIEnv %p\n", jvmHandle, env);
+        JNIEnv* env = NewtCommon_GetJNIEnv(1 /* asDaemon */, &shallBeDetached);
         if(NULL==env) {
+            DBG_PRINT("windowWillClose: null JNIEnv\n");
+            [pool release];
             return NO;
         }
-
         [newtView setDestroyNotifySent: true]; // earmark assumption of being closed
         closed = (*env)->CallBooleanMethod(env, javaWindowObject, windowDestroyNotifyID, force ? JNI_TRUE : JNI_FALSE);
         if(!force && !closed) {
@@ -1267,9 +1200,8 @@ NS_ENDHANDLER
             [newtView setDestroyNotifySent: false];
         }
 
-        /* if (shallBeDetached) {
-            (*jvmHandle)->DetachCurrentThread(jvmHandle);
-        } */
+        // detaching thread not required - daemon
+        // NewtCommon_ReleaseJNIEnv(shallBeDetached);
         DBG_PRINT( "*************** windowWillClose.X: %p, closed %d\n", (void *)(intptr_t)javaWindowObject, (int)closed);
     } else {
         DBG_PRINT( "*************** windowWillClose (skip)\n");