1 files changed, 66 insertions, 30 deletions

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);
+    }
+}
+