jnius: fix push/pop jnienv in order to avoid GIL going on using the previous thread env while we are still on the current thread

jnius/jnius_env.pxi

@@ -11,17 +11,22 @@ cdef JNIEnv *get_jnienv():
         env_stack = 0
     return env_current
 
-cdef void push_jnienv(JNIEnv *env):
+cdef void push_jnienv(JNIEnv *env) nogil:
     global env_stacks, env_stack, env_current
     if env_stack == 255:
-        raise Exception('Jnius: cannot push JNI env, too many entries')
+        with gil:
+            print('ERROR: Jnius cannot push JNI env, too many entries')
+        return
     env_stack += 1
     env_stacks[env_stack] = env_current = env
 
-cdef void pop_jnienv():
-    global env_stacks, env_stack
+cdef void pop_jnienv() nogil:
+    global env_stacks, env_stack, env_current
     if env_stack == 0:
-        raise Exception('Jnius: cannot pop JNI env, already at 0')
+        with gil:
+            print('ERROR: Jnius cannot pop JNI env, already at 0')
+        return
     env_stacks[env_stack] = NULL
     env_stack -= 1
     env_current = env_stacks[env_stack]
+

jnius/jnius_proxy.pxi

@@ -72,8 +72,9 @@ cdef class PythonJavaClass(object):
 
         return py_method(*args)
 
-cdef jobject invoke0(JNIEnv *j_env, jobject j_this, jobject j_proxy, jobject
+cdef jobject py_invoke0(JNIEnv *j_env, jobject j_this, jobject j_proxy, jobject
         j_method, jobjectArray args) with gil:
+
     from .reflect import get_signature, Method
     cdef jfieldID ptrField
     cdef jlong jptr
@@ -82,72 +83,79 @@ cdef jobject invoke0(JNIEnv *j_env, jobject j_this, jobject j_proxy, jobject
     cdef LocalRef ref
     cdef jobject j_arg
 
+    # get the python object
+    ptrField = j_env[0].GetFieldID(j_env,
+        j_env[0].GetObjectClass(j_env, j_this), "ptr", "J")
+    jptr = j_env[0].GetLongField(j_env, j_this, ptrField)
+    py_obj = <object><void *>jptr
+
+    # extract the method information
+    method = Method(noinstance=True)
+    ref = create_local_ref(j_env, j_method)
+    method.instanciate_from(create_local_ref(j_env, j_method))
+    ret_signature = get_signature(method.getReturnType())
+    args_signature = [get_signature(x) for x in method.getParameterTypes()]
+
+    # convert java argument to python object
+    # native java type are given with java.lang.*, even if the signature say
+    # it's a native type.
+    py_args = []
+    convert_signature = {
+        'Z': 'Ljava/lang/Boolean;',
+        'B': 'Ljava/lang/Byte;',
+        'C': 'Ljava/lang/Character;',
+        'S': 'Ljava/lang/Short;',
+        'I': 'Ljava/lang/Integer;',
+        'J': 'Ljava/lang/Long;',
+        'F': 'Ljava/lang/Float;',
+        'D': 'Ljava/lang/Double;'}
+
+    for index, arg_signature in enumerate(args_signature):
+        arg_signature = convert_signature.get(arg_signature, arg_signature)
+        j_arg = j_env[0].GetObjectArrayElement(j_env, args, index)
+        py_arg = convert_jobject_to_python(j_env, arg_signature, j_arg)
+        py_args.append(py_arg)
+
+    # really invoke the python method
+    name = method.getName()
+    ret = py_obj.invoke(method, *py_args)
+
+    # convert back to the return type
+    # use the populate_args(), but in the reverse way :)
+    t = ret_signature[:1]
+
+    # did python returned a "native" type ?
+    jtype = None
+
+    if ret_signature == 'Ljava/lang/Object;':
+        # generic object, try to manually convert it
+        tp = type(ret)
+        if tp == int:
+            jtype = 'J'
+        elif tp == float:
+            jtype = 'D'
+        elif tp == bool:
+            jtype = 'Z'
+    elif len(ret_signature) == 1:
+        jtype = ret_signature
+
     try:
-        push_jnienv(j_env)
+        return convert_python_to_jobject(j_env, jtype or ret_signature, ret)
+    except Exception as e:
+        traceback.print_exc(e)
 
-        # get the python object
-        ptrField = j_env[0].GetFieldID(j_env,
-            j_env[0].GetObjectClass(j_env, j_this), "ptr", "J")
-        jptr = j_env[0].GetLongField(j_env, j_this, ptrField)
-        py_obj = <object><void *>jptr
-
-        # extract the method information
-        method = Method(noinstance=True)
-        ref = create_local_ref(j_env, j_method)
-        method.instanciate_from(create_local_ref(j_env, j_method))
-        ret_signature = get_signature(method.getReturnType())
-        args_signature = [get_signature(x) for x in method.getParameterTypes()]
-
-        # convert java argument to python object
-        # native java type are given with java.lang.*, even if the signature say
-        # it's a native type.
-        py_args = []
-        convert_signature = {
-            'Z': 'Ljava/lang/Boolean;',
-            'B': 'Ljava/lang/Byte;',
-            'C': 'Ljava/lang/Character;',
-            'S': 'Ljava/lang/Short;',
-            'I': 'Ljava/lang/Integer;',
-            'J': 'Ljava/lang/Long;',
-            'F': 'Ljava/lang/Float;',
-            'D': 'Ljava/lang/Double;'}
-
-        for index, arg_signature in enumerate(args_signature):
-            arg_signature = convert_signature.get(arg_signature, arg_signature)
-            j_arg = j_env[0].GetObjectArrayElement(j_env, args, index)
-            py_arg = convert_jobject_to_python(j_env, arg_signature, j_arg)
-            py_args.append(py_arg)
-
-        # really invoke the python method
-        name = method.getName()
-        ret = py_obj.invoke(method, *py_args)
-
-        # convert back to the return type
-        # use the populate_args(), but in the reverse way :)
-        t = ret_signature[:1]
-
-        # did python returned a "native" type ?
-        jtype = None
-
-        if ret_signature == 'Ljava/lang/Object;':
-            # generic object, try to manually convert it
-            tp = type(ret)
-            if tp == int:
-                jtype = 'J'
-            elif tp == float:
-                jtype = 'D'
-            elif tp == bool:
-                jtype = 'Z'
-        elif len(ret_signature) == 1:
-            jtype = ret_signature
 
+cdef jobject invoke0(JNIEnv *j_env, jobject j_this, jobject j_proxy, jobject
+        j_method, jobjectArray args) nogil:
+    cdef jobject ret = NULL
+    push_jnienv(j_env)
+    with gil:
         try:
-            return convert_python_to_jobject(j_env, jtype or ret_signature, ret)
+            ret = py_invoke0(j_env, j_this, j_proxy, j_method, args)
         except Exception as e:
             traceback.print_exc(e)
-
-    finally:
-        pop_jnienv()
+    pop_jnienv()
+    return ret
 
 
 # now we need to create a proxy and pass it an invocation handler