VPP-205: jvpp plugin support.

Splits jvpp into two jars
jvpp-registry.jar - base jvpp functionality
jvpp-core.jar - Java wrapper for vpe.api

Plugins can be generated the same way jvpp-core.jar is.
Example (nsh):
https://gerrit.fd.io/r/#/c/2118/

Change-Id: I2254f90b2c3e423563bb91bf70877979f1e90a7d
Signed-off-by: Marek Gradzki <mgradzki@cisco.com>

vpp-api/java/jvpp-common/jvpp_common.h

@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2016 Cisco and/or its affiliates.
+ * 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.
+ */
+#ifndef __included_jvpp_common_h__
+#define __included_jvpp_common_h__
+//
+#include <vppinfra/types.h>
+#include <vlibapi/api.h>
+#include <vlibmemory/api.h>
+#include <jni.h>
+
+typedef struct {
+    /* Unique identifier used for matching replays with requests  */
+    volatile u32 context_id;
+
+    /* Spinlock */
+    volatile u32 lock;
+    u32 tag;
+
+    /* JNI Native Method Interface pointer for message handlers */
+    JNIEnv *jenv;
+
+    /* JNI Invoke Interface pointer for attachment of rx thread to java thread */
+    JavaVM *jvm;
+
+    /* Convenience */
+    unix_shared_memory_queue_t * vl_input_queue;
+    u32 my_client_index;
+} jvpp_main_t;
+
+extern jvpp_main_t jvpp_main __attribute__((aligned (64)));
+
+static_always_inline u32 vppjni_get_context_id(jvpp_main_t * jm) {
+    return __sync_add_and_fetch(&jm->context_id, 1);
+}
+
+static_always_inline void vppjni_lock(jvpp_main_t * jm, u32 tag) {
+    while (__sync_lock_test_and_set(&jm->lock, 1))
+        ;
+    jm->tag = tag;
+}
+
+static_always_inline void vppjni_unlock(jvpp_main_t * jm) {
+    jm->tag = 0;
+    CLIB_MEMORY_BARRIER();
+    jm->lock = 0;
+}
+
+/**
+ * Calls onError callback on callbackObject reference. Passes instance of callbackExceptionClass as parameter.
+ */
+void call_on_error(const char* callName, int contextId, int retval,
+        jclass callbackClass, jobject callbackObject,
+        jclass callbackExceptionClass);
+
+#endif /* __included_jvpp_common_h__ */