3 import java.io.IOException;
4 import java.nio.ByteBuffer;
5 import java.util.Arrays;
6 import java.util.ArrayList;
7 import java.util.HashMap;
11 import java.lang.reflect.*;
13 import java.util.concurrent.*;
14 import java.util.concurrent.atomic.AtomicBoolean;
17 /** Abstract class IoTRMIComm is a class that combines IoTRMIObject and IoTRMICall
19 * We will arbitrate packets into 2 queues and wake up the right threads/callers.
20 * We separate traffics one-directionally.
22 * @author Rahmadi Trimananda <rtrimana @ uci.edu>
26 public abstract class IoTRMIComm {
31 protected IoTRMIUtil rmiUtil;
32 protected byte[] methodBytes;
33 protected byte[] retValueBytes;
34 protected ConcurrentLinkedQueue<byte[]> methodQueue;
35 protected ConcurrentLinkedQueue<byte[]> returnQueue;
36 protected Map<Integer,AtomicBoolean> mapSkeletonId;
37 protected Map<String,AtomicBoolean> mapStubId;
38 protected AtomicBoolean didGetMethodBytes;
39 protected AtomicBoolean didGetReturnBytes;
40 protected int objectIdCounter = Integer.MAX_VALUE;
43 * Constructor (for skeleton)
45 public IoTRMIComm() throws
46 ClassNotFoundException, InstantiationException,
47 IllegalAccessException, IOException {
49 rmiUtil = new IoTRMIUtil();
52 methodQueue = new ConcurrentLinkedQueue<byte[]>();
53 returnQueue = new ConcurrentLinkedQueue<byte[]>();
54 mapSkeletonId = new HashMap<Integer,AtomicBoolean>();
55 mapStubId = new HashMap<String,AtomicBoolean>();
56 didGetMethodBytes = new AtomicBoolean(false);
57 didGetReturnBytes = new AtomicBoolean(false);
58 wakeUpThreadOnMethodCall();
59 wakeUpThreadOnReturnValue();
64 * wakeUpThreadOnMethodCall() wakes up the correct thread when receiving method call
66 private void wakeUpThreadOnMethodCall() {
68 Thread thread = new Thread() {
71 // Take the current method from the queue and wake up the correct thread
72 methodBytes = methodQueue.poll();
73 if (methodBytes != null) { // If there is method bytes
74 int currObjId = getObjectId(methodBytes);
75 AtomicBoolean methRecv = mapSkeletonId.get(currObjId);
76 didGetMethodBytes.set(false);
77 while(!methRecv.compareAndSet(false, true));
78 while(!didGetMethodBytes.get()); // While skeleton is still processing
88 * wakeUpThreadOnReturnValue() wakes up the correct thread when receiving return value
90 private void wakeUpThreadOnReturnValue() {
92 Thread thread = new Thread() {
95 // Take the current method from the queue and wake up the correct thread
96 retValueBytes = returnQueue.poll();
97 if (retValueBytes != null) { // If there is method bytes
98 int objectId = getObjectId(retValueBytes);
99 int methodId = getMethodId(retValueBytes);
100 String strKey = objectId + "-" + methodId;
101 AtomicBoolean retRecv = mapStubId.get(strKey);
102 didGetReturnBytes.set(false);
103 while(!retRecv.compareAndSet(false, true));
104 while(!didGetReturnBytes.get()); // While skeleton is still processing
114 * registerSkeleton() registers the skeleton to be woken up
116 public synchronized void registerSkeleton(int objectId, AtomicBoolean methodReceived) {
118 mapSkeletonId.put(objectId, methodReceived);
123 * registerStub() registers the skeleton to be woken up
125 public synchronized void registerStub(int objectId, int methodId, AtomicBoolean retValueReceived) {
127 String strKey = objectId + "-" + methodId;
128 mapStubId.put(strKey, retValueReceived);
133 * getObjectIdCounter() gets object Id counter
135 public int getObjectIdCounter() {
137 return objectIdCounter;
142 * setObjectIdCounter() sets object Id counter
144 public void setObjectIdCounter(int objIdCounter) {
146 objectIdCounter = objIdCounter;
151 * decrementObjectIdCounter() gets object Id counter
153 public void decrementObjectIdCounter() {
160 * setGetMethodBytes() set didGetMethodBytes to true after getting the bytes
162 public boolean setGetMethodBytes() {
164 return didGetMethodBytes.compareAndSet(false, true);
169 * setGetReturnBytes() set didGetReturnBytes if there is a new return value already
171 public synchronized boolean setGetReturnBytes() {
173 return didGetReturnBytes.compareAndSet(false, true);
178 * getMethodBytes() get the method in bytes
180 public byte[] getMethodBytes() throws IOException {
182 // Just return the methodBytes content
188 * static version of getObjectId()
190 public static int getObjectId(byte[] packetBytes) {
192 // Get object Id bytes
193 byte[] objectIdBytes = new byte[IoTRMIUtil.OBJECT_ID_LEN];
194 System.arraycopy(packetBytes, 0, objectIdBytes, 0, IoTRMIUtil.OBJECT_ID_LEN);
196 int objectId = IoTRMIUtil.byteArrayToInt(objectIdBytes);
202 * static version of getMethodId()
204 public static int getMethodId(byte[] packetBytes) {
206 // Get method Id bytes
207 byte[] methodIdBytes = new byte[IoTRMIUtil.METHOD_ID_LEN];
208 // Method Id is positioned after object Id in the byte array
209 System.arraycopy(packetBytes, IoTRMIUtil.OBJECT_ID_LEN, methodIdBytes, 0, IoTRMIUtil.METHOD_ID_LEN);
211 int methodId = IoTRMIUtil.byteArrayToInt(methodIdBytes);
217 * static version of getPacketType() - either method or return value (position is after object Id and method Id)
219 public static int getPacketType(byte[] packetBytes) {
221 // Get packet type bytes
222 byte[] packetTypeBytes = new byte[IoTRMIUtil.PACKET_TYPE_LEN];
223 int offset = IoTRMIUtil.OBJECT_ID_LEN + IoTRMIUtil.METHOD_ID_LEN;
224 System.arraycopy(packetBytes, offset, packetTypeBytes, 0, IoTRMIUtil.PACKET_TYPE_LEN);
225 // Get packet type (for now we assume 1 as method and -1 as return value
226 int packetType = IoTRMIUtil.byteArrayToInt(packetTypeBytes);
232 * getMethodParams() gets method params based on byte array received
234 * Basically this is the format of a method in bytes:
235 * 1) 32-bit value of object ID
236 * 2) 32-bit value of method ID
237 * 3) m parameters with n-bit value each (m x n-bit)
238 * For the parameters that don't have definite length,
239 * we need to extract the length from a preceding 32-bit
240 * field in front of it.
242 * For primitive objects:
243 * | 32-bit object ID | 32-bit method ID | m-bit actual data (fixed length) | ...
245 * For string, arrays, and non-primitive objects:
246 * | 32-bit object ID | 32-bit method ID | 32-bit length | n-bit actual data | ...
249 public Object[] getMethodParams(Class<?>[] arrCls, Class<?>[] arrGenValCls, byte[] methodBytes) {
251 // Byte scanning position
252 int pos = IoTRMIUtil.OBJECT_ID_LEN + IoTRMIUtil.METHOD_ID_LEN + IoTRMIUtil.PACKET_TYPE_LEN;
253 Object[] paramObj = new Object[arrCls.length];
254 for (int i=0; i < arrCls.length; i++) {
256 String paramType = arrCls[i].getSimpleName();
257 int paramSize = rmiUtil.getTypeSize(paramType);
258 // Get the 32-bit field in the byte array to get the actual
259 // length (this is a param with indefinite length)
260 if (paramSize == -1) {
261 byte[] bytPrmLen = new byte[IoTRMIUtil.PARAM_LEN];
262 System.arraycopy(methodBytes, pos, bytPrmLen, 0, IoTRMIUtil.PARAM_LEN);
263 pos = pos + IoTRMIUtil.PARAM_LEN;
264 paramSize = IoTRMIUtil.byteArrayToInt(bytPrmLen);
266 byte[] paramBytes = new byte[paramSize];
267 System.arraycopy(methodBytes, pos, paramBytes, 0, paramSize);
268 pos = pos + paramSize;
269 paramObj[i] = IoTRMIUtil.getParamObject(arrCls[i], arrGenValCls[i], paramBytes);
277 * sendReturnObj() abstract version
279 public abstract void sendReturnObj(Object retObj, byte[] methodBytes);
283 * sendReturnObj() abstract version
285 public abstract void sendReturnObj(Class<?>[] retCls, Object[] retObj, byte[] methodBytes);
289 * returnToBytes() takes array of objects and generates bytes
291 public byte[] returnToBytes(Class<?>[] retCls, Object[] retObj) {
293 // Get byte arrays and calculate method bytes length
294 int numbRet = retObj.length;
296 byte[][] objBytesArr = new byte[numbRet][];
297 for (int i = 0; i < numbRet; i++) {
298 // Get byte arrays for the objects
299 objBytesArr[i] = IoTRMIUtil.getObjectBytes(retObj[i]);
300 String clsName = retCls[i].getSimpleName();
301 int retObjLen = rmiUtil.getTypeSize(clsName);
302 if (retObjLen == -1) { // indefinite length - store the length first
303 retLen = retLen + IoTRMIUtil.RETURN_LEN;
305 retLen = retLen + objBytesArr[i].length;
307 // Construct return in byte array
308 byte[] retBytes = new byte[retLen];
310 // Iteration for copying bytes
311 for (int i = 0; i < numbRet; i++) {
313 String clsName = retCls[i].getSimpleName();
314 int retObjLen = rmiUtil.getTypeSize(clsName);
315 if (retObjLen == -1) { // indefinite length
316 retObjLen = objBytesArr[i].length;
317 byte[] retLenBytes = IoTRMIUtil.intToByteArray(retObjLen);
318 System.arraycopy(retLenBytes, 0, retBytes, pos, IoTRMIUtil.RETURN_LEN);
319 pos = pos + IoTRMIUtil.RETURN_LEN;
321 System.arraycopy(objBytesArr[i], 0, retBytes, pos, retObjLen);
322 pos = pos + retObjLen;
330 * remoteCall() abstract version
332 public abstract void remoteCall(int objectId, int methodId, Class<?>[] paramCls, Object[] paramObj);
336 * methodToBytes() returns byte representation of a method
338 public byte[] methodToBytes(int objectId, int methId, Class<?>[] paramCls, Object[] paramObj) {
340 // Initialized to the length of method ID
341 int methodLen = IoTRMIUtil.OBJECT_ID_LEN;
342 byte[] objId = IoTRMIUtil.intToByteArray(objectId);
343 // Get method ID in bytes
344 byte[] methodId = IoTRMIUtil.intToByteArray(methId);
345 // Get byte arrays and calculate method bytes length
346 int numbParam = paramObj.length;
347 methodLen = methodLen + IoTRMIUtil.METHOD_ID_LEN;
348 methodLen = methodLen + IoTRMIUtil.PACKET_TYPE_LEN;
349 byte[][] objBytesArr = new byte[numbParam][];
350 for (int i = 0; i < numbParam; i++) {
351 // Get byte arrays for the objects
352 objBytesArr[i] = IoTRMIUtil.getObjectBytes(paramObj[i]);
353 String clsName = paramCls[i].getSimpleName();
354 int paramLen = rmiUtil.getTypeSize(clsName);
355 if (paramLen == -1) { // indefinite length - store the length first
356 methodLen = methodLen + IoTRMIUtil.PARAM_LEN;
358 methodLen = methodLen + objBytesArr[i].length;
360 // Construct method in byte array
361 byte[] method = new byte[methodLen];
363 System.arraycopy(objId, 0, method, 0, IoTRMIUtil.METHOD_ID_LEN);
364 pos = pos + IoTRMIUtil.OBJECT_ID_LEN;
365 System.arraycopy(methodId, 0, method, pos, IoTRMIUtil.METHOD_ID_LEN);
366 pos = pos + IoTRMIUtil.METHOD_ID_LEN;
367 int packetType = IoTRMIUtil.METHOD_TYPE; // This is a method
368 byte[] packetTypeBytes = IoTRMIUtil.intToByteArray(packetType);
369 System.arraycopy(packetTypeBytes, 0, method, pos, IoTRMIUtil.PACKET_TYPE_LEN);
370 pos = pos + IoTRMIUtil.PACKET_TYPE_LEN;
371 // Second iteration for copying bytes
372 for (int i = 0; i < numbParam; i++) {
374 String clsName = paramCls[i].getSimpleName();
375 int paramLen = rmiUtil.getTypeSize(clsName);
376 if (paramLen == -1) { // indefinite length
377 paramLen = objBytesArr[i].length;
378 byte[] paramLenBytes = IoTRMIUtil.intToByteArray(paramLen);
379 System.arraycopy(paramLenBytes, 0, method, pos, IoTRMIUtil.PARAM_LEN);
380 pos = pos + IoTRMIUtil.PARAM_LEN;
382 System.arraycopy(objBytesArr[i], 0, method, pos, paramLen);
383 pos = pos + paramLen;
391 * getReturnValue() returns return value object
393 public Object getReturnValue(Class<?> retType, Class<?> retGenTypeVal) {
395 // Receive return value and return it to caller
396 // Now just strip off the object ID and method ID
397 int headerLen = IoTRMIUtil.OBJECT_ID_LEN + IoTRMIUtil.METHOD_ID_LEN + IoTRMIUtil.PACKET_TYPE_LEN;
398 int valByteLen = retValueBytes.length - headerLen;
399 byte[] retValBytes = new byte[valByteLen];
400 // Method Id is positioned after object Id in the byte array
401 Object retObj = null;
402 if (valByteLen != 0) {
403 System.arraycopy(retValueBytes, headerLen, retValBytes, 0, valByteLen);
404 retObj = IoTRMIUtil.getParamObject(retType, retGenTypeVal, retValBytes);
406 // This means the right object and method have gotten the return value, so we set this back to false
412 * getStructObjects() calls a method remotely by passing in parameters and getting a return Object
414 public Object[] getStructObjects(Class<?>[] retType, Class<?>[] retGenTypeVal) {
416 // Receive return value and return it to caller
417 // Now just strip off the object ID and method ID
418 int headerLen = IoTRMIUtil.OBJECT_ID_LEN + IoTRMIUtil.METHOD_ID_LEN + IoTRMIUtil.PACKET_TYPE_LEN;
419 int valByteLen = retValueBytes.length - headerLen;
420 byte[] retValBytes = new byte[valByteLen];
421 // Method Id is positioned after object Id in the byte array
422 System.arraycopy(retValueBytes, headerLen, retValBytes, 0, valByteLen);
423 Object[] retObj = getReturnObjects(retValBytes, retType, retGenTypeVal);
430 * remoteCall() calls a method remotely by passing in parameters and getting a return Object
432 public Object[] getReturnObjects(byte[] retBytes, Class<?>[] arrCls, Class<?>[] arrGenValCls) {
434 // Byte scanning position
436 Object[] retObj = new Object[arrCls.length];
437 for (int i=0; i < arrCls.length; i++) {
439 String retType = arrCls[i].getSimpleName();
440 int retSize = rmiUtil.getTypeSize(retType);
441 // Get the 32-bit field in the byte array to get the actual
442 // length (this is a param with indefinite length)
444 byte[] bytRetLen = new byte[IoTRMIUtil.RETURN_LEN];
445 System.arraycopy(retBytes, pos, bytRetLen, 0, IoTRMIUtil.RETURN_LEN);
446 pos = pos + IoTRMIUtil.RETURN_LEN;
447 retSize = IoTRMIUtil.byteArrayToInt(bytRetLen);
449 byte[] retObjBytes = new byte[retSize];
450 System.arraycopy(retBytes, pos, retObjBytes, 0, retSize);
452 retObj[i] = IoTRMIUtil.getParamObject(arrCls[i], arrGenValCls[i], retObjBytes);