Merge pull request #822 from nrgraham23/java_garbage_collection_bugfix

Java garbage collection bugfix

ompi/mpi/java/java/Comm.java

@@ -162,8 +162,8 @@ public class Comm implements Freeable, Cloneable
 	 */
 	public Comm dupWithInfo(Info info) throws MPIException
 	{
-	    MPI.check();
+		MPI.check();
-	    return new Comm(dupWithInfo(handle, info.handle));
+		return new Comm(dupWithInfo(handle, info.handle));
 	}
 
 	protected final native long dupWithInfo(long comm, long info) throws MPIException;
@@ -641,7 +641,9 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Request(iSend(handle, buf, count, type.handle, dest, tag));
+		Request req = new Request(iSend(handle, buf, count, type.handle, dest, tag));
+		req.addSendBufRef(buf);
+		return req;
 	}
 
 	private native long iSend(
@@ -666,7 +668,9 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Request(ibSend(handle, buf, count, type.handle, dest, tag));
+		Request req = new Request(ibSend(handle, buf, count, type.handle, dest, tag)); 
+		req.addSendBufRef(buf);
+		return req;
 	}
 
 	private native long ibSend(
@@ -691,7 +695,9 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Request(isSend(handle, buf, count, type.handle, dest, tag));
+		Request req = new Request(isSend(handle, buf, count, type.handle, dest, tag));
+		req.addSendBufRef(buf);
+		return req;
 	}
 
 	private native long isSend(
@@ -716,7 +722,9 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Request(irSend(handle, buf, count, type.handle, dest, tag));
+		Request req = new Request(irSend(handle, buf, count, type.handle, dest, tag));
+		req.addSendBufRef(buf);
+		return req;
 	}
 
 	private native long irSend(
@@ -741,7 +749,9 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Request(iRecv(handle, buf, count, type.handle, source, tag));
+		Request req = new Request(iRecv(handle, buf, count, type.handle, source, tag));
+		req.addRecvBufRef(buf);
+		return req;
 	}
 
 	private native long iRecv(
@@ -769,7 +779,9 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Prequest(sendInit(handle, buf, count, type.handle, dest, tag));
+		Prequest preq = new Prequest(sendInit(handle, buf, count, type.handle, dest, tag));
+		preq.addSendBufRef(buf);
+		return preq;
 	}
 
 	private native long sendInit(
@@ -794,7 +806,9 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Prequest(bSendInit(handle, buf, count, type.handle, dest, tag));
+		Prequest preq = new Prequest(bSendInit(handle, buf, count, type.handle, dest, tag));
+		preq.addSendBufRef(buf);
+		return preq;
 	}
 
 	private native long bSendInit(
@@ -819,7 +833,9 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Prequest(sSendInit(handle, buf, count, type.handle, dest, tag));
+		Prequest preq = new Prequest(sSendInit(handle, buf, count, type.handle, dest, tag));
+		preq.addSendBufRef(buf);
+		return preq;
 	}
 
 	private native long sSendInit(
@@ -844,7 +860,9 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Prequest(rSendInit(handle, buf, count, type.handle, dest, tag));
+		Prequest preq = new Prequest(rSendInit(handle, buf, count, type.handle, dest, tag));
+		preq.addSendBufRef(buf);
+		return preq;
 	}
 
 	private native long rSendInit(
@@ -869,7 +887,9 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Prequest(recvInit(handle, buf, count, type.handle, source, tag));
+		Prequest preq = new Prequest(recvInit(handle, buf, count, type.handle, source, tag));
+		preq.addRecvBufRef(buf);
+		return preq;
 	}
 
 	private native long recvInit(
@@ -1252,7 +1272,9 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Request(iBcast(handle, buf, count, type.handle, root));
+		Request req = new Request(iBcast(handle, buf, count, type.handle, root));
+		req.addSendBufRef(buf);
+		return req;
 	}
 
 	private native long iBcast(
@@ -1358,9 +1380,11 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iGather(handle, sendbuf, sendcount, sendtype.handle,
-		return new Request(iGather(handle, sendbuf, sendcount, sendtype.handle,
 				recvbuf, recvcount, recvtype.handle, root));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	/**
@@ -1381,9 +1405,10 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-
+		Request req = new Request(iGather(handle, null, 0, 0,
-		return new Request(iGather(handle, null, 0, 0,
 				buf, count, type.handle, root));
+		req.addRecvBufRef(buf);
+		return req;
 	}
 
 	private native long iGather(
@@ -1527,10 +1552,11 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iGatherv(
-		return new Request(iGatherv(
 				handle, sendbuf, sendcount, sendtype.handle,
 				recvbuf, recvcount, displs, recvtype.handle, root));
+		req.addSendBufRef(sendbuf);
+		return req;
 	}
 
 	/**
@@ -1553,9 +1579,10 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(recvbuf);
-
+		Request req = new Request(iGatherv(handle, null, 0, 0,
-		return new Request(iGatherv(handle, null, 0, 0,
 				recvbuf, recvcount, displs, recvtype.handle, root));
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	/**
@@ -1577,9 +1604,10 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(sendbuf);
-
+		Request req = new Request(iGatherv(handle, sendbuf, sendcount, sendtype.handle,
-		return new Request(iGatherv(handle, sendbuf, sendcount, sendtype.handle,
 				null, null, null, 0, root));
+		req.addSendBufRef(sendbuf);
+		return req;
 	}
 
 	private native long iGatherv(
@@ -1686,9 +1714,11 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iScatter(handle, sendbuf, sendcount, sendtype.handle,
-		return new Request(iScatter(handle, sendbuf, sendcount, sendtype.handle,
 				recvbuf, recvcount, recvtype.handle, root));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	/**
@@ -1709,9 +1739,10 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-
+		Request req = new Request(iScatter(handle, buf, count, type.handle,
-		return new Request(iScatter(handle, buf, count, type.handle,
 				null, 0, 0, root));
+		req.addSendBufRef(buf);
+		return req;
 	}
 
 	private native long iScatter(
@@ -1852,10 +1883,12 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iScatterv(
-		return new Request(iScatterv(
 				handle, sendbuf, sendcount, displs, sendtype.handle,
 				recvbuf, recvcount, recvtype.handle, root));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	/**
@@ -1877,9 +1910,10 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(sendbuf);
-
+		Request req = new Request(iScatterv(handle, sendbuf, sendcount, displs,
-		return new Request(iScatterv(handle, sendbuf, sendcount, displs,
 				sendtype.handle, null, 0, 0, root));
+		req.addSendBufRef(sendbuf);
+		return req;
 	}
 
 	/**
@@ -1900,9 +1934,10 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(recvbuf);
-
+		Request req = new Request(iScatterv(handle, null, null, null, 0,
-		return new Request(iScatterv(handle, null, null, null, 0,
 				recvbuf, recvcount, recvtype.handle, root));
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	private native long iScatterv(
@@ -2002,9 +2037,11 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iAllGather(handle, sendbuf, sendcount, sendtype.handle,
-		return new Request(iAllGather(handle, sendbuf, sendcount, sendtype.handle,
 				recvbuf, recvcount, recvtype.handle));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	/**
@@ -2022,7 +2059,9 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Request(iAllGather(handle, null, 0, 0, buf, count, type.handle));
+		Request req = new Request(iAllGather(handle, null, 0, 0, buf, count, type.handle));
+		req.addRecvBufRef(buf);
+		return req;
 	}
 
 	private native long iAllGather(
@@ -2127,10 +2166,12 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iAllGatherv(
-		return new Request(iAllGatherv(
 				handle, sendbuf, sendcount, sendtype.handle,
 				recvbuf, recvcount, displs, recvtype.handle));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	/**
@@ -2150,9 +2191,10 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-
+		Request req = new Request(iAllGatherv(
-		return new Request(iAllGatherv(
 				handle, null, 0, 0, buf, count, displs, type.handle));
+		req.addRecvBufRef(buf);
+		return req;
 	}
 
 	private native long iAllGatherv(
@@ -2227,9 +2269,11 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iAllToAll(handle, sendbuf, sendcount, sendtype.handle,
-		return new Request(iAllToAll(handle, sendbuf, sendcount, sendtype.handle,
 				recvbuf, recvcount, recvtype.handle));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	private native long iAllToAll(
@@ -2312,10 +2356,12 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iAllToAllv(
-		return new Request(iAllToAllv(
 				handle, sendbuf, sendcount, sdispls, sendtype.handle,
 				recvbuf, recvcount, rdispls, recvtype.handle));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	private native long iAllToAllv(long comm,
@@ -2385,10 +2431,12 @@ public class Comm implements Freeable, Cloneable
 
 		long[] sendHandles = convertTypeArray(sendTypes);
 		long[] recvHandles = convertTypeArray(recvTypes);
-
+		Request req = new Request(iAllToAllw(
-		return new Request(iAllToAllw(
 				handle, sendBuf, sendCount, sDispls, sendHandles,
 				recvBuf, recvCount, rDispls, recvHandles));
+		req.addSendBufRef(sendBuf);
+		req.addRecvBufRef(recvBuf);
+		return req;
 	}
 
 	private native long iAllToAllw(long comm,
@@ -2462,10 +2510,12 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iNeighborAllGather(
-		return new Request(iNeighborAllGather(
 				handle, sendbuf, sendcount, sendtype.handle,
 				recvbuf, recvcount, recvtype.handle));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	private native long iNeighborAllGather(
@@ -2540,10 +2590,12 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iNeighborAllGatherv(
-		return new Request(iNeighborAllGatherv(
 				handle, sendbuf, sendcount, sendtype.handle,
 				recvbuf, recvcount, displs, recvtype.handle));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	private native long iNeighborAllGatherv(
@@ -2617,10 +2669,12 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iNeighborAllToAll(
-		return new Request(iNeighborAllToAll(
 				handle, sendbuf, sendcount, sendtype.handle,
 				recvbuf, recvcount, recvtype.handle));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	private native long iNeighborAllToAll(
@@ -2698,10 +2752,12 @@ public class Comm implements Freeable, Cloneable
 	{
 		MPI.check();
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iNeighborAllToAllv(
-		return new Request(iNeighborAllToAllv(
 				handle, sendbuf, sendcount, sdispls, sendtype.handle,
 				recvbuf, recvcount, rdispls, recvtype.handle));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	private native long iNeighborAllToAllv(
@@ -2815,10 +2871,12 @@ public class Comm implements Freeable, Cloneable
 		MPI.check();
 		assertDirectBuffer(sendbuf, recvbuf);
 		op.setDatatype(type);
-
+		Request req = new Request(iReduce(
-		return new Request(iReduce(
 				handle, sendbuf, recvbuf, count,
 				type.handle, type.baseType, op, op.handle, root));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	/**
@@ -2842,10 +2900,11 @@ public class Comm implements Freeable, Cloneable
 		MPI.check();
 		assertDirectBuffer(buf);
 		op.setDatatype(type);
-
+		Request req = new Request(iReduce(
-		return new Request(iReduce(
 				handle, null, buf, count,
 				type.handle, type.baseType, op, op.handle, root));
+		req.addSendBufRef(buf);
+		return req;
 	}
 
 	private native long iReduce(
@@ -2946,9 +3005,11 @@ public class Comm implements Freeable, Cloneable
 		MPI.check();
 		assertDirectBuffer(sendbuf, recvbuf);
 		op.setDatatype(type);
-
+		Request req = new Request(iAllReduce(handle, sendbuf, recvbuf, count,
-		return new Request(iAllReduce(handle, sendbuf, recvbuf, count,
 				type.handle, type.baseType, op, op.handle));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	/**
@@ -2969,10 +3030,11 @@ public class Comm implements Freeable, Cloneable
 		MPI.check();
 		op.setDatatype(type);
 		assertDirectBuffer(buf);
-
+		Request req = new Request(iAllReduce(
-		return new Request(iAllReduce(
 				handle, null, buf, count,
 				type.handle, type.baseType, op, op.handle));
+		req.addRecvBufRef(buf);
+		return req;
 	}
 
 	private native long iAllReduce(
@@ -3075,10 +3137,12 @@ public class Comm implements Freeable, Cloneable
 		MPI.check();
 		op.setDatatype(type);
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iReduceScatter(
-		return new Request(iReduceScatter(
 				handle, sendbuf, recvbuf, recvcounts,
 				type.handle, type.baseType, op, op.handle));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	/**
@@ -3101,10 +3165,11 @@ public class Comm implements Freeable, Cloneable
 		MPI.check();
 		op.setDatatype(type);
 		assertDirectBuffer(buf);
-
+		Request req = new Request(iReduceScatter(
-		return new Request(iReduceScatter(
 				handle, null, buf, counts,
 				type.handle, type.baseType, op, op.handle));
+		req.addRecvBufRef(buf);
+		return req;
 	}
 
 	private native long iReduceScatter(
@@ -3202,10 +3267,12 @@ public class Comm implements Freeable, Cloneable
 		MPI.check();
 		op.setDatatype(type);
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iReduceScatterBlock(
-		return new Request(iReduceScatterBlock(
 				handle, sendbuf, recvbuf, recvcount,
 				type.handle, type.baseType, op, op.handle));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	/**
@@ -3226,10 +3293,11 @@ public class Comm implements Freeable, Cloneable
 		MPI.check();
 		op.setDatatype(type);
 		assertDirectBuffer(buf);
-
+		Request req = new Request(iReduceScatterBlock(
-		return new Request(iReduceScatterBlock(
 				handle, null, buf, count, type.handle,
 				type.baseType, op, op.handle));
+		req.addRecvBufRef(buf);
+		return req;
 	}
 
 	private native long iReduceScatterBlock(

ompi/mpi/java/java/File.java

@@ -396,7 +396,9 @@ public final class File
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Request(iReadAt(handle, offset, buf, count, type.handle));
+		Request req = new Request(iReadAt(handle, offset, buf, count, type.handle));
+		req.addRecvBufRef(buf);
+		return req;
 	}
 
 	private native long iReadAt(
@@ -417,7 +419,9 @@ public final class File
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Request(iWriteAt(handle, offset, buf, count, type.handle));
+		Request req = new Request(iWriteAt(handle, offset, buf, count, type.handle));
+		req.addSendBufRef(buf);
+		return req;
 	}
 
 	private native long iWriteAt(
@@ -552,7 +556,9 @@ public final class File
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Request(iRead(handle, buf, count, type.handle));
+		Request req = new Request(iRead(handle, buf, count, type.handle));
+		req.addRecvBufRef(buf);
+		return req;
 	}
 
 	private native long iRead(long fh, Buffer buf, int count, long type)
@@ -570,7 +576,9 @@ public final class File
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Request(iWrite(handle, buf, count, type.handle));
+		Request req = new Request(iWrite(handle, buf, count, type.handle));
+		req.addRecvBufRef(buf);
+		return req;
 	}
 
 	private native long iWrite(long fh, Buffer buf, int count, long type)
@@ -694,7 +702,9 @@ public final class File
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Request(iReadShared(handle, buf, count, type.handle));
+		Request req = new Request(iReadShared(handle, buf, count, type.handle));
+		req.addRecvBufRef(buf);
+		return req;
 	}
 
 	private native long iReadShared(long fh, Buffer buf, int count, long type)
@@ -713,7 +723,9 @@ public final class File
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Request(iWriteShared(handle, buf, count, type.handle));
+		Request req = new Request(iWriteShared(handle, buf, count, type.handle));
+		req.addSendBufRef(buf);
+		return req;
 	}
 
 	private native long iWriteShared(long fh, Buffer buf, int count, long type)

ompi/mpi/java/java/Intracomm.java

@@ -468,9 +468,11 @@ public class Intracomm extends Comm
 		MPI.check();
 		op.setDatatype(type);
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iScan(handle, sendbuf, recvbuf, count,
-		return new Request(iScan(handle, sendbuf, recvbuf, count,
 				type.handle, type.baseType, op, op.handle));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	/**
@@ -490,10 +492,11 @@ public class Intracomm extends Comm
 		MPI.check();
 		op.setDatatype(type);
 		assertDirectBuffer(buf);
-
+		Request req = new Request(iScan(
-		return new Request(iScan(
 				handle, null, buf, count,
 				type.handle, type.baseType, op, op.handle));
+		req.addSendBufRef(buf);
+		return req;
 	}
 
 	private native long iScan(
@@ -592,9 +595,11 @@ public class Intracomm extends Comm
 		MPI.check();
 		op.setDatatype(type);
 		assertDirectBuffer(sendbuf, recvbuf);
-
+		Request req = new Request(iExScan(handle, sendbuf, recvbuf, count,
-		return new Request(iExScan(handle, sendbuf, recvbuf, count,
 				type.handle, type.baseType, op, op.handle));
+		req.addSendBufRef(sendbuf);
+		req.addRecvBufRef(recvbuf);
+		return req;
 	}
 
 	/**
@@ -614,10 +619,11 @@ public class Intracomm extends Comm
 		MPI.check();
 		op.setDatatype(type);
 		assertDirectBuffer(buf);
-
+		Request req = new Request(iExScan(
-		return new Request(iExScan(
 				handle, null, buf, count,
 				type.handle, type.baseType, op, op.handle));
+		req.addRecvBufRef(buf);
+		return req;
 	}
 
 	private native long iExScan(

ompi/mpi/java/java/Message.java

@@ -152,7 +152,9 @@ public final class Message
 	{
 		MPI.check();
 		assertDirectBuffer(buf);
-		return new Request(imRecv(handle, buf, count, type.handle));
+		Request req = new Request(imRecv(handle, buf, count, type.handle));
+		req.addRecvBufRef(buf);
+		return req;
 	}
 
 	private native long imRecv(long message, Object buf, int count, long type)

ompi/mpi/java/java/Request.java

@@ -63,12 +63,16 @@
 
 package mpi;
 
+import java.nio.Buffer;
+
 /**
  * Request object.
  */
 public class Request implements Freeable
 {
 	protected long handle;
+	protected Buffer sendBuf;
+	protected Buffer recvBuf;
 
 	static
 	{
@@ -112,6 +116,32 @@ public class Request implements Freeable
 
 	private native void cancel(long request) throws MPIException;
 
+	/**
+	 * Adds a receive buffer to this Request object.  This method 
+	 * should be called by the internal api whenever a persistent 
+	 * request is created and any time a request object, that has 
+	 * an associated buffer, is returned from an opperation to protect 
+	 * the buffer from getting prematurely garbage collected.
+	 * @param buf buffer to add to the array list
+	 */
+	protected final void addRecvBufRef(Buffer buf)
+	{
+		this.recvBuf = buf;
+	}
+
+	/**
+	 * Adds a send buffer to this Request object.  This method 
+	 * should be called by the internal api whenever a persistent 
+	 * request is created and any time a request object, that has 
+	 * an associated buffer, is returned from an opperation to protect 
+	 * the buffer from getting prematurely garbage collected.
+	 * @param buf buffer to add to the array list
+	 */
+	protected final void addSendBufRef(Buffer buf)
+	{
+		this.sendBuf = buf;
+	}
+
 	/**
 	 * Test if request object is null.
 	 * @return true if the request object is null, false otherwise

ompi/mpi/java/java/Win.java

@@ -573,10 +573,11 @@ public final class Win implements Freeable
 	{
 		if(!origin_addr.isDirect())
 			throw new IllegalArgumentException("The origin must be direct buffer.");
-
+		Request req = new Request(rPut(handle, origin_addr, origin_count,
-		return new Request(rPut(handle, origin_addr, origin_count,
 				origin_datatype.handle, target_rank, target_disp,
 				target_count, target_datatype.handle, getBaseType(origin_datatype, target_datatype)));
+		req.addSendBufRef(origin_addr);
+		return req;
 	}
 
 	private native long rPut(long win, Buffer origin_addr, int origin_count,
@@ -605,10 +606,11 @@ public final class Win implements Freeable
 
 		if(!origin.isDirect())
 			throw new IllegalArgumentException("The origin must be direct buffer.");
-
+		Request req = new Request(rGet(handle, origin, orgCount, orgType.handle,
-		return new Request(rGet(handle, origin, orgCount, orgType.handle,
 				targetRank, targetDisp, targetCount, targetType.handle,
 				getBaseType(orgType, targetType)));
+		req.addRecvBufRef(origin);
+		return req;
 	}
 
 	private native long rGet(
@@ -638,10 +640,11 @@ public final class Win implements Freeable
 
 		if(!origin.isDirect())
 			throw new IllegalArgumentException("The origin must be direct buffer.");
-
+		Request req = new Request(rAccumulate(handle, origin, orgCount, orgType.handle,
-		return new Request(rAccumulate(handle, origin, orgCount, orgType.handle,
 				targetRank, targetDisp, targetCount, targetType.handle,
 				op, op.handle, getBaseType(orgType, targetType)));
+		req.addSendBufRef(origin);
+		return req;
 	}
 
 	private native long rAccumulate(
@@ -715,11 +718,12 @@ public final class Win implements Freeable
 
 		if(!origin.isDirect())
 			throw new IllegalArgumentException("The origin must be direct buffer.");
-
+		Request req = new Request(rGetAccumulate(handle, origin, orgCount, orgType.handle,
-		return new Request(rGetAccumulate(handle, origin, orgCount, orgType.handle,
 				resultAddr, resultCount, resultType.handle,
 				targetRank, targetDisp, targetCount, targetType.handle,
 				op, op.handle, getBaseType(orgType, targetType)));
+		req.addRecvBufRef(origin);
+		return req;
 	}
 
 	private native long rGetAccumulate(