8064407: (fc) FileChannel transferTo should use TransmitFile on Windows

Reviewed-by: alanb
Contributed-by: kirk.shoop@microsoft.com, v-valkop@microsoft.com

src/share/classes/sun/nio/ch/FileChannelImpl.java

@@ -38,6 +38,7 @@ import java.nio.channels.NonReadableChannelException;
 import java.nio.channels.NonWritableChannelException;
 import java.nio.channels.OverlappingFileLockException;
 import java.nio.channels.ReadableByteChannel;
+import java.nio.channels.SelectableChannel;
 import java.nio.channels.WritableByteChannel;
 import java.security.AccessController;
 import java.util.ArrayList;
@@ -407,30 +408,13 @@ public class FileChannelImpl
     //
     private static volatile boolean fileSupported = true;
 
-    private long transferToDirectly(long position, int icount,
-                                    WritableByteChannel target)
+    private long transferToDirectlyInternal(long position, int icount,
+                                            WritableByteChannel target,
+                                            FileDescriptor targetFD)
         throws IOException
     {
-        if (!transferSupported)
-            return IOStatus.UNSUPPORTED;
-
-        FileDescriptor targetFD = null;
-        if (target instanceof FileChannelImpl) {
-            if (!fileSupported)
-                return IOStatus.UNSUPPORTED_CASE;
-            targetFD = ((FileChannelImpl)target).fd;
-        } else if (target instanceof SelChImpl) {
-            // Direct transfer to pipe causes EINVAL on some configurations
-            if ((target instanceof SinkChannelImpl) && !pipeSupported)
-                return IOStatus.UNSUPPORTED_CASE;
-            targetFD = ((SelChImpl)target).getFD();
-        }
-        if (targetFD == null)
-            return IOStatus.UNSUPPORTED;
-        int thisFDVal = IOUtil.fdVal(fd);
-        int targetFDVal = IOUtil.fdVal(targetFD);
-        if (thisFDVal == targetFDVal) // Not supported on some configurations
-            return IOStatus.UNSUPPORTED;
+        assert !nd.transferToDirectlyNeedsPositionLock() ||
+               Thread.holdsLock(positionLock);
 
         long n = -1;
         int ti = -1;
@@ -440,7 +424,7 @@ public class FileChannelImpl
             if (!isOpen())
                 return -1;
             do {
-                n = transferTo0(thisFDVal, position, icount, targetFDVal);
+                n = transferTo0(fd, position, icount, targetFD);
             } while ((n == IOStatus.INTERRUPTED) && isOpen());
             if (n == IOStatus.UNSUPPORTED_CASE) {
                 if (target instanceof SinkChannelImpl)
@@ -461,6 +445,54 @@ public class FileChannelImpl
         }
     }
 
+    private long transferToDirectly(long position, int icount,
+                                    WritableByteChannel target)
+        throws IOException
+    {
+        if (!transferSupported)
+            return IOStatus.UNSUPPORTED;
+
+        FileDescriptor targetFD = null;
+        if (target instanceof FileChannelImpl) {
+            if (!fileSupported)
+                return IOStatus.UNSUPPORTED_CASE;
+            targetFD = ((FileChannelImpl)target).fd;
+        } else if (target instanceof SelChImpl) {
+            // Direct transfer to pipe causes EINVAL on some configurations
+            if ((target instanceof SinkChannelImpl) && !pipeSupported)
+                return IOStatus.UNSUPPORTED_CASE;
+
+            // Platform-specific restrictions. Now there is only one:
+            // Direct transfer to non-blocking channel could be forbidden
+            SelectableChannel sc = (SelectableChannel)target;
+            if (!nd.canTransferToDirectly(sc))
+                return IOStatus.UNSUPPORTED_CASE;
+
+            targetFD = ((SelChImpl)target).getFD();
+        }
+
+        if (targetFD == null)
+            return IOStatus.UNSUPPORTED;
+        int thisFDVal = IOUtil.fdVal(fd);
+        int targetFDVal = IOUtil.fdVal(targetFD);
+        if (thisFDVal == targetFDVal) // Not supported on some configurations
+            return IOStatus.UNSUPPORTED;
+
+        if (nd.transferToDirectlyNeedsPositionLock()) {
+            synchronized (positionLock) {
+                long pos = position();
+                try {
+                    return transferToDirectlyInternal(position, icount,
+                                                      target, targetFD);
+                } finally {
+                    position(pos);
+                }
+            }
+        } else {
+            return transferToDirectlyInternal(position, icount, target, targetFD);
+        }
+    }
+
     // Maximum size to map when using a mapped buffer
     private static final long MAPPED_TRANSFER_SIZE = 8L*1024L*1024L;
 
@@ -1176,7 +1208,8 @@ public class FileChannelImpl
     private static native int unmap0(long address, long length);
 
     // Transfers from src to dst, or returns -2 if kernel can't do that
-    private native long transferTo0(int src, long position, long count, int dst);
+    private native long transferTo0(FileDescriptor src, long position,
+                                    long count, FileDescriptor dst);
 
     // Sets or reports this file's position
     // If offset is -1, the current position is returned

src/share/classes/sun/nio/ch/FileDispatcher.java

@@ -25,7 +25,9 @@
 
 package sun.nio.ch;
 
-import java.io.*;
+import java.io.FileDescriptor;
+import java.io.IOException;
+import java.nio.channels.SelectableChannel;
 
 abstract class FileDispatcher extends NativeDispatcher {
 
@@ -53,4 +55,8 @@ abstract class FileDispatcher extends NativeDispatcher {
      */
     abstract FileDescriptor duplicateForMapping(FileDescriptor fd)
         throws IOException;
+
+    abstract boolean canTransferToDirectly(SelectableChannel sc);
+
+    abstract boolean transferToDirectlyNeedsPositionLock();
 }

src/solaris/classes/sun/nio/ch/FileDispatcherImpl.java

@@ -25,10 +25,10 @@
 
 package sun.nio.ch;
 
-import java.io.*;
+import java.io.FileDescriptor;
+import java.io.IOException;
 
-class FileDispatcherImpl extends FileDispatcher
-{
+class FileDispatcherImpl extends FileDispatcher {
 
     static {
         IOUtil.load();
@@ -108,6 +108,14 @@ class FileDispatcherImpl extends FileDispatcher
         return new FileDescriptor();
     }
 
+    boolean canTransferToDirectly(java.nio.channels.SelectableChannel sc) {
+        return true;
+    }
+
+    boolean transferToDirectlyNeedsPositionLock() {
+        return false;
+    }
+
     // -- Native methods --
 
     static native int read0(FileDescriptor fd, long address, int len)

src/solaris/native/sun/nio/ch/FileChannelImpl.c

@@ -154,10 +154,13 @@ Java_sun_nio_ch_FileChannelImpl_close0(JNIEnv *env, jobject this, jobject fdo)
 
 JNIEXPORT jlong JNICALL
 Java_sun_nio_ch_FileChannelImpl_transferTo0(JNIEnv *env, jobject this,
-                                            jint srcFD,
+                                            jobject srcFDO,
                                             jlong position, jlong count,
-                                            jint dstFD)
+                                            jobject dstFDO)
 {
+    jint srcFD = fdval(env, srcFDO);
+    jint dstFD = fdval(env, dstFDO);
+
 #if defined(__linux__)
     off64_t offset = (off64_t)position;
     jlong n = sendfile64(dstFD, srcFD, &offset, (size_t)count);

src/windows/classes/sun/nio/ch/FileDispatcherImpl.java

@@ -25,15 +25,16 @@
 
 package sun.nio.ch;
 
-import java.io.*;
+import java.io.FileDescriptor;
+import java.io.IOException;
+import java.security.PrivilegedAction;
 import sun.misc.SharedSecrets;
 import sun.misc.JavaIOFileDescriptorAccess;
 
-class FileDispatcherImpl extends FileDispatcher
-{
-    static {
-        IOUtil.load();
-    }
+class FileDispatcherImpl extends FileDispatcher {
+
+    // set to true if fast file transmission (TransmitFile) is enabled
+    private static final boolean fastFileTransfer;
 
     /**
      * Indicates if the dispatcher should first advance the file position
@@ -120,6 +121,36 @@ class FileDispatcherImpl extends FileDispatcher
         return result;
     }
 
+    boolean canTransferToDirectly(java.nio.channels.SelectableChannel sc) {
+        return fastFileTransfer && sc.isBlocking();
+    }
+
+    boolean transferToDirectlyNeedsPositionLock() {
+        return true;
+    }
+
+    static boolean isFastFileTransferRequested() {
+        String fileTransferProp = java.security.AccessController.doPrivileged(
+            new PrivilegedAction<String>() {
+                @Override
+                public String run() {
+                    return System.getProperty("jdk.net.enableFastFileTransfer");
+                }
+            });
+        boolean enable;
+        if ("".equals(fileTransferProp)) {
+            enable = true;
+        } else {
+            enable = Boolean.parseBoolean(fileTransferProp);
+        }
+        return enable;
+    }
+
+    static {
+        IOUtil.load();
+        fastFileTransfer = isFastFileTransferRequested();
+    }
+
     //-- Native methods
 
     static native int read0(FileDescriptor fd, long address, int len)

src/windows/native/sun/nio/ch/FileChannelImpl.c

@@ -31,6 +31,10 @@
 #include "nio.h"
 #include "nio_util.h"
 #include "sun_nio_ch_FileChannelImpl.h"
+#include "java_lang_Integer.h"
+
+#include <Mswsock.h>
+#pragma comment(lib, "Mswsock.lib")
 
 static jfieldID chan_fd; /* id for jobject 'fd' in java.io.FileChannel */
 
@@ -174,9 +178,42 @@ Java_sun_nio_ch_FileChannelImpl_close0(JNIEnv *env, jobject this, jobject fdo)
 
 JNIEXPORT jlong JNICALL
 Java_sun_nio_ch_FileChannelImpl_transferTo0(JNIEnv *env, jobject this,
-                                            jint srcFD,
+                                            jobject srcFD,
                                             jlong position, jlong count,
-                                            jint dstFD)
+                                            jobject dstFD)
 {
-    return IOS_UNSUPPORTED;
+    const int PACKET_SIZE = 524288;
+
+    HANDLE src = (HANDLE)(handleval(env, srcFD));
+    SOCKET dst = (SOCKET)(fdval(env, dstFD));
+    DWORD chunkSize = (count > java_lang_Integer_MAX_VALUE) ?
+        java_lang_Integer_MAX_VALUE : (DWORD)count;
+    BOOL result = 0;
+
+    jlong pos = Java_sun_nio_ch_FileChannelImpl_position0(env, this, srcFD, position);
+    if (pos == IOS_THROWN) {
+        return IOS_THROWN;
+    }
+
+    result = TransmitFile(
+        dst,
+        src,
+        chunkSize,
+        PACKET_SIZE,
+        NULL,
+        NULL,
+        TF_USE_KERNEL_APC
+    );
+    if (!result) {
+        int error = WSAGetLastError();
+        if (WSAEINVAL == error && count >= 0) {
+            return IOS_UNSUPPORTED_CASE;
+        }
+        if (WSAENOTSOCK == error) {
+            return IOS_UNSUPPORTED_CASE;
+        }
+        JNU_ThrowIOExceptionWithLastError(env, "transfer failed");
+        return IOS_THROWN;
+    }
+    return chunkSize;
 }

test/java/nio/channels/FileChannel/TransferToChannel.java

@@ -24,6 +24,8 @@
 /* @test
  * @bug 4652496
  * @summary Test transferTo with different target channels
+ * @run main TransferToChannel
+ * @run main/othervm -Djdk.net.enableFastFileTransfer TransferToChannel
  */
 
 import java.nio.channels.FileChannel;