From 3f143b8d6b5c20098e041e22be42216e668a4a0b Mon Sep 17 00:00:00 2001
From: Dmitry Neverov <dmitry.neverov@gmail.com>
Date: Thu, 13 May 2010 09:50:44 -0700
Subject: [PATCH] Fix missing flush in StreamCopyThread

It is possible to miss flush() invocation in StreamCopyThread.
In this case some data will not be sent to remote host and we will
wait forever (or until timeout) in src.read().

Use a counter to keep track of the flush requests.

Change-Id: Ia818be9b109a1674d9e2a9c78e125ab248cfb75b
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
 .../jgit/util/io/StreamCopyThread.java        | 22 ++++++++++++-------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/util/io/StreamCopyThread.java b/org.eclipse.jgit/src/org/eclipse/jgit/util/io/StreamCopyThread.java
index a2b954017..50f42ad4f 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/util/io/StreamCopyThread.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/util/io/StreamCopyThread.java
@@ -47,6 +47,7 @@
 import java.io.InputStream;
 import java.io.InterruptedIOException;
 import java.io.OutputStream;
+import java.util.concurrent.atomic.AtomicInteger;
 
 /** Thread to copy from an input stream to an output stream. */
 public class StreamCopyThread extends Thread {
@@ -56,7 +57,7 @@ public class StreamCopyThread extends Thread {
 
 	private final OutputStream dst;
 
-	private volatile boolean doFlush;
+	private final AtomicInteger flushCounter = new AtomicInteger(0);
 
 	/**
 	 * Create a thread to copy data from an input stream to an output stream.
@@ -82,10 +83,8 @@ public StreamCopyThread(final InputStream i, final OutputStream o) {
 	 * the request.
 	 */
 	public void flush() {
-		if (!doFlush) {
-			doFlush = true;
-			interrupt();
-		}
+		flushCounter.incrementAndGet();
+		interrupt();
 	}
 
 	@Override
@@ -94,10 +93,8 @@ public void run() {
 			final byte[] buf = new byte[BUFFER_SIZE];
 			for (;;) {
 				try {
-					if (doFlush) {
-						doFlush = false;
+					if (needFlush())
 						dst.flush();
-					}
 
 					final int n;
 					try {
@@ -125,4 +122,13 @@ public void run() {
 			}
 		}
 	}
+
+	private boolean needFlush() {
+		int i = flushCounter.get();
+		if (i > 0) {
+			flushCounter.decrementAndGet();
+			return true;
+		}
+		return false;
+	}
 }