File locking fixed + test.

NnClassLoader.js

@@ -20,6 +20,7 @@ var File = java.io.File;
 var Files = java.nio.file.Files;
 var SCO = java.nio.file.StandardCopyOption;
 var System = java.lang.System;
+var Thread = java.lang.Thread;
 
 
 var DEBUG = java.lang.Boolean.getBoolean('NnClassLoader.debug');
@@ -153,7 +154,7 @@ function bytesToHex(b) {
 }
 
 function withOkLock(fun) {
-	var ok = file(path(WORK_DIR, ".ok"));
+	var ok = file(path(WORK_DIR, ".ok-" + MAVEN_VERSION));
 
 	if (ok.exists())
 		return;
@@ -165,14 +166,25 @@ function withOkLock(fun) {
 	if (!workDir.exists())
 		throw "Failed to create directory: " + WORK_DIR;
 
-	var lock = file(path(WORK_DIR, ".lock"));
-	lock.createNewFile();
+	var lockFile = file(path(WORK_DIR, ".lock"));
 
 	var RandomAccessFile = java.io.RandomAccessFile;
-	var raf = new RandomAccessFile(lock, "rw");
+	var OverlappingFileLockException = java.nio.channels.OverlappingFileLockException;
+
+	var raf = new RandomAccessFile(lockFile, "rw");
 
 	try {
-		var lock = raf.getChannel().lock();
+		var lock = null;
+
+		do {
+			try {
+				lock = raf.getChannel().lock();
+			}
+			catch(e if e instanceof OverlappingFileLockException) {
+				Thread.sleep(50);
+			}
+		}
+		while (lock === null);
 
 		try {
 			if (ok.exists())
@@ -183,8 +195,7 @@ function withOkLock(fun) {
 			ok.createNewFile();
 		}
 		finally {
-			if (lock != null)
-				lock.release();
+			lock.release();
 		}
 	}
 	finally {
@@ -310,7 +321,7 @@ function debugPrintStream() {
 }
 
 function setContextClassLoader(ldr) {
-	var th = java.lang.Thread.currentThread();
+	var th = Thread.currentThread();
 
 	var oldLdr = th.getContextClassLoader();
 

test/test-file-lock.js

@@ -0,0 +1,107 @@
+var Thread = java.lang.Thread;
+var File = java.io.File;
+var RandomAccessFile = java.io.RandomAccessFile;
+var OverlappingFileLockException = java.nio.channels.OverlappingFileLockException;
+var MapMode = java.nio.channels.FileChannel.MapMode;
+
+var stateFile = new File("/tmp/state");
+
+stateFile.createNewFile();
+
+var stateRaf = new RandomAccessFile(stateFile, "rw");
+var buf = stateRaf.getChannel().map(MapMode.READ_WRITE, 0, 24);
+
+function put(idx, v) {
+	buf.putLong(idx * 8, v);
+}
+
+function get(idx) {
+	return buf.getLong(idx * 8);
+}
+
+if (stateRaf.length() === 0) {
+	put(0, 1);
+	put(1, 2);
+	put(2, 3);
+}
+
+var lockFile = new File('/tmp/my_tmp_lock');
+lockFile.createNewFile();
+
+function withLock(fun) {
+	var raf = new RandomAccessFile(lockFile, "rw");
+
+	try {
+		var lock = null;
+
+		do {
+			try {
+				lock = raf.getChannel().lock();
+			}
+			catch(e if e instanceof OverlappingFileLockException) {
+				Thread.sleep(1);
+			}
+		}
+		while (lock === null)
+
+		try {
+			fun();
+		}
+		finally {
+			lock.release();
+		}
+	}
+	finally {
+		raf.close();
+	}
+}
+
+var THREADS = 16;
+var ITERATIONS = 100000;
+
+var pool = java.util.concurrent.Executors.newFixedThreadPool(THREADS);
+
+var futs = [];
+
+for (var i = 0; i < THREADS; i++) {
+	futs.push(pool['submit(Runnable)'](function() {
+		for (var j = 0; j < ITERATIONS; j++)
+			withLock(function() {
+				var min = get(0);
+				var mid = get(1);
+				var max = get(2);
+
+				// java.lang.System.out.println("  --> " + max + " = " + mid + " + " + min);
+
+				// Fibonacci sequence check
+				if (max !== min + mid)
+					throw "Error: " + max + " != " + mid + " + " + min;
+
+				// Too big value - restart the sequence.
+				if (max == 23416728348467684) { 
+					min = 1;
+					mid = 2;
+					max = 3;
+				}
+				else {
+					var oldMax = max;
+					var oldMid = mid;
+
+					max = max + mid;
+					mid = oldMax;
+					min = oldMid;
+				}
+
+				put(0, min);
+				put(1, mid);
+				put(2, max);
+
+				// buf.force();
+			})
+	}));
+}
+
+for each( var fut in futs)
+	fut.get();
+
+print('OK');