Fixed 742. Stress / robustness testing no longer provides erratic exceptions.

svn changeset:1529/svn branch:trunk

2 files changed, 367 insertions, 246 deletions

diff --git a/src/com/itmill/toolkit/service/License.java b/src/com/itmill/toolkit/service/License.java
index 327368802e..44fc17f70f 100644
--- a/src/com/itmill/toolkit/service/License.java
+++ b/src/com/itmill/toolkit/service/License.java
@@ -84,6 +84,49 @@ public class License {
 	 */
 	private Document licenseXML = null;
 
+	private boolean hasBeenRead;
+
+	/**
+	 * License properties
+	 */
+	private String number;
+
+	private String product;
+
+	private String edition;
+
+	private String versionDescription;
+
+	private String licenseeName;
+
+	private String purpose;
+
+	private int maxConcurrentUsers;
+
+	private int maxJVMs;
+
+	private String validUntilYear;
+
+	private String validUntilMonth;
+
+	private String validUntilDay;
+
+	private String classPrefix;
+
+	private int equalsToMajor;
+
+	private int equalsToOrIsLessThanMajor;
+
+	private int equalsToOrIsMoreThanMajor;
+
+	private int equalsToMinor;
+
+	private int equalsToOrIsLessThanMinor;
+
+	private int equalsToOrIsMoreThanMinor;
+
+	private boolean printLimitsOnInit;
+
 	/**
 	 * The signature has already been checked and is valid.
 	 */
@@ -100,9 +143,13 @@ public class License {
 	 *             Error parsing the license file
 	 * @throws IOException
 	 *             Error reading the license file
+	 * @throws LicenseSignatureIsInvalid
+	 * @throws LicenseFileHasNotBeenRead
+	 * @throws InvalidLicenseFile
 	 */
 	public void readLicenseFile(InputStream is) throws SAXException,
-			IOException {
+			IOException, InvalidLicenseFile, LicenseFileHasNotBeenRead,
+			LicenseSignatureIsInvalid {
 
 		// Once the license has been read, it stays
 		if (hasBeenRead())
@@ -116,6 +163,26 @@ public class License {
 		} catch (ParserConfigurationException e) {
 			throw new RuntimeException(e);
 		}
+
+		// Check validity of the signature
+		if (!isSignatureValid())
+			throw new LicenseSignatureIsInvalid();
+
+		// Read license contents to Java properties
+		number = this.getLicenseNumber();
+		product = this.getProductName();
+		edition = this.getProductEdition();
+		versionDescription = this.getVersionDescription();
+		licenseeName = this.getLicenseeName();
+		purpose = this.getPurpose();
+		maxConcurrentUsers = this.getMaxConcurrentUsers();
+		maxJVMs = this.getMaxJVMs();
+		classPrefix = getClassPrefix();
+		printLimitsOnInit = getPrintLimitsOnInit();
+		parseValidUntil();
+		parseVersion();
+
+		hasBeenRead = true;
 	}
 
 	/**
@@ -124,15 +191,18 @@ public class License {
 	 * @return true if the license-file has already been read.
 	 */
 	public boolean hasBeenRead() {
-		return licenseXML != null;
+		return hasBeenRead;
 	}
 
 	/** Should the license description be printed on (first) application init. */
-	public boolean shouldLimitsBePrintedOnInit()
-			throws LicenseFileHasNotBeenRead, LicenseSignatureIsInvalid,
-			InvalidLicenseFile {
+	public boolean shouldLimitsBePrintedOnInit() {
+		return printLimitsOnInit;
+	}
 
-		checkThatLicenseDOMisValid();
+	public boolean getPrintLimitsOnInit() throws LicenseFileHasNotBeenRead,
+			LicenseSignatureIsInvalid, InvalidLicenseFile {
+		// default value
+		printLimitsOnInit = true;
 
 		NodeList lL = licenseXML.getElementsByTagName("limits");
 		if (lL == null || lL.getLength() == 0)
@@ -156,39 +226,39 @@ public class License {
 	 *             if the license file has been changed or signature is
 	 *             otherwise invalid.
 	 */
-	public String getDescription() throws LicenseFileHasNotBeenRead,
-			InvalidLicenseFile, LicenseSignatureIsInvalid {
-
-		checkThatLicenseDOMisValid();
+	public String getDescription(String target)
+			throws LicenseFileHasNotBeenRead, InvalidLicenseFile,
+			LicenseSignatureIsInvalid {
 
 		StringBuffer d = new StringBuffer();
 		d.append("------------------ License Info -----------------------\n");
 
-		d.append("License number: " + getLicenseNumber() + "\n");
-
-		d.append("Product: " + getProductName());
-		if (getProductEdition() != null)
-			d.append("  Edition: " + getProductEdition());
+		d.append("Product: " + product);
+		if (edition != null)
+			d.append("  Edition: " + edition);
 		d.append("\n");
 
+		d.append("Target: " + target + "\n");
+
+		d.append("License number: " + number + "\n");
+
 		// Print version info
-		String versionDescription = getVersionDescription();
 		if (versionDescription != null)
 			d.append("Version: " + versionDescription + "\n");
 
-		if (getLicenseeName() != null)
-			d.append("Licensed to: " + getLicenseeName() + "\n");
+		if (this.licenseeName != null)
+			d.append("Licensed to: " + licenseeName + "\n");
 
-		if (getPurpose() != null)
-			d.append("Use is limited to: " + getPurpose() + "\n");
+		if (purpose != null)
+			d.append("Use is limited to: " + purpose + "\n");
 
-		if (getMaxConcurrentUsers() >= 0)
+		if (maxConcurrentUsers >= 0)
 			d.append("Maximum number of concurrent (active) users allowed: "
-					+ getMaxConcurrentUsers() + "\n");
+					+ maxConcurrentUsers + "\n");
 
-		if (getMaxJVMs() >= 0)
+		if (maxJVMs >= 0)
 			d.append("Maximum number of JVM:s this license"
-					+ " can be used concurrently: " + getMaxJVMs() + "\n");
+					+ " can be used concurrently: " + maxJVMs + "\n");
 
 		// Print valid-until date
 		NodeList vuL = licenseXML.getElementsByTagName("valid-until");
@@ -223,18 +293,6 @@ public class License {
 		return d.toString();
 	}
 
-	private void checkThatLicenseDOMisValid() throws LicenseFileHasNotBeenRead,
-			InvalidLicenseFile, LicenseSignatureIsInvalid {
-
-		// Check that the license file has already been read
-		if (!hasBeenRead())
-			throw new LicenseFileHasNotBeenRead();
-
-		// Check validity of the signature
-		if (!isSignatureValid())
-			throw new LicenseSignatureIsInvalid();
-	}
-
 	/**
 	 * Checks if the license valid for given usage?
 	 * 
@@ -263,67 +321,76 @@ public class License {
 	 * @throws LicenseViolation
 	 * 
 	 */
-	public void check(Class applicationClass, int concurrentUsers,
-			int majorVersion, int minorVersion, String productName,
-			String productEdition) throws LicenseFileHasNotBeenRead,
-			LicenseSignatureIsInvalid, InvalidLicenseFile, LicenseViolation {
-
-		checkThatLicenseDOMisValid();
-
+	public void check(Class applicationClass, int majorVersion,
+			int minorVersion, String productName, String productEdition)
+			throws LicenseFileHasNotBeenRead, LicenseSignatureIsInvalid,
+			InvalidLicenseFile, LicenseViolation {
 		// Check usage
 		checkProductNameAndEdition(productName, productEdition);
 		checkVersion(majorVersion, minorVersion);
-		checkConcurrentUsers(concurrentUsers);
 		checkApplicationClass(applicationClass);
-		checkDate();
+		checkValidUntil();
 	}
 
-	private void checkDate() throws LicenseViolation {
+	private void parseValidUntil() {
 		NodeList vuL = licenseXML.getElementsByTagName("valid-until");
 		if (vuL != null && vuL.getLength() > 0) {
 			Element e = (Element) vuL.item(0);
-			String year = e.getAttribute("year");
-			String month = e.getAttribute("month");
-			String day = e.getAttribute("day");
-			Calendar cal = Calendar.getInstance();
-			if ((year != null && year.length() > 0 && Integer.parseInt(year) < cal
-					.get(Calendar.YEAR))
-					|| (month != null && month.length() > 0 && Integer
-							.parseInt(month) < (1 + cal.get(Calendar.MONTH)))
-					|| (day != null && day.length() > 0 && Integer
-							.parseInt(day) < cal.get(Calendar.DAY_OF_MONTH)))
-				throw new LicenseViolation("The license is valid until " + year
-						+ "-" + month + "-" + day);
+			validUntilYear = e.getAttribute("year");
+			validUntilMonth = e.getAttribute("month");
+			validUntilDay = e.getAttribute("day");
 		}
 	}
 
-	private void checkApplicationClass(Class applicationClass)
-			throws LicenseViolation {
-		// check class
-		NodeList appL = licenseXML.getElementsByTagName("application");
-		if (appL != null && appL.getLength() > 0) {
-			String classPrefix = ((Element) appL.item(0))
-					.getAttribute("classPrefix");
-			if (classPrefix != null && classPrefix.length() > 0
-					&& !applicationClass.getName().startsWith(classPrefix))
-				throw new LicenseViolation(
-						"License limits application class prefix to '"
-								+ classPrefix
-								+ "' but requested application class is '"
-								+ applicationClass.getName() + "'");
+	private void parseVersion() {
+		// by default version check is not active
+		equalsToMajor = -1;
+		equalsToOrIsLessThanMajor = -1;
+		equalsToOrIsMoreThanMajor = -1;
+		equalsToMinor = -1;
+		equalsToOrIsLessThanMinor = -1;
+		equalsToOrIsMoreThanMinor = -1;
+
+		// parse version
+		NodeList verL = licenseXML.getElementsByTagName("version");
+		if (verL != null && verL.getLength() > 0) {
+			NodeList checks = verL.item(0).getChildNodes();
+			for (int i = 0; i < checks.getLength(); i++) {
+				Node n = checks.item(i);
+				if (n.getNodeType() == Node.ELEMENT_NODE) {
+					Element e = (Element) n;
+					String tag = e.getTagName();
+					String eq = e.getAttribute("equals-to");
+					String eqol = e.getAttribute("equals-to-or-is-less-than");
+					String eqom = e.getAttribute("equals-to-or-is-more-than");
+					if ("major".equalsIgnoreCase(tag)) {
+						if (eq != null && eq.length() > 0) {
+							equalsToMajor = Integer.parseInt(eq);
+						} else if (eqol != null && eqol.length() > 0) {
+							equalsToOrIsLessThanMajor = Integer.parseInt(eqol);
+						} else if (eqom != null && eqom.length() > 0) {
+							equalsToOrIsMoreThanMajor = Integer.parseInt(eqom);
+						}
+					} else if ("minor".equalsIgnoreCase(tag)) {
+						if (eq != null && eq.length() > 0) {
+							equalsToMinor = Integer.parseInt(eq);
+						} else if (eqol != null && eqol.length() > 0) {
+							equalsToOrIsLessThanMinor = Integer.parseInt(eqol);
+						} else if (eqom != null && eqom.length() > 0) {
+							equalsToOrIsMoreThanMinor = Integer.parseInt(eqom);
+						}
+					}
+				}
+			}
 		}
 	}
 
-	private void checkConcurrentUsers(int concurrentUsers)
-			throws TooManyConcurrentUsers {
-		int max = getMaxConcurrentUsers();
-		if (max >= 0 && concurrentUsers > max)
-			throw new TooManyConcurrentUsers(
-					"Currently "
-							+ concurrentUsers
-							+ " concurrent users are connected, while license sets limit to "
-							+ max);
-
+	private String getClassPrefix() {
+		NodeList appL = licenseXML.getElementsByTagName("application");
+		if (appL != null && appL.getLength() > 0) {
+			return ((Element) appL.item(0)).getAttribute("classPrefix");
+		}
+		return null;
 	}
 
 	private int getMaxConcurrentUsers() {
@@ -350,57 +417,6 @@ public class License {
 		return -1;
 	}
 
-	private void checkVersion(int majorVersion, int minorVersion)
-			throws LicenseViolation {
-		// check version
-		NodeList verL = licenseXML.getElementsByTagName("version");
-		if (verL != null && verL.getLength() > 0) {
-			NodeList checks = verL.item(0).getChildNodes();
-			for (int i = 0; i < checks.getLength(); i++) {
-				Node n = checks.item(i);
-				if (n.getNodeType() == Node.ELEMENT_NODE) {
-					Element e = (Element) n;
-					String tag = e.getTagName();
-					String eq = e.getAttribute("equals-to");
-					String eqol = e.getAttribute("equals-to-or-is-less-than");
-					String eqom = e.getAttribute("equals-to-or-is-more-than");
-					int value = -1;
-					if ("major".equalsIgnoreCase(tag)) {
-						value = majorVersion;
-					} else if ("minor".equalsIgnoreCase(tag)) {
-						value = minorVersion;
-					}
-					if (value >= 0) {
-						if (eq != null && eq.length() > 0)
-							if (value != Integer.parseInt(eq))
-								throw new LicenseViolation("Product " + tag
-										+ " version is " + value
-										+ " but license requires it to be "
-										+ eq);
-						if (eqol != null && eqol.length() > 0)
-							if (value > Integer.parseInt(eqol))
-								throw new LicenseViolation(
-										"Product "
-												+ tag
-												+ " version is "
-												+ value
-												+ " but license requires it to be equal or less than"
-												+ eqol);
-						if (eqom != null && eqom.length() > 0)
-							if (value < Integer.parseInt(eqom))
-								throw new LicenseViolation(
-										"Product "
-												+ tag
-												+ " version is "
-												+ value
-												+ " but license requires it to be equal or more than"
-												+ eqom);
-					}
-				}
-			}
-		}
-	}
-
 	private String getVersionDescription() {
 
 		StringBuffer v = new StringBuffer();
@@ -439,31 +455,6 @@ public class License {
 		v.append(tag + " version " + relation + " " + num);
 	}
 
-	private void checkProductNameAndEdition(String productName,
-			String productEdition) throws InvalidLicenseFile, LicenseViolation {
-		// Check product name
-		if (productName == null || productName.length() == 0)
-			throw new IllegalArgumentException(
-					"productName must not be empty or null");
-		if (productEdition != null && productEdition.length() == 0)
-			throw new IllegalArgumentException(
-					"productEdition must either be null (not present) or non-empty string");
-		String name = getProductName();
-		if (!name.equals(productName))
-			throw new LicenseViolation("The license file is for product '"
-					+ name + "' but it was requested to be used with '"
-					+ productName + "'");
-
-		// Check product edition
-		String edition = getProductEdition();
-		if (productEdition != null || edition != null)
-			if (edition == null || !edition.equals(productEdition))
-				throw new LicenseViolation("Requested edition '"
-						+ productEdition + "', but license-file is for '"
-						+ edition + "'");
-
-	}
-
 	private String getProductEdition() throws InvalidLicenseFile {
 		Element prod = (Element) licenseXML.getElementsByTagName("product")
 				.item(0);
@@ -541,7 +532,7 @@ public class License {
 		return lic.getAttribute("number");
 	}
 
-	private String getNormalizedLisenceData() throws InvalidLicenseFile,
+	private String getNormalizedLicenseData() throws InvalidLicenseFile,
 			LicenseFileHasNotBeenRead {
 
 		// License must be read before
@@ -650,7 +641,6 @@ public class License {
 			return true;
 
 		try {
-
 			// Get X.509 factory implementation
 			CertificateFactory x509factory = CertificateFactory
 					.getInstance("X.509");
@@ -665,12 +655,11 @@ public class License {
 			// Verify signature with DSA
 			Signature dsa = Signature.getInstance("SHA1withDSA");
 			dsa.initVerify(publicKey);
-			dsa.update(getNormalizedLisenceData().getBytes("UTF-8"));
+			dsa.update(getNormalizedLicenseData().getBytes("UTF-8"));
 			if (dsa.verify(getSignature())) {
 				signatureIsValid = true;
 				return true;
 			}
-
 		} catch (NoSuchAlgorithmException e) {
 			throw new RuntimeException(e);
 		} catch (InvalidKeyException e) {
@@ -687,6 +676,110 @@ public class License {
 		return false;
 	}
 
+	private void checkApplicationClass(Class applicationClass)
+			throws LicenseViolation {
+		if (classPrefix != null && classPrefix.length() > 0
+				&& !applicationClass.getName().startsWith(classPrefix))
+			throw new LicenseViolation(
+					"License limits application class prefix to '"
+							+ classPrefix
+							+ "' but requested application class is '"
+							+ applicationClass.getName() + "'");
+	}
+
+	public void checkConcurrentUsers(int concurrentUsers)
+			throws TooManyConcurrentUsers {
+		if (maxConcurrentUsers >= 0 && concurrentUsers > maxConcurrentUsers)
+			throw new TooManyConcurrentUsers(
+					"Currently "
+							+ concurrentUsers
+							+ " concurrent users are connected, while license sets limit to "
+							+ maxConcurrentUsers);
+
+	}
+
+	private void checkValidUntil() throws LicenseViolation {
+		Calendar cal = Calendar.getInstance();
+		if ((validUntilYear != null && validUntilYear.length() > 0 && Integer
+				.parseInt(validUntilYear) < cal.get(Calendar.YEAR))
+				|| (validUntilMonth != null && validUntilMonth.length() > 0 && Integer
+						.parseInt(validUntilMonth) < (1 + cal
+						.get(Calendar.MONTH)))
+				|| (validUntilDay != null && validUntilDay.length() > 0 && Integer
+						.parseInt(validUntilDay) < cal
+						.get(Calendar.DAY_OF_MONTH)))
+			throw new LicenseViolation("The license is valid until "
+					+ validUntilYear + "-" + validUntilMonth + "-"
+					+ validUntilDay);
+	}
+
+	private void checkVersion(int majorVersion, int minorVersion)
+			throws LicenseViolation {
+		// check minor version
+		if ((equalsToMinor != -1) && (equalsToMinor != minorVersion))
+			throw new LicenseViolation("Product minor version is "
+					+ minorVersion + " but license requires it to be "
+					+ equalsToMinor);
+
+		if ((equalsToOrIsLessThanMinor != -1)
+				&& (equalsToOrIsLessThanMinor < minorVersion))
+			throw new LicenseViolation("Product minor version is "
+					+ minorVersion
+					+ " but license requires it to be equal or less than"
+					+ equalsToOrIsLessThanMinor);
+
+		if ((equalsToOrIsMoreThanMinor != -1)
+				&& (equalsToOrIsMoreThanMinor > minorVersion))
+			throw new LicenseViolation("Product minor version is "
+					+ minorVersion
+					+ " but license requires it to be equal or more than"
+					+ equalsToOrIsMoreThanMinor);
+
+		// check major version
+		if ((equalsToMajor != -1) && (equalsToMajor != majorVersion))
+			throw new LicenseViolation("Product major version is "
+					+ majorVersion + " but license requires it to be "
+					+ equalsToMajor);
+
+		if ((equalsToOrIsLessThanMajor != -1)
+				&& (equalsToOrIsLessThanMajor < majorVersion))
+			throw new LicenseViolation("Product major version is "
+					+ majorVersion
+					+ " but license requires it to be equal or less than"
+					+ equalsToOrIsLessThanMajor);
+
+		if ((equalsToOrIsMoreThanMajor != -1)
+				&& (equalsToOrIsMoreThanMajor > majorVersion))
+			throw new LicenseViolation("Product major version is "
+					+ majorVersion
+					+ " but license requires it to be equal or more than"
+					+ equalsToOrIsMoreThanMajor);
+
+	}
+
+	private void checkProductNameAndEdition(String productName,
+			String productEdition) throws InvalidLicenseFile, LicenseViolation {
+		// Check product name
+		if (productName == null || productName.length() == 0)
+			throw new IllegalArgumentException(
+					"productName must not be empty or null");
+		if (productEdition != null && productEdition.length() == 0)
+			throw new IllegalArgumentException(
+					"productEdition must either be null (not present) or non-empty string");
+		if (!product.equals(productName))
+			throw new LicenseViolation("The license file is for product '"
+					+ product + "' but it was requested to be used with '"
+					+ productName + "'");
+
+		// Check product edition
+		if (productEdition != null || edition != null)
+			if (edition == null || !edition.equals(productEdition))
+				throw new LicenseViolation("Requested edition '"
+						+ productEdition + "', but license-file is for '"
+						+ edition + "'");
+
+	}
+
 	public class LicenseViolation extends Exception {
 
 		private static final long serialVersionUID = -1907168254265902098L;
diff --git a/src/com/itmill/toolkit/terminal/web/ApplicationServlet.java b/src/com/itmill/toolkit/terminal/web/ApplicationServlet.java
index 36e778044d..38e25ba7e1 100644
--- a/src/com/itmill/toolkit/terminal/web/ApplicationServlet.java
+++ b/src/com/itmill/toolkit/terminal/web/ApplicationServlet.java
@@ -164,17 +164,18 @@ public class ApplicationServlet extends HttpServlet implements
 
 	private static final String SESSION_BINDING_LISTENER = "itmill-toolkit-bindinglistener";
 
-	private WeakHashMap applicationToDirtyWindowSetMap = new WeakHashMap();
+	private static HashMap applicationToDirtyWindowSetMap = new HashMap();
 
-	private WeakHashMap applicationToServerCommandStreamLock = new WeakHashMap();
+	private static HashMap applicationToServerCommandStreamLock = new HashMap();
 
-	private static WeakHashMap applicationToLastRequestDate = new WeakHashMap();
+	private static HashMap applicationToLastRequestDate = new HashMap();
 
-	private static WeakHashMap applicationToAjaxAppMgrMap = new WeakHashMap();
+	private static HashMap applicationToAjaxAppMgrMap = new HashMap();
 
-	private WeakHashMap licenseForApplicationClass = new WeakHashMap();
+	// License for ApplicationServlets
+	private static HashMap licenseForApplicationClass = new HashMap();
 
-	private static WeakHashMap licensePrintedForApplicationClass = new WeakHashMap();
+	private static HashMap licensePrintedForApplicationClass = new HashMap();
 
 	// TODO Should default or base theme be the default?
 	protected static final String DEFAULT_THEME = "base";
@@ -545,7 +546,9 @@ public class ApplicationServlet extends HttpServlet implements
 				application = createApplication(request);
 
 			// Sets the last application request date
-			applicationToLastRequestDate.put(application, new Date());
+			synchronized (applicationToLastRequestDate) {
+				applicationToLastRequestDate.put(application, new Date());
+			}
 
 			// Invokes context transaction listeners
 			((WebApplicationContext) application.getContext())
@@ -712,8 +715,7 @@ public class ApplicationServlet extends HttpServlet implements
 					// If other than html or ajax mode is requested
 					if (wb.getRenderingMode() == WebBrowser.RENDERING_MODE_UNDEFINED
 							&& !(window instanceof DebugWindow)) {
-						// TODO More informal message should be given is browser
-						// is not supported
+						// TODO More informal message should be given to browser
 						response.setContentType("text/html");
 						BufferedWriter page = new BufferedWriter(
 								new OutputStreamWriter(out));
@@ -753,11 +755,11 @@ public class ApplicationServlet extends HttpServlet implements
 					paintTarget.close();
 
 					// For exception handling, memorize the current dirty status
-					WeakHashMap dirtyWindows = (WeakHashMap) applicationToDirtyWindowSetMap
+					HashMap dirtyWindows = (HashMap) applicationToDirtyWindowSetMap
 							.get(application);
 
 					if (dirtyWindows == null) {
-						dirtyWindows = new WeakHashMap();
+						dirtyWindows = new HashMap();
 						applicationToDirtyWindowSetMap.put(application,
 								dirtyWindows);
 					}
@@ -1452,12 +1454,14 @@ public class ApplicationServlet extends HttpServlet implements
 	 * @param application
 	 */
 	private void initializeLicense(Application application) {
-
-		License license = (License) licenseForApplicationClass.get(application
-				.getClass());
-		if (license == null) {
-			license = new License();
-			licenseForApplicationClass.put(application.getClass(), license);
+		License license;
+		synchronized (licenseForApplicationClass) {
+			license = (License) licenseForApplicationClass.get(application
+					.getClass());
+			if (license == null) {
+				license = new License();
+				licenseForApplicationClass.put(application.getClass(), license);
+			}
 		}
 		application.setToolkitLicense(license);
 	}
@@ -1481,49 +1485,67 @@ public class ApplicationServlet extends HttpServlet implements
 			throws LicenseFileHasNotBeenRead, LicenseSignatureIsInvalid,
 			InvalidLicenseFile, LicenseViolation, SAXException {
 		License license = application.getToolkitLicense();
-		if (!license.hasBeenRead()) {
-			InputStream lis;
-			try {
-				URL url = getServletContext().getResource(
-						"/WEB-INF/itmill-toolkit-license.xml");
-				if (url == null) {
-					throw new RuntimeException(
-							"License file could not be read. "
-									+ "You can install it to "
-									+ "WEB-INF/itmill-toolkit-license.xml.");
+
+		if (!license.hasBeenRead())
+			// Lock threads that have not yet read license
+			synchronized (license) {
+				if (!license.hasBeenRead()) {
+					InputStream lis;
+					try {
+						URL url = getServletContext().getResource(
+								"/WEB-INF/itmill-toolkit-license.xml");
+						if (url == null) {
+							throw new RuntimeException(
+									"License file could not be read. "
+											+ "You can install it to "
+											+ "WEB-INF/itmill-toolkit-license.xml.");
+						}
+						lis = url.openStream();
+						license.readLicenseFile(lis);
+					} catch (MalformedURLException e) {
+						// This should not happen
+						throw new RuntimeException(e);
+					} catch (IOException e) {
+						// This should not happen
+						throw new RuntimeException(e);
+					}
+
+					// For each application class, print license description -
+					// once
+					if (!licensePrintedForApplicationClass
+							.containsKey(applicationClass)) {
+						licensePrintedForApplicationClass.put(applicationClass,
+								Boolean.TRUE);
+						if (license.shouldLimitsBePrintedOnInit()) {
+							System.out.println(license
+									.getDescription(application.getClass()
+											.toString()));
+						}
+					}
+
+					// Checks license validity
+					try {
+						license.check(applicationClass, VERSION_MAJOR,
+								VERSION_MINOR, "IT Mill Toolkit", null);
+					} catch (LicenseFileHasNotBeenRead e) {
+						application.close();
+						throw e;
+					} catch (LicenseSignatureIsInvalid e) {
+						application.close();
+						throw e;
+					} catch (InvalidLicenseFile e) {
+						application.close();
+						throw e;
+					} catch (LicenseViolation e) {
+						application.close();
+						throw e;
+					}
 				}
-				lis = url.openStream();
-				license.readLicenseFile(lis);
-			} catch (MalformedURLException e) {
-				// This should not happen
-				throw new RuntimeException(e);
-			} catch (IOException e) {
-				// This should not happen
-				throw new RuntimeException(e);
 			}
-		}
 
-		// For each application class, print license description - once
-		if (!licensePrintedForApplicationClass.containsKey(applicationClass)) {
-			licensePrintedForApplicationClass.put(applicationClass,
-					Boolean.TRUE);
-			if (license.shouldLimitsBePrintedOnInit())
-				System.out.print(license.getDescription());
-		}
-
-		// Checks license validity
+		// Checks concurrent user limit
 		try {
-			license.check(applicationClass, getNumberOfActiveUsers() + 1,
-					VERSION_MAJOR, VERSION_MINOR, "IT Mill Toolkit", null);
-		} catch (LicenseFileHasNotBeenRead e) {
-			application.close();
-			throw e;
-		} catch (LicenseSignatureIsInvalid e) {
-			application.close();
-			throw e;
-		} catch (InvalidLicenseFile e) {
-			application.close();
-			throw e;
+			license.checkConcurrentUsers(getNumberOfActiveUsers() + 1);
 		} catch (LicenseViolation e) {
 			application.close();
 			throw e;
@@ -1540,14 +1562,17 @@ public class ApplicationServlet extends HttpServlet implements
 	 * @return the Number of active application instances in the server.
 	 */
 	private int getNumberOfActiveUsers() {
-
-		Set apps = applicationToLastRequestDate.keySet();
 		int active = 0;
-		long now = System.currentTimeMillis();
-		for (Iterator i = apps.iterator(); i.hasNext();) {
-			Date lastReq = (Date) applicationToLastRequestDate.get(i.next());
-			if (now - lastReq.getTime() < ACTIVE_USER_REQUEST_INTERVAL)
-				active++;
+
+		synchronized (applicationToLastRequestDate) {
+			Set apps = applicationToLastRequestDate.keySet();
+			long now = System.currentTimeMillis();
+			for (Iterator i = apps.iterator(); i.hasNext();) {
+				Date lastReq = (Date) applicationToLastRequestDate
+						.get(i.next());
+				if (now - lastReq.getTime() < ACTIVE_USER_REQUEST_INTERVAL)
+					active++;
+			}
 		}
 
 		return active;
@@ -1712,10 +1737,10 @@ public class ApplicationServlet extends HttpServlet implements
 	 */
 	protected void addDirtyWindow(Application application, Window window) {
 		synchronized (applicationToDirtyWindowSetMap) {
-			WeakHashMap dirtyWindows = (WeakHashMap) applicationToDirtyWindowSetMap
+			HashMap dirtyWindows = (HashMap) applicationToDirtyWindowSetMap
 					.get(application);
 			if (dirtyWindows == null) {
-				dirtyWindows = new WeakHashMap();
+				dirtyWindows = new HashMap();
 				applicationToDirtyWindowSetMap.put(application, dirtyWindows);
 			}
 			dirtyWindows.put(window, Boolean.TRUE);
@@ -1729,7 +1754,7 @@ public class ApplicationServlet extends HttpServlet implements
 	 */
 	protected void removeDirtyWindow(Application application, Window window) {
 		synchronized (applicationToDirtyWindowSetMap) {
-			WeakHashMap dirtyWindows = (WeakHashMap) applicationToDirtyWindowSetMap
+			HashMap dirtyWindows = (HashMap) applicationToDirtyWindowSetMap
 					.get(application);
 			if (dirtyWindows != null)
 				dirtyWindows.remove(window);
@@ -1792,10 +1817,9 @@ public class ApplicationServlet extends HttpServlet implements
 	 * @return
 	 */
 	protected Map getDirtyWindows(Application app) {
-		WeakHashMap dirtyWindows;
+		HashMap dirtyWindows;
 		synchronized (applicationToDirtyWindowSetMap) {
-			dirtyWindows = (WeakHashMap) applicationToDirtyWindowSetMap
-					.get(app);
+			dirtyWindows = (HashMap) applicationToDirtyWindowSetMap.get(app);
 		}
 		return (Map) dirtyWindows;
 	}
@@ -1863,8 +1887,11 @@ public class ApplicationServlet extends HttpServlet implements
 				synchronized (application) {
 
 					// Session expiration
-					Date lastRequest = (Date) applicationToLastRequestDate
-							.get(application);
+					Date lastRequest;
+					synchronized (applicationToLastRequestDate) {
+						lastRequest = (Date) applicationToLastRequestDate
+								.get(application);
+					}
 					if (lastRequest != null
 							&& lastRequest.getTime()
 									+ request.getSession()
@@ -1984,22 +2011,23 @@ public class ApplicationServlet extends HttpServlet implements
 							synchronized (lock) {
 								lock.notifyAll();
 							}
-						applicationToServerCommandStreamLock.remove(apps[i]);
 
+						// Remove application from hashmaps
+						synchronized (applicationToServerCommandStreamLock) {
+							applicationToServerCommandStreamLock
+									.remove(apps[i]);
+						}
+						synchronized (applicationToDirtyWindowSetMap) {
+							applicationToDirtyWindowSetMap.remove(apps[i]);
+						}
+						synchronized (applicationToLastRequestDate) {
+							applicationToLastRequestDate.remove(apps[i]);
+						}
+						synchronized (applicationToAjaxAppMgrMap) {
+							applicationToAjaxAppMgrMap.remove(apps[i]);
+						}
 						// Remove application from applications list
 						applications.remove(apps[i]);
-
-						// Remove application from hashmap
-						// TODO remove check
-						if (applicationToAjaxAppMgrMap
-								.get((Application) apps[i]) == null) {
-							System.out
-									.println("ERROR: tried to remove nonexistent application ("
-											+ (Application) apps[i] + ")");
-						} else {
-							applicationToAjaxAppMgrMap
-									.remove((Application) apps[i]);
-						}
 					}
 				}
 			}