Double-Checked Locking

[QiAnXinCodeSafe]

launcher/launcher-impl/glassfish/src/main/java/com/sun/web/security/RealmAdapter.java

Lines 511 to 522 in 0339f0b

	if (cnonces == null) {
	String appName = webDesc.getApplication().getAppName();
	synchronized (this) {
	if (this.haCNonceCacheMap == null) {
	this.haCNonceCacheMap = appCNonceCacheMapProvider.get();
	}
	if (this.haCNonceCacheMap != null) {
	//get the initialized HA CNonceCache
	cnonces = haCNonceCacheMap.get(appName);
	}
	if (cnonces == null) {

Double-Checked Locking is widely cited and used as an efficient method for implementing lazy initialization in a multithreaded environment.
Unfortunately, it will not work reliably in a platform independent way when implemented in Java, without additional synchronization.
declares the cnonces field volatile offers a much more elegant solution