Replace Collections.synchronizedMap() with ConcurrentHashMap?

[Jack Cai <gr...@gmail.com>]

I came across some occurances of Collections.synchronizedMap( new HashMap())
in Geronimo source code, and think it might be better to use
ConcurrentHashMap instead, especially in the case of hot classes like
ContextManager. I did a full search and found the below matches. If no
objections I'll create a patch to replace them.

-Jack

./plugins/console/console-filter/src/main/java/org/apache/geronimo/console/filter/XSRFHandler.java:
private Map<String, String> sessionMap = Collections.synchronizedMap(new
HashMap<String, String>());
./framework/modules/geronimo-crypto/src/main/java/org/apache/geronimo/crypto/EncryptionManager.java:
private static final Map<String, Encryption> ENCRYPTORS =
Collections.synchronizedMap(new HashMap<String, Encryption>());
./framework/modules/geronimo-plugin/src/main/java/org/apache/geronimo/system/plugin/PluginInstallerGBean.java:
asyncKeys = Collections.synchronizedMap(new HashMap<Object,
DownloadResults>());
./framework/modules/geronimo-plugin/src/main/java/org/apache/geronimo/system/plugin/PluginInstallerGBean.java:
asyncKeys = Collections.synchronizedMap(new HashMap<Object,
DownloadResults>());
./framework/modules/geronimo-plugin/src/main/java/org/apache/geronimo/system/plugin/PluginInstallerGBean.java:
asyncKeys = Collections.synchronizedMap(new HashMap<Object,
DownloadResults>());
./framework/modules/geronimo-jmx-remoting/src/main/java/org/apache/geronimo/jmxremoting/Authenticator.java:
private Map<String, LoginContext> contextMap =
Collections.synchronizedMap(new HashMap<String, LoginContext>());
./framework/modules/geronimo-security/src/main/java/org/apache/geronimo/security/ContextManager.java:
private static Map<SubjectId, Subject> subjectIds =
Collections.synchronizedMap(new HashMap<SubjectId, Subject>());