Author: rgodfrey
Date: Tue Jul 17 05:00:57 2007
New Revision: 556898
URL: http://svn.apache.org/viewvc?view=rev&rev=556898
Log:
QPID-541 : Change to use threadlocal maps for intern for the common case to
avoid excessive synchronization. In the uncommon case will require more lookup.
Modified:
incubator/qpid/branches/M2/java/common/src/main/java/org/apache/qpid/framing/AMQShortString.java
Modified:
incubator/qpid/branches/M2/java/common/src/main/java/org/apache/qpid/framing/AMQShortString.java
URL:
http://svn.apache.org/viewvc/incubator/qpid/branches/M2/java/common/src/main/java/org/apache/qpid/framing/AMQShortString.java?view=diff&rev=556898&r1=556897&r2=556898
==============================================================================
---
incubator/qpid/branches/M2/java/common/src/main/java/org/apache/qpid/framing/AMQShortString.java
(original)
+++
incubator/qpid/branches/M2/java/common/src/main/java/org/apache/qpid/framing/AMQShortString.java
Tue Jul 17 05:00:57 2007
@@ -39,7 +39,16 @@
public final class AMQShortString implements CharSequence,
Comparable<AMQShortString>
{
- private static final Map<AMQShortString, WeakReference<AMQShortString>>
internMap =
+ private static final ThreadLocal<Map<AMQShortString,
WeakReference<AMQShortString>>> _localInternMap =
+ new ThreadLocal<Map<AMQShortString,
WeakReference<AMQShortString>>>()
+ {
+ protected Map<AMQShortString, WeakReference<AMQShortString>>
initialValue()
+ {
+ return new WeakHashMap<AMQShortString,
WeakReference<AMQShortString>>();
+ };
+ };
+
+ private static final Map<AMQShortString, WeakReference<AMQShortString>>
_globalInternMap =
new WeakHashMap<AMQShortString, WeakReference<AMQShortString>>();
private static final Logger _logger =
LoggerFactory.getLogger(AMQShortString.class);
@@ -51,6 +60,7 @@
public AMQShortString(byte[] data)
{
+
_data = ByteBuffer.wrap(data);
_length = data.length;
}
@@ -387,23 +397,39 @@
public AMQShortString intern()
{
+
hashCode();
- synchronized(internMap)
+
+ Map<AMQShortString, WeakReference<AMQShortString>> localMap =
+ _localInternMap.get();
+
+ WeakReference<AMQShortString> ref = localMap.get(this);
+ AMQShortString internString;
+
+ if(ref != null)
+ {
+ internString = ref.get();
+ if(internString != null)
+ {
+ return internString;
+ }
+ }
+
+
+ synchronized(_globalInternMap)
{
- WeakReference<AMQShortString> ref = internMap.get(this);
- if(ref != null)
+ ref = _globalInternMap.get(this);
+ if((ref == null) || ((internString = ref.get()) == null))
{
- AMQShortString internString = ref.get();
- if(internString != null)
- {
- return internString;
- }
+ internString = new AMQShortString(getBytes());
+ ref = new WeakReference(internString);
+ _globalInternMap.put(internString, ref);
}
- AMQShortString internString = new AMQShortString(getBytes());
- internMap.put(internString, new WeakReference(internString));
- return internString;
}
+ localMap.put(internString, ref);
+ return internString;
+
}
}
