activated rhino’s require() method and module.exports object; both work, but the default implementation cannot load packages which in turn require modules in relative subdirs.
a new property called commonjs.dir can be used to define an additional search directory. the app dir is added automatically.
as Map key, not the DbSource instance. Using the instance as key is both inefficient and
error prone (see fd0b77bc11).
Additional changes:
- modified getConnection() to check if the DB is oracle. "SELECT 1" is invalid
for Oracle DBs and lead to Helma dropping in-use connections every minute.
- set DbSource name final
The source of the deadlock problem seems that during DbSource.getConnection() ResourceProperties instances are compared using their equals() method, which is synchronized in Hashtable and can/does lead to deadlocks (see http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6582568).
This commit overwrites equals with an unsynchronized version. Note that this implementation might return a wrong result if one of the two instances is modified during this method call, but at least doesn't throw a ConcurrentModificationException.
the statistics of a cache instance for an application can be retrieved
by calling `app.__app__.getCacheStatistics()`. That's not very useful for the
default `ObjectCache` but essential for looking into what more complex cache
impls like `SwarmCache` do
we could remove all the other cache statistics methods like `getCacheUsage`
and output that info in the map returned by `getCacheStatistics()`
i had to bump java to 1.5 for the generics.. if that's a problem we can
remove the generics
one of our apps was stuck in a deadlock in ResourceProperties.size(),
see excerpt of the stack trace below. this fix synchronizes various overriding
methods since they are synchronized in Hashtable as well.
removed superfluous toString method too.
```
"app-230":
at java.util.Hashtable.size(Hashtable.java:206)
- waiting to lock <0xa13f8548> (a helma.util.ResourceProperties)
at helma.util.ResourceProperties.size(ResourceProperties.java:529)
at java.util.Hashtable.equals(Hashtable.java:742)
- locked <0xa1065708> (a helma.util.ResourceProperties)
at helma.objectmodel.db.DbSource.equals(DbSource.java:292)
...
"app-439":
at java.util.Hashtable.size(Hashtable.java:206)
- waiting to lock <0xa1065708> (a helma.util.ResourceProperties)
at helma.util.ResourceProperties.size(ResourceProperties.java:529)
at java.util.Hashtable.equals(Hashtable.java:742)
- locked <0xa13f8548> (a helma.util.ResourceProperties)
at helma.objectmodel.db.DbSource.equals(DbSource.java:292)
...
```
