Peter Reilly wrote:
On 9/21/07, Steve Loughran <[EMAIL PROTECTED]> wrote:
Peter Reilly wrote:
1) Some of the traces seem to imply a bug.
clearly :)
org.apache.tools.ant.taskdefs.Property$PropertyResolver.evaluate(Property.java:110)
at
org.apache.tools.ant.PropertyHelper.getProperty(PropertyHelper.java:787)
- locked <0x00002aaab4013548> (a
org.apache.tools.ant.PropertyHelper)
at
org.apache.tools.ant.PropertyHelper.parseNextProperty(PropertyHelper.java:541)
at
org.apache.tools.ant.PropertyHelper.parseProperties(PropertyHelper.java:502)
at
org.apache.tools.ant.RuntimeConfigurable.maybeConfigure(RuntimeConfigurable.java:390)
The intent of Property.PropertyResolver is I think to remain in
the Property task - the trace seems to imply that it has
escaped from that task.
I think it is looping. There is a per-thread stack to detect this, but
it isnt working. Otherwise the loop wouldnt happen.
This could be some wierd race condition in the JVM itself, which may be
reordering operations in the single thread. Remember, unless your
variable is tagged as volatile, or the block is synchronized, Java can
swap the order of actions. It can even reorder volatile access in Java <1.5
I know, but 1) I do not know why a ThreadLocal (shudder) is needed
here, this means that the code is more complicated than it needs to be.
and
I presume its a way of preventing recursion down the resolution path.
When I did something like this in some grid-standard XML variant of the
smartfrog language I just passed the stack down as an explicit parameter.
I dont like threadlocals as they are a way to consume more memory than
usual.
2) even with the above, the clone operation should have protected
the rest of the system as the tasks deletete is only added to
the cloned property helper which is local to the method.
makes sense
In any case, I think that the code is too slow for a very common code
path in ant.
well, let's get it working, then worry about performance. Actually, both
may be the same solution. If we can move to a stack param then the
concurrency logic changes.
-steve
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