[KIEKER-530] ExecutionTrace, export set or copy of set

[rju]

JIRA Issue: KIEKER-530 ExecutionTrace, export set or copy of set Original Reporter: Jan Waller

---

#!java
/**
 * Returns a sorted set (unmodifiable) of {@link Execution}s in this trace.
 * 
 * @return the sorted set of {@link Execution}s in this trace
 */
public final SortedSet<Execution> getTraceAsSortedExecutionSet() {
    synchronized (this) {
        // TODO copy set? depends on whether later changes should be reflected ...
        return Collections.unmodifiableSortedSet(this.set);
    }
}

Checklist:

[rju]

author André van Hoorn -- Mon, 29 Jul 2013 16:55:55 +0200

Check whether add is called after getTraceAsSortedExecutionSet

[rju]

author André van Hoorn -- Mon, 2 Sep 2013 14:58:57 +0200

Replying to [avh|comment:4]:
> Check whether add is called after getTraceAsSortedExecutionSet

The add and getTraceAsSortedExecutionSet methods are currently called from the following places:

• TraceReconstructionFilter. The inputExecutions method creates ExecutionTrace objects and put them to pendingTraces and timeoutMap Maps. For each new Execution, The TraceReconstructionFilter looks up the corresponding ExecutionTrace (if existent, by trace ID) from the pendingTraces map and (if present) removes it from the timeoutMap. The removal from the timeoutMap involves a Comparator<ExecutionTrace>, which uses the getTraceAsSortedExecutionSet method to access the tin property of the first execution in the returned execution set. A call to getTraceAsSortedExecutionSet could be avoided here by providing a dedicated method for the earliest tin in an ExecutionTrace. But the situation seems fine. The add method is used to add the Execution to the ExecutionTrace (which is newly created if lookup failed). Conclusion for this class: Mixed use of add and getTraceAsSortedExecutionSet --- the latter being called very frequently as part of the map lookups.
• ExecutionTraceHashContainerAllocationEquivalence and ExecutionTraceHashContainerAssemblyEquivalence. These classes are used in the TraceEquivalenceClassFilter and call the getTraceAsSortedExecutionSet once at construction time to construct a hash code but potentially more frequently as part of the equals method (in case the hash key matches). However, for the latter, I don't really see why the ExecutionTrace's equals method is not used ...
• In various tests, the getTraceAsSortedExecutionSet method is used to obtain the set of Execution}}s from the complete (i.e., no more {{Execution}}s will be added) from the {{ExecutionTrace. Hence, for each ExecutionTrace a copy would be created once.

[rju]

author André van Hoorn -- Mon, 2 Sep 2013 16:18:12 +0200

Add comment that internal list returned (unmodifiable)

[rju]

author André van Hoorn -- Thu, 5 Sep 2013 15:20:15 +0200

Replying to [avh|comment:6]:
> Add comment that internal list returned (unmodifiable)

Extended the method comment in changeset:cad3fadaf4170cd9c79f918f95b610f19f21ce04/kieker-git

diff --git a/src/tools/kieker/tools/traceAnalysis/systemModel/ExecutionTrace.java b/src/tools/kieker/tools/traceAnalysis/systemModel/ExecutionTrace
index d42d272..8f12521 100644
--- a/src/tools/kieker/tools/traceAnalysis/systemModel/ExecutionTrace.java
+++ b/src/tools/kieker/tools/traceAnalysis/systemModel/ExecutionTrace.java
 -202,6 +202,10  public class ExecutionTrace extends AbstractTrace {
        /**
         * Returns a sorted set (unmodifiable) of {link Execution}s in this trace.
         * 
+        * Note that the returned data structure is the (wrapped )internal data structure of this {link ExecutionTrace} object, to which further elements may be added
+        * by the {link ExecutionTrace#add(Execution)} method. Consider to create a copy of the returned list, while synchronizing on this (i.e., the
+        * {link ExecutionTrace}) object.
+        * 
         * return the sorted set of {link Execution}s in this trace
         */
        public final SortedSet<Execution> getTraceAsSortedExecutionSet() {