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https://issues.apache.org/jira/browse/METRON-601?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15712230#comment-15712230
]
ASF GitHub Bot commented on METRON-601:
---------------------------------------
Github user nickwallen commented on a diff in the pull request:
https://github.com/apache/incubator-metron/pull/381#discussion_r90467298
--- Diff:
metron-platform/metron-test-utilities/src/main/java/org/apache/metron/test/mock/MockHTable.java
---
@@ -437,15 +463,14 @@ public ResultScanner getScanner(byte[] family, byte[]
qualifier)
return getScanner(scan);
}
- List<Put> putLog = new ArrayList<>();
--- End diff --
Good that we're digging into this. I'm not totally sure that this is
thread-safe. You may be right. I have used `memoize` for a thread-safe,
lazy-loading cache. That's the use case I've seen others use it for. But
maybe with that hammer, everything is looking like a nail to me. :)
But in my opinion if `memoize` is not thread-safe, then `synchronizedList`
is not either. See the code snippets below. What `synchronizedList` is doing
seems to be a subset of what `memoize` does. No?
```
MemoizingSupplier(Supplier<T> delegate) {
this.delegate = delegate;
}
public T get() {
if(!this.initialized) {
synchronized(this) {
if(!this.initialized) {
Object t = this.delegate.get();
this.value = t;
this.initialized = true;
return t;
}
}
}
return this.value;
}
}
```
versus
```
ThreadSafeSupplier(Supplier<T> delegate) {
this.delegate = delegate;
}
public T get() {
Supplier var1 = this.delegate;
synchronized(this.delegate) {
return this.delegate.get();
}
}
}
```
> MockHTable Put Log is Not Thread Safe
> -------------------------------------
>
> Key: METRON-601
> URL: https://issues.apache.org/jira/browse/METRON-601
> Project: Metron
> Issue Type: Sub-task
> Reporter: Nick Allen
> Assignee: Nick Allen
>
> The MockHTable uses an ArrayList to store a log of Puts that have been
> submitted against the MockHTable. The MockHTable, along with the put log, is
> accessed from multiple threads during the integration tests. Access to the
> Put log is not thread safe, which is likely at least one cause of METRON-597.
> The Put log is used by multiple tests, but more so by the
> ProfilerIntegrationTest. This tests polls the list to block the thread until
> the expected number of Puts have been submitted. This is likely why this
> test is more impacted by this issue than others.
> The Put Log needs to made thread safe. See
> `org.apache.metron.test.mock.MockHTable.putLog`
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