Fix race in Thread.list

eregon · eregon · commit 2ef87ecb4063 · 2019-03-19T19:31:27.000+01:00
diff --git a/src/main/java/org/truffleruby/core/thread/ThreadManager.java b/src/main/java/org/truffleruby/core/thread/ThreadManager.java
@@ -626,7 +626,8 @@ private void doKillOtherThreads() {
 
     @TruffleBoundary
     public Object[] getThreadList() {
-        return runningRubyThreads.toArray(new Object[runningRubyThreads.size()]);
+        // This must not pre-allocate an array, or it could contain null's.
+        return runningRubyThreads.toArray();
     }
 
     @TruffleBoundary

Original file line number	Diff line number	Diff line change
`@@ -626,7 +626,8 @@ private void doKillOtherThreads() {`
`626`	`626`
`627`	`627`	`@TruffleBoundary`
`628`	`628`	`public Object[] getThreadList() {`
`629`		`- return runningRubyThreads.toArray(new Object[runningRubyThreads.size()]);`
	`629`	`+ // This must not pre-allocate an array, or it could contain null's.`
	`630`	`+ return runningRubyThreads.toArray();`
`630`	`631`	`}`
`631`	`632`
`632`	`633`	`@TruffleBoundary`