Improve ThreadFinder array handling

1 files changed, 5 insertions, 3 deletions

diff --git a/spark-common/src/main/java/me/lucko/spark/common/util/ThreadFinder.java b/spark-common/src/main/java/me/lucko/spark/common/util/ThreadFinder.java
index cc0722a..0d1cbd3 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/util/ThreadFinder.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/util/ThreadFinder.java
@@ -42,7 +42,7 @@ public final class ThreadFinder {
     // cache the approx active count at the time of construction.
     // the usages of this class are likely to be somewhat short-lived, so it's good
     // enough to just cache a value on init.
-    private final int approxActiveCount = ROOT_THREAD_GROUP.activeCount();
+    private int approxActiveCount = ROOT_THREAD_GROUP.activeCount();
 
     /**
      * Gets a stream of all known active threads.
@@ -50,10 +50,12 @@ public final class ThreadFinder {
      * @return a stream of threads
      */
     public Stream<Thread> getThreads() {
-        Thread[] threads = new Thread[this.approxActiveCount + 20]; // +20 to allow a bit of growth for newly created threads
-        while (ROOT_THREAD_GROUP.enumerate(threads, true) == threads.length) {
+        Thread[] threads = new Thread[this.approxActiveCount + 10]; // +10 to allow a bit of growth for newly created threads
+        int len;
+        while ((len = ROOT_THREAD_GROUP.enumerate(threads, true)) == threads.length) {
             threads = new Thread[threads.length * 2];
         }
+        this.approxActiveCount = len;
         return Arrays.stream(threads).filter(Objects::nonNull);
     }