1 files changed, 12 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/gc/marking-thread-count.js b/js/src/jit-test/tests/gc/marking-thread-count.js
new file mode 100644
index 0000000000..5b90e14186
--- /dev/null
+++ b/js/src/jit-test/tests/gc/marking-thread-count.js
@@ -0,0 +1,12 @@
+// |jit-test| skip-if: helperThreadCount() === 0
+
+let initialGCHelperThreadCount = gcparam('helperThreadCount');
+
+let prevHelperThreadCount = helperThreadCount();
+for (let i of [0, 1, 4, 8, 4, 0]) {
+  gcparam('markingThreadCount', i);
+  assertEq(gcparam('markingThreadCount'), i);
+  assertEq(gcparam('helperThreadCount'), initialGCHelperThreadCount);
+  assertEq(true, helperThreadCount() >= Math.max(prevHelperThreadCount, i));
+  prevHelperThreadCount = helperThreadCount();
+}