1 files changed, 54 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/gc/bug-1505622.js b/js/src/jit-test/tests/gc/bug-1505622.js
new file mode 100644
index 0000000000..3f6f83c076
--- /dev/null
+++ b/js/src/jit-test/tests/gc/bug-1505622.js
@@ -0,0 +1,54 @@
+// Test that we don't repeatedly trigger last-ditch GCs.
+
+// Turn of any zeal which will disrupt GC number checks.
+gczeal(0);
+
+function allocUntilFail() {
+  gc(null, 'shrinking');
+
+  const initialSize = gcparam("gcBytes");
+  const initialMaxSize = gcparam("maxBytes");
+  const initGCNumber = gcparam("majorGCNumber");
+
+  // Set a small heap limit.
+  gcparam("maxBytes", initialSize + 16 * 1024);
+
+  let error;
+  try {
+    let a = [];
+    while (true) {
+      a.push(Symbol()); // Symbols are tenured.
+    }
+  } catch(err) {
+    error = err;
+  }
+
+  const finalGCNumber = gcparam("majorGCNumber");
+
+  // Resetore heap limit.
+  gcparam("maxBytes", initialMaxSize);
+
+  gc();
+  assertEq(error, "out of memory");
+  return finalGCNumber - initGCNumber;
+}
+
+// Set the time limit for skipping last ditch GCs to 5 seconds.
+gcparam("minLastDitchGCPeriod", 5);
+assertEq(gcparam("minLastDitchGCPeriod"), 5);
+
+// Allocate up to the heap limit. This triggers a last ditch GC.
+let gcCount = allocUntilFail();
+assertEq(gcCount, 1)
+
+// Allocate up to the limit again. The second time we fail without
+// triggering a GC.
+gcCount = allocUntilFail();
+assertEq(gcCount, 0)
+
+// Wait for time limit to expire.
+sleep(6);
+
+// Check we trigger a GC again.
+gcCount = allocUntilFail();
+assertEq(gcCount, 1)