From b4fe423690a23441673a103514a58a71b1f22d0d Mon Sep 17 00:00:00 2001
From: Daniel Dinu <daniedin@amazon.com>
Date: Thu, 12 Sep 2019 22:48:00 -0700
Subject: [PATCH] Fix stack overflow in KernelHost.run()

This commit fixes issue #778.
---
 packages/jsii-runtime/lib/host.ts         |  2 +-
 packages/jsii-runtime/package.json        |  2 +-
 packages/jsii-runtime/test/stress-test.ts | 26 +++++++++++++++++++++++
 3 files changed, 28 insertions(+), 2 deletions(-)
 create mode 100755 packages/jsii-runtime/test/stress-test.ts

diff --git a/packages/jsii-runtime/lib/host.ts b/packages/jsii-runtime/lib/host.ts
index 0f64ec06ae..6c57d80071 100644
--- a/packages/jsii-runtime/lib/host.ts
+++ b/packages/jsii-runtime/lib/host.ts
@@ -14,7 +14,7 @@ export class KernelHost {
             return; // done
         }
 
-        this.processRequest(req, () => this.run());
+        this.processRequest(req, () => setImmediate(() => this.run()));
     }
 
     private callbackHandler(callback: api.Callback) {
diff --git a/packages/jsii-runtime/package.json b/packages/jsii-runtime/package.json
index 0fcfb4df55..69d37d6740 100644
--- a/packages/jsii-runtime/package.json
+++ b/packages/jsii-runtime/package.json
@@ -10,7 +10,7 @@
   "scripts": {
     "build": "tsc --build && chmod +x bin/jsii-runtime && /bin/bash ./bundle.sh",
     "watch": "tsc --build -w",
-    "test": "/bin/bash test/playback-test.sh",
+    "test": "/bin/bash test/playback-test.sh && node test/stress-test.js",
     "package": "package-js"
   },
   "devDependencies": {
diff --git a/packages/jsii-runtime/test/stress-test.ts b/packages/jsii-runtime/test/stress-test.ts
new file mode 100755
index 0000000000..3af65107ec
--- /dev/null
+++ b/packages/jsii-runtime/test/stress-test.ts
@@ -0,0 +1,26 @@
+import { InputOutput, Input, Output } from "../lib/in-out";
+import { KernelHost } from "../lib/host";
+
+const requestCount = 250000;
+
+class FakeInputOutput extends InputOutput {
+    debug = false;
+    private count: number = 0;
+
+    write(_: Output) { }
+
+    read(): Input | undefined {
+        if(this.count == requestCount) {
+            return undefined;
+        }
+
+        ++this.count;
+        return { api: 'stats' };
+    }
+}
+
+const inout = new FakeInputOutput();
+const host = new KernelHost(inout, { debug: false, noStack: false });
+host.run();
+
+console.info("jsii-runtime stress test succeeded");