[inspector] avoid cloning of async call chains

test/inspector/debugger/collect-old-async-call-chains.js

Index: test/inspector/debugger/collect-old-async-call-chains.js
diff --git a/test/inspector/debugger/collect-old-async-call-chains.js b/test/inspector/debugger/collect-old-async-call-chains.js
new file mode 100644
index 0000000000000000000000000000000000000000..f96df88fd5e152c29a32d26747703237ed53381e
--- /dev/null
+++ b/test/inspector/debugger/collect-old-async-call-chains.js
@@ -0,0 +1,171 @@
+// Copyright 2017 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+InspectorTest.log('Checks that we drop old async call chains.');
+
+Protocol.Debugger.enable();
+Protocol.Runtime.enable();
+InspectorTest.runAsyncTestSuite([
+  async function testInfrastructure() {
+    Protocol.Debugger.setAsyncCallStackDepth({maxDepth: 128});
+    await setMaxAsyncTaskStacks(1024);
+    runWithAsyncChainPromise(1, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(1024);
+    runWithAsyncChainPromise(2, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(1024);
+    runWithAsyncChainPromise(5, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(1024);
+    runWithAsyncChainSetTimeout(1, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(1024);
+    runWithAsyncChainSetTimeout(2, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(1024);
+    runWithAsyncChainSetTimeout(5, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+  },
+
+  async function testZeroLimit() {
+    const limit = 0;
+    Protocol.Debugger.setAsyncCallStackDepth({maxDepth: 128});
+
+    await setMaxAsyncTaskStacks(limit);
+    runWithAsyncChainPromise(1, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(limit);
+    runWithAsyncChainPromise(2, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(limit);
+    runWithAsyncChainSetTimeout(1, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(limit);
+    runWithAsyncChainSetTimeout(2, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+  },
+
+  async function testOneLimit() {
+    const limit = 1;
+    Protocol.Debugger.setAsyncCallStackDepth({maxDepth: 128});
+
+    await setMaxAsyncTaskStacks(limit);
+    runWithAsyncChainPromise(1, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(limit);
+    runWithAsyncChainPromise(2, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(limit);
+    runWithAsyncChainSetTimeout(1, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(limit);
+    runWithAsyncChainSetTimeout(2, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+  },
+
+  async function testTwoLimit() {
+    const limit = 2;
+    Protocol.Debugger.setAsyncCallStackDepth({maxDepth: 128});
+
+    await setMaxAsyncTaskStacks(limit);
+    runWithAsyncChainPromise(1, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(limit);
+    runWithAsyncChainPromise(2, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(limit);
+    runWithAsyncChainPromise(3, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(limit);
+    runWithAsyncChainSetTimeout(1, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(limit);
+    runWithAsyncChainSetTimeout(2, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+    await setMaxAsyncTaskStacks(limit);
+    runWithAsyncChainSetTimeout(3, 'console.trace(42)');
+    dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+  },
+
+  async function testMoreThanTwoLimit() {
+    for (let limit = 3; limit <= 7; ++limit) {
+      Protocol.Debugger.setAsyncCallStackDepth({maxDepth: 128});
+
+      await setMaxAsyncTaskStacks(limit);
+      runWithAsyncChainPromise(1, 'console.trace(42)');
+      dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+      await setMaxAsyncTaskStacks(limit);
+      runWithAsyncChainPromise(2, 'console.trace(42)');
+      dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+      await setMaxAsyncTaskStacks(limit);
+      runWithAsyncChainPromise(3, 'console.trace(42)');
+      dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+      await setMaxAsyncTaskStacks(limit);
+      runWithAsyncChainSetTimeout(1, 'console.trace(42)');
+      dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+      await setMaxAsyncTaskStacks(limit);
+      runWithAsyncChainSetTimeout(2, 'console.trace(42)');
+      dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+
+      await setMaxAsyncTaskStacks(limit);
+      runWithAsyncChainSetTimeout(3, 'console.trace(42)');
+      dumpAsyncChainLength(await Protocol.Runtime.onceConsoleAPICalled());
+    }
+  },
+]);
+
+function runWithAsyncChainPromise(len, source) {
+  InspectorTest.log(`Run expression '${source}' with async chain len: ${len}`);
+  let then = '.then(() => 1)';
+  let pause = `.then(() => { ${source} })`;
+  Protocol.Runtime.evaluate({
+    expression: `Promise.resolve()${then.repeat(len - 1)}${pause}`
+  });
+}
+
+function runWithAsyncChainSetTimeout(len, source) {
+  InspectorTest.log(`Run expression '${source}' with async chain len: ${len}`);
+  let setTimeoutPrefix = '() => setTimeout(';
+  let setTimeoutSuffix = ', 0)';
+  Protocol.Runtime.evaluate({
+    expression: `setTimeout(${setTimeoutPrefix.repeat(len - 1)}'${source}'${setTimeoutSuffix.repeat(len - 1)}, 0)`
+  });
+}
+
+function dumpAsyncChainLength(message) {
+  let stackTrace = message.params.asyncStackTrace || message.params.stackTrace.parent;
+  let asyncChainCount = 0;
+  while (stackTrace) {
+    ++asyncChainCount;
+    stackTrace = stackTrace.parent;
+  }
+  InspectorTest.log(`actual async chain len: ${asyncChainCount}\n`);
+}
+
+async function setMaxAsyncTaskStacks(max) {
+  let expression = `setMaxAsyncTaskStacks(${max})`;
+  InspectorTest.log(expression);
+  await Protocol.Runtime.evaluate({expression});
+}