Replace %RunMicrotasks with %PerformMicrotaskCheckpoint

This replaces Runtime_RunMicrotasks with Runtime_PerformMicrotaskCheckpoint.

RunMicrotasks forcibly runs Microtasks even when the microtasks are suppressed,
and may causes nested Microtasks in a problematic way. E.g. that confuses
v8::MicrotasksScope::IsRunningMicrotasks() and GetEnteredOrMicrotaskContext().

OTOH, PerformMicrotaskCheckpoint() doesn't run cause the failure as it
respects the microtask suppressions.

As all existing tests don't call RunMicrotasks() in the suppressed situation
(like Promise.resolve().then(()=>{%RunMicrotasks();})), this change should
not affect to these tests.

Change-Id: Ib043a0cc8e482e022d375084d65ea98a6f54ef3d
Reviewed-on: https://chromium-review.googlesource.com/c/1360095
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Taiju Tsuiki <tzik@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58068}

src/runtime/runtime-promise.cc

@@ -80,10 +80,10 @@ RUNTIME_FUNCTION(Runtime_EnqueueMicrotask) {
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
-RUNTIME_FUNCTION(Runtime_RunMicrotasks) {
+RUNTIME_FUNCTION(Runtime_PerformMicrotaskCheckpoint) {
   HandleScope scope(isolate);
   DCHECK_EQ(0, args.length());
-  isolate->RunMicrotasks();
+  MicrotasksScope::PerformCheckpoint(reinterpret_cast<v8::Isolate*>(isolate));
   return ReadOnlyRoots(isolate).undefined_value();
 }
 

src/runtime/runtime.h

@@ -230,7 +230,7 @@ namespace internal {
   F(ReportMessage, 1, 1)                           \
   F(ReThrow, 1, 1)                                 \
   F(RunMicrotaskCallback, 2, 1)                    \
-  F(RunMicrotasks, 0, 1)                           \
+  F(PerformMicrotaskCheckpoint, 0, 1)              \
   F(StackGuard, 0, 1)                              \
   F(Throw, 1, 1)                                   \
   F(ThrowApplyNonFunction, 1, 1)                   \

test/debugger/debug/es6/debug-promises/evaluate-across-microtasks.js

@@ -51,7 +51,7 @@ LogX("start")();
 // Make sure that the debug event listener was invoked.
 assertTrue(listenerComplete);
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 var expectation =
   [ "[0] debugger", "[1] start", "[1] then 1",

test/debugger/debug/es6/debug-promises/proxy-as-promise.js

@@ -39,4 +39,4 @@ function listener(event, exec_state, event_data, data) {}
 Debug.setBreakOnUncaughtException();
 Debug.setListener(listener);
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();

test/debugger/debug/es6/debug-promises/reject-in-constructor-opt.js

@@ -40,22 +40,22 @@ function bar(a,b) {
 }
 
 foo();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 foo();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 %OptimizeFunctionOnNextCall(foo);
 
 // bar likely gets inlined into foo.
 foo();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 %NeverOptimizeFunction(bar);
 %OptimizeFunctionOnNextCall(foo);
 
 // bar does not get inlined into foo.
 foo();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(0, expected_events);

test/debugger/debug/es8/async-debug-builtin-predictions.js

@@ -57,7 +57,7 @@ async function foo() {
 
 foo();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 Debug.setListener(null);
 Debug.clearBreakOnException();

test/debugger/debug/es8/async-debug-caught-exception-cases.js

@@ -197,7 +197,7 @@ function runPart(n) {
 
     events = 0;
     consumer(producer);
-    %RunMicrotasks();
+    %PerformMicrotaskCheckpoint();
 
     Debug.setListener(null);
     if (caught) {

test/debugger/debug/es8/async-debug-caught-exception.js

@@ -37,7 +37,7 @@ log = [];
 Debug.setListener(listener);
 Debug.setBreakOnException();
 caught_throw();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 Debug.setListener(null);
 Debug.clearBreakOnException();
 assertEquals(["a"], log);
@@ -48,7 +48,7 @@ log = [];
 Debug.setListener(listener);
 Debug.setBreakOnUncaughtException();
 caught_throw();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 Debug.setListener(null);
 Debug.clearBreakOnUncaughtException();
 assertEquals([], log);
@@ -69,7 +69,7 @@ log = [];
 Debug.setListener(listener);
 Debug.setBreakOnException();
 caught_reject();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 Debug.setListener(null);
 Debug.clearBreakOnException();
 assertEquals([], log);
@@ -80,7 +80,7 @@ log = [];
 Debug.setListener(listener);
 Debug.setBreakOnUncaughtException();
 caught_reject();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 Debug.setListener(null);
 Debug.clearBreakOnUncaughtException();
 assertEquals([], log);
@@ -95,7 +95,7 @@ async function propagate_inner() { return thrower(); }
 async function propagate_outer() { return propagate_inner(); }
 
 propagate_outer();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals(["a"], log);
 assertNull(exception);
 
@@ -104,7 +104,7 @@ log = [];
 async function propagate_await() { await 1; return thrower(); }
 async function propagate_await_outer() { return propagate_await(); }
 propagate_await_outer();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals(["a"], log);
 assertNull(exception);
 
@@ -113,7 +113,7 @@ Debug.setBreakOnUncaughtException();
 
 log = [];
 Promise.resolve().then(() => Promise.reject()).catch(() => log.push("d")); // Exception c
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals(["d"], log);
 assertNull(exception);
 

test/debugger/debug/es8/async-debug-step-abort-at-break.js

@@ -48,6 +48,6 @@ debugger;            // B3 StepNext
 
 late_resolve(3);     // B4 Continue
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(5, step_count);

test/debugger/debug/es8/async-debug-step-continue-at-break.js

@@ -48,6 +48,6 @@ debugger;            // B3 Continue
 
 late_resolve(3);
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(5, step_count);

test/debugger/debug/es8/async-debug-step-in-and-out.js

@@ -44,6 +44,6 @@ f();
 
 late_resolve(3);
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(4, step_count);

test/debugger/debug/es8/async-debug-step-in-out-out.js

@@ -44,6 +44,6 @@ f();
 
 late_resolve(3);
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(4, step_count);

test/debugger/debug/es8/async-debug-step-in.js

@@ -44,6 +44,6 @@ f().then(value => assertEquals(4, value));
 
 late_resolve(3);
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(7, step_count);

test/debugger/debug/es8/async-debug-step-nested.js

@@ -51,6 +51,6 @@ f1();
 
 late_resolve(3);
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(6, step_count);

test/debugger/debug/es8/async-debug-step-next-constant.js

@@ -32,6 +32,6 @@ async function f() {
 
 f();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(3, step_count);

test/debugger/debug/es8/async-debug-step-next.js

@@ -44,6 +44,6 @@ f();
 
 late_resolve(3);
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(3, step_count);

test/debugger/debug/es8/async-debug-step-out.js

@@ -42,6 +42,6 @@ f();
 
 late_resolve(3);   // B2 Continue
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(3, step_count);

test/debugger/debug/es8/debug-async-break-on-stack.js

@@ -21,7 +21,7 @@ function assertEqualsAsync(expected, run, msg) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (hadError) throw actual;
 
@@ -67,7 +67,7 @@ function setbreaks() {
 
 f();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEqualsAsync(2, async () => break_count);
 assertEqualsAsync(null, async () => exception);

test/debugger/debug/es8/debug-async-break.js

@@ -21,7 +21,7 @@ function assertEqualsAsync(expected, run, msg) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (hadError) throw actual;
 
@@ -65,7 +65,7 @@ Debug.setBreakPoint(f, 5);
 
 f();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEqualsAsync(3, async () => break_count);
 assertEqualsAsync(null, async () => exception);

test/debugger/debug/es8/debug-async-liveedit.js

@@ -94,7 +94,7 @@ function patch(fun, from, to) {
   assertPromiseValue("Cat", promise);
   assertTrue(patch_attempted);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   // At this point one iterator is live, but closed, so the patch will succeed.
   patch(asyncfn, "'Cat'", "'Capybara'");
@@ -143,4 +143,4 @@ function patch(fun, from, to) {
                }));
 })();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();

test/debugger/debug/es8/promise-finally.js

@@ -35,7 +35,7 @@ Promise.resolve()
   .finally(() => thenable)
   .catch(e => caughtException = e);
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 Debug.setListener(null);
 Debug.clearBreakOnException();

test/js-perf-test/AsyncAwait/baseline-babel-es2017.js

@@ -160,10 +160,10 @@ function Setup() {
     return a;
   })();
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 }
 
 function Basic() {
   a();
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 }

test/js-perf-test/AsyncAwait/baseline-naive-promises.js

@@ -34,7 +34,7 @@ function Setup() {
   b = function b(p) { return p; };
   a = function a(p) { return p; };
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 }
 
 function Basic() {
@@ -48,5 +48,5 @@ function Basic() {
    .then(c)
    .then(b)
    .then(a);
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 }

test/js-perf-test/AsyncAwait/native.js

@@ -34,10 +34,10 @@ function Setup() {
   b = async function b() { return c(); };
   a = async function a() { return b(); };
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 }
 
 function Basic() {
   a();
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 }

test/js-perf-test/Inspector/debugger.js

@@ -69,7 +69,7 @@ function AsyncStacksInstrumentation() {
     p = p.then(nopCallback);
   }
   p = p.then(() => done = true);
-  while (!done) %RunMicrotasks();
+  while (!done) %PerformMicrotaskCheckpoint();
 }
 
 })();

test/js-perf-test/Modules/run.js

@@ -23,21 +23,21 @@ const iterations = 10000;
 function BasicExport() {
   let success = false;
   import("basic-export.js").then(m => { m.bench(); success = true; });
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   if (!success) throw new Error(666);
 }
 
 function BasicImport() {
   let success = false;
   import("basic-import.js").then(m => { m.bench(); success = true; });
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   if (!success) throw new Error(666);
 }
 
 function BasicNamespace() {
   let success = false;
   import("basic-namespace.js").then(m => { m.bench(); success = true; });
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   if (!success) throw new Error(666);
 }
 

test/mjsunit/code-coverage-block.js

@@ -213,7 +213,7 @@ TestCoverage(
     nop();                                // 0100
   }                                       // 0150
 }();                                      // 0200
-%RunMicrotasks();                         // 0250
+%PerformMicrotaskCheckpoint();            // 0250
 `,
 [{"start":0,"end":299,"count":1},
  {"start":1,"end":201,"count":6},  // TODO(jgruber): Invocation count is off.
@@ -662,7 +662,7 @@ async function f() {                      // 0000
   await 42;                               // 0100
 };                                        // 0150
 f();                                      // 0200
-%RunMicrotasks();                         // 0250
+%PerformMicrotaskCheckpoint();            // 0250
 `,
 [{"start":0,"end":299,"count":1},
  {"start":0,"end":151,"count":3},

test/mjsunit/es6/microtask-delivery.js

@@ -40,7 +40,7 @@ function assertArrayValues(expected, actual) {
 }
 
 function assertOrdering(expected) {
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   assertArrayValues(expected, ordering);
 }
 

test/mjsunit/es8/async-arrow-lexical-arguments.js

@@ -21,7 +21,7 @@ function assertEqualsAsync(expected, run, msg) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (hadError) throw actual;
 

test/mjsunit/es8/async-arrow-lexical-new.target.js

@@ -21,7 +21,7 @@ function assertEqualsAsync(expected, run, msg) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (hadError) throw actual;
 

test/mjsunit/es8/async-arrow-lexical-super.js

@@ -21,7 +21,7 @@ function assertEqualsAsync(expected, run, msg) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (hadError) throw actual;
 

test/mjsunit/es8/async-arrow-lexical-this.js

@@ -21,7 +21,7 @@ function assertEqualsAsync(expected, run, msg) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (hadError) throw actual;
 

test/mjsunit/es8/async-await-basic.js

@@ -23,7 +23,7 @@ function assertThrowsAsync(run, errorType, message) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (!hadError) {
     throw new MjsUnitAssertionError(
@@ -57,7 +57,7 @@ function assertEqualsAsync(expected, run, msg) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (hadError) throw actual;
 
@@ -402,7 +402,7 @@ assertDoesNotThrow(gaga);
     }
   }
   foo().then(() => log.push("c"));
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   assertEquals(["b", "a", "c"], log);
 }
 
@@ -416,7 +416,7 @@ assertDoesNotThrow(gaga);
     }
   }
   foo().then(() => log.push("c"));
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   assertEquals(["b", "a", "c"], log);
 }
 
@@ -430,7 +430,7 @@ assertDoesNotThrow(gaga);
     }
   }
   foo().then(() => log.push("c"));
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   assertEquals(["a", "b", "c"], log);
 }
 
@@ -445,7 +445,7 @@ assertDoesNotThrow(gaga);
     }
   }
   foo().then(() => log.push("c"));
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   assertEquals(["b", "c", "a"], log);
 }
 
@@ -459,7 +459,7 @@ assertDoesNotThrow(gaga);
     }
   }
   foo().then(() => log.push("c"));
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   assertEquals(["b", "a", "c"], log);
 }
 
@@ -473,7 +473,7 @@ assertDoesNotThrow(gaga);
     }
   }
   foo().then(() => log.push("c"));
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   assertEquals(["a", "b", "c"], log);
 }
 
@@ -488,7 +488,7 @@ assertDoesNotThrow(gaga);
     }
   }
   foo().then(() => log.push("c"));
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   assertEquals(["b", "a", "c"], log);
 }
 
@@ -502,7 +502,7 @@ assertDoesNotThrow(gaga);
     }
   }
   foo().then(() => log.push("c"));
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   assertEquals(["b", "a", "c"], log);
 }
 
@@ -516,7 +516,7 @@ assertDoesNotThrow(gaga);
     }
   }
   foo().then(() => log.push("c"));
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   assertEquals(["a", "b", "c"], log);
 }
 
@@ -531,7 +531,7 @@ assertDoesNotThrow(gaga);
     }
   }
   foo().then(() => log.push("c"));
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   assertEquals(["b", "c", "a"], log);
 }
 
@@ -545,7 +545,7 @@ assertDoesNotThrow(gaga);
     }
   }
   foo().then(() => log.push("c"));
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   assertEquals(["b", "c", "a"], log);
 }
 
@@ -559,7 +559,7 @@ assertDoesNotThrow(gaga);
     }
   }
   foo().then(() => log.push("c"));
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   assertEquals(["a", "b", "c"], log);
 }
 
@@ -585,7 +585,7 @@ assertDoesNotThrow(gaga);
 
   var ans;
   f2().then(x => ans = x).catch(e => ans = e);
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   assertEquals([0], ans);
 }
 

test/mjsunit/es8/async-await-no-constructor.js

@@ -23,5 +23,5 @@ async function bar() {
 
 foo();
 bar();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals(2, count);

test/mjsunit/es8/async-await-species.js

@@ -21,7 +21,7 @@ function assertEqualsAsync(expected, run, msg) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (hadError) throw actual;
 

test/mjsunit/es8/async-destructuring.js

@@ -21,7 +21,7 @@ function assertThrowsAsync(run, errorType, message) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (!hadError) {
     throw new MjsUnitAssertionError(
@@ -55,7 +55,7 @@ function assertEqualsAsync(expected, run, msg) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (hadError) throw actual;
 
@@ -77,7 +77,7 @@ function assertEqualsAsync(expected, run, msg) {
   assertEquals(1, y);
   assertEquals(1, z);
   assertEquals(0, w);
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
   assertEquals(1, y);
   assertEquals(1, z);
   assertEquals(1, w);

test/mjsunit/es8/async-function-try-finally.js

@@ -21,7 +21,7 @@ function assertThrowsAsync(run, errorType, message) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (!hadError) {
     throw new MjsUnitAssertionError(
@@ -55,7 +55,7 @@ function assertEqualsAsync(expected, run, msg) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (hadError) throw actual;
 

test/mjsunit/harmony/async-from-sync-iterator.js

@@ -24,7 +24,7 @@ function assertThrowsAsync(run, errorType, message) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (!hadError) {
     throw new MjsUnitAssertionError(
@@ -185,7 +185,7 @@ class MyError extends Error {};
   testFailure = error;
 });
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 if (testFailed) {
   throw testFailure;
 }
@@ -619,7 +619,7 @@ if (testFailed) {
   testFailure = error;
 });
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 if (testFailed) {
   throw testFailure;
 }
@@ -663,7 +663,7 @@ if (testFailed) {
 
   // Cycle through `f` to extract iterator methods
   f().catch(function() { %AbortJS("No error should have occurred"); });
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   assertEquals(typeof extractedNext, "function");
   assertThrowsAsync(() => extractedNext.call(undefined), TypeError);

test/mjsunit/harmony/async-generators-basic.js

@@ -21,7 +21,7 @@ function assertThrowsAsync(run, errorType, message) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (!hadError) {
     throw new MjsUnitAssertionError(
@@ -55,7 +55,7 @@ function assertEqualsAsync(expected, run, msg) {
 
   assertFalse(hadValue || hadError);
 
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (hadError) throw actual;
 
@@ -448,7 +448,7 @@ async function* asyncGeneratorForNestedResumeNext() {
 }
 it = asyncGeneratorForNestedResumeNext();
 it.next().then(logIterResult, AbortUnreachable);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals([
   { value: "rootbeer", done: false },
   { value: "float", done: false },
@@ -464,7 +464,7 @@ let asyncGeneratorExprForNestedResumeNext = async function*() {
 };
 it = asyncGeneratorExprForNestedResumeNext();
 it.next().then(logIterResult, AbortUnreachable);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals([
   { value: "first", done: false },
   { value: "second", done: false },
@@ -482,7 +482,7 @@ let asyncGeneratorMethodForNestedResumeNext = ({
 }).method;
 it = asyncGeneratorMethodForNestedResumeNext();
 it.next().then(logIterResult, AbortUnreachable);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals([
   { value: "remember", done: false },
   { value: "the cant!", done: false },
@@ -498,7 +498,7 @@ let asyncGeneratorCallEvalForNestedResumeNext =
       yield await Resolver("rainbow!");`);
 it = asyncGeneratorCallEvalForNestedResumeNext();
 it.next().then(logIterResult, AbortUnreachable);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals([
   { value: "reading", done: false },
   { value: "rainbow!", done: false },
@@ -514,7 +514,7 @@ let asyncGeneratorNewEvalForNestedResumeNext =
       yield await Resolver("BB!");`);
 it = asyncGeneratorNewEvalForNestedResumeNext();
 it.next().then(logIterResult, AbortUnreachable);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals([
   { value: 731, done: false },
   { value: "BB!", done: false },
@@ -536,7 +536,7 @@ async function* asyncGeneratorForNestedResumeThrow() {
 }
 it = asyncGeneratorForNestedResumeThrow();
 it.next().then(logIterResult, logError);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals([
   "throw1",
   "throw2",
@@ -556,7 +556,7 @@ let asyncGeneratorExprForNestedResumeThrow = async function*() {
 };
 it = asyncGeneratorExprForNestedResumeThrow();
 it.next().then(logIterResult, logError);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals([
   "throw3",
   "throw4",
@@ -578,7 +578,7 @@ let asyncGeneratorMethodForNestedResumeThrow = ({
 }).method;
 it = asyncGeneratorMethodForNestedResumeThrow();
 it.next().then(logIterResult, logError);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals([
   "throw5",
   "throw6",
@@ -598,7 +598,7 @@ let asyncGeneratorCallEvalForNestedResumeThrow =
       AbortUnreachable();`);
 it = asyncGeneratorCallEvalForNestedResumeThrow();
 it.next().then(logIterResult, logError);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals([
   "throw7",
   "throw8",
@@ -618,7 +618,7 @@ let asyncGeneratorNewEvalForNestedResumeThrow =
       AbortUnreachable();`);
 it = asyncGeneratorNewEvalForNestedResumeThrow();
 it.next().then(logIterResult, logError);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals([
   "throw9",
   "throw10",
@@ -636,7 +636,7 @@ async function* asyncGeneratorForNestedResumeReturn() {
 }
 it = asyncGeneratorForNestedResumeReturn();
 it.next().then(logIterResult, logError);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals([
   { value: "step1", done: false },
   { value: "step2", done: true },
@@ -651,7 +651,7 @@ let asyncGeneratorExprForNestedResumeReturn = async function*() {
 };
 it = asyncGeneratorExprForNestedResumeReturn();
 it.next().then(logIterResult, logError);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals([
   { value: "step3", done: false },
   { value: "step4", done: true },
@@ -668,7 +668,7 @@ let asyncGeneratorMethodForNestedResumeReturn = ({
 }).method;
 it = asyncGeneratorMethodForNestedResumeReturn();
 it.next().then(logIterResult, logError);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals([
   { value: "step5", done: false },
   { value: "step6", done: true },
@@ -683,7 +683,7 @@ let asyncGeneratorCallEvalForNestedResumeReturn =
       yield "step7";`);
 it = asyncGeneratorCallEvalForNestedResumeReturn();
 it.next().then(logIterResult, logError);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals([
   { value: "step7", done: false },
   { value: "step8", done: true },
@@ -698,7 +698,7 @@ let asyncGeneratorNewEvalForNestedResumeReturn =
       yield "step9";`);
 it = asyncGeneratorNewEvalForNestedResumeReturn();
 it.next().then(logIterResult, logError);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals([
   { value: "step9", done: false },
   { value: "step10", done: true },

test/mjsunit/harmony/for-await-of.js

@@ -1257,7 +1257,7 @@ let testFailure;
   testFailure = error;
 });
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 if (testFailed) {
   throw testFailure;

test/mjsunit/harmony/import-from-compilation-errored.js

@@ -7,7 +7,7 @@
 var error1, error2;
 import('modules-skip-12.js').catch(e => error1 = e);
 import('modules-skip-12.js').catch(e => error2 = e);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(error1, error2);
 assertInstanceof(error1, SyntaxError);

test/mjsunit/harmony/import-from-evaluation-errored.js

@@ -7,7 +7,7 @@
 var error1, error2;
 import('modules-skip-11.js').catch(e => error1 = e);
 import('modules-skip-11.js').catch(e => error2 = e);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(error1, error2);
 assertEquals(typeof error1, "symbol");

test/mjsunit/harmony/import-from-fetch-errored.js

@@ -7,7 +7,7 @@
 var error1, error2;
 import('no-such-file').catch(e => error1 = e);
 import('no-such-file').catch(e => error2 = e);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(error1, error2);
 assertEquals(typeof error1, "string");

test/mjsunit/harmony/import-from-instantiation-errored.js

@@ -7,7 +7,7 @@
 var error1, error2;
 import('modules-skip-10.js').catch(e => error1 = e);
 import('modules-skip-10.js').catch(e => error2 = e);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(error1, error2);
 assertInstanceof(error1, SyntaxError);

test/mjsunit/harmony/modules-import-1.js

@@ -7,6 +7,6 @@
 var life;
 import('modules-skip-1.js').then(namespace => life = namespace.life());
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(42, life);

test/mjsunit/harmony/modules-import-10.js

@@ -9,7 +9,7 @@ import('modules-skip-6.js').then(namespace => life = namespace.life);
 
 assertEquals(undefined, Object.life);
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(42, Object.life);
 assertEquals("42", life);

test/mjsunit/harmony/modules-import-11.js

@@ -18,5 +18,5 @@ async function test() {
 }
 
 test();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertTrue(ran);

test/mjsunit/harmony/modules-import-12.js

@@ -15,5 +15,5 @@ async function test() {
 }
 
 test();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertTrue(ran);

test/mjsunit/harmony/modules-import-13.js

@@ -19,7 +19,7 @@ async function test1() {
 }
 
 test1();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertTrue(ran);
 
 ran = false;
@@ -36,5 +36,5 @@ async function test2() {
 }
 
 test2();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertTrue(ran);

test/mjsunit/harmony/modules-import-14.js

@@ -22,5 +22,5 @@ async function test() {
 }
 
 test();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertTrue(ran);

test/mjsunit/harmony/modules-import-15.js

@@ -17,7 +17,7 @@ async function test1() {
 }
 
 test1();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertTrue(ran);
 
 ran = false;
@@ -37,7 +37,7 @@ async function test2() {
 }
 
 test2();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertTrue(ran);
 
 ran = false;
@@ -53,5 +53,5 @@ async function test3() {
 }
 
 test3();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertTrue(ran);

test/mjsunit/harmony/modules-import-16.js

@@ -12,7 +12,7 @@ var body = "import('modules-skip-1.js').then(ns => { x = ns.life();" +
 var func = new Function(body);
 func();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals(42, x);
 assertTrue(ran);
 
@@ -21,7 +21,7 @@ var body = "import('modules-skip-1.js').then(ns => { x = ns.life();" +
     " ran = true;} ).catch(err => %AbortJS(err))"
 eval("var func = new Function(body); func();");
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals(42, x);
 assertTrue(ran);
 
@@ -31,6 +31,6 @@ var body = "eval(import('modules-skip-1.js').then(ns => { x = ns.life();" +
 var func = new Function(body);
 func();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals(42, x);
 assertTrue(ran);

test/mjsunit/harmony/modules-import-17.js

@@ -6,6 +6,6 @@
 
 var ns;
 import('modules-skip-13.js').then(x => ns = x);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals(42, ns.default);
 assertEquals(ns, ns.self);

test/mjsunit/harmony/modules-import-2.js

@@ -12,7 +12,7 @@ import('modules-skip-2.js').catch(err => msg = err.message);
 assertEquals(undefined, life);
 assertEquals(undefined, msg);
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertEquals(42, life);
 assertEquals('42 is not the answer', msg);

test/mjsunit/harmony/modules-import-3.js

@@ -17,6 +17,6 @@ async function foo () {
 
 foo();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertTrue(ran);

test/mjsunit/harmony/modules-import-5.js

@@ -9,5 +9,5 @@ let x = 'modules-skip-1.js';
 import(x).then(namespace => life = namespace.life());
 x = 'modules-skip-2.js';
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals(42, life);

test/mjsunit/harmony/modules-import-6.js

@@ -25,5 +25,5 @@ async function test() {
 
 test();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertTrue(ran);

test/mjsunit/harmony/modules-import-7.js

@@ -19,6 +19,6 @@ async function test() {
 
 test();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertTrue(ran);

test/mjsunit/harmony/modules-import-8.js

@@ -43,7 +43,7 @@ async function test1() {
 
 test1();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertTrue(ran);
 
@@ -66,7 +66,7 @@ async function test2() {
 
 test2();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertTrue(ran);
 
@@ -86,6 +86,6 @@ async function test3() {
 
 test3();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 assertTrue(ran);

test/mjsunit/harmony/modules-import-9.js

@@ -18,5 +18,5 @@ async function test() {
 }
 
 test();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertTrue(ran);

test/mjsunit/harmony/weakrefs/cleanupsome-dereffed-and-cleared-weakref.js

@@ -25,7 +25,7 @@ let weak_ref;
 })();
 
 // Clear the KeepDuringJob set.
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 weak_ref.deref();
 o = null;
@@ -37,7 +37,7 @@ gc();
 wf.cleanupSome();
 assertEquals(0, cleanup_count);
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // Next turn.
 
 // This GC detects the WeakRef as dirty.

test/mjsunit/harmony/weakrefs/cleanupsome-dereffed-weakref.js

@@ -25,7 +25,7 @@ let weak_ref;
 })();
 
 // Clear the KeepDuringJob set.
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 weak_ref.deref();
 o = null;
@@ -37,7 +37,7 @@ gc();
 wf.cleanupSome();
 assertEquals(0, cleanup_count);
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // Next turn.
 
 // Now the WeakRef can be cleared.
@@ -51,7 +51,7 @@ assertEquals(weak_ref, cleanup_cells[0]);
 // The cleanup task is not executed again since all WeakCells have been
 // processed.
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // Next turn.
 
 assertEquals(1, cleanup_count);

test/mjsunit/harmony/weakrefs/cleanupsome-weakref.js

@@ -31,7 +31,7 @@ gc();
 wf.cleanupSome();
 assertEquals(0, cleanup_count);
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // Next turn.
 
 // Now the WeakRef can be cleared.

test/mjsunit/harmony/weakrefs/clear-after-deref.js

@@ -28,7 +28,7 @@ let wr;
 gc();
 assertNotEquals(undefined, wr.deref());
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // New turn.
 
 let o = wr.deref();

test/mjsunit/harmony/weakrefs/two-weakrefs.js

@@ -38,7 +38,7 @@ gc();
   assertNotEquals(undefined, wr2.deref());
 })();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // New turn.
 
 assertEquals(0, cleanup_count);
@@ -47,7 +47,7 @@ wr1.deref();
 o1 = null;
 gc(); // deref makes sure we don't clean up wr1
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // New turn.
 
 assertEquals(0, cleanup_count);
@@ -56,7 +56,7 @@ wr2.deref();
 o2 = null;
 gc(); // deref makes sure we don't clean up wr2
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // New turn.
 
 assertEquals(1, cleanup_count);
@@ -64,7 +64,7 @@ assertEquals(wr1, cleared_cells1[0]);
 
 gc();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // New turn.
 
 assertEquals(2, cleanup_count);

test/mjsunit/harmony/weakrefs/weakcell-and-weakref.js

@@ -34,12 +34,12 @@ gc();
   assertNotEquals(undefined, weak_ref.deref());
 })();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // Next turn.
 
 gc();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // Next turn.
 
 assertTrue(cleanup_called);

test/mjsunit/harmony/weakrefs/weakref-creation-keeps-alive.js

@@ -33,14 +33,14 @@ gc();
   assertNotEquals(undefined, wr.deref());
 })();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // Next turn.
 
 assertFalse(cleanup_called);
 
 gc();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // Next turn.
 
 assertTrue(cleanup_called);

test/mjsunit/harmony/weakrefs/weakref-deref-keeps-alive.js

@@ -29,12 +29,12 @@ let strong = {a: wr.deref(), b: wr_control.deref()};
 
 gc();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // Next turn.
 
 gc();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // Next turn.
 
 // We have a strong reference to the objects, so the WeakRefs are not cleared yet.
@@ -57,7 +57,7 @@ gc();
   assertEquals(undefined, wr_control.deref());
 })();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // Next turn.
 
 assertEquals(1, cleanup_count);
@@ -66,7 +66,7 @@ assertEquals(wc, cleanup_cells[0]);
 
 gc();
 
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 // Next turn.
 
 assertEquals(2, cleanup_count);

test/mjsunit/regress/regress-5405.js

@@ -11,7 +11,7 @@ let log = [];
     return 10;
   }
 })();
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 
 (function() {
   with ({get ['.new.target']() { log.push('new.target') }}) {

test/mjsunit/regress/regress-5691.js

@@ -18,6 +18,6 @@ Promise.resolve(Promise.resolve()).then(() => log += "|fast-resolve");
 (class extends Promise {}).resolve(Promise.resolve()).then(() => log += "|slow-resolve");
 
 log += "|start";
-  %RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals("|start|turn1|fast-resolve|turn2|turn3|slow-resolve|turn4\n\
 |start|turn1|fast-resolve|turn2|turn3|slow-resolve|turn4", result);

test/mjsunit/regress/regress-682349.js

@@ -9,5 +9,5 @@ function f() {
   success = (f.caller === null);
 }
 Promise.resolve().then(f);
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertTrue(success);

test/mjsunit/regress/regress-740694.js

@@ -17,6 +17,6 @@ var error;
 var promise = __f_0();
 promise.then(assertUnreachable,
              err => { done = true; error = err });
-%RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertTrue(error.startsWith('Error reading'));
 assertTrue(done);

test/mjsunit/regress/regress-797581.js

@@ -17,7 +17,7 @@ function TryToLoadModule(filename, expect_error, token) {
   }
 
   import(filename).catch(SetError);
-  %RunMicrotasks();
+  %PerformMicrotaskCheckpoint();
 
   if (expect_error) {
     assertTrue(caught_error instanceof SyntaxError);

test/mjsunit/regress/regress-800651.js

@@ -27,5 +27,5 @@ function g() {
   let namespace = Promise.resolve().then(importUndefined);
 }
 g();
-  %RunMicrotasks();
+%PerformMicrotaskCheckpoint();
 assertEquals(list, [1,2]);

test/mjsunit/test-async.js

@@ -80,7 +80,7 @@ var testAsync;
     }
 
     drainMicrotasks() {
-      %RunMicrotasks();
+      %PerformMicrotaskCheckpoint();
     }
 
     done_() {
@@ -111,7 +111,7 @@ var testAsync;
   testAsync = function(test, name) {
     let assert = new AsyncAssertion(test, name);
     test(assert);
-    %RunMicrotasks();
+    %PerformMicrotaskCheckpoint();
     assert.done_();
   }
 })();