From 1408ec24e43898d8f8760846392d2fb77e0d9cbd Mon Sep 17 00:00:00 2001
From: Yusuke Suzuki <ysuzuki@apple.com>
Date: Fri, 8 Aug 2025 14:40:42 -0700
Subject: [PATCH] Do not set setStatus and monitorRunDependencies for wasm
 tests

emscripten generates the following code,

```
  if (Module["setStatus"]) {
    Module["setStatus"]("Running...");
    setTimeout(() => {
      setTimeout(() => Module["setStatus"](""), 1);
      doRun();
    }, 1);
  } else {
    doRun();
  }
```

And this code is ran in the first iteration of wasm benchmarks since it
includes setup code. This causes a problem since it has artificially
inserted setTimeout with 1ms.

1. It can insert 1ms wait time artificially. This is not so great since
   it reduces CPU pstate randomly, causing weird perf cliff depending on
   CPU's powner management instead of JS engine's quality.
2. The spec requires setTimeout to have some throttling mechanism. So we
   can hit some artificial large delay more than 1ms based on how many
   nestings we did before (https://webkit.org/blog/13083/speedometer-2-1/)

This patch removes setStatus and monitorRunDependencies so that we will not
use this `setTimeout` code path generated by emscripten. This is already done
for SpiderMonkey shell. So we expand it for the other engines as well.

Close #118
---
 JetStreamDriver.js | 29 ++---------------------------
 1 file changed, 2 insertions(+), 27 deletions(-)

diff --git a/JetStreamDriver.js b/JetStreamDriver.js
index 7bfa1e2a..5cc41ee1 100644
--- a/JetStreamDriver.js
+++ b/JetStreamDriver.js
@@ -1271,28 +1271,13 @@ class WasmEMCCBenchmark extends AsyncBenchmark {
                 postRun: [],
                 noInitialRun: true,
                 print: print,
-                printErr: printErr,
-                setStatus: function(text) {
-                },
-                totalDependencies: 0,
-                monitorRunDependencies: function(left) {
-                    this.totalDependencies = Math.max(this.totalDependencies, left);
-                    Module.setStatus(left ? 'Preparing... (' + (this.totalDependencies-left) + '/' + this.totalDependencies + ')' : 'All downloads complete.');
-                },
+                printErr: printErr
             };
 
             globalObject.Module = Module;
             ${super.prerunCode};
         `;
 
-        if (isSpiderMonkey) {
-            str += `
-                // Needed because SpiderMonkey shell doesn't have a setTimeout.
-                Module.setStatus = null;
-                Module.monitorRunDependencies = null;
-            `;
-        }
-
         return str;
     }
 };
@@ -1413,14 +1398,7 @@ class WasmLegacyBenchmark extends Benchmark {
                 preRun: [],
                 postRun: [],
                 print: globalObject.print,
-                printErr: globalObject.print,
-                setStatus: function(text) {
-                },
-                totalDependencies: 0,
-                monitorRunDependencies: function(left) {
-                    this.totalDependencies = Math.max(this.totalDependencies, left);
-                    Module.setStatus(left ? 'Preparing... (' + (this.totalDependencies-left) + '/' + this.totalDependencies + ')' : 'All downloads complete.');
-                }
+                printErr: globalObject.print
             };
             globalObject.Module = Module;
             `;
@@ -1451,9 +1429,6 @@ class WasmLegacyBenchmark extends Benchmark {
                 };
             };
 
-            Module.setStatus = null;
-            Module.monitorRunDependencies = null;
-
             Promise.resolve(42).then(() => {
                 try {
                     andThen();