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POWhy V8 in Node.JS is faster than in my native C++ addon?
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  1. POWhy V8 in Node.JS is faster than in my native C++ addon?
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    copied!<p>Why Google's V8 JavaScript engine in my C++ addon works significantly slower than in Node.JS?</p> <p>I've tried to write some stupidly simple code for generating prime numbers in the JavaScript and ran it in V8 via my C++ addon and directly in Node.JS.</p> <p>I was quite shocked, because both should be using the same JavaScript engine and both have executed the same code (time in milliseconds, less is better):</p> <pre><code>V8 in Node.JS: 495517 V8 in Node.JS C++ Addon: 623598 </code></pre> <p>Here is the source of JavaScript module and source of C++ addon that runs same JavaScript code (and I think problem not in the interop, because measuring of time works directly in JS):</p> <p><em>index.js</em>:</p> <pre class="lang-js prettyprint-override"><code>var jsInNodeJsPrimeGeneratorBenchmark = require("./javascript.js"); var jsInNativePrimeGeneratorBenchmark = require("./native"); console.log("V8 in Node.JS: ", jsInNodeJsPrimeGeneratorBenchmark.primeGeneratorBenchmark()); console.log("V8 in Node.JS C++ Addon: ", jsInNativePrimeGeneratorBenchmark.primeGeneratorBenchmark()); </code></pre> <p><em>javascript.js</em>:</p> <pre class="lang-js prettyprint-override"><code>function primeGeneratorBenchmark() { var result, primeNumberCounter, i, j, isPrime, start, end; i = 3; primeNumberCounter = 1; start = Date.now(); while (primeNumberCounter &lt; 100000) { isPrime = true; for (j = 2; j &lt; i; j++) { if (i % j === 0) { isPrime = false; break; } } if (isPrime) { result = i; primeNumberCounter++; } i++; } end = Date.now(); return end - start; } exports.primeGeneratorBenchmark = primeGeneratorBenchmark; </code></pre> <p><em>native.cpp</em>:</p> <pre class="lang-cpp prettyprint-override"><code>#include &lt;node.h&gt; v8::Handle&lt;v8::Value&gt; primeGeneratorBenchmark(const v8::Arguments &amp;arguments); void registerModule(v8::Handle&lt;v8::Object&gt; target); v8::Handle&lt;v8::Value&gt; primeGeneratorBenchmark(const v8::Arguments &amp;arguments) { v8::HandleScope handleScope; v8::Local&lt;v8::Context&gt; context = arguments.Holder()-&gt;CreationContext(); v8::Context::Scope scope(context); const char *sourceStringC = "var result, primeNumberCounter, i, j, isPrime, start, end, time;\n" "i = 3;\n" "primeNumberCounter = 1;\n" "start = Date.now();\n" "while (primeNumberCounter &lt; 100000) {\n" " isPrime = true;\n" " for (j = 2; j &lt; i; j++) {\n" " if (i % j === 0) {\n" " isPrime = false;\n" " break;\n" " }\n" " }\n" " if (isPrime) {\n" " result = i;\n" " primeNumberCounter++;\n" " }\n" " i++;\n" "}\n" "end = Date.now();\n" "time = end - start;\n"; v8::Local&lt;v8::String&gt; sourceStringV8 = v8::String::New(sourceStringC); v8::Local&lt;v8::Script&gt; script = v8::Script::Compile(sourceStringV8); script-&gt;Run(); v8::Local&lt;v8::Value&gt; timeResult = v8::Context::GetCurrent()-&gt;Global()-&gt;Get(v8::String::New("time")); return handleScope.Close(timeResult); } void registerModule(v8::Handle&lt;v8::Object&gt; target) { target-&gt;Set(v8::String::NewSymbol("primeGeneratorBenchmark"), v8::FunctionTemplate::New(primeGeneratorBenchmark)-&gt;GetFunction()); } NODE_MODULE(native, registerModule); </code></pre>
 

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