Javet Engine Pool

Motivation

• It takes quite some time to spawn a V8Runtime, especially in Node.js mode.

• It takes a lot of time to initialize a V8Runtime to prepare for script execution.

• V8Runtime is not recommended to be used in multi-threaded environments. (Though Javet allows it to be used that way.)

Goals

• Provide a basic user experience similar to a database connection pool.

• Minimize the performance overhead of V8Runtime creation and initialization.

• Free applications from explicitly closing V8Runtime from time to time.

• Allow easy extension.

Usage

// Create a Javet engine pool.
try (IJavetEnginePool<V8Runtime> javetEnginePool = new JavetEnginePool<>()) {
    // Get a Javet engine from the pool.
    try (IJavetEngine<V8Runtime> javetEngine = javetEnginePool.getEngine()) {
        // Get a V8 runtime from the engine.
        V8Runtime v8Runtime = javetEngine.getV8Runtime();
        // Create a Javet console interceptor.
        JavetStandardConsoleInterceptor javetConsoleInterceptor =
                new JavetStandardConsoleInterceptor(v8Runtime);
        // Register the Javet console to V8 global object.
        javetConsoleInterceptor.register(v8Runtime.getGlobalObject());
        // V8 console log is redirected to JVM console log.
        v8Runtime.getExecutor("console.log('Hello Javet from Pool');").executeVoid();
        // Unregister the Javet console to V8 global object.
        javetConsoleInterceptor.unregister(v8Runtime.getGlobalObject());
        // close() is not necessary because the Javet engine pool handles that.
        v8Runtime.lowMemoryNotification();
        // Force V8 to GC.
    }
}

Please refer to the source code for more detail.