linrongbin16 Posts

linrongbin16

•Created by linrongbin16 on 9/22/2024 in #help

Is it possible to embed `deno_core` with a self-managed event loop?

And the 2nd question is: does the API deno_core::JsRuntime::run_event_loop only run 1 tick? or it try to wait everything inside its internal queue to complete? Because after reading some tutorials and source code of deno_core, I found there's already some queues inside deno_core, I guess they're for the queueMicrotask and built-in async/await functions. For example, if we have below sample code:

async function readFile(filename) {
   // Read a file in async mode
}

async function sleepFor(seconds) {
  // Sleep for seconds
}

const content = await readFile("README.md");
console.log(`We have read: ${content}`);
await sleepFor(10);
console.log(`We have sleep for 10s`);

async function readFile(filename) {
   // Read a file in async mode
}

async function sleepFor(seconds) {
  // Sleep for seconds
}

const content = await readFile("README.md");
console.log(`We have read: ${content}`);
await sleepFor(10);
console.log(`We have sleep for 10s`);

Once the deno_core::JsRuntime execute it, I guess the 1st console.log will not be printed, instead it's been put in the internal queue and wait for the async readFile function done. Correct? Then we call the js_runtime.run_event_loop().await , once it's completed, is the only 1st console.log been printed? Or both two console.log are been printed? i.e. the run_event_loop API runs for only 1 tick, or wait for all the tasks done? If it only runs for 1 tick, then I can embed it into my command line TUI application. Because the TUI application is using tokio runtime with the crossterm library. I want to use tokio::select! on both the crossterm's EventStream (it receives terminal keyboard/mouse events, such as key pressed, mouse clicked, etc) and the deno_core::JsRuntime::run_event_loop. Only 1 tick will never block the terminal events. If it waits for all async tasks done, then it means it cannot work along with the tokio runtime managed by my TUI application. Because it will block the terminal.

1 replies

DDeno

•Created by linrongbin16 on 3/14/2024 in #help

Does V8 engine eventloop/threading model conflict with rust?

hi, I am trying to embed deno's rusty_v8 into rust application. I am confused about the eventloop/threading model between v8 engine and rust. because js/ts has the async/await feature (which helps to avoid blocking IO/network, and other things), and v8 engine also has an eventloop itself. I think when v8 engine is running it's eventloop, it will cause rust main thread blocking? How should I do to make v8 and rust running together?

3 replies