Fix long running processes

_posts/2024-07-20-micropython-1.md

@@ -79,13 +79,6 @@ mp.runPython("import fonts; print(fonts.gunship30)")
 
 Note that I've got access to my compiled in code here. 
 
-<section class = "micropython-simulator">
-<div id="editor"></div>
-<button id=run title="Run code (Ctrl-Enter)" aria-title="Run code (Ctrl-Enter)">Run</button>
-<canvas height="240" width="240" class = screen></canvas>
-<pre id="micropython-stdout"></pre>
-</section>
-
 <script src="{{page.assets}}/cm6.bundle.min.js"></script>
 <script src="{{page.assets}}/simulator.js" type = "module"></script>
 

assets/blog/micropython/example_micropython.py

@@ -1,6 +1,6 @@
+import asyncio
 import gc
 import struct
-import time
 from array import array
 
 import console
@@ -102,7 +102,10 @@ while True:
     )
 
     display.draw(buf)
-    # The 'await' is necessary here to yield back to the JS event loop
-    # I tried to figure out how to hide this inside the JS implementation of sleep but
-    # couldn't make it work.
-    await time.sleep(0.2)
+
+    # Note: Because of the way the webassembly port works, this code is actually running like an asyncio thread
+    # This call to asyncio.sleep yeilds back to the JS event loop and gives the browser a chance to update the display.
+    #  This is not needed on a real device.
+    # There is way to make it so that a bare time.sleep() will work but it requires emcripten's ASYNCIFY feature
+    # Which apparently kills performance. See https://github.com/tomhodson/micropython/commit/2fa6373d226b65f977486ecda32b8786cd1dceed
+    await asyncio.sleep(0.2)

assets/blog/micropython/simulator.js

@@ -6,9 +6,6 @@ class USBCPowerSupplySimulator extends HTMLElement {
     });
 
     mp.registerJsModule("console", { log: (s) => console.log(s) });
-    mp.registerJsModule("time", {
-      sleep: async (s) => await new Promise((r) => setTimeout(r, s * 1000)),
-    });
     mp.registerJsModule("display", {
       draw: (buf) => {
         let bytes = [...buf].flatMap((x) => [x, x, x, 255]);
@@ -45,10 +42,7 @@ class USBCPowerSupplySimulator extends HTMLElement {
       mp_console.scrollTo(0, mp_console.scrollHeight);
     };
 
-    const [mp, view] = await Promise.all([
-      this.init_mp(ctx, stdoutWriter),
-      this.init_editor(),
-    ]);
+    const view = await this.init_editor();
 
     const runPython = async () => {
       mp_console.innerText = "";