sync

.gitignore

@@ -1,3 +1,7 @@
+.vscode
+.idea
+.history
+
 lib-cov
 *.seed
 *.log
@@ -17,3 +21,5 @@ deps
 build
 out
 *.xcodeproj
+
+.DS_Store

.python-version

@@ -0,0 +1 @@
+2.7.18

.vscode/settings.json

@@ -0,0 +1,14 @@
+{
+  "files.associations": {
+    "*.gz": "json",
+    "*.sql": "sql",
+    ".*yml": "yaml",
+    "locale": "c",
+    "ios": "c",
+    "array": "c",
+    "string": "c",
+    "string_view": "c",
+    "vector": "c",
+    "learnuv.h": "c"
+  }
+}

README.md

@@ -1,84 +1,90 @@
-# learnuv
+# experiment-libuv
 
-Learn uv for fun and profit, a self guided workshop to [the library](https://github.com/libuv/libuv) that powers Node.js.
+This is a fork of [thlorenz/learnuv](https://github.com/thlorenz/learnuv), where I did my own exploration.
 
-![screenshot](assets/screenshot.png)
+## How it started
 
-## Before You Start
+It all started with this article series: [Event Loop and the Big Picture — NodeJS Event Loop Part 1](https://blog.insiderattack.net/event-loop-and-the-big-picture-nodejs-event-loop-part-1-1cb67a182810).
 
-Read the [learnuv gitbook](http://thlorenz.github.io/learnuv/book) which explains some libuv and related C language
-concepts that will help you complete the exercises.
+The articles explain how the Node.js event loop works under the hood, and how it maps to libuv phases. I wanted to go deeper — not just read about it, but actually run libuv locally and see it in action.
 
-## Installation
+So I forked `learnuv` and worked through the C exercises to understand the raw event loop: timers, I/O polling, idle handlers, check handlers, and close handlers.
 
-Requires [Python](https://www.python.org/downloads/) 2.6 or 2.7 to be installed.
-If python is not in your path set the environment variable `PYTHON` to its
-location. For example on Windows: `set PYTHON=C:\Python27\python.exe`
+Once I had a feel for the libuv internals, I went back to Node.js and wrote [`nodejs/event_loop_sandbox/index.js`](nodejs/event_loop_sandbox/index.js) — a JavaScript sandbox that maps each libuv concept onto the corresponding Node.js APIs (`setTimeout`, `setImmediate`, `process.nextTick`, Promises, etc.).
 
-```sh
-git clone https://github.com/thlorenz/learnuv && cd learnuv
-npm install
-```
-
-## Getting Started
+## Repository structure
 
-```sh
-./learnuv help
+```
+src/                        # C exercises using libuv (forked from learnuv)
+  01_system_info.c
+  02_idle.c
+  03_fs_readsync.c
+  04_fs_readasync.c
+  05_fs_readasync_context.c
+  06_fs_allasync.c
+  07_tcp_echo_server.c
+  08_horse_race.c
+  event_loop_sandbox/       # libuv event loop diagrams
+    libuv-event-loop.png
+    node-event-loop.png
+  ...
+nodejs/
+  event_loop_sandbox/
+    index.js                # Node.js sandbox mapping libuv phases to JS APIs
 ```
 
-## Building
-
-**learnuv** comes with build commands that you can use instead of the manual steps explained further below.
-
-- **./learnuv ninja**
-    Compile your sources with ninja, stored inside `./out/Debug`
-- **./learnuv make**
-    Compile your sources with make, stored inside `./out/Debug`
-- **./learnuv xcode**
-    Generate a learnuv Xcode project, named `./learnuv.xcodeproj`
-
-### Windows Caveats
+## Before You Start (C side)
 
-Ninja and Make do not work on windows except via [cygwin](https://www.cygwin.com/).
+1. C Introduction — https://www.w3schools.com/c/c_intro.php
+2. Pointers — https://www.w3schools.com/c/c_pointers.php
+3. Address-Of / Dereference
+4. Struct — https://www.w3schools.com/c/c_structs.php
+5. Automatic Allocation vs Dynamic Allocation (malloc)
+6. NULL
+7. Typecast — https://www.tutorialspoint.com/cprogramming/c_type_casting.htm
+8. LibUV guidebook (5 mins reading) — https://thlorenz.com/learnuv/book/
 
-### Ninja
+And the official [LibUV documentation](https://docs.libuv.org/en/v1.x/guide/introduction.html).
 
-Highly recommended since it builds faster than any of the other options, so [get ninja](https://ninja-build.org/)
-and do:
+## Setup for `macOS 14.5 23F79`
 
 ```sh
-./gyp_learnuv.py -f ninja
-ninja -C out/Debug
-./out/Debug/01_system_info
+npm install
 ```
 
-### Make
+```sh
+pyenv install 2.7 &&
+pyenv local 2.7.18
+```
 
-Works on Linux and OSX.
+```sh
+pip install six # https://github.com/thlorenz/learnuv/issues/45
+```
 
 ```sh
-./gyp_learnuv.py -f make
-make -C out
-./out/Debug/01_system_info
+eval "$(pyenv init -)" # for some reason it's not working from ~/.zshrc
 ```
 
-### Xcode
+```sh
+./learnuv
+```
 
-Works on OSX only. Highly recommended to ease debugging and code navigation.
+```sh
+./learnuv xcode
+```
 
 ```sh
-./gyp_learnuv.py -f xcode
 open learnuv.xcodeproj
 ```
 
-### Visual Studio
-
-Works on Windows only. **TODO** need to adapt [vcbuild.bat](https://github.com/joyent/libuv/blob/master/vcbuild.bat).
+```sh
+./learnuv verify
+```
 
-## Running
+## Running the Node.js sandbox
 
-```
-./learnuv
+```sh
+node nodejs/event_loop_sandbox
 ```
 
 ## License

exercises/07_tcp_echo_server/exercise.js

@@ -1,86 +1,98 @@
-'use strict';
-var net = require('net')
-  , colors = require('ansicolors')
-  , format = require('util').format
-  , table = require('text-table')
+"use strict";
+var net = require("net"),
+  colors = require("ansicolors"),
+  format = require("util").format,
+  table = require("text-table");
 
-var HOST = '0.0.0.0'
-  , PORT = 7000;
+var HOST = "0.0.0.0",
+  PORT = 7001;
 
-var exercise = require('workshopper-exercise')()
+var exercise = require("workshopper-exercise")();
 
 exercise.requireSubmission = false;
-exercise.addSetup(checkClientResponse);  
+exercise.addSetup(checkClientResponse);
 
 module.exports = exercise;
 
 function log() {
-  console.log(colors.green('progress ') + colors.brightBlack(format.apply(this, arguments)));
+  console.log(
+    colors.green("progress ") +
+      colors.brightBlack(format.apply(this, arguments))
+  );
 }
 
 function checkClientResponse(mode, cb) {
   var progress = {
-      connected       : false
-    , responded       : false
-    , correctResponse : false
-    , closed          : false
-    , error           : false
-  }
+    connected: false,
+    responded: false,
+    correctResponse: false,
+    closed: false,
+    error: false,
+  };
 
-  var fail = false
-    , quit = false
-    , finished = false
-    , msg = 'Hello Server can you echo?'
-    , timeout
+  var fail = false,
+    quit = false,
+    finished = false,
+    msg = "Hello Server can you echo?",
+    timeout;
 
   function finish() {
     clearTimeout(timeout);
     if (finished) return;
     finished = true;
 
-    var arr = Object.keys(progress)
-      .reduce(function key(acc, k) {
-        if (k === 'error') { fail = fail || !!progress[k]; return acc }
-        fail = fail || !progress[k]
-        var label = colors.blue(k[0].toUpperCase() + k.slice(1));
-        acc.push([ label, progress[k] ? colors.green('OK') : colors.red('NOT OK') ])
-        return acc
-      }, [])
+    var arr = Object.keys(progress).reduce(function key(acc, k) {
+      if (k === "error") {
+        fail = fail || !!progress[k];
+        return acc;
+      }
+      fail = fail || !progress[k];
+      var label = colors.blue(k[0].toUpperCase() + k.slice(1));
+      acc.push([
+        label,
+        progress[k] ? colors.green("OK") : colors.red("NOT OK"),
+      ]);
+      return acc;
+    }, []);
+
+    console.log("\n" + table(arr));
 
-    console.log('\n' + table(arr));
-
-    if (progress.error) console.error('\nEncountered an error', progress.error);
-    cb(fail && mode === 'verify' ? new Error('Sorry something was not quite right yet :(') : null);
+    if (progress.error) console.error("\nEncountered an error", progress.error);
+    cb(
+      fail && mode === "verify"
+        ? new Error("Sorry something was not quite right yet :(")
+        : null
+    );
   }
 
   // give up after 3s, i.e. if server is irresponsive or doesn't quit
   timeout = setTimeout(finish, 3000);
 
   var client = new net.Socket();
-  log('Client connecting to server');
+  log("Client connecting to server");
   client
     .connect(PORT, HOST, function onconnection() {
       progress.connected = true;
       log('Client sending "%s"', msg);
       client.write(msg);
-    }) 
-    .on('error', function onerror(err) {
+    })
+    .on("error", function onerror(err) {
       progress.error = err;
       finish();
     })
-    .on('data', function ondata(data) {
-      progress.responded = true
+    .on("data", function ondata(data) {
+      progress.responded = true;
       var res = data.toString();
       log('Server responded with "%s"', msg);
 
-      progress.correctResponse = (res === msg)
+      progress.correctResponse = res === msg;
 
-      log('Telling server to quit');
-      client.write('QUIT');
+      log("Telling server to quit");
+      client.write("QUIT");
     })
-    .on('close', function onclose() {
+    .on("close", function onclose() {
       progress.closed = true;
-      log('Server closed connection')
-      finish()
-    })
+      log("Server closed connection");
+      finish();
+    });
 }

exercises/07_tcp_echo_server/problem.md

@@ -13,7 +13,7 @@ So lets start with the easy part.
 
 ### Starting the Server and Listening on a Port
 
-First of all we need to initialize our server `tcp_server`. 
+First of all we need to initialize our server `tcp_server`.
 This is done via [`uv_tcp_init`](http://docs.libuv.org/en/latest/tcp.html#c.uv_tcp_init).
 Our server represents the TCP `handle`.
 
@@ -57,8 +57,8 @@ you to carefully read through the code and understand the concepts and technique
 
 ## Hint
 
-Use `nc localhost 7000` to test your server (finish via `Ctrl-D`) and/or stop the server by sending `QUIT`. 
-You can also send entire files, i.e. `cat package.json | netcat localhost 7000`.
+Use `nc localhost 7001` to test your server (finish via `Ctrl-D`) and/or stop the server by sending `QUIT`.
+You can also send entire files, i.e. `cat package.json | netcat localhost 7001`.
 
 On windows you may have to use telnet or putty.