Thread Example Out of Date

[PeteHaughie]

Description

I went looking for a solution to a slowdown problem and thought threading might be the answer. I checked out the example and it no longer works because the http urls from the initial array are all dead.

Expected Behavior

I would have expected the threading example to a) work and b) be of some more practical use.

Current Behavior

Example sketch does not function.

Steps to Reproduce

1. Attempt to run the thread example.

/**
 * Thread function example
 * by Daniel Shiffman.  
 * 
 * This example demonstrates how to use thread() to spawn
 * a process that happens outside of the main animation thread.
 *
 * When thread() is called, the draw() loop will continue while
 * the code inside the function passed to thread() will operate
 * in the background.
 *
 */

// This sketch will load data from all of these URLs in a separate thread
String[] urls = {
  "http://processing.org", 
  "http://www.processing.org/exhibition/", 
  "http://www.processing.org/reference/", 
  "http://www.processing.org/reference/libraries", 
  "http://www.processing.org/reference/tools",   
  "http://www.processing.org/reference/environment",   
  "http://www.processing.org/learning/", 
  "http://www.processing.org/learning/basics/", 
  "http://www.processing.org/learning/topics/", 
  "http://www.processing.org/learning/gettingstarted/",
  "http://www.processing.org/download/", 
  "http://www.processing.org/shop/", 
  "http://www.processing.org/about/"
};

// This will keep track of whether the thread is finished
boolean finished = false;
// And how far along
float percent = 0;

// A variable to keep all the data loaded
String allData;

void setup() {
  size(640, 360);
  // Spawn the thread!
  thread("loadData");
}

void draw() {
  background(0);
  
  // If we're not finished draw a "loading bar"
  // This is so that we can see the progress of the thread
  // This would not be necessary in a sketch where you wanted to load data in the background
  // and hide this from the user, allowing the draw() loop to simply continue
  if (!finished) {
    stroke(255);
    noFill();
    rect(width/2-150, height/2, 300, 10);
    fill(255);
    // The size of the rectangle is mapped to the percentage completed
    float w = map(percent, 0, 1, 0, 300);
    rect(width/2-150, height/2, w, 10);
    textSize(16);
    textAlign(CENTER);
    fill(255);
    text("Loading", width/2, height/2+30);
  } 
  else {
    // The thread is complete!
    textAlign(CENTER);
    textSize(24);
    fill(255);
    text("Finished loading. Click the mouse to load again.", width/2, height/2);
  }
}

void mousePressed() {
   thread("loadData");
}

void loadData() {
  // The thread is not completed
  finished = false;
  // Reset the data to empty
  allData = "";
  
  // Look at each URL
  // This example is doing some highly arbitrary things just to make it take longer
  // If you had a lot of data parsing you needed to do, this can all happen in the background
  for (int i = 0; i < urls.length; i++) {
    String[] lines = loadStrings(urls[i]);
    // Demonstrating some arbitrary text splitting, joining, and sorting to make the thread take longer
    String allTxt = join(lines, " ");
    String[] words = splitTokens(allTxt, "\t+\n <>=\\-!@#$%^&*(),.;:/?\"\'");
    for (int j = 0; j < words.length; j++) {
      words[j] = words[j].trim();
      words[j] = words[j].toLowerCase();
    }
    words = sort(words);
    allData += join(words, " ");
    percent = float(i)/urls.length;
  }
  
  String[] words = split(allData," ");
  words = sort(words);
  allData = join(words, " ");
  
  // The thread is completed!
  finished = true;
}

Your Environment

• Processing version: 4
• Operating System and OS version: Mac Os Sequoia 15.0
• Other information: Intel 2019 MacBook Pro 16GB

Possible Causes / Solutions