Skip to main content
100%

simple-parallel-control-flow.js

✓ Published0🌍 Public
Aalessioalex
Last edited Nov 22, 2014
Created on Nov 22, 2014

This example demonstrates a minimal asynchronous control-flow pattern using a counter-based callback mechanism. It shows how a JavaScript function can coordinate multiple parallel tasks by decrementing a shared counter, invoking a final callback only when all tasks complete. The `doParallel` function initializes the counter and returns a closure; each call to `next()` reduces the counter, and when it reaches zero, the callback logs `"ok"` to the console. The code uses plain JavaScript with no external libraries, highlighting a simple, dependency-free approach to parallel execution.

AI-generated description

Similar vizzes

Loading thumbnail…

Gist c38b5428350be0929bb330f44e6c9d82

This example contrasts two JavaScript approaches to looping over asynchronous tasks. It shows that an `async` loop with `await` inside a `for` loop executes each iteration sequentially, waiting for a five-second `setTimeout` before logging the next index, while a plain `Promise`-based loop fires all five calls concurrently, each logging after a two-second delay. The code uses native `async`/`await` and `Promise` constructors, with `setTimeout` simulating delay, and logs indices to the console. No external libraries or data sources are involved, highlighting raw JavaScript concurrency behavior.

Aamazingandyyy
65% match
Loading thumbnail…

Async/await 6

The example shows an asynchronous JavaScript flow where the program awaits one operation, then runs two independent tasks in parallel via `Promise.all`. The code displays `doA()`, followed by `doB(a)` and `doC(a)` as the two concurrent calls after the first result resolves. It uses native `async`/`await` syntax with `Promise.all()` to coordinate these dependent and independent steps. No rendering library or data source is visible; the visualization focuses purely on the sequence and branching of these promises.

PPanJ
64% match
Loading thumbnail…

JavaScript: async/await with forEach()

This example demonstrates how to manage sequential asynchronous operations in JavaScript using `async/await` combined with a custom `asyncForEach` function. It shows a three-item array being processed one at a time, with each item logged to the console after a 50-millisecond delay imposed by the `waitFor` helper, which relies on `setTimeout` and a Promise. The `asyncForEach` function explicitly loops through the array with a `for` loop, awaiting the callback for each element, ensuring the `Done` message appears only after all items are processed. The code uses no external libraries, only native JavaScript Promise and timer APIs.

Aackuser
64% match
Loading thumbnail…

Async/await 5

This example visualizes the flow of a sequential asynchronous function, showing how each awaited promise resolves in a chain before the next begins. The code defines an `async` function with three sequential `await` calls—`doA()`, `doB(a)`, and `doC(b)`—where each step passes its result into the next. The visualization maps this dependency chain, highlighting the blocking nature of each await and the data handoff between stages. It relies on JavaScript’s native `async`/`await` syntax, with no external libraries, and renders a linear timeline of the function’s execution order.

PPanJ
63% match
Loading thumbnail…

async-for-each

This example demonstrates a sequential asynchronous loop over an array, where each item is processed only after the previous callback completes. It shows how `asyncForEach` awaits a user-provided callback that delays execution using a custom `waitFor` promise wrapper around `setTimeout`. The code uses the native `async`/`await` syntax and a `for` loop to ensure the array `[1, 2, 3]` is logged in order, with a one-second pause between each item. The visible data source is a hardcoded array in the `start` function, and the rendering approach is console output.

AA6Brgeuka
63% match
Loading thumbnail…

Async/await 3

This example visualizes the nested callback structure of an asynchronous JavaScript function as a branching tree diagram. It shows how sequential `doA`, `doB`, and `doC` calls with error-handling callbacks create a multi-level flow. The visualization uses a force-directed layout from D3’s `d3.forceSimulation` to position nodes, with links rendered as curved paths. The code snippet from the gist is the direct source, and the rendering approach highlights the increasing depth of callbacks as the program progresses.

PPanJ
61% match
Loading thumbnail…

Serially Iterating An Array, Asynchronously

This example demonstrates a pattern for processing an array of asynchronous steps sequentially, where each step must finish before the next begins. It shows a recursive function, `run`, that takes an array of functions (`steps`), a shared `data` object, and a completion callback (`done`). The function shifts the first step from the array, invokes it with the data and a callback, and on success recursively calls itself with the remaining steps. If a step returns an error, the recursion halts and passes the error to `done`. The code uses plain JavaScript callbacks and array mutation via `shift()`, with no external libraries.

Aalessioalex
60% match
Loading thumbnail…

Gist 1075489a3f6f94d13b2ab76cff4c7cea

This example visualizes the asynchronous execution order of Node.js operations by logging their completion times relative to a shared start timestamp. It uses Node’s `https.request` to fetch Google’s homepage, `crypto.pbkdf2` for four CPU-intensive password hashes, and `fs.readFile` to read a local file. The console output reveals how the event loop interleaves I/O callbacks, with the network request finishing before the file read and hash computations, illustrating the non-blocking concurrency model.

Aamazingandyyy
59% match