Go WaitGroup: Difference between revisions

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The main goroutine calls <code>Add()</code> to set the number of goroutines to wait for. Then it can  block on <code>Wait()</code> until all other goroutines have finished. When each of the counted goroutines runs, they should call <code>Done()</code> when finished, to increment the counting semaphore.
The main goroutine calls <code>Add()</code> to set the number of goroutines to wait for. Then it can  block on <code>Wait()</code> until all other goroutines have finished. When each of the counted goroutines runs, they should call <code>Done()</code> when finished, to increment the counting semaphore.
Note that the <code>WaitGroup</code> instance must be passed by pointer, not value. <font color=darkkhaki>Why?</font>

Revision as of 21:33, 1 September 2023

External

Internal

Overview

A WaitGroup is a counting semaphore that waits for a set of goroutines to finish.

The main goroutine calls Add() to set the number of goroutines to wait for. Then it can block on Wait() until all other goroutines have finished. When each of the counted goroutines runs, they should call Done() when finished, to increment the counting semaphore.

Note that the WaitGroup instance must be passed by pointer, not value. Why?