Ruby Thread Pool

A future is somewhat a promise except you pass it a block to execute in another thread.

Ruby thread pool. Higher level abstractions use global thread pools by default for running asynchronous operations without creating new threads more often than necessary. Each thread should be wrapped before it runs application code so if your application manually delegates work to other threads such as via thread new or concurrent ruby features that use thread pools you should immediately wrap the block. Ruby thread pool a thread pool is useful when you wish to do some work in a thread but do not know how much work you will be doing in advance. Thread pools allow you to control the number of active threads at any given time.

Concurrent ruby provides several global thread pools. Ruby threads are a lightweight and efficient way to achieve concurrency in your code. Thread future accepts an optional argument of type thread pool if you want the block executed in an existing thread pool. In this case it might be more beneficial to start a predefined set of.

Fortunately there is a better way. In the following example we are using the celluloid gem to do this for you. Thread pools are particularly useful when there are a large number of short tasks to be performed rather than a small number of longer tasks. The value returned by the block will be the value of the promise.

To start a new thread just associate a block with a call to thread new. A new thread will be created to execute the code in the block and the original thread will return from thread new immediately and resume execution with the next. These executors are lazy loaded so they do not create overhead when not needed. One solution is to use a thread pool.

Spawning one thread for each task is potentially expensive as threads are not free. You can find examples of thread pool implementations in gems like puma concurrent ruby celluloid pmap parallel and ruby thread. A thread pool is a group of pre instantiated reusable threads that are available to perform work as needed. Require rubygems require thread pool pool threadpool new threads 10 pool execute puts i m writing from a thread pool join it s often useful to make sure that the properties of ruby s blocks don t bite you.

A simple executor style threadpool for ruby with tests yay usage. Celluloid is now unmaintaned but the general idea of worker pools still applies.