This library is a component for [Amp](https://amphp.org) that provides native threading, multiprocessing, process synchronization, shared memory, and task workers. Like other Amp components, this library uses [Coroutines](http://amphp.org/amp/coroutines/) built from [Promises](http://amphp.org/amp/promises/) and [Generators](http://www.php.net/manual/en/language.generators.overview.php) to make writing asynchronous code more like writing synchronous code.
To be as flexible as possible, this library comes with a collection of non-blocking concurrency tools that can be used independently as needed, as well as an "opinionated" worker API that allows you to assign units of work to a pool of worker threads or processes.
- [pthreads extension](https://pecl.php.net/package/pthreads): Best extension option for concurrency in PHP, but it requires PHP to be compiled with `--enable-maintainer-zts` to enable thread-safety.
- [sysvmsg extension](http://php.net/manual/en/book.sem.php): Required for sharing memory between forks or processes.
##### Installation
The recommended way to install is with the [Composer](http://getcomposer.org/) package manager. (See the [Composer installation guide](https://getcomposer.org/doc/00-intro.md) for information on installing and using Composer.)
Want to hack on the source? A [Vagrant](http://vagrantup.com) box is provided with the repository to give a common development environment for running concurrent threads and processes, and comes with a bunch of handy tools and scripts for testing and experimentation.
Starting up and logging into the virtual machine is as simple as
vagrant up && vagrant ssh
Once inside the VM, you can install PHP extensions with [Pickle](https://github.com/FriendsOfPHP/pickle), switch versions with `newphp VERSION`, and test for memory leaks with [Valgrind](http://valgrind.org).
