This changes how the AsyncPool works so that it does not immediately always start all of the workers in the pool.
Instead, workers will be started only when an idle worker was not found.
This allows for significant memory footprint reductions while idle.
In effect the async-workers setting in pocketmine.yml now dictates a _maximum_ pool size, not a fixed pool size.
This commit contains quite a few breaking changes with respect to how AsyncTasks are handled. This is necessary to allow separation of the ServerScheduler and the AsyncPool, because in the future the ServerScheduler may be removed and instead there will be isolated per-plugin sync-task schedulers - but we cannot have every plugin with its own worker pool for memory usage reasons if nothing else.
The following things have changed:
- ServerScheduler: scheduleAsyncTask(), scheduleAsyncTaskToWorker(), getAsyncTaskPoolSize(), increaseAsyncTaskPoolSize() and similar methods have all been removed. Additionally the static \$WORKERS field has been removed.
- Server: added API method getAsyncPool(). This grants you direct access to the server's AsyncPool. Calls to getScheduler()->scheduleAsyncTask() and scheduleAsyncTaskToWorker() should be replaced with getAsyncPool()->submitTask() and submitTaskToWorker() respectively.
this implementation was god-awful bad and it was entirely avoidable to make it this complicated.
This utilizes the fact that pthreads treats static properties as thread-local. AsyncTask local storage now utilizes a \SplObjectStorage stored in an AsyncTask private static field.
All plugins will need to bump the API if they want to use this.
NOTE THAT THIS IS NOT THE FINAL API 2.0.0 AND THAT THERE WILL BE MORE CHANGES.
To start updating, you might also want to read https://secure.php.net/manual/en/migration70.php and specifically https://secure.php.net/manual/en/migration70.incompatible.php
To compile PHP7 with some of the required dependencies, use https://gist.github.com/shoghicp/166ab26ce5cc7a390f45
ONLY LINUX IS TESTED, DO NOT ASK FOR OTHER PLATFORMS!
----- THIS VERSION IS NOT SUPPORTED -----
This version WILL crash randomly in unexpected places due to PHP7, pthreads, PocketMine or cosmic rays.
Handle with care, and store under direct sunlight for the best performance.
