How to read a file asynchronously?

Question

PHP

Hello habr users.

As you know in php multi-threading (threads) is not very well developed, therefore the script should work in single-threaded mode and any long task should not stop its execution.

I want to be able to do 3 things at the same time:

1. Accept new connections to the server.
   
2. Send requests to third-party resources.
   
3. Read files on disk.
   

All of the above tasks should not slow down the execution of the script.
To solve the problem, I would use stream .

But my problem is with reading the contents of a file on disk.
I googled asynchronous file reading with php and found this swoole function , but its problem is that it waits for the callback function to complete.

I need to read a file, but the script only needs to create a 'task' to read the file and not wait for the file to be successfully read. (When the content is received, the callback function should run, and upon completion, all used memory should be destroyed).

I pass all 'tasks' to the stream_select function .

Unfortunately, I can’t provide code examples, because I have no idea what function to call to read the file asynchronously.

Note: perhaps this task is simple, and there is already a ready-made function for asynchronous reading using stream, and I'm just blind.

Answer 1

Create a task and go on executing the code while the task is being solved - this is about promises.
There are no built-in promises in php, but you can add their support yourself manually:
https://habr.com/ru/company/skyeng/blog/453296/