[BUG]: Remove broken sockets from socket collection if write request fails

[hollodotme]

Expected Behavior

When the attempt to write to a socket fails, because the socket is already closed, blocked or terminated, this socket must be removed from the socket collection, so subsequent requests will open new sockets for processing.

Actual Behavior

The broken socket is not removed from the socket collection and the client tries to reuse the broken socket for subsequent requests.

Steps to Reproduce the Problem

1. Send a request
2. Kill the underlying php-fpm child process
3. Send a second request (Raises a WriteFailedException here https://github.com/hollodotme/fast-cgi-client/blob/v3.1.2/src/Sockets/Socket.php#L410)
4. Send a third request, it uses the same socket as the second request, which is broken

Specifications

• Package version: v3.1.2
• PHP version: >= 7.1

Further comments

This issue emerged from brefphp/bref#713.

[Nyholm]

Does it make sense to also retry to write to a new socket? Or should that be handled by the caller?

[hollodotme]

There is no retrying mechanism at all in the client right now and even though it's probably not hard to implement in that case, I'd like to leave this responsibility to the caller/user. This also would be a BC break, because callers won't get notified (by an exception) about broken streams anymore and an automatic retry is not what everyone wants in that case.

But I also understand that a retry can totally make sense and would reduce efforts on the user's end. I do think about prefixed methods which will add a retry mechanism when sending requests, like: Client#retryRequest($connection, $request, $maxRetries = 5) and Client#retryAsyncRequest($connection, $request, $maxRetries = 5). This way the user can choose to use retry or not, it would be a clear new feature (no BC break), it would seperate concerns of the client's methods. Anyway, this should not be part of this issue, but a new feature request. (-:

I'm trying to fix this bug by today and release v3.1.3. 🤞