Warn about too low value for stream_select's tv_usec parameter

[hollodotme]

Subject	Details
Issue type	Feature request
Plugin	Php Inspections (EA Extended)
Language level	PHP4+

Current behaviour (description/screenshot:)

When using the stream_select function it is highly recommended by the official PHP documentation, that the tv_usec parameter is set to at least 200000 when tv_sec is set to 0 to keep CPU usage at a reasonable level.

There is currently no inspection warning when using a lower tv_usec value.

Expected behaviour

There should be a probable bug warning when the following conditions are met:

• tv_sec is set to 0
• tv_usec is set to a value lower than 200000

The warning message should contain a hint, that the given value may cause too high CPU usage.

The inspection should also apply if a static value in form of a constant is given to the function, like this:

<?php declare(strict_types=1);

class MyStream
{
    private const TV_USEC = 20000;

    # ...

    public function hasResponse() : bool
    {
        $read = [$this->resource];
        $write = $except = [];
       
        stream_select($read, $write, $except, 0, self::TV_USEC);

        return 1 === count($read);
    }
}

Environment details

PhpStorm 2018.2.3 (but all versions)

[kalessil]

Uh, that's a very good catch @hollodotme. Will it be fine for you if I'll take this into Ultimate?

[hollodotme]

Fine for me @kalessil. 😬

[kalessil]

Also a question: did you hit the issue in production (perhaps a ticket on GitHub)?

[hollodotme]

Yes, it was a long existing bug in hollodotme/fast-cgi-client, that popped up during this discussion and was fixed in the last release.

It was quite hidden, because the tv_usec value was defined in a class constant. (That's why I mentioned the second part of this issue.) 😄

[kalessil]

Implemented!