Incompatibility with pthreads

[LuckyFellow]

Environment

• PHP: 7.2.14 (cli) ( ZTS )
• decimal: 1.1.1
• pthreads: 3.2.0 (http://php.net/manual/en/book.pthreads.php / https://github.com/krakjoe/pthreads)
• libmpdec: 2.4.2
• OS: docker, debian:stretch

Summary

Without threads, operations work as expected.
As soon as operations are performed in a seperate thread, some result in "INF".

Reproducing Code

<?php

$thread = new class() extends Thread {

    public function run() {
        var_dump((new Decimal\Decimal("1"))->mul("9"));
        var_dump((new Decimal\Decimal("1"))->mul("10"));
    }
};

$thread->start() && $thread->join();
?>

Expected Output

object(Decimal\Decimal)#39 (2) {
  ["value"]=>
  string(1) "9"
  ["precision"]=>
  int(28)
}
object(Decimal\Decimal)#42 (2) {
  ["value"]=>
  string(2) "10"
  ["precision"]=>
  int(28)
}

Actual Output

object(Decimal\Decimal)#3 (2) {
  ["value"]=>
  string(1) "9"
  ["precision"]=>
  int(28)
}
PHP Warning:  Loss of data on string conversion in /app/test.php on line 7
object(Decimal\Decimal)#2 (2) {
  ["value"]=>
  string(3) "INF"
  ["precision"]=>
  int(28)
}

[rtheunissen]

Fixed in 48920be, will confirm that it is safe and correct, then release a patch.

[rtheunissen]

Released as v1.1.2 ✨

[LuckyFellow]

Awesome, thank you very much!
The operations seem to work correctly in different threads now.

Running the "Reproducing Code" from above will issue the following warning now though:

context.c:55: warning: mpd_setminalloc: ignoring request to set MPD_MINALLOC a second time

[rtheunissen]

I'll get on that asap, thanks for the report.

[krakjoe]

Hi @rtheunissen ... I read the libmpdec source, it actually does require that contexts are truly global, I committed to both your active branches the fixes for that, hope I didn't make a mess of logs or do it badly ...

@LuckyFellow leaving this for you to close ...

[rtheunissen]

@krakjoe @LuckyFellow I've fixed this a little bit differently in b211485 which has been released as part of 1.2.0. Thanks for your help with this one Joe. 🙏

I'll wait for confirmation before we close this.

[LuckyFellow]

I can confirm, that there is no warning issued anymore and the operations function properly.

Thank you very much!