Io\Poll\Context::wait() prevent integer overflow

[marc-mabe]

This prevents integer overflow in case of SIZEOF_INT < SIZEOF_ZEND_LONG

[devnexen]

Hi @marc-mabe ; overflow check is safe_emalloc job here, so it s basically all about getting a tailored error message ?Not sure it s worth it honestly. Other unwarranted changes I see as well as variables declarations, we moved away from iso 90 a while ago.

[devnexen]

I m not sure the upper range check is correct/relevant on 64 bits anyway.

[marc-mabe]

@devnexen max_events is limited by two things:

1. int cast
2. size_t memory allocation

The int cast is the problematic one.
I came to these lines while working on #19079 where size_t matters as well but as it's limited by the int cast I thought this is something that should be handled unrelated to to the work in #19079 - so I created this PR.

I'll update this PR to checking for max_events > INT_MAX only.

Hope it makes more sense now.

[devnexen]

alright can we also have a test along these lines ?

--TEST--
  Io\Poll\Context::wait(): Parameter validation
  --FILE--
  <?php
  require_once __DIR__ . '/poll.inc';

  $poll_ctx = new Io\Poll\Context();

  try {
      $poll_ctx->wait(timeout: Time\Duration::fromSeconds(1)->negate());
  } catch (Throwable $e) {
      echo $e::class, ': ', $e->getMessage(), PHP_EOL;
  }

  try {
      $poll_ctx->wait(maxEvents: -1);
  } catch (Throwable $e) {
      echo $e::class, ': ', $e->getMessage(), PHP_EOL;
  }

  try {
      $poll_ctx->wait(maxEvents: 0);
  } catch (Throwable $e) {
      echo $e::class, ': ', $e->getMessage(), PHP_EOL;
  }

  try {
      $poll_ctx->wait(maxEvents: PHP_INT_MAX);
  } catch (Throwable $e) {
      echo $e::class, ': ', $e->getMessage(), PHP_EOL;
  }

  var_dump($poll_ctx->wait(Time\Duration::fromSeconds(0), 64));

  ?>
  --EXPECTF--
  ValueError: Io\Poll\Context::wait(): Argument #1 ($timeout) must not
  ValueError: Io\Poll\Context::wait(): Argument #2 ($maxEvents) must be greater than 0
  ValueError: Io\Poll\Context::wait(): Argument #2 ($maxEvents) must be greater than 0
  ValueError: Io\Poll\Context::wait(): Argument #2 ($maxEvents) must be less than or equal to %d
  array(0) {
  }