ResourceOutputStream treats open stream as closed

[psafarov]

Here is a problem which occurs if the script is run from systemd

Amp\Loop::run(function() {
    $resourceOutputStream = new ByteStream\ResourceOutputStream(\STDOUT);
    // Throws Amp\ByteStream\StreamException: The stream was closed by the peer
    yield $resourceOutputStream->write('test');
});

I figured out that it stops happening if feof check of the stream is removed in ResourceOutputStream.php:74. Apparently it is not correct to use feof for checking if stream is open or not, but I am not sure what can be done here as it has been added for a reason.

[bwoebi]

No idea why feof() is being used, this only makes sense for readability checks - it has no purpose in ResourceOutputStream.

@trowski can you please revisit #40? The fix looks not correct to me...

[trowski]

@bwoebi I think what really fixed #40 was failing after multiple writes of 0 length. On macOS feof() detects IPC pipes being closed, but I always had mixed results with network sockets. If it causes trouble on other systems, we can probably drop the two if-statements with feof() and rely on failing after multiple 0-length writes.

[kelunik]

Failing after multiple 0-length writes still isn't the optimal solution, but might be OK given we don't really support TLS renegotiation.

[kelunik]

Running the example via the shell yields the following output:

array(9) {
  ["timed_out"]=>
  bool(false)
  ["blocked"]=>
  bool(true)
  ["eof"]=>
  bool(false)
  ["wrapper_type"]=>
  string(3) "PHP"
  ["stream_type"]=>
  string(5) "STDIO"
  ["mode"]=>
  string(2) "wb"
  ["unread_bytes"]=>
  int(0)
  ["seekable"]=>
  bool(true)
  ["uri"]=>
  string(12) "php://stdout"
}
test

Running the same script with systemd yields:

array(9) {
  ["timed_out"]=>
  bool(false)
  ["blocked"]=>
  bool(true)
  ["eof"]=>
  bool(false)
  ["wrapper_type"]=>
  string(3) "PHP"
  ["stream_type"]=>
  string(10) "tcp_socket"
  ["mode"]=>
  string(2) "r+"
  ["unread_bytes"]=>
  int(0)
  ["seekable"]=>
  bool(false)
  ["uri"]=>
  string(12) "php://stdout"
}
PHP Fatal error:  Uncaught Amp\ByteStream\StreamException: The stream was closed by the peer

[kelunik]

Finally released v1.6.0. 🎉