Issue with getIsWindows() change.

[epicwally]

The recent added check in the $descriptors array for windows has broken functionality for me. Running on a linux machine. Previously had the 'a' descriptor, but now with the getIsWindows() check on line 286, it's returning false, giving a 'w' descriptor. If I am building a small pdf this doesn't seem to be a problem, but for larger pdfs it just hangs. I have temporarily commented out the change here returning it to using the 'a', and everything seems to be in order again.

[mikehaertl]

Hmm, please have a look at issue #6 for why this was changed. I don't have much time currently to look into this. But maybe you can do some research and find a fix that makes everyone happy?

[mkloosterman]

It seems that there are 2 issues here. When proc_open is configured with the stderr descriptor as:
2 => array('pipe','w')
there is a deadlock condition for generating large PDF's. But when the workaround:
2 => array('pipe','a')
is applied, the error reporting breaks on Windows.

Here is a fix that should address both issues. Open the stderr stream in write mode (which will keep the error reporting working) but then set both streams to non-blocking mode. I have tested it on Linux and it addresses the deadlock issue. The error reporting still works fine.

$descriptors = array(
    1 => array('pipe','w'),
    2 => array('pipe','w')
);
$process = proc_open($command, $descriptors, $pipes, $this->procCwd, $this->procEnv, $this->procOptions);

if (is_resource($process)) {
    // set streams to non blocking mode
    stream_set_blocking($pipes[1], 0);
    stream_set_blocking($pipes[2], 0);
    $this->_stdOut = trim(stream_get_contents($pipes[1]));
    $this->_stdErr = trim(stream_get_contents($pipes[2]));
    fclose($pipes[1]);
    fclose($pipes[2]);
...

[mikehaertl]

@epicwally @mkloosterman I'm hesitant to change this. I remember having messed around with this a lot. And I think we even already tried the stream_set_blocking() at some point - which opened other issues again. See here:

mikehaertl/phpwkhtmltopdf#78 (comment)

So this still needs more research. I'm open for any input, though.

[mikehaertl]

@epicwally Does it help if you keep the pipe configuration as it is and only add the stream_set_blocking() parts that @mkloosterman suggests?

[mikehaertl]

Closing this, as there was no further feedback.

I'm more than willing to improve pipe/blocking configuration, but it must be handled with care and take all error reports into account. ~~~So feel free to comment on #6 hich I would reopen if we find a better setup.~~~ Update: I try keep #20 updated with our latest findings.