Profiling an intermediate hook is sometimes empty

[danielbachhuber]

When profiling an intermediate hook (e.g. wp profile hook plugins_loaded:before), some environments don't log any results:

In debugging this initial report, the callback hooked into register_tick_function() is only fired once.

[danielbachhuber]

This is a bug in PHP 7 https://bugs.php.net/bug.php?id=72966

Related thread from another profiling plugin khromov/wp-performance-profiler#1

[austinginder]

One of the comments in https://bugs.php.net/bug.php?id=71448 mentioned the following:

PHP 7.1 supports async signals, see https://wiki.php.net/rfc/async_signals. It looks like pcntl_async_signals() is not documented yet. This allows handling signals without using ticks.

Maybe this issue can be resolved by recoding how intermediate hooks work with PHP7.1?

[lkraav]

Yeah, after running into this now, and going through the PHP bug discussion - it actually was a bug in PHP5, and PHP7 fixed the leak.

Looks like profile intermediate hooks won't work at all on PHP 7.0, and the only way forward for PHP 7.1+ is to modernize our approach here like upstream has noted (via @austinginder).

[uprise10]

Is there another way to profile the (for example) wp_head:before hook? Or is switching back to PHP 5.6 the only option for now?

[danielbachhuber]

PHP 5.6 is the only option.

[pcfreak30]

See #160 @danielbachhuber @uprise10 @lkraav @austinginder

[ehausen]

So currently this won't work on PHP 7.1+ either, correct?

(But could be made to work?)

[tobias992]

Hello,
i am not a professional on github. Sorry for my question if it's stupid. For this bug here looks like there is a fix (https://gist.github.com/danielbachhuber/6bc4276ce559ddaa8b809a17c5ad6cd5) - there is a way to download this wp-cli profile package including this fix?

[tdiam]

Hello, i am not a professional on github. Sorry for my question if it's stupid. For this bug here looks like there is a fix (https://gist.github.com/danielbachhuber/6bc4276ce559ddaa8b809a17c5ad6cd5) - there is a way to download this wp-cli profile package including this fix?

Assuming you have WP-CLI and the profile command installed, you can apply the patch with the following one-liner:

wget -qO- https://gist.githubusercontent.com/danielbachhuber/6bc4276ce559ddaa8b809a17c5ad6cd5/raw/9ca11c146c88f481367494e62eb940835b0bcd95/wp-cli-profile-command-160.diff | patch -p1 -d ~/.wp-cli/packages/vendor/wp-cli/profile-command/

However, bear in mind that the patch by @danielbachhuber isn't complete and there are missing parts. Specifically, the FileStreamWrapper class in the patch does not fully implement streamWrapper .

For example, WordPress when loading the translation files (load_textdomain function), uses the fseek operation which is not implemented in the patch and so the command breaks:

Warning: fseek(): Stream does not support seeking in /home/user/public_html/wp-includes/pomo/streams.php on line 197

Also, this leaves *_file.php files behind, which you can easily cleanup:

find . -name '*_file.php' -delete