Having access to the hash allows to produce stats in other ways (such as StatsD) without having to parse JSON of data that is available in memory. An example of this workaround is fa6ba1f507/lib/puma/plugin/statsd.rb (L112-L114)
* Add pumactl command to print thread backtraces
Completes 1 of 2 items from #1964
This commit adds an endpoint to the status app to print thread
backtraces, and control cli command to call that endpoint.
I tried this locally by starting a server with:
```sh
bundle exec bin/puma test/rackup/hello.ru \
--control-url="unix://test.sock" \
--control-token="token"
```
and then printing the backtraces with:
```sh
bundle exec bin/pumactl thread-backtraces \
--control-url="unix://test.sock" \
--control-token="token"
```
* Log threads as JSON in control app
With this commit the status app sends the thread backtraces as an array
of objects with `name` and `backtrace` keys, rather than as a string
matching the SIGINFO output.
While working on this I noticed that we logged the thread TID twice.
This commit simplifies that so we only log the thread TID once, with
both the label (I don't know when the label would get set) and name if
they are available.
* Add frozen string literal everywhere it wasnt already
* Enforce stopgap for tests
* Small amount of integration test cleanup
* Parallelize and freeze Test_app_status
* Big cleanup for test_binder
* Whitespace fix
* Fix: Invalid JSON on gc-stats
Credits of this patch should be for @jdsundberg, who reported the issue
but never sent a patch. Link to his bug report is below.
Closes#1687.
* Update tests so JSON response is correctly parsed
JSON without a whitespace between key and values wasn't being correctly
parsed (for example: `key: 'value'` was processed ok, but `key:'value'`
wasn't).
