Xdebug's Code Coverage speedup
Besides a debugging and development aid, Xdebug also implements the back-end code to provide code coverage information for use with PHPUnit. Code coverage tells you how much of your code base is actually being tested by your unit tests. It's a very useful feature, but sadly, it slows down PHP's execution quite a lot. One part of this slowdown is the overhead to record the information internally, but another part is because I have to overload lots of opcodes. (Opcodes are PHP's internal execution units, similar to assembler instructions) They are always overloaded even if code coverage is not used, because it's only safe to overload them for the whole request.
The upcoming Xdebug 2.2 has a few changes to improve code coverage performance. First of all, the speed with which information about code coverage is recorded has been improved by contributions by Taavi Burns. And secondly, Xdebug 2.2 features a new setting, xdebug.coverage_enable with which it is possible to disable the overloading of code coverage specific opcodes. By default that setting will still be on.
Just to show how those improvements have effect on the speed, I've run a benchmark (running Apache Zeta Components Graph's tests) to compare Xdebug 2.1.2 against Xdebug 2.2-dev.
The results are as follows:
|
Version |
With CC |
Without CC |
With coverage_enable=0 |
Without Xdebug |
|
2.1.2 |
06:44 |
00:49 |
not available |
00:32 |
|
2.2-dev |
05:37 |
00:48 |
00:46 |
00:32 |
Another benchmark, run by Ross McFarlane gives: @derickr Based on 3 runs each, execution of 254 tests with 1070 assertions has dropped from 19s to 12s. Nice work!.
In Xdebug 2.2 I would also like to introduce modes. Each mode will set a default configuration for Xdebug's setting to be the most optimal for that specific tasks. Examples of tasks could be: "profiling", "debugging" or "tracing". Let me know (in the comments) whether you think that's a good idea.
Comments
I love the idea of Modes.
At present my workplace is looking to switch on XDebug on a production (but low-traffic) server to help identify areas of dead code. We don't have full unit-test coverage, so this would go some way to help turn these up.
Being able to use a lightweight mode that just showed details like method calls would be great for this.
Very nice improvement. Is there any plan to enable code coverage only for a file or a set of files ?
Is there any plan to enable code coverage only for a file or a set of files ? — mageekguy
This is already possible as you need to start and stop code coverage with xdebug_start_code_coverage() and xdebug_stop_code_coverage(). Only the files that are included and functions that are executed when code coverage collection is active will then be part of the returned data.
I know that, but with this solution, the result is the code coverage of all files included during execution, and not only a specific file. I think that it must be interesting to have xdebug_start_code_coverage('/path/to/class/file') to get the code coverage only for this file.
Nice work and sounds like a neat idea! :)
Life Line
I think this was my favourite photo of the set that I took. It's not at maximum coverage, but it does have a sun spot group (4508) just on the cusp of the terminator.
#eclipse #eclipse2026 #SolarEclipse #London #Astronomy #AstroPhotography #Photography
No totality here in London, but still had a great evening out in the local park and taking some snaps.
I did have a nice Solar Filter that I made for my lens, and had many conversations with people from different backgrounds. Kids loves to look through my filter after I was done (ran out of battery power).
More photos later...
#london #eclipse2026 #eclipse #photography
I walked 0.9km in 9m28s
I walked 1.2km in 19m05s
Merged pull request #1100
Fixed issue #2267: Application slow when debugger is not listening on…
I walked 4.7km in 48m18s
I walked 3.0km in 1h10m24s
Is there somebody who runs PHP on native windows (with Xdebug) and can run a simple script for me?
It must be in a file (`test.php`):
```
<?php
echo microtime(true), "\n";
xdebug_connect_to_client();
echo microtime(true), "\n";
```And run like:
php -dxdebug.log_level=11 -dxdebug.log=c:\temp\xdebug-i.log -dxdebug.client_host=localhost -dxdebug.client_port=9111 -dxdebug.mode=debug c:\temp\test.php
With the port 9111 not open.
Would love to see the output and log file (in a DM).
I walked 5.5km in 55m06s
@harry_wood This is this list of 100 Go-mistakes that I was talking about: https://100go.co/
Updated a crossing
I walked 2.1km in 20m08s
Enjoying my afternoon and evening out at Lords for some cricket!
I walked 3.2km in 38m54s
I walked 9.1km in 1h34m28s
Updated a gate
Updated a bakery shop
Updated a convenience shop
I walked 8.1km in 1h32m18s
I walked 5.6km in 59m13s
Updated a restaurant and a cafe; Confirmed 2 restaurants and a cafe
I walked 6.7km in 1h8m27s
I walked 4.7km in 50m02s
I got myself a sheet of Sun-safe filter material, and McGuyvered a pop-up filter for my lens.
The first attempt sort of worked, but I didn't get the filter 100% straight. Luckily I have more material.
But this is sort of my first attempt, and a few sunspots are clearly visible on the right of the image.
Warning: Never look at the Sun without protection!
#Sun #Photography #Astronomy #AstroPhotography
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