Parallel Execution & Thread Budget¶

Speed up your QA runs by distributing work across multiple CPU cores.

Enable parallel execution¶

Set processes in your flow options:

'flows' => [
    'options' => [
        'processes' => 4,  // total CPU cores budget
    ],
    'qa' => ['jobs' => ['phpcs_src', 'phpstan_src', 'phpmd_src', 'parallel_lint']],
],

Or override from the CLI:

githooks flow qa --processes=4

How thread budgeting works¶

The processes value is the total CPU cores available, not the number of parallel jobs. GitHooks distributes threads across jobs that support internal parallelism:

Tool	Internal parallelism flag
phpcs / phpcbf	`--parallel`
parallel-lint	`-j`
psalm	`--threads`
phpstan	Worker count from `.neon` config (read-only)

For example, with processes: 4 and two threadable jobs (phpcs and parallel-lint), each gets approximately 2 threads.

Monitor thread usage¶

Use --monitor to see the actual thread usage after execution:

githooks flow qa --processes=4 --monitor

Check your system¶

githooks system:info

Shows detected CPU count and current processes configuration. Warns if processes exceeds available CPUs.

Tips¶

Start with processes equal to your CPU core count.
PHPStan worker count is configured in the .neon file (maximumNumberOfProcesses), not via GitHooks. It is accounted for in the budget but not adjustable at runtime.
Use --monitor to verify that the budget is being distributed as expected.