Preferences.jl

Persist thread, warmup and log defaults in the active controller project. These APIs require PerfChecker 1.1.0 or newer.

Start Julia in a project containing PerfChecker (] add PerfChecker if needed).

using PerfChecker
set_check_preferences!(threads=2, repeat=false, quiet=true)
check_preferences()
config = PerfConfig(:profile; path=pwd(), threads=1) # explicit value wins
reset_check_preferences!(:threads) # remove local value and inherit again

The returned dictionary contains threads=2, repeat=false, quiet=true immediately after the setter. It writes LocalPreferences.toml beside the controller's active Project. Reading preferences or running a normal check does not write it. PerfConfig.path chooses the workload environment and does not choose preference storage.

Precedence is collector defaults → inherited preferences → explicit options. Local preferences override exported project values; a suite freezes its resolved defaults before preparing workers. Changes affect future checks without restarting Julia.

threads must be a positive integer representable as Int, excluding Bool; repeat and quiet must be Boolean. repeat controls optional allocation/profile/network warmup. BenchmarkTools and Chairmarks use their own sampling options. quiet suppresses package-management logs, not workload output.

Shared settings, reset and saved evidence

The local file produced by the first setter contains:

[PerfChecker]
check_threads = 2
check_repeat = false
check_quiet = true

set_check_preferences!(threads=2, export_prefs=true) # Project.toml
reset_check_preferences!(:threads; export_prefs=true)
reset_check_preferences!(block_inheritance=true) # block all three inherited values

A reset without keys selects all three settings at the chosen storage level, preserving other packages' preferences. Ordinary reset allows inheritance; block_inheritance=true uses Preferences.jl clear markers. Unknown/invalid settings are rejected before writes. No path, command or credential can be saved through these APIs.

Investigations and TestItems use their own explicit scenario/item thread setting (one by default). Saved check_configuration retains values, origins and config_hash; workers receive resolved values rather than rereading preferences. A cache hit records the current request's configuration; cache identity uses effective values, not whether they came from explicit or persistent options.