studio_one.hpp File Reference

Per-host quirks for PreSonus Studio One. More...

#include <pulp/format/host_quirks.hpp>
#include <pulp/format/host_version.hpp>

Go to the source code of this file.

Namespaces
namespace	pulp
namespace	pulp::format
	What the product grants a device: the quota table indexed by capability tier and live thermal state.
namespace	pulp::format::host_quirks

Functions
void	pulp::format::host_quirks::apply_studio_one (HostQuirks &q, HostVersion)
	Populate Studio One host-gated flags onto q.

Detailed Description

Per-host quirks for PreSonus Studio One.

Studio One's VST3 host serializes IComponentHandler::restartComponent notifications through a non-thread-safe lane: calls that arrive from the audio thread (most commonly kLatencyChanged from a delay-line resize) can deadlock the host or be silently dropped. Cubase / Nuendo / Reaper accept the call from any thread; Studio One does not.

The independent fix marshals restartComponent calls to the UI thread when the host is detected as Studio One. The dispatch lives here; the VST3 adapter consults the flag to decide whether to post the notification through core/events::EventLoop rather than invoking the host handler directly.

Rows covered

• studio_one_restart_component_ui_thread — UI-thread restart marshalling for any audio-thread-emitted notification (the field primarily targets kLatencyChanged but the adapter can layer on the same defense for kParamValuesChanged and friends).

Version handling

The threading contract appears in every Studio One release Pulp has surveyed (5.x and 6.x). apply_studio_one fires the flag unconditionally; if a future Studio One release switches to a thread-safe restart-component lane, add an is_before(major, minor) guard at that point.

Tier status

LessonOnly as of the 2026-05-26 iPlug2-audit batch — documented from Steinberg's VST3 SDK threading contract + PreSonus user-forum reports, no in-tree bench yet. Promote to Speculative after the per-symptom isolation tests ship; promote to Validated after Studio One bench evidence lands.

Reference-Lineage: independent reproducer=#3045 docs=https://steinbergmedia.github.io/vst3_dev_portal/pages/Technical+Documentation/Workflow+Diagrams/Edit+Controller+Call+Sequence.html