plugin_main_thread.hpp

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#pragma once
 
// Plugin-mode main-thread cooperation.
//
// Standalone macOS apps register a Cocoa `MainThreadDispatcher` backend from
// `WindowHost::create()` so cross-subsystem work can post to
// `dispatch_get_main_queue()`. In plugin mode (AU v3 / VST3 / CLAP loaded
// inside a DAW like Logic / Cubase / Bitwig), there is no Pulp window — the DAW
// owns the main `NSApplication`/`CFRunLoop`. Without an explicit registration,
// `MainThreadDispatcher::call_async` returns false and adapter-side code that
// asks "please run this on the host's main thread" no-ops.
//
// The helpers in this header let format adapters and plugin instance owners
// register a process-wide Cocoa backend at instantiation time and unregister
// it at teardown. On non-macOS platforms the calls degrade to no-ops so
// adapter code can call them unconditionally; the dispatcher then simply
// stays in its "no backend" state on those platforms (Windows / Linux own
// their own message-loop integration paths).
//
// Reference-counted under the hood — call register_plugin_backend() once
// per loaded plugin instance, and `unregister_plugin_backend()` once on
// teardown. The first register installs a backend; subsequent registers bump
// the refcount; the last unregister removes the backend. Safe to call from
// any thread.
 
#include <pulp/events/main_thread_dispatcher.hpp>
 
namespace pulp::events {

MainThreadDispatcher::Token register_plugin_backend();

bool unregister_plugin_backend(MainThreadDispatcher::Token token);

bool plugin_backend_available();
 
} // namespace pulp::events