From 26e0d17833745d1d0ac70afdd7d8805d9232ab90 Mon Sep 17 00:00:00 2001
From: Robbert van der Helm <mail@robbertvanderhelm.nl>
Date: Mon, 22 Aug 2022 12:31:09 +0200
Subject: [PATCH] Fix VST3 event loop leaking
This should have never used MaybeUninit in the first place.
---
src/wrapper/vst3/inner.rs | 24 ++++++++++++++----------
src/wrapper/vst3/view.rs | 14 +++++++-------
2 files changed, 21 insertions(+), 17 deletions(-)
diff --git a/src/wrapper/vst3/inner.rs b/src/wrapper/vst3/inner.rs
index 9f6d4984..0476285a 100644
--- a/src/wrapper/vst3/inner.rs
+++ b/src/wrapper/vst3/inner.rs
@@ -3,7 +3,6 @@ use crossbeam::atomic::AtomicCell;
use crossbeam::channel::{self, SendTimeoutError};
use parking_lot::RwLock;
use std::collections::{HashMap, HashSet, VecDeque};
-use std::mem::MaybeUninit;
use std::sync::atomic::{AtomicBool, AtomicU32, Ordering};
use std::sync::Arc;
use std::time::Duration;
@@ -53,11 +52,11 @@ pub(crate) struct WrapperInner<P: Vst3Plugin> {
/// through [`Self::do_maybe_async()`] instead. That method posts the task to the host's
/// `IRunLoop` instead of it's available.
///
- /// This RwLock is only needed because it has to be initialized late. There is no reason to
- /// mutably borrow the event loop, so reads will never be contested.
+ /// This AtomicRefCell+Option is only needed because it has to be initialized late. There is no
+ /// reason to mutably borrow the event loop, so reads will never be contested.
///
/// TODO: Is there a better type for Send+Sync late initializaiton?
- pub event_loop: AtomicRefCell<MaybeUninit<OsEventLoop<Task, Self>>>,
+ pub event_loop: AtomicRefCell<Option<OsEventLoop<Task, Self>>>,
/// Whether the plugin is currently processing audio. In other words, the last state
/// `IAudioProcessor::setActive()` has been called with.
@@ -281,7 +280,7 @@ impl<P: Vst3Plugin> WrapperInner<P> {
plug_view: RwLock::new(None),
- event_loop: AtomicRefCell::new(MaybeUninit::uninit()),
+ event_loop: AtomicRefCell::new(None),
is_processing: AtomicBool::new(false),
// Some hosts, like the current version of Bitwig and Ardour at the time of writing,
@@ -321,7 +320,7 @@ impl<P: Vst3Plugin> WrapperInner<P> {
// is separate from the internal COM-style reference count.
let wrapper: Arc<WrapperInner<P>> = wrapper.into();
*wrapper.event_loop.borrow_mut() =
- MaybeUninit::new(OsEventLoop::new_and_spawn(Arc::downgrade(&wrapper)));
+ Some(OsEventLoop::new_and_spawn(Arc::downgrade(&wrapper)));
wrapper
}
@@ -351,7 +350,7 @@ impl<P: Vst3Plugin> WrapperInner<P> {
#[must_use]
pub fn do_maybe_async(&self, task: Task) -> bool {
let event_loop = self.event_loop.borrow();
- let event_loop = unsafe { event_loop.assume_init_ref() };
+ let event_loop = event_loop.as_ref().unwrap();
if event_loop.is_main_thread() {
unsafe { self.execute(task) };
true
@@ -480,9 +479,14 @@ impl<P: Vst3Plugin> WrapperInner<P> {
}
// After the state has been updated, notify the host about the new parameter values
- let task_posted = unsafe { self.event_loop.borrow().assume_init_ref() }.do_maybe_async(
- Task::TriggerRestart(RestartFlags::kParamValuesChanged as i32),
- );
+ let task_posted =
+ self.event_loop
+ .borrow()
+ .as_ref()
+ .unwrap()
+ .do_maybe_async(Task::TriggerRestart(
+ RestartFlags::kParamValuesChanged as i32,
+ ));
nih_debug_assert!(task_posted, "The task queue is full, dropping task...");
}
diff --git a/src/wrapper/vst3/view.rs b/src/wrapper/vst3/view.rs
index 02a75360..fbe5102a 100644
--- a/src/wrapper/vst3/view.rs
+++ b/src/wrapper/vst3/view.rs
@@ -508,13 +508,13 @@ impl<P: Vst3Plugin> Drop for RunLoopEventHandler<P> {
// handle those in the regular event loop so no work gets lost
let mut posting_failed = false;
while let Some(task) = self.tasks.pop() {
- posting_failed |= !unsafe {
- self.inner
- .event_loop
- .borrow()
- .assume_init_ref()
- .do_maybe_async(task)
- };
+ posting_failed |= !self
+ .inner
+ .event_loop
+ .borrow()
+ .as_ref()
+ .unwrap()
+ .do_maybe_async(task);
}
if posting_failed {