vanja/yabridge
1
0
Fork 0
mirror of https://github.com/robbert-vdh/yabridge.git synced 2026-05-07 03:50:11 +02:00
Code Issues Packages Projects Releases Wiki Activity

Get rid of message loop skipping and EditorOpening

Browse Source 
This special behaviour is no longer needed now that event handling is
fully concurrent and the Win32 message loop no longer blocks
`dispatch()` calls.
This commit is contained in:
Robbert van der Helm
2020-11-07 22:06:58 +01:00
parent e2603df522
commit d2500ff31d
5 changed files with 42 additions and 132 deletions
Download Patch File Download Diff File Expand all files Collapse all files
CHANGELOG.md
+5 -3
View File
@@ -31,9 +31,11 @@ Versioning](https://semver.org/spec/v2.0.0.html).
expected.
- And probably many more improvements.
I have been testing this extensively to make sure that the change does not
introduce any regressions, but please let me know if this does break anything
for you.
Aside from these more noticeable changes, this has also made it possible to
remove a lot of checks and behaviour that existed solely to work around the
limitations introduced by the event handling system. I have been testing this
extensively to make sure that the change does not introduce any regressions,
but please let me know if this does break anything for you.
TODO: Remove known issue about opening Kontakt and certain other plugins causing playback to stall, since this is no longer the case
src/wine-host/bridges/group.cpp
+13 -33
View File
@@ -161,22 +161,6 @@ void GroupBridge::handle_incoming_connections() {
main_context.run();
}
bool GroupBridge::should_skip_message_loop() {
// We do not need additional locking since the call to `AEffect::dispatcher`
// and the actual event handling and message loop handling are performed
// within the IO context and these values thus can't change while another
// the message loop is being running
std::lock_guard lock(active_plugins_mutex);
for (auto& [parameters, value] : active_plugins) {
auto& [thread, bridge] = value;
if (bridge->should_skip_message_loop()) {
return true;
}
}
return false;
}
void GroupBridge::accept_requests() {
group_socket_acceptor.async_accept(
[&](const boost::system::error_code& error,
@@ -245,25 +229,21 @@ void GroupBridge::async_handle_events() {
}
}
// Handle Win32 messages unless plugins are in the middle of opening
// their editor
if (!should_skip_message_loop()) {
std::lock_guard lock(active_plugins_mutex);
std::lock_guard lock(active_plugins_mutex);
MSG msg;
MSG msg;
// Keep the loop responsive by not handling too many events at once
//
// For some reason the Melda plugins run into a seemingly infinite
// timer loop for a little while after opening a second editor.
// Without this limit everything will get blocked indefinitely. How
// could this be fixed?
for (int i = 0; i < max_win32_messages &&
PeekMessage(&msg, nullptr, 0, 0, PM_REMOVE);
i++) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
// Keep the loop responsive by not handling too many events at once
//
// For some reason the Melda plugins run into a seemingly infinite timer
// loop for a little while after opening a second editor. Without this
// limit everything will get blocked indefinitely. How could this be
// fixed?
for (int i = 0; i < max_win32_messages &&
PeekMessage(&msg, nullptr, 0, 0, PM_REMOVE);
i++) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
});
}
src/wine-host/bridges/group.h
-11
View File
@@ -155,17 +155,6 @@ class GroupBridge {
*/
void handle_incoming_connections();
/**
* Returns true if the message loop should not be run at this time. This is
* necessary because hosts will always call either `effEditOpen()` and then
* `effEditGetRect()` or the other way around. If the message loop is
* handled in between these two actions, then some plugins will either
* freeze or sometimes outright crash. Because every plugin has to be run
* from the same thread, this is a simple way to synchronize blocking the
* mesage loop between the different plugin instances.
*/
bool should_skip_message_loop();
private:
/**
* Listen on the group socket for incoming requests to host a new plugin
src/wine-host/bridges/vst2.cpp
+17 -40
View File
@@ -262,10 +262,6 @@ Vst2Bridge::Vst2Bridge(MainContext& main_context,
});
}
bool Vst2Bridge::should_skip_message_loop() const {
return std::holds_alternative<EditorOpening>(editor);
}
void Vst2Bridge::handle_dispatch() {
sockets.host_vst_dispatch.receive_events(
std::nullopt, [&](Event& event, bool /*on_main_thread*/) {
@@ -337,20 +333,6 @@ intptr_t Vst2Bridge::dispatch_wrapper(AEffect* plugin,
// We have to intercept GUI open calls since we can't use
// the X11 window handle passed by the host
switch (opcode) {
case effEditGetRect: {
// Some plugins will have a race condition if the message loops gets
// handled between the call to `effEditGetRect()` and
// `effEditOpen()`, although this behavior never appears on Windows
// as hosts will always either call these functions in sequence or
// in reverse. We need to temporarily stop handling messages when
// this happens.
if (!std::holds_alternative<Editor>(editor)) {
editor = EditorOpening{};
}
return plugin->dispatcher(plugin, opcode, index, value, data,
option);
} break;
case effEditOpen: {
// Create a Win32 window through Wine, embed it into the window
// provided by the host, and let the plugin embed itself into
@@ -361,8 +343,8 @@ intptr_t Vst2Bridge::dispatch_wrapper(AEffect* plugin,
// should get a unique window class
const std::string window_class =
"yabridge plugin " + sockets.base_dir.string();
Editor& editor_instance = editor.emplace<Editor>(
config, window_class, x11_handle, plugin);
Editor& editor_instance =
editor.emplace(config, window_class, x11_handle, plugin);
return plugin->dispatcher(plugin, opcode, index, value,
editor_instance.get_win32_handle(),
@@ -373,7 +355,7 @@ intptr_t Vst2Bridge::dispatch_wrapper(AEffect* plugin,
plugin->dispatcher(plugin, opcode, index, value, data, option);
// Cleanup is handled through RAII
editor = std::monostate();
editor.reset();
return return_value;
} break;
@@ -385,29 +367,24 @@ intptr_t Vst2Bridge::dispatch_wrapper(AEffect* plugin,
}
void Vst2Bridge::handle_win32_events() {
std::visit(overload{[](Editor& editor) { editor.handle_win32_events(); },
[](std::monostate&) {
MSG msg;
if (editor) {
editor->handle_win32_events();
} else {
MSG msg;
for (int i = 0;
i < max_win32_messages &&
PeekMessage(&msg, nullptr, 0, 0, PM_REMOVE);
i++) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
},
[](EditorOpening&) {
// Don't handle any events in this particular case
// as explained in `Vst2Bridge::editor`
}},
editor);
for (int i = 0; i < max_win32_messages &&
PeekMessage(&msg, nullptr, 0, 0, PM_REMOVE);
i++) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
}
void Vst2Bridge::handle_x11_events() {
std::visit(overload{[](Editor& editor) { editor.handle_x11_events(); },
[](auto&) {}},
editor);
if (editor) {
editor->handle_x11_events();
}
}
class HostCallbackDataConverter : DefaultDataConverter {
src/wine-host/bridges/vst2.h
+7 -45
View File
@@ -35,13 +35,6 @@
#include "../editor.h"
#include "../utils.h"
/**
* A marker struct to indicate that the editor is about to be opened.
*
* @see Vst2Bridge::editor
*/
struct EditorOpening {};
/**
* This hosts a Windows VST2 plugin, forwards messages sent by the Linux VST
* plugin and provides host callback function for the plugin to talk back.
@@ -78,19 +71,6 @@ class Vst2Bridge {
std::string plugin_dll_path,
std::string endpoint_base_dir);
/**
* Returns true if the message loop should be skipped. This happens when the
* editor is in the process of being opened. In VST hosts on Windows
* `effEditOpen()` and `effEditGetRect()` will always be called in sequence,
* but in our approach there will be an opportunity to handle events in
* between these two calls. Most plugins will handle this just fine, but
* some plugins end up blocking indefinitely while waiting for the other
* function to be called, hence why this function is needed. For
* individually hosted plugins this check is done implicitely in
* `Vst2Bridge::handle_win32_events()`.
*/
bool should_skip_message_loop() const;
/**
* Handle events until the plugin exits. The actual events are posted to
* `main_context` to ensure that all operations to could potentially
@@ -105,17 +85,17 @@ class Vst2Bridge {
void handle_dispatch();
/**
* Handle X11 events for the editor window if it is open. This can be run
* safely from any thread.
* Handle X11 events for the editor window if it is open. This can safely be
* run from any thread.
*/
void handle_x11_events();
/**
* Run the message loop for this plugin. This is only used for the
* individual plugin host. When hosting multiple plugins, a simple central
* message loop with a check to `should_skip_message_loop()` should be used
* instead. This is run on a timer in the same IO context as the one that
* handles the events, i.e. `main_context`.
* individual plugin host, so that we can filter out some unnecessary timer
* events. When hosting multiple plugins, a simple central message loop
* should be used instead. This is run on a timer in the same IO context as
* the one that handles the events, i.e. `main_context`.
*
* Because of the way the Win32 API works we have to process events on the
* same thread as the one the window was created on, and that thread is the
@@ -224,25 +204,7 @@ class Vst2Bridge {
* Wine window, and embedding that Wine window into a window provided by the
* host. Should be empty when the editor is not open.
*
* This field can have three possible states:
*
* - `std::nullopt` when the editor is closed.
* - An `Editor` object when the editor is open.
* - `EditorOpening` when the editor is not yet open, but the host has
* already called `effEditGetRect()` and is about to call `effEditOpen()`.
* This is needed because there is a race condition in some bugs that
* cause them to crash or enter an infinite Win32 message loop when
* `effEditGetRect()` gets dispatched and we then enter the message loop
* loop before `effEditOpen()` gets called. Most plugins will handle this
* just fine, but a select few plugins make the assumption that the editor
* is already open once `effEditGetRect()` has been called, even if
* `effEditOpen` has not yet been dispatched. VST hsots on Windows will
* call these two events in sequence, so the bug would never occur there.
* To work around this we'll use this third state to temporarily stop
* processing Windows events in the one or two ticks between these two
* events.
*
* @see should_postpone_message_loop
*/
std::variant<std::monostate, Editor, EditorOpening> editor;
std::optional<Editor> editor;
};