From e099255b92634d2d50b54056ec2bf068d078d566 Mon Sep 17 00:00:00 2001
From: Robbert van der Helm <mail@robbertvanderhelm.nl>
Date: Tue, 8 Dec 2020 17:59:59 +0100
Subject: [PATCH] Generate a unique ID and store the new component

---
 src/wine-host/bridges/vst3.cpp | 22 ++++++++++------------
 src/wine-host/bridges/vst3.h   | 25 +++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 12 deletions(-)

diff --git a/src/wine-host/bridges/vst3.cpp b/src/wine-host/bridges/vst3.cpp
index 791810b8..618b41c9 100644
--- a/src/wine-host/bridges/vst3.cpp
+++ b/src/wine-host/bridges/vst3.cpp
@@ -56,20 +56,14 @@ void Vst3Bridge::run() {
                 Steinberg::IPtr<Steinberg::Vst::IComponent> component =
                     module->getFactory()
                         .createInstance<Steinberg::Vst::IComponent>(args.cid);
-
-                // TODO: Next steps are:
-                //       - Generate a new unique ID using an atomic size_t and
-                //         fetch-and-add.
-                //       - Add an `std::map<size_t,
-                //         Steinberg::IPtr<Steinberg::Vst::IComponent>`
-                //         to this class and add `component` with the generated
-                //         ID to that.
-                //       - Add that ID to `YaComponent` and set it in the object
-                //         we create here.
                 if (component) {
-                    // TODO: Generate a unique instance ID
+                    std::lock_guard lock(component_instances_mutex);
+
+                    const size_t instance_id = generate_instance_id();
+                    component_instances[instance_id] = std::move(component);
+
                     return std::make_optional<YaComponent::Arguments>(
-                        component, 420691337);
+                        component, instance_id);
                 } else {
                     return std::nullopt;
                 }
@@ -78,3 +72,7 @@ void Vst3Bridge::run() {
                 return *plugin_factory;
             }});
 }
+
+size_t Vst3Bridge::generate_instance_id() {
+    return current_instance_id.fetch_add(1);
+}
diff --git a/src/wine-host/bridges/vst3.h b/src/wine-host/bridges/vst3.h
index c5f52d5c..161e030c 100644
--- a/src/wine-host/bridges/vst3.h
+++ b/src/wine-host/bridges/vst3.h
@@ -59,6 +59,13 @@ class Vst3Bridge : public HostBridge {
     void run() override;
 
    private:
+    /**
+     * Generate a nique instance identifier using an atomic fetch-and-add. This
+     * is used to be able to refer to specific instances created for
+     * `IPluginFactory::createInstance()`.
+     */
+    size_t generate_instance_id();
+
     /**
      * The IO context used for event handling so that all events and window
      * message handling can be performed from a single thread, even when hosting
@@ -90,4 +97,22 @@ class Vst3Bridge : public HostBridge {
      * information during its initialization.
      */
     std::unique_ptr<YaPluginFactory> plugin_factory;
+
+    /**
+     * Used to assign unique identifier to instances created for
+     * `IPluginFactory::createInstance()`.
+     *
+     * @related enerate_instance_id
+     */
+    std::atomic_size_t current_instance_id;
+
+    // Below are managed instances we created for
+    // `IPluginFactory::createInstance()`. The keys in all of these maps are the
+    // unique identifiers we generated for them so we can identify specific
+    // instances. The mutexes are used for operations that insert or remove
+    // items, and not for regular access.
+
+    std::map<size_t, Steinberg::IPtr<Steinberg::Vst::IComponent>>
+        component_instances;
+    std::mutex component_instances_mutex;
 };