From 6568fe9a845407b5d55fd1fde2fd3c19153469b1 Mon Sep 17 00:00:00 2001
From: "Mr. Big Britches" <111622360+MrBigBritches@users.noreply.github.com>
Date: Thu, 15 Oct 2026 16:39:40 -0700
Subject: [PATCH] Implement Missing NGS2 System Functions Lock & Unlock (#1542)

* Implement NGS2 SystemLock

* Implement NGS2 SystemUnlock

* Add guard for system_handle value of 0

* Return correct error code from system_handle guard

* Validate NGS2 system handles before locking

---------

Co-authored-by: nmzik <Nmzik@mail.ru>
---
 src/libs/libAudio.cpp |  2 ++
 src/libs/ngs2.cpp     | 48 +++++++++++++++++++++++++++++++++++--------
 src/libs/ngs2.h       |  2 ++
 3 files changed, 44 insertions(+), 8 deletions(-)

diff --git a/src/libs/libAudio.cpp b/src/libs/libAudio.cpp
index 704d2b29e..2069a82b6 100644
--- a/src/libs/libAudio.cpp
+++ b/src/libs/libAudio.cpp
@@ -1147,6 +1147,8 @@ LIB_DEFINE(InitAudio_1_Ngs2) {
 	LIB_FUNC("mPYgU4oYpuY", Ngs2::Ngs2SystemCreateWithAllocator);
 	LIB_FUNC("u-WrYDaJA3k", Ngs2::Ngs2SystemDestroy);
 	LIB_FUNC("vU7TQ62pItw", Ngs2::Ngs2SystemGetInfo);
+	LIB_FUNC("gThZqM5PYlQ", Ngs2::Ngs2SystemLock);
+	LIB_FUNC("JXRC5n0RQls", Ngs2::Ngs2SystemUnlock);
 	LIB_FUNC("U546k6orxQo", Ngs2::Ngs2RackCreateWithAllocator);
 	LIB_FUNC("cLV4aiT9JpA", Ngs2::Ngs2RackCreate);
 	LIB_FUNC("0eFLVCfWVds", Ngs2::Ngs2RackQueryBufferSize);
diff --git a/src/libs/ngs2.cpp b/src/libs/ngs2.cpp
index fbb4ed9f9..3c89831ff 100644
--- a/src/libs/ngs2.cpp
+++ b/src/libs/ngs2.cpp
@@ -28,6 +28,8 @@ namespace Ngs2 {
 
 LIB_NAME("Ngs2", "Ngs2");
 
+constexpr int32_t NGS2_ERROR_INVALID_SYSTEM_HANDLE =
+    static_cast<int32_t>(0x804a8201u);
 constexpr int32_t NGS2_ERROR_INVALID_OUT_ADDRESS =
     static_cast<int32_t>(0x804a8010u);
 constexpr int32_t NGS2_ERROR_INVALID_NUM_WAVEFORM_BLOCKS =
@@ -889,6 +891,15 @@ static Ngs2Internal* Ngs2CreateSystemInternal(const Ngs2SystemOption*      optio
 	return ngs;
 }
 
+static Ngs2Internal* Ngs2FindSystem(uintptr_t system_handle) {
+	for (auto* ngs = g_ngs_list; ngs != nullptr; ngs = ngs->next) {
+		if (reinterpret_cast<uintptr_t>(ngs) == system_handle) {
+			return ngs;
+		}
+	}
+	return nullptr;
+}
+
 static bool Ngs2RackIsCustom(Ngs2RackType type) {
 	switch (type) {
 		case Ngs2RackType::CustomSubmixer:
@@ -1110,7 +1121,6 @@ int KYTY_SYSV_ABI Ngs2SystemGetInfo(uintptr_t system_handle, Ngs2SystemInfo* inf
                                     size_t info_size) {
 	constexpr int32_t ERROR_INVALID_OUT_ADDRESS   = static_cast<int32_t>(0x804a8010u);
 	constexpr int32_t ERROR_INVALID_OUT_SIZE      = static_cast<int32_t>(0x804a8011u);
-	constexpr int32_t ERROR_INVALID_SYSTEM_HANDLE = static_cast<int32_t>(0x804a8201u);
 
 	if (info == nullptr) {
 		return ERROR_INVALID_OUT_ADDRESS;
@@ -1119,13 +1129,9 @@ int KYTY_SYSV_ABI Ngs2SystemGetInfo(uintptr_t system_handle, Ngs2SystemInfo* inf
 		return ERROR_INVALID_OUT_SIZE;
 	}
 
-	auto* ngs     = reinterpret_cast<Ngs2Internal*>(system_handle);
-	auto* current = g_ngs_list;
-	while (current != nullptr && current != ngs) {
-		current = current->next;
-	}
-	if (current == nullptr) {
-		return ERROR_INVALID_SYSTEM_HANDLE;
+	auto* ngs = Ngs2FindSystem(system_handle);
+	if (ngs == nullptr) {
+		return NGS2_ERROR_INVALID_SYSTEM_HANDLE;
 	}
 
 	Common::LockGuard lock(ngs->mutex);
@@ -2625,6 +2631,32 @@ int KYTY_SYSV_ABI Ngs2VoiceGetStateFlags(uintptr_t voice_handle, uint32_t* state
 	return OK;
 }
 
+int KYTY_SYSV_ABI Ngs2SystemLock(uintptr_t system_handle) {
+	PRINT_NAME();
+
+	auto* ngs = Ngs2FindSystem(system_handle);
+	if (ngs == nullptr) {
+		return NGS2_ERROR_INVALID_SYSTEM_HANDLE;
+	}
+
+	ngs->mutex.Lock();
+
+	return OK;
+}
+
+int KYTY_SYSV_ABI Ngs2SystemUnlock(uintptr_t system_handle) {
+	PRINT_NAME();
+
+	auto* ngs = Ngs2FindSystem(system_handle);
+	if (ngs == nullptr) {
+		return NGS2_ERROR_INVALID_SYSTEM_HANDLE;
+	}
+
+	ngs->mutex.Unlock();
+
+	return OK;
+}
+
 } // namespace Ngs2
 
 } // namespace Libs::Audio
diff --git a/src/libs/ngs2.h b/src/libs/ngs2.h
index fe814ed2f..bb4cf236c 100644
--- a/src/libs/ngs2.h
+++ b/src/libs/ngs2.h
@@ -33,6 +33,8 @@ int KYTY_SYSV_ABI Ngs2SystemCreate(const Ngs2SystemOption*      option,
                                    const Ngs2ContextBufferInfo* buffer_info, uintptr_t* handle);
 int KYTY_SYSV_ABI Ngs2SystemGetInfo(uintptr_t system_handle, Ngs2SystemInfo* info,
                                     size_t info_size);
+int KYTY_SYSV_ABI Ngs2SystemLock(uintptr_t system_handle);
+int KYTY_SYSV_ABI Ngs2SystemUnlock(uintptr_t system_handle);
 int KYTY_SYSV_ABI Ngs2SystemSetGrainSamples(uintptr_t system_handle, uint32_t num_samples);
 int KYTY_SYSV_ABI Ngs2RackQueryBufferSize(uint32_t rack_id, const Ngs2RackOption* option,
                                           Ngs2ContextBufferInfo* buffer_info);