1 files changed, 46 insertions, 0 deletions

diff --git a/src/core/hle/service/os/mutex.cpp b/src/core/hle/service/os/mutex.cpp
new file mode 100644
index 000000000..6009f4866
--- /dev/null
+++ b/src/core/hle/service/os/mutex.cpp
@@ -0,0 +1,46 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "core/core.h"
+#include "core/hle/kernel/k_event.h"
+#include "core/hle/kernel/k_synchronization_object.h"
+#include "core/hle/service/os/mutex.h"
+
+namespace Service {
+
+Mutex::Mutex(Core::System& system) : m_system(system) {
+    m_event = Kernel::KEvent::Create(system.Kernel());
+    m_event->Initialize(nullptr);
+
+    // Register the event.
+    Kernel::KEvent::Register(system.Kernel(), m_event);
+
+    ASSERT(R_SUCCEEDED(m_event->Signal()));
+}
+
+Mutex::~Mutex() {
+    m_event->GetReadableEvent().Close();
+    m_event->Close();
+}
+
+void Mutex::lock() {
+    // Infinitely retry until we successfully clear the event.
+    while (R_FAILED(m_event->GetReadableEvent().Reset())) {
+        s32 index;
+        Kernel::KSynchronizationObject* obj = &m_event->GetReadableEvent();
+
+        // The event was already cleared!
+        // Wait for it to become signaled again.
+        ASSERT(R_SUCCEEDED(
+            Kernel::KSynchronizationObject::Wait(m_system.Kernel(), &index, &obj, 1, -1)));
+    }
+
+    // We successfully cleared the event, and now have exclusive ownership.
+}
+
+void Mutex::unlock() {
+    // Unlock.
+    ASSERT(R_SUCCEEDED(m_event->Signal()));
+}
+
+} // namespace Service