nvflinger: Fix for BufferQueue event handling.

src/core/hle/kernel/hle_ipc.cpp

@@ -29,7 +29,8 @@ void SessionRequestHandler::ClientDisconnected(SharedPtr<ServerSession> server_s
 
 SharedPtr<Event> HLERequestContext::SleepClientThread(SharedPtr<Thread> thread,
                                                       const std::string& reason, u64 timeout,
-                                                      WakeupCallback&& callback) {
+                                                      WakeupCallback&& callback,
+                                                      Kernel::SharedPtr<Kernel::Event> event) {
 
     // Put the client thread to sleep until the wait event is signaled or the timeout expires.
     thread->wakeup_callback =
@@ -41,7 +42,12 @@ SharedPtr<Event> HLERequestContext::SleepClientThread(SharedPtr<Thread> thread,
         return true;
     };
 
-    auto event = Kernel::Event::Create(Kernel::ResetType::OneShot, "HLE Pause Event: " + reason);
+    if (!event) {
+        // Create event if not provided
+        event = Kernel::Event::Create(Kernel::ResetType::OneShot, "HLE Pause Event: " + reason);
+    }
+
+    event->Clear();
     thread->status = THREADSTATUS_WAIT_HLE_EVENT;
     thread->wait_objects = {event};
     event->AddWaitingThread(thread);

src/core/hle/kernel/hle_ipc.h

@@ -118,10 +118,12 @@ public:
      * @param callback Callback to be invoked when the thread is resumed. This callback must write
      * the entire command response once again, regardless of the state of it before this function
      * was called.
+     * @param event Event to use to wake up the thread. If unspecified, an event will be created.
      * @returns Event that when signaled will resume the thread and call the callback function.
      */
     SharedPtr<Event> SleepClientThread(SharedPtr<Thread> thread, const std::string& reason,
-                                       u64 timeout, WakeupCallback&& callback);
+                                       u64 timeout, WakeupCallback&& callback,
+                                       Kernel::SharedPtr<Kernel::Event> event = nullptr);
 
     void ParseCommandBuffer(u32_le* src_cmdbuf, bool incoming);
 

src/core/hle/service/nvflinger/buffer_queue.cpp

@@ -13,8 +13,8 @@ namespace Service {
 namespace NVFlinger {
 
 BufferQueue::BufferQueue(u32 id, u64 layer_id) : id(id), layer_id(layer_id) {
-    native_handle = Kernel::Event::Create(Kernel::ResetType::OneShot, "BufferQueue NativeHandle");
-    native_handle->Signal();
+    buffer_wait_event =
+        Kernel::Event::Create(Kernel::ResetType::Sticky, "BufferQueue NativeHandle");
 }
 
 void BufferQueue::SetPreallocatedBuffer(u32 slot, IGBPBuffer& igbp_buffer) {
@@ -26,10 +26,7 @@ void BufferQueue::SetPreallocatedBuffer(u32 slot, IGBPBuffer& igbp_buffer) {
     LOG_WARNING(Service, "Adding graphics buffer {}", slot);
 
     queue.emplace_back(buffer);
-
-    if (buffer_wait_event) {
-        buffer_wait_event->Signal();
-    }
+    buffer_wait_event->Signal();
 }
 
 boost::optional<u32> BufferQueue::DequeueBuffer(u32 width, u32 height) {
@@ -48,8 +45,6 @@ boost::optional<u32> BufferQueue::DequeueBuffer(u32 width, u32 height) {
         return boost::none;
     }
 
-    buffer_wait_event = nullptr;
-
     itr->status = Buffer::Status::Dequeued;
     return itr->slot;
 }
@@ -88,9 +83,7 @@ void BufferQueue::ReleaseBuffer(u32 slot) {
     ASSERT(itr->status == Buffer::Status::Acquired);
     itr->status = Buffer::Status::Free;
 
-    if (buffer_wait_event) {
-        buffer_wait_event->Signal();
-    }
+    buffer_wait_event->Signal();
 }
 
 u32 BufferQueue::Query(QueryType type) {
@@ -106,10 +99,5 @@ u32 BufferQueue::Query(QueryType type) {
     return 0;
 }
 
-void BufferQueue::SetBufferWaitEvent(Kernel::SharedPtr<Kernel::Event>&& wait_event) {
-    ASSERT_MSG(!buffer_wait_event, "buffer_wait_event only supports a single waiting thread!");
-    buffer_wait_event = std::move(wait_event);
-}
-
 } // namespace NVFlinger
 } // namespace Service

src/core/hle/service/nvflinger/buffer_queue.h

@@ -77,14 +77,13 @@ public:
     boost::optional<const Buffer&> AcquireBuffer();
     void ReleaseBuffer(u32 slot);
     u32 Query(QueryType type);
-    void SetBufferWaitEvent(Kernel::SharedPtr<Kernel::Event>&& wait_event);
 
     u32 GetId() const {
         return id;
     }
 
-    Kernel::SharedPtr<Kernel::Event> GetNativeHandle() const {
-        return native_handle;
+    Kernel::SharedPtr<Kernel::Event> GetBufferWaitEvent() const {
+        return buffer_wait_event;
     }
 
 private:
@@ -92,9 +91,6 @@ private:
     u64 layer_id;
 
     std::vector<Buffer> queue;
-    Kernel::SharedPtr<Kernel::Event> native_handle;
-
-    /// Used to signal waiting thread when no buffers are available
     Kernel::SharedPtr<Kernel::Event> buffer_wait_event;
 };
 

src/core/hle/service/nvflinger/nvflinger.cpp

@@ -152,9 +152,6 @@ void NVFlinger::Compose() {
                      igbp_buffer.width, igbp_buffer.height, igbp_buffer.stride, buffer->transform);
 
         buffer_queue->ReleaseBuffer(buffer->slot);
-
-        // TODO(Subv): Figure out when we should actually signal this event.
-        buffer_queue->GetNativeHandle()->Signal();
     }
 }
 

src/core/hle/service/vi/vi.cpp

@@ -495,7 +495,7 @@ private:
                 ctx.WriteBuffer(response.Serialize());
             } else {
                 // Wait the current thread until a buffer becomes available
-                auto wait_event = ctx.SleepClientThread(
+                ctx.SleepClientThread(
                     Kernel::GetCurrentThread(), "IHOSBinderDriver::DequeueBuffer", -1,
                     [=](Kernel::SharedPtr<Kernel::Thread> thread, Kernel::HLERequestContext& ctx,
                         ThreadWakeupReason reason) {
@@ -506,8 +506,8 @@ private:
                         ctx.WriteBuffer(response.Serialize());
                         IPC::ResponseBuilder rb{ctx, 2};
                         rb.Push(RESULT_SUCCESS);
-                    });
-                buffer_queue->SetBufferWaitEvent(std::move(wait_event));
+                    },
+                    buffer_queue->GetBufferWaitEvent());
             }
         } else if (transaction == TransactionId::RequestBuffer) {
             IGBPRequestBufferRequestParcel request{ctx.ReadBuffer()};
@@ -565,7 +565,7 @@ private:
         LOG_WARNING(Service_VI, "(STUBBED) called id={}, unknown={:08X}", id, unknown);
         IPC::ResponseBuilder rb{ctx, 2, 1};
         rb.Push(RESULT_SUCCESS);
-        rb.PushCopyObjects(buffer_queue->GetNativeHandle());
+        rb.PushCopyObjects(buffer_queue->GetBufferWaitEvent());
     }
 
     std::shared_ptr<NVFlinger::NVFlinger> nv_flinger;