From aae957819ec9e0499f39843520283e15cb3fe949 Mon Sep 17 00:00:00 2001
From: Billy Laws <blaws05@gmail.com>
Date: Sun, 18 Sep 2022 15:30:24 +0100
Subject: [PATCH] Simplify BufferView locking by requiring buffer manager be
 locked

Avoids the need to repeat the lookup after locking since recreations are impossible if buffer manager is locked.
---
 app/src/main/cpp/skyline/gpu/buffer.h         | 41 +++++--------------
 .../maxwell_3d/constant_buffers.cpp           |  2 +
 2 files changed, 12 insertions(+), 31 deletions(-)

diff --git a/app/src/main/cpp/skyline/gpu/buffer.h b/app/src/main/cpp/skyline/gpu/buffer.h
index 3ccb96d3..e4374657 100644
--- a/app/src/main/cpp/skyline/gpu/buffer.h
+++ b/app/src/main/cpp/skyline/gpu/buffer.h
@@ -382,45 +382,24 @@ namespace skyline::gpu {
         vk::DeviceSize GetOffset() const;
 
         /**
-         * @brief Templated lock function that ensures correct locking of the delegate's underlying buffer
+         * @note The buffer manager **MUST** be locked prior to calling this
          */
-        template<bool TryLock, typename LockFunction, typename UnlockFunction>
-        std::conditional_t<TryLock, bool, void> LockWithFunction(LockFunction lock, UnlockFunction unlock) {
-            while (true) {
-                auto preLockBuffer{delegate->GetBuffer()};
-                if constexpr (TryLock) {
-                    if (!lock(preLockBuffer))
-                        return false;
-                } else {
-                    lock(preLockBuffer);
-                }
-                auto postLockBuffer{delegate->GetBuffer()};
-                if (preLockBuffer == postLockBuffer)
-                    break;
-
-                preLockBuffer->unlock();
-            };
-
-            ResolveDelegate();
-
-            if constexpr (TryLock)
-                return true;
-            else
-                return;
-        }
-
         void lock() {
-            LockWithFunction<false>([](Buffer *buffer) { buffer->lock(); }, [](Buffer *buffer) { buffer->unlock(); });
+            delegate->GetBuffer()->lock();
         }
 
+        /**
+         * @note The buffer manager **MUST** be locked prior to calling this
+         */
         bool try_lock() {
-            return LockWithFunction<true>([](Buffer *buffer) { return buffer->try_lock(); }, [](Buffer *buffer) { buffer->unlock(); });
+            return delegate->GetBuffer()->try_lock();
         }
 
+        /**
+         * @note The buffer manager **MUST** be locked prior to calling this
+         */
         bool LockWithTag(ContextTag tag) {
-            bool result{};
-            LockWithFunction<false>([&result, tag](Buffer *buffer) { result = buffer->LockWithTag(tag); }, [](Buffer *buffer) { buffer->unlock(); });
-            return result;
+            return delegate->GetBuffer()->LockWithTag(tag);
         }
 
         void unlock() {
diff --git a/app/src/main/cpp/skyline/gpu/interconnect/maxwell_3d/constant_buffers.cpp b/app/src/main/cpp/skyline/gpu/interconnect/maxwell_3d/constant_buffers.cpp
index 6aa7d523..4c1ae404 100644
--- a/app/src/main/cpp/skyline/gpu/interconnect/maxwell_3d/constant_buffers.cpp
+++ b/app/src/main/cpp/skyline/gpu/interconnect/maxwell_3d/constant_buffers.cpp
@@ -30,6 +30,7 @@ namespace skyline::gpu::interconnect::maxwell3d {
     }
 
     void ConstantBuffer::Read(CommandExecutor &executor, span<u8> dstBuffer, size_t srcOffset) {
+        executor.AcquireBufferManager();
         ContextLock lock{executor.tag, view};
         view.Read(lock.IsFirstUsage(), FlushHostCallback, dstBuffer, srcOffset);
     }
@@ -44,6 +45,7 @@ namespace skyline::gpu::interconnect::maxwell3d {
         auto &view{*selectorState.UpdateGet(ctx).view};
         auto srcCpuBuf{data.cast<u8>()};
 
+        ctx.executor.AcquireBufferManager();
         ContextLock lock{ctx.executor.tag, view};
 
         // First attempt the write without setting up the gpu copy callback as a fast path