all: Refactor to much nicer fb abstraction that is less absolutely te…

…rrifying
brain-anti-freeze · Apr 3, 2024 · 62ef16e · 62ef16e
1 parent 11533d3
commit 62ef16e
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Showing 11 changed files with 466 additions and 332 deletions.
diff --git a/src/backend.cpp b/src/backend.cpp
@@ -1,6 +1,11 @@
 #include "backend.h"
 #include "vblankmanager.hpp"
 #include "convar.h"
+#include "wlserver.hpp"
+
+#include "wlr_begin.hpp"
+#include <wlr/types/wlr_buffer.h>
+#include "wlr_end.hpp"
 
 extern void sleep_until_nanos(uint64_t nanos);
 extern bool env_to_bool(const char *env);
@@ -37,6 +42,44 @@ namespace gamescope
         return true;
     }
 
+    /////////////////
+    // CBaseBackendFb
+    /////////////////
+
+    CBaseBackendFb::CBaseBackendFb( wlr_buffer *pClientBuffer )
+        : m_pClientBuffer{ pClientBuffer }
+    {
+    }
+
+    CBaseBackendFb::~CBaseBackendFb()
+    {
+        // I do not own the client buffer, but I released that in DecRef.
+        m_pClientBuffer = nullptr;
+    }
+
+    uint32_t CBaseBackendFb::IncRef()
+    {
+        uint32_t uRefCount = IBackendFb::IncRef();
+        if ( m_pClientBuffer && uRefCount == 1 )
+        {
+            wlserver_lock();
+            wlr_buffer_lock( m_pClientBuffer );
+            wlserver_unlock( false );
+        }
+        return uRefCount;
+    }
+    uint32_t CBaseBackendFb::DecRef()
+    {
+        uint32_t uRefCount = IBackendFb::DecRef();
+        if ( m_pClientBuffer && uRefCount == 0 )
+        {
+            wlserver_lock();
+            wlr_buffer_unlock( m_pClientBuffer );
+            wlserver_unlock();
+        }
+        return uRefCount;
+    }
+
     /////////////////
     // CBaseBackend
     /////////////////

diff --git a/src/backend.h b/src/backend.h
@@ -4,6 +4,7 @@
 #include "gamescope_shared.h"
 #include "vulkan_include.h"
 #include "convar.h"
+#include "rc.h"
 
 #include <cassert>
 #include <span>
@@ -141,6 +142,24 @@ namespace gamescope
         std::atomic<uint64_t> m_uCompletedPresents = { 0u };
     };
 
+    class IBackendFb : public IRcObject<false /* Reference does NOT own. The wlr_buffer import + notarizer owns the object*/ >
+    {
+        // Dummy
+    };
+
+    class CBaseBackendFb : public IBackendFb
+    {
+    public:
+        CBaseBackendFb( wlr_buffer *pClientBuffer );
+        virtual ~CBaseBackendFb();
+
+        uint32_t IncRef() override;
+        uint32_t DecRef() override;
+
+    private:
+        wlr_buffer *m_pClientBuffer = nullptr;
+    };
+
     class IBackend
     {
     public:
@@ -169,10 +188,10 @@ namespace gamescope
 
         // For DRM, this is
         // dmabuf -> fb_id.
-        virtual uint32_t ImportDmabufToBackend( wlr_buffer *pBuffer, wlr_dmabuf_attributes *pDmaBuf ) = 0;
-        virtual void LockBackendFb( uint32_t uFbId ) = 0;
-        virtual void UnlockBackendFb( uint32_t uFbId ) = 0;
-        virtual void DropBackendFb( uint32_t uFbId ) = 0;
+        //
+        // shared_ptr owns the structure.
+        // Rc manages acquire/release of buffer to/from client while imported.
+        virtual std::shared_ptr<IBackendFb> ImportDmabufToBackend( wlr_buffer *pBuffer, wlr_dmabuf_attributes *pDmaBuf ) = 0;
 
         virtual bool UsesModifiers() const = 0;
         virtual std::span<const uint64_t> GetSupportedModifiers( uint32_t uDrmFormat ) const = 0;