core/surface/buffer: Buffer lock/release fixes (#7110)

src/protocols/types/Buffer.cpp

@@ -1,5 +1,10 @@
 #include "Buffer.hpp"
 
+IHLBuffer::~IHLBuffer() {
+    if (locked() && resource)
+        sendRelease();
+}
+
 void IHLBuffer::sendRelease() {
     resource->sendRelease();
 }
@@ -8,3 +13,54 @@ void IHLBuffer::sendReleaseWithSurface(SP<CWLSurfaceResource> surf) {
     if (resource && resource->good())
         resource->sendReleaseWithSurface(surf);
 }
+
+void IHLBuffer::lock() {
+    nLocks++;
+}
+
+void IHLBuffer::unlock() {
+    nLocks--;
+
+    ASSERT(nLocks >= 0);
+
+    if (nLocks == 0)
+        sendRelease();
+}
+
+void IHLBuffer::unlockWithSurface(SP<CWLSurfaceResource> surf) {
+    nLocks--;
+
+    ASSERT(nLocks >= 0);
+
+    if (nLocks == 0)
+        sendReleaseWithSurface(surf);
+}
+
+bool IHLBuffer::locked() {
+    return nLocks > 0;
+}
+
+void IHLBuffer::unlockOnBufferRelease(WP<CWLSurfaceResource> surf) {
+    unlockSurface           = surf;
+    hlEvents.backendRelease = events.backendRelease.registerListener([this](std::any data) {
+        if (unlockSurface.expired())
+            unlock();
+        else
+            unlockWithSurface(unlockSurface.lock());
+        hlEvents.backendRelease.reset();
+    });
+}
+
+CHLBufferReference::CHLBufferReference(SP<IHLBuffer> buffer_, SP<CWLSurfaceResource> surface_) : buffer(buffer_), surface(surface_) {
+    buffer->lock();
+}
+
+CHLBufferReference::~CHLBufferReference() {
+    if (buffer.expired())
+        return;
+
+    if (surface)
+        buffer->unlockWithSurface(surface.lock());
+    else
+        buffer->unlock();
+}

src/protocols/types/Buffer.hpp

@@ -8,9 +8,7 @@
 
 class IHLBuffer : public Aquamarine::IBuffer {
   public:
-    virtual ~IHLBuffer() {
-        ;
-    }
+    virtual ~IHLBuffer();
     virtual Aquamarine::eBufferCapability caps()                        = 0;
     virtual Aquamarine::eBufferType       type()                        = 0;
     virtual void                          update(const CRegion& damage) = 0;
@@ -18,6 +16,12 @@ class IHLBuffer : public Aquamarine::IBuffer {
     virtual bool                          good()                        = 0;
     virtual void                          sendRelease();
     virtual void                          sendReleaseWithSurface(SP<CWLSurfaceResource>);
+    virtual void                          lock();
+    virtual void                          unlock();
+    virtual void                          unlockWithSurface(SP<CWLSurfaceResource> surf);
+    virtual bool                          locked();
+
+    void                                  unlockOnBufferRelease(WP<CWLSurfaceResource> surf /* optional */);
 
     SP<CTexture>                          texture;
     bool                                  opaque = false;
@@ -26,4 +30,22 @@ class IHLBuffer : public Aquamarine::IBuffer {
     struct {
         CHyprSignalListener backendRelease;
     } hlEvents;
+
+  private:
+    int                    nLocks = 0;
+
+    WP<CWLSurfaceResource> unlockSurface;
+};
+
+// for ref-counting. Releases in ~dtor
+// surface optional
+class CHLBufferReference {
+  public:
+    CHLBufferReference(SP<IHLBuffer> buffer, SP<CWLSurfaceResource> surface);
+    ~CHLBufferReference();
+
+    WP<IHLBuffer> buffer;
+
+  private:
+    WP<CWLSurfaceResource> surface;
 };

src/protocols/types/SurfaceRole.hpp

@@ -6,6 +6,7 @@ enum eSurfaceRole {
     SURFACE_ROLE_LAYER_SHELL,
     SURFACE_ROLE_EASTER_EGG,
     SURFACE_ROLE_SUBSURFACE,
+    SURFACE_ROLE_CURSOR,
 };
 
 class ISurfaceRole {

src/protocols/types/WLBuffer.cpp

@@ -29,7 +29,6 @@ bool CWLBufferResource::good() {
 }
 
 void CWLBufferResource::sendRelease() {
-    released = true;
     resource->sendRelease();
 }
 

src/protocols/types/WLBuffer.hpp

@@ -24,8 +24,6 @@ class CWLBufferResource {
 
     WP<CWLBufferResource>        self;
 
-    bool                         released = false;
-
   private:
     CWLBufferResource(SP<CWlBuffer> resource_);