[Refactor] (P13 W5 S4c): the XFB lifetime lookup, the deferred-destroy drain and the PBO readback target build without a transport.

MobileGL/MG_Impl/Pipe/Verb/TextureReadbackEmit.inc

@@ -62,7 +62,11 @@
         //     the reply form's UploadSubData is what creates it.
         MG_Pipe::MGPipeHandle PackBufferReadbackTarget(const SharedPtr<MG_State::GLState::BufferObject>& pbo,
                                                        Uint64 end) {
-            if (!pbo || MG_Config::Ipc.PboReadbackSync != 0) return MG_Pipe::kMGPipeNullHandle;
+            if (!pbo) return MG_Pipe::kMGPipeNullHandle;
+#if MOBILEGL_BUILD_DISAGGREGATED
+            // The transport's own fallback knob (MOBILEGL_IPC_PBO_READBACK_SYNC): the reply form.
+            if (MG_Config::Ipc.PboReadbackSync != 0) return MG_Pipe::kMGPipeNullHandle;
+#endif
             if (!BufferWritebackIsReachable(*pbo) || pbo->IsMapped()) return MG_Pipe::kMGPipeNullHandle;
             if (end > 0x7FFFFFFFull) return MG_Pipe::kMGPipeNullHandle;
             return MG_Pipe::MGPipeSlots().FindByLifetimeId(MG_Pipe::MGPipeKind::Buffer, pbo->GetLifetimeId());

MobileGL/MG_Pipe/PipeMutation.h

@@ -281,6 +281,10 @@ namespace MobileGL::MG_Pipe {
     // the new session serves its first record. Objects of the ended session that are still
     // alive find themselves unpublished, so their deaths put nothing on the new wire.
     void MGPipeForgetEndedSession();
+#else
+    // P13 W5: without a transport nothing applies off the GL thread, so no destroy is ever
+    // deferred to the next verb hook (the record arm's BeforeReadOnlyVerb still calls this).
+    inline void MGPipeDrainDeferredDestroys() {}
 #endif
 
     void MGPipeEmitResourceCreate(MG_State::GLState::BufferObject& buffer);

MobileGL/MG_State/GLState/Core.cpp

@@ -1556,7 +1556,7 @@ namespace MobileGL::MG_State {
             return it != m_transformFeedbackObjects.end() && it->second.everBound;
         }
 
-#if MOBILEGL_BUILD_DISAGGREGATED
+#if MOBILEGL_BUILD_RECORD_ARM
         Uint64 GLContext::GetTransformFeedbackLifetimeId(Uint index) const {
             const auto found = m_transformFeedbackObjects.find(index);
             return found == m_transformFeedbackObjects.end() ? 0 : found->second.lifetimeId;

MobileGL/MG_State/GLState/Core.h

@@ -571,7 +571,7 @@ namespace MobileGL {
                 // Never returns 0 - the counter starts at 1 so a zero-initialised memo slot cannot
                 // be mistaken for a live object.
                 Uint64 GetBoundTransformFeedbackLifetimeId() const { return m_boundTransformFeedbackLifetimeId; }
-#if MOBILEGL_BUILD_DISAGGREGATED
+#if MOBILEGL_BUILD_RECORD_ARM
                 Uint64 GetTransformFeedbackLifetimeId(Uint index) const;
 #endif
                 // Whether the object carrying this identity still has an OPEN capture span - one