[AI Task] [Tizen.Multimedia.Remoting] Remove triple enumeration in ScreenMirroring.SendGenericMouseEvent

[JoonghyunCho]

Summary

ScreenMirroring.SendGenericMouseEvent enumerated its IEnumerable<UibcMouseInfo> input three times (Any() → Count() → foreach) on the UIBC high-frequency mouse-input path, and threw the semantically wrong ArgumentNullException for an empty collection (while an actual null input crashed with NullReferenceException).

This change materializes the input exactly once and uses the correct argument-validation exception types, with no public API signature change.

Changes

• src/Tizen.Multimedia.Remoting/ScreenMirroring/ScreenMirroring.cs
  • SendGenericMouseEvent now validates null input up front via ArgumentNullException.ThrowIfNull.
  • The input sequence is materialized once (as IReadOnlyList<UibcMouseInfo> fast path, ToArray() fallback), removing the Any() + Count() + foreach triple enumeration — deferred LINQ sequences are now executed a single time.
  • Empty input now throws ArgumentException (was ArgumentNullException).
  • Added the <exception cref="ArgumentException"> XML doc tag; marshalling and the native call are unchanged.

Mode

Refactoring

Verification

• Build: passed (dotnet build on Tizen.Multimedia.Remoting — 0 errors)
• Tests: N/A
• Benchmark: skipped (sdb error: no device attached — sdb devices lists no targets)

Fixes #7643

🤖 Generated with Claude Code

[JoonghyunCho]

⚠️ Benchmark skipped: Encountered an issue with sdb device connection/deployment/execution, so the benchmark could not be run. Manual benchmark verification is required. Error: sdb devices reports no attached devices (List of devices attached — empty).

[gemini-code-assist]

Code Review

This pull request refactors the SendGenericMouseEvent method in ScreenMirroring.cs to prevent multiple enumerations of uibcMouseInfos, introduce proper null validation, and fix a potential indexing bug by replacing the foreach loop with a standard for loop. The reviewer provided valuable feedback pointing out a potential memory leak during unmanaged memory allocation and suggested a refactoring to ensure proper cleanup using a try-finally block, alongside simplifying pointer arithmetic.

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[gemini-code-assist]

Memory Leak and Pointer Arithmetic Improvement

There is a potential memory leak in the allocation of unmanaged memory, and the pointer arithmetic can be significantly simplified.

1. Memory Leak:
   If Marshal.AllocHGlobal(Marshal.SizeOf(uibcObject)) throws an exception (such as OutOfMemoryException), or if Marshal.StructureToPtr throws an exception, the previously allocated unmanagedUibcMouse memory will be leaked because the try block has not been entered yet.

2. Pointer Arithmetic:
   Instead of checking IntPtr.Size == 4 and performing manual pointer arithmetic with ToInt32() or ToInt64(), you can use IntPtr.Add or the + operator, which is cleaner, safer, and cross-platform.

Here is a suggested refactoring to address both issues:

            var size = Marshal.SizeOf(typeof(Native.UibcMouse));
            IntPtr unmanagedUibcMouse = IntPtr.Zero;
            IntPtr unmanagedUibcObject = IntPtr.Zero;

            try
            {
                unmanagedUibcMouse = Marshal.AllocHGlobal(size * uibcMouseInfosSize);
                for (int i = 0; i < uibcMouseInfosSize; i++)
                {
                    IntPtr unmanagedUibcMousePtr = unmanagedUibcMouse + (i * size);
                    Marshal.StructureToPtr(uibcMouse[i], unmanagedUibcMousePtr, false);
                }

                Native.UibcMouseEvent uibcObject;
                uibcObject.size = uibcMouseInfosSize;
                uibcObject.type = type;
                uibcObject.uibcMouse = unmanagedUibcMouse;

                unmanagedUibcObject = Marshal.AllocHGlobal(Marshal.SizeOf(uibcObject));
                Marshal.StructureToPtr(uibcObject, unmanagedUibcObject, false);

                Native.SendGenericMouseEvent(Handle, unmanagedUibcObject).ThrowIfError("Failed to send generic mouse event");
            }
            finally
            {
                if (unmanagedUibcMouse != IntPtr.Zero)
                {
                    Marshal.FreeHGlobal(unmanagedUibcMouse);
                }
                if (unmanagedUibcObject != IntPtr.Zero)
                {
                    Marshal.FreeHGlobal(unmanagedUibcObject);
                }
            }

[JoonghyunCho]

🤖 [AI Review]

Reviewed — no findings.

Scope checked:

• Verified the single materialization (uibcMouseInfos as IReadOnlyList<UibcMouseInfo> ?? uibcMouseInfos.ToArray()) removes all three prior enumerations (Any(), Count(), foreach) without changing element order or count semantics.
• ArgumentNullException.ThrowIfNull is valid here — Tizen.Multimedia.Remoting targets net8.0.
• Empty input now throws ArgumentException instead of the previously incorrect ArgumentNullException; the new <exception cref="ArgumentException"> doc tag matches, and the member is [EditorBrowsable(Never)].
• Confirmed the rewritten index-based loop assigns id/x/y to the same slots as the old i++ side-effect pattern, and the second marshaling loop's re-scoped int i keeps identical bounds.
• Null check moved ahead of ValidateState: only affects exception precedence for a null argument on a disposed/invalid-state instance, which is standard guard ordering.

No 🔴 critical issues, no 🟡 suggestions to flag.

---

Automated review — final merge decision rests with human reviewers.

[JoonghyunCho]

🤖 [AI Review]
Addressed review feedback in commit 9261cda. Summary: moved the unmanaged buffer allocations in SendGenericMouseEvent inside a try/finally so unmanagedUibcMouse can no longer leak if a subsequent allocation or StructureToPtr throws, and replaced the 32/64-bit pointer arithmetic branching with IntPtr addition.

[github-actions]

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