csharp: Add a SafePtr wrapper in debug modedevs/vitorsousa/pin-unpin

This wrapper will trigger `ObjectDisposedException` when trying to call
a method on object after it was disposed.

It is enabled only with `--buildtype=debug` when configuring meson.

3 files changed, 61 insertions, 2 deletions

diff --git a/src/bindings/mono/eo_mono/EoWrapper.cs b/src/bindings/mono/eo_mono/EoWrapper.cs
index b6ea619923..e1174a9fe8 100644
--- a/src/bindings/mono/eo_mono/EoWrapper.cs
+++ b/src/bindings/mono/eo_mono/EoWrapper.cs
@@ -9,11 +9,55 @@ namespace Efl
 namespace Eo
 {
 
+#if EFL_DEBUG
+
+public class SafeIntPtr
+{
+    private IntPtr handle;
+    private bool disposed;
+
+    private SafeIntPtr(IntPtr ptr)
+    {
+        handle = ptr;
+    }
+
+    public static implicit operator IntPtr(SafeIntPtr ptr)
+    {
+        if (ptr.disposed)
+        {
+          throw new ObjectDisposedException("Object has been disposed");
+        }
+        return ptr.handle;
+    }
+
+    public static implicit operator SafeIntPtr(IntPtr ptr)
+    {
+        return new SafeIntPtr(ptr);
+    }
+
+    public void Dispose()
+    {
+        disposed = true;
+        handle = IntPtr.Zero;
+    }
+
+    public long ToInt64()
+    {
+        return handle.ToInt64();
+    }
+}
+
+#endif
+
 public abstract class EoWrapper : IWrapper, IDisposable
 {
     protected readonly object eventLock = new object();
     protected bool inherited = false;
-    protected System.IntPtr handle = IntPtr.Zero;
+#if EFL_DEBUG
+    protected SafeIntPtr handle;
+#else
+    protected IntPtr handle;
+#endif
 
     private static Efl.EventCb ownershipUniqueDelegate = new Efl.EventCb(OwnershipUniqueCallback);
     private static Efl.EventCb ownershipSharedDelegate = new Efl.EventCb(OwnershipSharedCallback);
@@ -91,7 +135,11 @@ public abstract class EoWrapper : IWrapper, IDisposable
         if (disposing && handle != System.IntPtr.Zero)
         {
             IntPtr h = handle;
+#if EFL_DEBUG
+            handle.Dispose();
+#else
             handle = IntPtr.Zero;
+#endif
             Efl.Eo.Globals.efl_mono_native_dispose(h);
         }
         else
@@ -103,6 +151,9 @@ public abstract class EoWrapper : IWrapper, IDisposable
             }
 
             Monitor.Exit(Efl.All.InitLock);
+#if EFL_DEBUG
+            handle.Dispose();
+#endif
         }
     }
 
@@ -110,7 +161,7 @@ public abstract class EoWrapper : IWrapper, IDisposable
     /// <returns>A string with the type and the native pointer for this object.</returns>
     public override String ToString()
     {
-        return $"{this.GetType().Name}@[0x{(UInt64)handle:x}]";
+        return $"{this.GetType().Name}@[0x{handle.ToInt64():x}]";
     }
 
     /// <summary>Releases the underlying native instance.</summary>
diff --git a/src/bindings/mono/meson.build b/src/bindings/mono/meson.build
index 69a5f8491f..39fbde549e 100644
--- a/src/bindings/mono/meson.build
+++ b/src/bindings/mono/meson.build
@@ -148,6 +148,10 @@ if get_option('mono-beta')
   extra_cs_args += '-d:EFL_BETA'
 endif
 
+if get_option('buildtype') == 'debug'
+  extra_cs_args += '-d:EFL_DEBUG'
+endif
+
 efl_mono_install_dir = join_paths(dir_lib, 'efl-mono-'+version_major)
 efl_mono_xml_doc = join_paths(meson.current_build_dir(), 'efl_mono.xml')
 
diff --git a/src/tests/efl_mono/Eo.cs b/src/tests/efl_mono/Eo.cs
index be66f0842c..465646d03b 100644
--- a/src/tests/efl_mono/Eo.cs
+++ b/src/tests/efl_mono/Eo.cs
@@ -522,6 +522,10 @@ class TestObjectDeletion
         part.Del();
 
         Test.AssertNull(obj.OnePart);
+
+#if EFL_DEBUG
+        Test.AssertRaises<ObjectDisposedException>(() => part.SetParent(null));
+#endif
     }
 }