public void VerifyAddPinsObject()
{
var expected = new string('x', 5);
var weakref = new WeakReference(expected);
using (var handles = new GCHandleCollection())
{
handles.Add(expected);
expected = null;
RunFullGarbageCollection();
Assert.IsTrue(weakref.IsAlive);
}
}
public void GCHandleCollectionStress()
{
for (int i = 0; i < 1000; i++)
{
using (var handles = new GCHandleCollection())
{
for (int j = 0; j < 100; j++)
{
IntPtr p = handles.Add(new byte[1]);
Assert.AreNotEqual(IntPtr.Zero, p);
}
}
}
}
public void VerifyDisposeUnpinsObjects()
{
var expected = new string('x', 5);
var weakref = new WeakReference(expected);
using (var handles = new GCHandleCollection())
{
handles.Add(expected);
expected = null; // needed to allow GC to work
}
GC.Collect();
Assert.IsFalse(weakref.IsAlive);
}
/// <summary>
/// Gets the NATIVE_indexcolumn structure that represents the object.
/// </summary>
/// <param name="handles">GC handle collection to add any pinned handles.</param>
/// <returns>The NATIVE_indexcolumn structure.</returns>
internal NATIVE_INDEX_COLUMN GetNativeIndexColumn(ref GCHandleCollection handles)
{
NATIVE_INDEX_COLUMN indexColumn = new NATIVE_INDEX_COLUMN();
indexColumn.columnid = this.columnid.Value;
indexColumn.relop = (uint)this.relop;
indexColumn.grbit = (uint)this.grbit;
if (this.pvData != null)
{
indexColumn.pvData = handles.Add(this.pvData);
indexColumn.cbData = (uint)this.pvData.Length;
}
return(indexColumn);
}
public void VerifyDisposeUnpinsObjects()
{
var expected = new string('x', 5);
var weakref = new WeakReference(expected);
using (var handles = new GCHandleCollection())
{
handles.Add(expected);
expected = null; // needed to allow GC to work
}
RunFullGarbageCollection();
// In DEBUG test code, the objects remain alive for an indeterminate amount of time, for some reason.
// Note that they do get collected if a RETAIL test code is used, even if the product code is DEBUG
// so it must be something to do with assigning the local variable 'expected' to null and the effect that
// it has on garbage collecting weak references to it.
#if !DEBUG
Assert.IsFalse(weakref.IsAlive);
#endif
}