/// <summary>
/// Acquires a lease on a safe handle. This method is intended to be used in the initializer of a <c>using</c>
/// statement.
/// </summary>
/// <param name="handle">The <see cref="SafeHandle"/> to lease.</param>
/// <returns>A <see cref="SafeHandleLease"/>, which must be disposed to release the resource.</returns>
/// <exception cref="ObjectDisposedException">If the lease could not be acquired.</exception>
public static SafeHandleLease Lease(this SafeHandle handle)
{
if (handle is null)
{
throw new ArgumentNullException(nameof(handle));
}
var success = false;
try
{
handle.DangerousAddRef(ref success);
if (!success)
{
throw new ObjectDisposedException(handle.GetType().FullName);
}
return(new SafeHandleLease(handle));
}
catch
{
if (success)
{
handle.DangerousRelease();
}
throw;
}
}
public static SafeHandleLease Lease(this SafeHandle handle)
{
RoslynDebug.AssertNotNull(handle);
var success = false;
try
{
handle.DangerousAddRef(ref success);
if (!success)
{
throw new ObjectDisposedException(handle.GetType().FullName);
}
return(new SafeHandleLease(handle));
}
catch
{
if (success)
{
handle.DangerousRelease();
}
throw;
}
}
public static object Format(object value)
{
// If it's null, return a known string for null values
if (value == null)
{
return(NullInstance);
}
// Give another partial implementation a chance to provide its own string representation
string result = null;
AdditionalCustomizedToString(value, ref result);
if (result != null)
{
return(result);
}
// Format arrays with their element type name and length
Array arr = value as Array;
if (arr != null)
{
return($"{arr.GetType().GetElementType()}[{((Array)value).Length}]");
}
// Format ICollections as the name and count
ICollection c = value as ICollection;
if (c != null)
{
return($"{c.GetType().Name}({c.Count})");
}
// Format SafeHandles as their type, hash code, and pointer value
SafeHandle handle = value as SafeHandle;
if (handle != null)
{
return($"{handle.GetType().Name}:{handle.GetHashCode()}(0x{handle.DangerousGetHandle():X})");
}
// Format IntPtrs as hex
if (value is IntPtr)
{
return($"0x{value:X}");
}
// If the string representation of the instance would just be its type name,
// use its id instead.
string toString = value.ToString();
if (toString == null || toString == value.GetType().FullName)
{
return(IdOf(value));
}
// Otherwise, return the original object so that the caller does default formatting.
return(value);
}