[HandleProcessCorruptedStateExceptions] //
#endif // FEATURE_CORRUPTING_EXCEPTIONS
public void Undo()
{
if (currSC == null)
{
return; // mutiple Undo()s called on this switcher object
}
if (currEC != null)
{
Contract.Assert(currEC == Thread.CurrentThread.GetMutableExecutionContext(), "SecurityContextSwitcher used from another thread");
Contract.Assert(currSC == currEC.SecurityContext, "SecurityContextSwitcher context mismatch");
// restore the saved security context
currEC.SecurityContext = prevSC.DangerousGetRawSecurityContext();
}
else
{
// caller must have already restored the ExecutionContext
Contract.Assert(Thread.CurrentThread.GetExecutionContextReader().SecurityContext.IsSame(prevSC));
}
currSC = null; // this will prevent the switcher object being used again
bool bNoException = true;
#if !FEATURE_PAL && FEATURE_IMPERSONATION
try
{
if (wic != null)
{
bNoException &= wic.UndoNoThrow();
}
}
catch
{
// Failfast since we can't continue safely...
bNoException &= cssw.UndoNoThrow();
System.Environment.FailFast(Environment.GetResourceString("ExecutionContext_UndoFailed"));
}
#endif
bNoException &= cssw.UndoNoThrow();
if (!bNoException)
{
// Failfast since we can't continue safely...
System.Environment.FailFast(Environment.GetResourceString("ExecutionContext_UndoFailed"));
}
}