Hello,

For the sake of completeness. After the discussion on thread  
cancellation a friend of mine pointed me to this [1] paper. It  
describes the design, semantics and implementation of a raise_in  
operation in Haskell.

The paper does a good job in describing the problems of this  
operation. It also shows how to solve them by introducing two  
combinators to unconditionally block or unblock asynchronous  
exceptions in a given scope.

Best,

Daniel

[1]
@inproceedings{378858,
  author = {Simon Marlow and Simon Peyton Jones and Andrew Moran and  
John Reppy},
  title = {Asynchronous exceptions in Haskell},
  booktitle = {PLDI '01: Proceedings of the ACM SIGPLAN 2001  
conference on Programming language design and implementation},
  year = {2001},
  isbn = {1-58113-414-2},
  pages = {274--285},
  location = {Snowbird, Utah, United States},
  doi = {http://doi.acm.org/10.1145/378795.378858},
  publisher = {ACM Press},
  address = {New York, NY, USA},
  }