• Stabilizers currently require the MLton sources, this should be fixed by the next release


  • Stabilizers are released under the MLton License


  • Download and build a source copy of MLton

  • Extract the tar.gz file attached to this page

  • Some examples are provided in the "examples/" sub directory, more examples will be added to this page in the following week

Bug reports / Suggestions

  • Please send any errors you encounter to schatzp and lziarek at

  • We are looking to expand the usability of stabilizers

  • Please send any suggestions and desired functionality to the above email addresses


  • This is an alpha release. We expect to have another release shortly with added functionality soon

  • More documentation, such as signatures and descriptions of functionality, will be forthcoming


signature STABLE =
     type checkpoint

     val stable: ('a -> 'b) -> ('a -> 'b)
     val stabilize: unit -> 'a

     val stableCP: (('a -> 'b) * (unit -> unit)) ->
                    (('a -> 'b) *  checkpoint)
     val stabilizeCP: checkpoint -> unit

     val unmonitoredAssign: ('a ref * 'a) -> unit
     val monitoredAssign: ('a ref * 'a) -> unit

Stable provides functions to manage stable sections.

  • type checkpoint

    handle used to stabilize contexts other than the current one.

  • stable f

    returns a function identical to f that will execute within a stable section.

  • stabilize ()

    unrolls the effects made up to the current context to at least the nearest enclosing stable section. These effects may have propagated to other threads, so all affected threads are returned to a globally consistent previous state. The return is undefined because control cannot resume after stabilize is called.

  • stableCP (f, comp)

    returns a function f' and checkpoint tag cp. Function f' is identical to f but when applied will execute within a stable section. comp will be executed if f' is later stabilized. cp is used by stabilizeCP to stabilize a given checkpoint.

  • stabilizeCP cp

    same as stabilize except that the (possibly current) checkpoint to stabilize is provided.

  • unmonitoredAssign (r, v)

    standard assignment (:=). The version of CML distributed rebinds := to a monitored version so interesting effects can be recorded.

  • monitoredAssign (r, v)

    the assignment operator that should be used in programs that use stabilizers. := is rebound to this by including CML.


Also see