Ruby » Ruby master

• cont.c : Introdule ensure rollback mechanism. Please see below.

    * internal.h (ruby_register_rollback_func_for_ensure): catch up above change.
      Add rollback mechanism API.
  
    * vm_core.h (typedef struct rb_vm_struct): catch up above change.
      Introdule ensure-rollback relation table.
  
    * vm_core.h (typedef struct rb_thread_struct): catch up above change.
      Introdule ensure stack.
  
    * eval.c (rb_ensure): catch up above change.
      Introdule ensure stack.
  
    * hash.c : New function for rollback ensure, and register it to
      ensure-rollback relation table. [ruby-dev:47803] [Bug #9105]
  
    Ensure Rollback Mechanism:
    A rollback's function is a function to rollback a state before ensure's
    function execution.
    When the jump of callcc is across the scope of rb_ensure,
    ensure's functions and rollback's functions are executed appropriately
    for keeping consistency.
  
    Current API is unstable, and only internal use.
  
    ruby_register_rollback_func_for_ensure(ensure_func,rollback_func)
    This API create relation ensure's function to rollback's function.
    By registered rollback's function, it is executed When jumpping into
    corresponding rb_ensure scope.
  

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43688 b2dd03c8-39d4-4d8f-98ff-823fe69b080e