P. S. Almeida. Balloon Types: Controlling Sharing of State in Data Types. In European Conference on Object-Oriented Programming, June 1997.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....transform function can be reasoned about as extra method of its old class. 6 Related Work Euclid [41] is one of the rst languages that considered the problem of aliasing. 37] stressed the need for better treatment of aliasing in object oriented programs. Early work on Islands [36] and Balloons [3] focused on fully encapsulated objects where all subobjects an object can access are not accessible outside the object. Universes [53] also enforces full encapsulation, except for read only references. However, full encapsulation signi cantly limits expressiveness, and is often more than is ....

P. S. Almeida. Balloon types: Controlling sharing of state in data types. In European Conference for Object-Oriented Programming (ECOOP), June 1997.

....11 12 Figure 8: Violation of Encapsulation in [15] 5.2 Related Type Systems Euclid [33] was one of the rst languages that considered the problem of aliasing. 30] stressed the need for better treatment of aliasing in object oriented programs. Early work on Islands [29] and Balloons [3] focused on fully encapsulated objects where all subobjects an object could access were not accessible outside the object. However, full encapsulation signi cantly limits expressiveness, and is often more than is needed. The work on ESC Java pointed out that encapsulation is required only for ....

P. S. Almeida. Balloon types: Controlling sharing of state in data types. In European Conference for Object-Oriented Programming (ECOOP), June 1997.

....tree, or 3) y is the special owner self,orthisThread,orunique. 7.3 Related Type Systems Euclid [31] is one of the first languages that considered the problem of aliasing. 27] stressed the need for better treatment of aliasing in object oriented programs. Early work on Islands [26] and Balloons [3] focused on fully encapsulated objects where all subobjects an object can access are not accessible outside the object. Universes [40] also enforces full encapsulation, except for immutable objects. However, full encapsulation significantly limits expressiveness, and is often more than is needed. ....

P. S. Almeida. Balloon types: Controlling sharing of state in data types. In European Conference for Object-Oriented Programming (ECOOP), June 1997.

....12 13 Figure 8: Violation of Encapsulation in [15] 5.2 Related Type Systems Euclid [33] was one of the first languages that considered the problem of aliasing. 30] stressed the need for better treatment of aliasing in object oriented programs. Early work on Islands [29] and Balloons [3] focused on fully encapsulated objects where all subobjects an object could access were not accessible outside the object. However, full encapsulation significantly limits expressiveness, and is often more than is needed. The work on ESC Java pointed out that encapsulation is required only for ....

P. S. Almeida. Balloon types: Controlling sharing of state in data types. In European Conference for Object-Oriented Programming (ECOOP), June 1997.

....of resource management and usage protocols in the context of device drivers and other low level systems code. Ownership types, which describe a limited static or dynamic scope within which sharing can occur, can also be used to control aliasing. Early work such as Islands [Hog91] and Balloons [Alm97] imposed strict rules on sharing objects between components, significantly limiting expressiveness. ESC Java s specification system enables program specific reasoning about pivot objects that are similar to our owned objects [DLN98] however, their system could not guarantee that pivot objects are ....

P.S. Almeida. Balloon Types: Controlling Sharing of State in Data Types, Proceedings of ECOOP '97, pp. 32-59, 1997.

....alias control and on security; we review both topics in the following two subsections. 7.1. Alias Control Reference semantics permeate object oriented programming languages, it is thus not surprising that the issue of controlling aliasing has been the focus of numerous papers in the recent years [39, 40, 34, 41, 6, 42, 43, 44]. We will discuss brie y the most relevant works. In [6] we proposed exible alias protection to control potential aliasing amongst components of an aggregate object (or owner) Aliasing mode declarations specify constraints on sharing of references. The mode rep protects representation objects ....

....types. Both papers have been presented in the context of a simple programming language without inheritance or subtyping. There is no obvious way to maintain containment in the presence of either. Con ned types were designed to support both concepts. Hogg s Islands [40] and Almeida s Balloons [41] have similar aims. An Island or Balloon is an owner object that protects its internal representation from aliasing. The main di erence from [6] is that both proposals strive for full encapsulation, that is, all objects reachable from an owner are protected from aliasing. This is equivalent to ....

[Article contains additional citation context not shown here]

Almeida PS. Balloon types: Controlling sharing of state in data types. ECOOP'97|Object-Oriented Programming, 11th European Conference, Aksit M, Matsuoka S (eds.), vol. 1241 of LNCS. SpringerVerlag: Jyvaskyla, Finland, 1997; 32-59.

....that implement predicate dispatch making it unsuitable for our experiments. Furthermore, it is unclear how dicult it would be to link predicate dispatch to optimization based on aliasing information. Our work can also be seen as complimentary to recent work on alias controlling type systems [1, 10, 9, 16, 26, 25]. These type systems use static type information to control problems caused by aliases into the internal state of an object from outside the class implementing it, such as representation exposure and argument exposure. Such type systems also seem important for reasoning in a modular fashion about ....

P. S. Almeida. Balloon types: Controlling sharing of state in data types. In M. Aksit and S. Matsuoka, editors, ECOOP '97 | Object-Oriented Programming 11th European Conference, Jyvaskyla, Finland, volume 1241 of Lecture Notes in Computer Science, pages 32-59. Springer-Verlag, New York, NY, June 1997.

....types and gives some examples. Section 3 shows the performance improvements obtained by object heaps. Finally, Section 4 shows a conservative analysis for identifying sandwich types. Section 5 concludes our paper. 2 Sandwich Types The notion of sandwich types is a generalization of balloon types [Alm97]. All objects in a balloon can be accesses only via a distinguished balloon object. However, this excludes container types such as e.g. lists or sets. These types usually contain methods to return their elements. Thus, these elements can be accessed from outside. However, there is often an ....

....y 2 INTERNAL (s) x . A sandwich is a sandwich object x together with the set of its internal objects. A is a sandwich type i for all states s every object x of type A in s is a sandwich object. Remark: If there is no lower slice, a sandwich object is also a balloon object according to [Alm97]. Observe that the attributes of internal objects need not be private. Example: Consider the following implementation of a doubly linked list (next and previous are used to navigate in the list) class LIST (T ) is private attr head : LIST CELL(T ) private attr end : LIST CELL(T ) private ....

P. S. Almeida. Balloon types: Controlling sharing of state in data types. Lecture Notes in Computer Science, 1241:32-59, 1997.

.... scope g public void exposeData( f anObject = privateData; aliasing part of state with an accessible variable g public void exposeData(Object[ array) f array[0] privateData.elementAt(0) aliasing with a parameter g public Object[ exposeData(int i) f Object[ array = new Object[1]; array[0] privateData.elementAt(i) return array; aliasing with a returned object g g Figure 1: An example for a spectrum of situations that cause variable mutability 5 classes is interdependent. Therefore, the analysis requires iterative processing. Each iteration determines ....

....variables, but also by modi cations on the states of objects to which these variables refer. The complete state of an object becomes more complicated [17] This reference semantics has been the focus of many works that address ways to control aliasing and sharing of state and to improve locality [1, 14, 17]. Our work was originally motivated by observing the need to identify immutability of static elds in order to ensure isolation properties while composing Java components. Lack of isolation poses serious integrity, scalability and security problems. In C , the const speci er can be applied to ....

P. S. Almeida. Balloon types: Controlling sharing of state in data types. In M. Aksit and S. Matsuoka, editors, Lecture Notes in Computer Science, volume 1241, pages 32-59, Jyvaskyla, Finland, June 1997. ECOOP'97, 11th European Conference on Object-Oriented Programming.

....arbitrarily in the heap. Some full alias protection schemes allow dynamic aliases across encapsulation boundaries to provide temporary access to objects representations, and enforce restrictions so that the dynamic aliases cannot be stored in to objects variables and become static aliases [12, 1]. Unfortunately, dynamic aliases can still be used to corrupt objects representations from outside the abstraction boundary unless they are carefully managed. 4 Mutability Aliasing problems arise when state is modified, so some aliasing management schemes address the mutability of state. One ....

....with null, so swapping is basically a more flexible version of a destructive read, with similar costs and benefits [10] 5. 3 Copy Assignment Reading a unique variable results in a copy of the unique object being created, again preserving the uniqueness of the object stored in the variable [1]. Eiffel s expanded types are effectively passed and updated by copy assignment, as are parameters passed by value in Pascal, so their semantics are reasonably conventional if not necessarily object oriented, because frequent creation of new objects devalues object identity. Of course, copy ....

[Article contains additional citation context not shown here]

P. S. Almeida. Balloon types: Controlling sharing of state in data types. In ECOOP Proceedings, 1997.

....object oriented programs. Beside the fact that they do not address distribution, the way they detect parallelism is radically dioeerent from other works: instead of testing Bernstein s conditions, they look for operations that commute (for instance, associative operations) Almeida presented in [2] a type system that relies on an abstract interpretation of object oriented programs as a checking mechanism. This type system classies objects in two categories, standard types and balloon types where objects of the second type must have a self contained accessibility and must not be shared. With ....

P. S. Almeida. Balloon types: controlling sharing of states in data types. In Proc. ECOOP), LNCS 1241, pages 3259. Springer Verlag, 1997.

....not be in line with simplicity and modularity principles of OO languages. 2 The problem There are two different cases for possibly having outside references to the values of attributes (instance variables) of an object. In the following, we refer to these cases access leakage. In other contexts [1, 2, 6, 7], this is called aliasing or partial sharing of object state. Access leakage is a potential source of violations of class encapsulation. Definition 3. Input and output leakage) When a target object t is created by some caller object c or more data is put into the target object t by giving ....

.... well as CLU [13] and Argus [12] allows one to define immutable objects (following our terminology, those are shallow immutable) As to the theoretical studies on the subject, problems caused by aliasing (having multiple references to an object) are dealt e.g. in [6, 7] theory of islands) and [1, 2] (balloon types) The motivation behind islands and balloon types is to make it easier to reason about program correctness. Islands and balloons are transitive closures of object references, and the idea is that there exist no outside references into such closures. i.e. the idea in those works ....

[Article contains additional citation context not shown here]

P.S. Almeida. Balloon Types: Controlling Sharing of State in Data Types. In Proceedings of ECOOP'97, LNCS 1241, pages 32 -- 59, June 1997.

....a secure version of the class (i.e. one that includes access control checks) Annotation of classes with checks could be included to check field accesses between objects [21] as we mentioned in Section 4. A related topic to access control is aliasing control, e.g. Confined types [4] Balloons [1] or Islands [11] Confined types is a recent effort to control the visibility of kernel objects by controlling the visibility of class names. A confined type is a class whose objects are invisible to specific user programs. The advantage of this approach is that the confinement of a type is ....

P. S. Almeida. Balloon Types: Controlling Sharing of State in Data Types. In M. Aksit and S. Matsuoka, editors, ECOOP '97 --- Object-Oriented Programming 11th European Conference, Jyvaskyla, Finland, volume 1241 of Lecture Notes in Computer Science, pages 32--59. Springer-Verlag, New York, NY, June 1997.

....alias control and on security; we review both topics in the following two subsections. 7. 1 Alias Control Reference semantics permeate object oriented programming languages, it is thus not surprising that the issue of controlling aliasing has been the focus of numerous papers in the recent years [19, 18, 1, 29, 10, 20, 7]. In [29] we proposed flexible alias protection to control potential aliasing amongst components of an aggregate object (or owner) Aliasing mode declarations specify constraints on sharing of references. The mode rep protects representation objects from exposure. In essence, rep objects belong ....

....types. Both papers have been presented in the context of a simple programming language without inheritance or subtyping. There is no obvious way to maintain containment in the presence of either. Confined types were designed to support both concepts. Hogg s Islands [18] and Almeida s Balloons [1] have similar aims. An Island or Balloon is an owner object that protects its internal representation from aliasing. The main difference to [29] is that both proposals strive for full encapsulation, that is, all objects reachable from an owner are protected from aliasing. This is equivalent to ....

[Article contains additional citation context not shown here]

P. S. Almeida. Balloon types: Controlling sharing of state in data types. In M. Aksit and S. Matsuoka, editors, ECOOP'97---Object-Oriented Programming, 11th European Conference, volume 1241 of Lecture Notes in Computer Science, pages 32--59, Jyvaskyla, Finland, 9--13 June 1997. Springer.

....on alias control and security; we review both topics in the following two subsections. 7. 1 Alias Control Reference semantics permeate object oriented programming languages, it is thus not surprising that the issue of controlling aliasing has been the focus of numerous papers in the recent years [19, 18, 1, 30, 10, 20, 7]. In [30] we proposed exible alias protection to control potential aliasing amongst components of an aggregate object (or owner) Aliasing mode declarations specify constraints on sharing of references. The mode rep protects representation objects from exposure. In essence, rep objects belong ....

....types. Both papers have been presented in the context of a simple programming language without inheritance or subtyping. There is no obvious way to maintain containment in the presence of either. Con ned types were designed to support both concepts. Hogg s Islands [18] and Almeida s Balloons [1] have similar aims. An Island or Balloon is an owner object that protects its internal representation from aliasing. The main di erence to [30] is that both proposals strive for full encapsulation, that is, all objects reachable from an owner are protected from aliasing. This is equivalent to ....

[Article contains additional citation context not shown here]

P. S. Almeida. Balloon types: Controlling sharing of state in data types. In M. Aksit and S. Matsuoka, editors, ECOOP'97|Object-Oriented Programming, 11th European Conference, volume 1241 of Lecture Notes in Computer Science, pages 32-59, Jyvaskyla, Finland, 9-13 June 1997. Springer.

....on alias control and security; we review both topics in the following two subsections. 7. 1 Alias Control Reference semantics permeate object oriented programming languages, it is thus not surprising that the issue of controlling aliasing has been the focus of numerous papers in the recent years [19, 18, 1, 30, 10, 20, 7]. In [30] we proposed exible alias protection to control potential aliasing amongst components of an aggregate object (or owner) Aliasing mode declarations specify constraints on sharing of references. The mode rep protects representation objects from exposure. In essence, rep objects belong ....

....types. Both papers have been presented in the context of a simple programming language without inheritance or subtyping. There is no obvious way to maintain containment in the presence of either. Con ned types were designed to support both concepts. Hogg s Islands [18] and Almeida s Balloons [1] have similar aims. An Island or Balloon is an owner object that protects its internal representation from aliasing. The main di erence to [30] is that both proposals strive for full encapsulation, that is, all objects reachable from an owner are protected from aliasing. This is equivalent to ....

[Article contains additional citation context not shown here]

P. S. Almeida. Balloon types: Controlling sharing of state in data types. In M. Aksit and S. Matsuoka, editors, ECOOP'97|Object-Oriented Programming, 11th European Conference, volume 1241 of Lecture Notes in Computer Science, pages 32-59, Jyvaskyla, Finland, 9-13 June 1997. Springer.

.... a view to cheap synchronisation [Lea96] and the transfer of resources at low cost [SaCa96] The need to assure exclusive ownership is related to other general work on aliasing protection, such as the Geneva Convention [HLHW92] alias free pointers [Mins96] islands [Hogg91] and balloon types [Alme97] Much of this work focuses on who has control over resources and whether further aliases may be granted. In this paper, a different slant is taken. Many C programmers prefer the so called orthodox canonical form (OCF) Cope92, Lea93] with its emphasis on the uniform value semantics of ....

P S Almeida, "Balloon types: controlling sharing of state in data types", Proc. 11th European Conf. Object-Oriented Prog. (1997), Springer Verlag, 32-59.

....on alias control and security; we review both topics in the following two subsections. 7. 1 Alias Control Reference semantics permeate object oriented programming languages, it is thus not surprising that the issue of controlling aliasing has been the focus of numerous papers in the recent years [19, 18, 1, 30, 10, 20, 7]. In [30] we proposed flexible alias protection to control potential aliasing amongst components of an aggregate object (or owner) Aliasing mode declarations specify constraints on sharing of references. The mode rep protects representation objects from exposure. In essence, rep objects belong ....

....types. Both papers have been presented in the context of a simple programming language without inheritance or subtyping. There is no obvious way to maintain containment in the presence of either. Confined types were designed to support both concepts. Hogg s Islands [18] and Almeida s Balloons [1] have similar aims. An Island or Balloon is an owner object that protects its internal representation from aliasing. The main difference to [30] is that both proposals strive for full encapsulation, that is, all objects reachable from an owner are protected from aliasing. This is equivalent to ....

[Article contains additional citation context not shown here]

P. S. Almeida. Balloon types: Controlling sharing of state in data types. In M. Aksit and S. Matsuoka, editors, ECOOP'97---Object-Oriented Programming, 11th European Conference, volume 1241 of Lecture Notes in Computer Science, pages 32--59, Jyvaskyla, Finland, 9--13 June 1997. Springer.

.... a view to cheap synchronisation [Lea96] and the transfer of resources at low cost [SaCa96] The need to assure exclusive ownership is related to other general work on aliasing protection, such as the Geneva Convention [HLHW92] alias free pointers [Mins96] islands [Hogg91] and balloon types [Alme97] Much of this work focuses on who has control over resources and whether further aliases may be granted. In this paper, a different slant is taken. Many C programmers prefer the so called orthodox canonical form (OCF) Cope92, Lea93] with its emphasis on the uniform value semantics of ....

P S Almeida, "Balloon types: controlling sharing of state in data types", Proc. 11th European Conf. Object-Oriented Prog. (1997), Springer Verlag, 32-59.

....all sharing of internal state between modules, some sort of object sharing is unavoidable in practical systems. The Island proposal is important methodologically in that it is specifically targeted at static safety guarantees rather than optional annotations. In a similar vein, Balloon types [5] demonstrate how a similar degree of safety may be provided with fewer annotations and more sophisticated static analysis. However, balloon types only guarantee safety against static aliasing (i.e. aliases though state variables) and not against dynamic aliasing (aliasing through local variable ....

....hardware. Sequential consistency [23] is the most natural candidate for such a top level programming model. Sequential consistency is central to the notion of object safety in the proposed language. The great 1. Protection against dynamic aliasing using opaque balloon types is mentioned in [5], but the details presented are only concerned with immutable objects. 6 challenge is reconciling the high level sequentially consistent model with the weak consistency model supported by the hardware. The latter are responsible for up to 80 or performance improvements of modern ....

[Article contains additional citation context not shown here]

P.S. Almeida, Balloon Types: Controlling Sharing of State in Data Types, Proceedings of ECOOP '97, pp. 32-59, 1997.

No context found.

P. S. Almeida. Balloon types: Controlling sharing of state in data types. In Proceedings ECOOP'97, volume 1241 of LNCS, pages 32-59. Springer-Verlag, June 1997.

No context found.

P. S. Almeida. Balloon Types: Controlling Sharing of State in Data Types. In European Conference on Object-Oriented Programming, June 1997.

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P. S. Almeida. Balloon types: Controlling sharing of state in data types. In European Conference for Object-Oriented Programming (ECOOP), June 1997.

No context found.

P.S. Almeida. Balloon Types: Controlling Sharing of State in Data Types, Proceedings of ECOOP 97, pp. 32-59, 1997.

No context found.

P. S. Almeida. Balloon types: Controlling sharing of state in data types. In European Conference for Object-Oriented Programming (ECOOP), June 1997.

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