Marc Shapiro, Peter Dickman, and David Plainfoss e. SSP Chains: Robust, Distributed References Supporting Acyclic garbage Collection. Technical Report 1799, INRIA, November 1992.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....entire complet reference up to the (instantiated) anchor. The stub, as well as the tracker and the rest of the complet reference, are generated automatically by the FarGo Compiler, which accepts as input the anchor class. The tracker(s) are responsible for achieving location transparency (as in [15, 6]) Upon the arrival of a complet to a new site, a new tracker is generated there and is set to directly point to that complet. Then, the tracker at the old site is set to point to the tracker at the new site. After several hops, a chain of trackers is being formed, and each tracker forwards ....

M. Shapiro, P. Dickman, and D. Plainfosse. SSP chains: Robust, distributed references supporting acyclic garbage collection. In Proceedings of the ACM Symposium on Principles of Distributed Computing, Vancouver, August 1992. ACM.

....for distributed object systems. Some of the algorithms based on reference counting or reference listing are given by Bevan [7] Watson An Euler cycle in a connected directed graph is a cycle that traverses each edge of the graph exactly once. and Watson [38] Piquer [27] Shapiro et al.[34] and Birrel et al. 8] Rodriguez Rivera et al. 31] propose an algorithm based on reference listing augmented with back tracing. A similar approach is followed by Maheshwari [26] Rodriguez et al. 30] also suggest an algorithm based on reference listing with partial tracing in order to collect ....

M. Shapiro, P. Dickman, and D. Plainfosse. SSP chains: Robust, distributed references supporting acyclic garbage collection. Rapports de Recherche 1799, Institut National de la Recherche en Informatique et Automatique, Nov. 1992. Also available as Broadcast Technical Report 1.

....listing is similar to reference counting except that instead of maintaining a count of the references held for an object, the actual list of objects which hold the references is kept. This improves resilience to message and space failures at the cost of some memory overhead. Shapiro et al. [35] and Birrel [8] use this technique for distributed garbage collection. 3.2.2 Hybrid techniques Reference counting and reference listing are unable to collect cyclic garbage but they do not require synchronization among processors and are scalable. Therefore hybrid schemes have been proposed that ....

Marc Shapiro, Peter Dickman, and David Plainfoss'e. SSP chains: Robust, distributed references supporting acyclic garbage collection. Rapports de Recherche 1799, Institut National de la Recherche en Informatique et Automatique, November 1992. Also available as Broadcast Technical Report 1.

....Other algorithms require direct connectivity with the owner: this may not necessarily be a valid assumption in the presence of rewalls, which make some part of the network invisible [1] Finally, except for irc, none of these algorithms support mobile objects. Shapiro, Dickman and Plainfoss e [30, 29] analyse the problem of third party dependency and are the rst to propose a mechanism to collapse chains of pointers. Details of their algorithm is presented in the related work section. At this point, it is important to note that their technique supports mobile objects and partial connectivity: ....

....chapter on the subject and the garbage collection home page [13] with more than 1600 references. Section 3 gave an overview and a discussion of the current work on distributed reference counting. Two di erent approaches however deserve a further comparison. Shapiro, Dickman and Plainfoss e [30, 29] were the rst to study the problem of third party dependency. However, we rst draw our attention to Dickman who has independently published an algorithm for restructuring di usion trees [7] since the rst publication of our algorithm. Dickman s algorithm assumes a model of communication based on ....

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Marc Shapiro, Peter Dickman, and David Plainfosse. SSP Chains: Robust, Distributed References Supporting Acyclic Garbage Collection. Rapport de Recherche 1799, INRIARocquencourt, November 1992.

.... hence low communiD ti n costs) Although standard reference countifi algorifiqq are vulnerable to out of orderdeli ery of reference count mani pulati on messages, leadi ng to premature reclamati on of li ve objects, manydiA i buted schemes have been proposed to handle or avo i such racecondifi 6 [6, 39, 16, 29, 36, 7, 26]. On the other hand, reference countiD algoriD ) cannot collect cycles of garbage, although cycli connecti)q between objectsi n di) fiA6kfi) systems are faiU common. For example, objectsi n clifi t server systems may hold references to each other, and oftenthi communi6DU(A i bi6DU(A#6kfiqfi [40] ....

Marc Shapiro, Peter Dic man, and David Plainfosse. SSP chains: Robust, distributed references supporting acyclic garbage collection. Rapports de Recherche 1799, Institut National de la Recherche en Informatique et Automatique, November 1992. 261

.... complexity in distributed programming by taking away the need to define object locations, but incurs additional communications overhead as the location transparent reference must be resolved or evaluated to a direct reference to the remote object [47, 113, 162] As stated by Shapiro et al. [164], it is essential for performance that a stub contain the actual address of its target , where a stub is a type of reference. However, this requirement leads to di#culties when the embedded location becomes invalid through object migration. An object reference that does not require knowledge of ....

....83] is used to translate the remote invocation from the stub to a local invocation on the server object. Figure 1 shows a typical client server system that uses stubs and skeletons to perform remote invocation. A further alternative used to manage location referencing is that of stub scion pairs [164] (SSPs) A stub is maintained as the object reference on the client side and a scion is maintained for each stub on the server side; a stub scion pair is produced for each object reference created. When an object reference is moved, a new stub scion pair is created to produce a chain of pointers ....

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Marc Shapiro, Peter Dickman and David PlainFosse. SSP Chains: Robust, Distributed References Supporting Acyclic Garbage Collection. Technical Report 1799, INRIA, Rocquencourt, France, November 1992. BIBLIOGRAPHY 279

....repository of structured data. PerDiS is unique compared to similar systems in that it combines with DSM approaches to persistency, security and fault tolerance. The approach to persistency is SOTA, implementing persistence by reachability and employing the Larchant garbage collection algorithm [175]. 8 Mobile Agents As de ned by the OMG Common Facility Task Force in its RFP3 for mobile agent facilities, Agents are small to medium grained objects; they can move, and they can start or stop their execution autonomously . There has been much research interest in such mobile agents as an ....

M. Shapiro, P. Dickman, and D. Plainfosse. SSP Chains: Robust, Distributed References Supporting Acyclic Garbage Collection. Technical report, Institut National de Recherche en Informatique et Automatique, Rocquencourt, 1992. Also available as Broadcast Technical Report 1.

.... hence low communication costs) Although standard reference counting algorithms are vulnerable to out of order delivery of reference count manipulation messages, leading to premature reclamation of live objects, many distributed schemes have been proposed to handle or avoid such race conditions [6, 39, 16, 29, 36, 7, 26]. On the other hand, reference counting algorithms cannot collect cycles of garbage, although cyclic connections between objects in distributed systems are fairly common. For example, objects in client server systems may hold references to each other, and often this communication is ....

Marc Shapiro, Peter Dickman, and David Plainfoss'e. SSP chains: Robust, distributed references supporting acyclic garbage collection. Rapports de Recherche 1799, Institut National de la Recherche en Informatique et Automatique, November 1992.

....are not considered since 2.2. Garbage Collection Schemes 56 Figure 2.13 In the reference listing method, each cell has a list of references as opposed to a counter. Reference Listing Reference Counting a 3 RT3 RT2 RT1 a RT3 RT2 RT1 it is out of the scope of this report. Shapiro et al. SDP92] propose the SSP Chains (Stub Scion Pairs) implementation of reference listing. The proposal is for what they call a classical distributed system 7 and avoids race conditions using time stamped messages. In principle this makes the proposal unsuitable for LINDA as the concept of time stamps ....

Marc Shapiro, Peter Dickman, and David Plainfoss e. SSP Chains: Robust, Distributed References Supporting Acyclic garbage Collection. Technical Report 1799, INRIA, November 1992.

....call it Global Tuple Space (GTS) Reference Counting: Each cell has a count of the number of nodes pointing to it, consequently every cell with counter 0 (zero) is garbage [Col60] Reference Listing: Each cell has a list of cells pointing to it. If a cell s list is empty, it is garbage [SDP92] As we said before, all garbage collection ideas are based on either a data structure, or on counting listing the references for a cell. However, Linda provides neither a data structure of its tuple spaces nor references to them. We shall not go into the details of these searching algorithms ....

Marc Shapiro, Peter Dickman, and David Plainfosse. SSP Chains: Robust, Distributed References Supporting Acyclic garbage Collection. Technical Report 1799, INRIA, November 1992.

....messages. For example, a proxy could maintain a list of member addresses, and send point to point messages to each. Each process in a system must have local proxies. Proxies must themselves be managed, requiring additional infrastructure to track the existence and locations of members [27] and maintain consistency among proxies, again with a range of transparency options. Since several proxies could serve as channels to the same group, or even vice versa, identity comparisons among channel proxies are meaningless at the application level. 4 Interfaces As is the case for objects, ....

Shapiro, M., P. Dickman, & D. Plainfoss'e, SSP Chains: Robust, Distributed References Supporting Acyclic Garbage Collection, Rapport de Recherche INRIA 1799, 1992.

....reference can never scale worldwide. The main problem with encoding location information is that once the object moves to another location the reference becomes invalid. Middleware systems use techniques such as forwarding pointers or broadcast to deal with this situation (see, for example, [2, 9, 13]) However, both techniques have inherent scalability problems that make them unsuitable for global middleware. It is also unclear how forwarding pointers can deal with heavily replicated objects. Our solution to these problems is the introduction of persistent location independent object identi ....

M. Shapiro, P. Dickman, and D. Plainfosse. \SSP Chains: Robust, Distributed References Supporting Acyclic Garbage Collection." Technical Report 1799, INRIA, Rocquencourt, France, Nov. 1992.

.... jumping from site to site, this allows sites to reclaim the space that was occupied by a mobile program, hereby avoiding zombie references as in indirect reference counting [29] To the best of our knowledge, Shapiro, Gruber and Plainfoss e [36] and subsequently Shapiro, Dickman, and Plainfoss e [34, 35, 31] were the rst to address the issue of shortcutting chains of pointers. They introduce the notion of SSP chains. A chain starts its existence by a single SSP (Scion Stub pair) it increases when sending the reference of a local object, or when migrating an object to some other site. In addition, ....

Marc Shapiro, Peter Dickman, and David Plainfosse. SSP Chains: Robust, Distributed References Supporting Acyclic Garbage Collection. Rapport de Recherche 1799, INRIA-Rocquencourt, November 1992.

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Marc Shapiro, Peter Dickman, and David Plainfosse. SSP Chains: Robust, Distributed References Supporting Acyclic Garbage Collection. Rapport de Recherche 1799, INRIA-Rocquencourt, November 1992.

....There is no assumption to which process, if any, or in what order propagate messages are delivered. If mutators were allowed to exchange messages, the pointers they contain must be taken into account by the GC algorithm. This is probably straightforward, using techniques such as SSP Chains [26], but has not been considered yet. It is convenient to think of a granule as an object, but note that granules are not necessarily the same as language level objects, which can be larger or smaller. After a granule replica changes value, either by assignment or by being the target of a ....

....partition the memory: they trace references internal to a partition, and count references that cross partition boundaries. This replaces the unfeasible global trace with the weaker problem of tracing each partition. In previous distributed GCs, a partition was often identified with a process [26]. This is a natural design option as those GCs were conceived for distributed systems based on RPC (Remote Procedure Call) in which cross partition pointers were tracked at the process border. However, Larchant is based on DSM, therefore, memory partitioning is di#erent: i) a bunch may be ....

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Marc Shapiro, Peter Dickman, and David Plainfosse. SSP chains: Robust, distributed references supporting acyclic garbage collection. Rapport de Recherche 1799, Institut National de Recherche en Informatique et Automatique, Rocquencourt (France), November 1992. http://www-sor.inria.fr/SOR/docs/SSPC - rr1799.html. 238, 241, 248

....are optional, allowing some nodes to act as pure servers. Applications interact with PerDiS through a languagedependent API, which connects to the language independent ULL. Communication between a ULL and its corresponding PD, and communication between PDs, is based on stub scion pair chains [23], an object request broker supporting garbage collection and migration. The ULL deals with application level memory mapping, data transformations (e.g. swizzling and unswizzling) and management of clusters, locks and transactions. When the application, through the API and the ULL, needs locks or ....

Marc Shapiro, Peter Dickman, and David Plainfoss'e. SSP chains: Robust, distributed references supporting acyclic garbage collection. Rapport de Recherche 1799, INRIA, Rocquencourt, November 1992. Also available as Broadcast Technical Report #1. ftp://ftp.inria. fr/INRIA/Projects/SOR/SSPCrr1799.ps.gz.

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Marc Shapiro, Peter Dickman, and David Plainfoss'e. SSP chains: Robust, distributed references supporting acyclic garbage collection. Rapport de Recherche 1799, Institut National de la Recherche en Informatique et Automatique, Rocquencourt (France), nov 1992. Also available as Broadcast Technical Report #1.

....therefore we do not consider back tracing any further. 2.3 Hybrid Collection Algorithms Practical DGC algorithms are a hybrid of tracing, counting, and time out. For instance a hybrid DGC is used in the commercial remote object system Java RMI [28] Two systems that we developed, SSP Chains [24] and PerDiS [9] are also based on hybrid DGC; they will be examined in more detail in the later sections. A distributed system is typically partitioned for locality. In the DGC context, we call each part a space. DGC algorithms typically focus on collecting references that cross the boundaries ....

....After introducing the main properties of our detector, we will present the algorithm and argue for its scalability and fault tolerance. More detail can be found elsewhere [15] 3.1 Introduction Terminology. In this paper, we use the terminology of the Stub Scion Pair Chains system (SSPC) [24]. Stubs and Scions. Each remote reference R from object A in space X to object B in space Y is represented by a local pointer in X from object A to a special object stub X (R) called a stub and used as a proxy in X for object B, and a local pointer in Y from another special object scion Y (R) ....

Marc Shapiro, Peter Dickman, and David Plainfosse. SSP chains: Robust, distributed references supporting acyclic garbage collection. Rapport de Recherche 1799, Institut National de la Recherche en Informatique et Automatique, Rocquencourt (France), November 1992. http://www-sor.inria.fr/publi/SSPC rr1799.html.

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Marc Shapiro, Peter Dickman, and David Plainfoss e. SSP Chains: Robust, Distributed References Supporting Acyclic garbage Collection. Technical Report 1799, INRIA, November 1992.

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Marc Shapiro, Peter Dickman, and David Plainfosse. SSP chains: Robust, distributed references supporting acyclic garbage collection. Rapports de Recherche 1799, Institut National de la Recherche en Informatique et Automatique, November 1992. Also available as Broadcast Technical Report 1.

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Marc Shapiro, Peter Dickman, and David Plainfosse. SSP chains: Robust, distributed references supporting acyclic garbage collection. Rapports de Recherche 1799, Institut National de la Recherche en Informatique et Automatique, November 1992. Also available as Broadcast Technical Report 1.

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M. Shapiro, P. Dickman, and D. Plainfoss e. SSP Chains: Robust, Distributed References Supporting Acyclic Garbage Collection. Technical Report 1799, 1992.

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Marc Shapiro, Peter Dickman, and David Plainfosse. SSP chains: Robust, distributed references supporting acyclic garbage collection. Rapport de Recherche 1799, Institut National de Recherche en Informatique et Automatique, Rocquencourt (France), November 1992.

No context found.

Marc Shapiro, Peter Dickman, and David Plainfosse. SSP chains: Robust, distributed references supporting acyclic garbage collection. Rapports de Recherche 1799, Institut National de la Recherche en Informatique et Automatique, November 1992. Also available as Broadcast Technical Report 1.

No context found.

Marc Shapiro, Peter Dickman, and David Plainfoss e. SSP chains: Robust, distributed references supporting acyclic garbage collection. Rapports de Recherche 1799, Institut National de la Recherche en Informatique et Automatique, November 1992. Also available as Broadcast Technical Report 1.

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