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From: Gorka Guardiola <paurea@gmail.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: Re: [9fans] A little more ado about async Tclunk
Date: Sun, 31 Oct 2010 14:06:46 +0100	[thread overview]
Message-ID: <AANLkTi==Bt0Hbu247eEAerEG2=JCyav2B5rdgA94pk12@mail.gmail.com> (raw)
In-Reply-To: <AANLkTikOPW8bzguWAd-3=kT1orykv7kz-PaD2PhdFaH-@mail.gmail.com>

After some research and reading I believe that deadly embrace was first used in:

E. W. Dijkstra "EWD108: Een algorithme ter voorkoming van de dodelijke
omarming" (in Dutch; "An algorithm for the prevention of the deadly
embrace" or so I 've been told.

as a synonym for deadlock or actually to describe a cycle in the WFG which is
the same. (the bankers algorithm is an algoritm to prevent deadlock).

Hoare cites Dijstra when he uses the term deadly embrace:
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.104.9460&rep=rep1&type=pdf
http://www.eecs.ucf.edu/~dcm/Teaching/COP4600-Fall2010/Literature/Semaphors-Djikstra.pdf

Hoare is talking about the events which happen when the process is in
an environment,
that is, what kind of inputs can make a process go forward. He is talking about
empty intersection of the possible events in the environment and the events of
the process. In Hoare's model, livelock and deadlock cannot be distinguished,
so deadly embrace in his terminology means both. This is because he is
establishing
an equivalence relation between all the processes which produce the same
interaction with the environment (a process is identified by trace).

So, yeah, deadlock is a synonym for deadly embrace. Yes, in Hoare's model
they are indistinguishable, so when he says deadly embrace, he can refer
to both.



  reply	other threads:[~2010-10-31 13:06 UTC|newest]

Thread overview: 101+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-27  3:02 Venkatesh Srinivas
2010-10-27  4:23 ` erik quanstrom
2010-10-27  6:27   ` Bruce Ellis
2010-10-27 13:50     ` Charles Forsyth
2010-10-27 13:53       ` Gorka Guardiola
2010-10-27 13:55         ` Francisco J Ballesteros
2010-10-27 14:12         ` John Floren
2010-10-27 14:13       ` Eric Van Hensbergen
2010-10-27 14:48         ` Venkatesh Srinivas
2010-10-27 15:45           ` erik quanstrom
2010-10-27 15:54             ` Venkatesh Srinivas
2010-10-27 21:04               ` Bruce Ellis
2010-10-28 12:12               ` Charles Forsyth
2010-10-28 13:32                 ` Bruce Ellis
2010-10-28 14:30                 ` Gorka Guardiola
2010-10-28 14:39                   ` Gorka Guardiola
2010-10-28 14:58                     ` erik quanstrom
2010-10-28 14:41                   ` Francisco J Ballesteros
2010-10-28 14:45                     ` Eric Van Hensbergen
2010-10-28 14:56                       ` Francisco J Ballesteros
2010-10-28 15:37                         ` Nathaniel W Filardo
2010-10-28 15:40                           ` erik quanstrom
2010-10-28 15:53                           ` Francisco J Ballesteros
2010-10-28 19:17                             ` Venkatesh Srinivas
2010-10-28 19:24                 ` Venkatesh Srinivas
2010-10-28 20:18                   ` Charles Forsyth
2010-10-28 20:32                     ` Venkatesh Srinivas
2010-10-28 20:55                       ` Nemo
2010-10-28 21:22                         ` Venkatesh Srinivas
2010-10-28 22:17                           ` Francisco J Ballesteros
2010-10-28 23:51                     ` Gorka Guardiola
2010-10-29  5:37                       ` Bruce Ellis
2010-10-29  7:44                         ` Gorka Guardiola
2010-10-29  8:51                           ` Bruce Ellis
2010-10-29  9:01                       ` Charles Forsyth
2010-10-29  8:58                         ` Bruce Ellis
2010-10-29 16:38                           ` Charles Forsyth
2010-10-29  9:45                         ` Gorka Guardiola
2010-10-29  9:56                           ` Bruce Ellis
2010-10-29 16:01                           ` Charles Forsyth
2010-10-29 15:58                             ` Venkatesh Srinivas
2010-10-29 16:02                             ` roger peppe
2010-10-29 16:17                               ` Bruce Ellis
2010-10-29 16:47                                 ` roger peppe
2010-10-29 16:04                           ` Charles Forsyth
2010-10-29 14:14                         ` Eric Van Hensbergen
2010-10-29 15:21                           ` roger peppe
2010-10-29 15:36                             ` erik quanstrom
2010-10-29 15:39                             ` Eric Van Hensbergen
2010-10-29 15:49                             ` Charles Forsyth
2010-10-29 15:50                               ` Eric Van Hensbergen
2010-10-29 15:59                                 ` Bruce Ellis
2010-10-29 16:28                                   ` Venkatesh Srinivas
2010-10-29 17:16                                     ` erik quanstrom
2010-10-29 16:47                               ` David Leimbach
2010-10-29 17:13                                 ` Charles Forsyth
2010-10-29 17:22                                   ` David Leimbach
2010-10-29 17:26                                     ` erik quanstrom
2010-10-29 17:47                                       ` Bruce Ellis
2010-10-29 19:33                                         ` roger peppe
2010-10-29 20:27                                           ` Bruce Ellis
2010-10-29 20:41                                             ` Gorka Guardiola
2010-10-29 20:44                                               ` Bruce Ellis
2010-10-29 22:31                                                 ` Bakul Shah
2010-10-29 22:39                                                 ` roger peppe
2010-10-29 22:43                                                   ` Bruce Ellis
2010-10-29 23:07                                                     ` roger peppe
2010-10-29 23:28                                                       ` Bruce Ellis
2010-10-30  9:08                                                         ` Nemo
2010-10-31  5:39                                                           ` Bruce Ellis
2010-10-31  8:52                                                             ` roger peppe
2010-10-31  8:57                                                               ` Bruce Ellis
2010-10-31 10:25                                                                 ` fgergo
2010-10-31 11:11                                                                   ` fgergo
2010-10-31 11:21                                                                   ` Bruce Ellis
2010-10-31 11:23                                                                 ` roger peppe
2010-10-31 13:06                                                                   ` Gorka Guardiola [this message]
2010-10-31 13:07                                                                     ` Gorka Guardiola
2010-10-31 13:22                                                                       ` Gorka Guardiola
2010-11-02 14:29                                                                     ` Richard Miller
2010-10-31 14:21                                                               ` Eric Van Hensbergen
2010-10-31 22:17                                                                 ` Bruce Ellis
2010-10-31 22:32                                                                   ` EBo
2010-10-31 22:41                                                                   ` Steve Simon
2010-11-02 13:49                                                                   ` Richard Miller
2010-11-02 14:02                                                                     ` Eric Van Hensbergen
2010-10-29 18:27                                       ` David Leimbach
2010-10-29 17:18                                 ` Charles Forsyth
2010-10-29 17:17                                   ` erik quanstrom
2010-10-29 17:25                                     ` David Leimbach
2010-10-29 18:03                                   ` Eric Van Hensbergen
2010-10-29 18:54                                   ` Gorka Guardiola
2010-10-29 19:30                                     ` David Leimbach
2010-10-29 20:20                                     ` erik quanstrom
2010-10-29 15:55                         ` Venkatesh Srinivas
2010-10-29 13:12                     ` roger peppe
2010-10-29 13:20                       ` Lucio De Re
2010-10-29 15:51                       ` Charles Forsyth
2010-10-29 16:36                       ` Charles Forsyth
2010-10-27 15:09       ` David Leimbach
2010-10-28 21:39 erik quanstrom

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