http://www.read.cs.ucla.edu/111/ 2008-09-07T17:51:59-07:00 http://www.read.cs.ucla.edu/111/ http://www.read.cs.ucla.edu/111/lib/images/favicon.ico text/html 2007-12-15T17:16:25-07:00 Timur Shevekhman http://www.read.cs.ucla.edu/111/notes/lec14?rev=1197767785&do=diff by Angel Darquea, Kristie Van, and Chris Wible File System Robustness (Continued) Failure Models Things were made to be broken, or at least, to last a long time before they are broken. In Lecture 13 we were introduced to the Golden Rule of Atomicity and the concept of operating systems journaling. Journaling added to the robustness of the file system and greatly improved recovery from a crash but still relied on the assumption that the actual disk never fails completely and catastrophically … text/html 2007-12-15T16:29:15-07:00 Timur Shevekhman http://www.read.cs.ucla.edu/111/notes/lec17?rev=1197764955&do=diff Server Utilization and Robustness Nicholas Brown, Steven Snyder, Rob Green, Huy Le, Timur Shevekhman It is recommended that you review the concept of RPCs before reading on. Serial Programming The server outline pseudocode below is reprinted from the previous lecture's introduction to distributed systems, and is an example of serial programming. This server is a remote procedure call server; it proccesses RPC requests from clients, performs the required actions, and returns a response messag… text/html 2007-12-13T11:26:56-07:00 Eddie Kohler http://www.read.cs.ucla.edu/111/notes/lec9?rev=1197574016&do=diff by Nazia Habib, Jeffrey Tan, and Michael Vysin Synchronization II Pipe Buffer Consider a process P2 that reads what another process P1 writes. Since this pipe can only handle one transfer at a time, the following situation will occur: * P1 blocks until P2 reads from it. * When P2 reads, it copies characters from P1’s memory into its memory. * P1 restarts when its characters are copied by P2. text/html 2007-12-12T23:32:34-07:00 Alan Chao http://www.read.cs.ucla.edu/111/notes/lec18?rev=1197531154&do=diff By: Bumhwan Cha, Alan Chao, Dan Hirsch, Juan M. Navarro, Charles Roh Quiz Questions 1. There exists a UNIX feature called "close-on-exec" file descriptor. Such a file descriptor is closed on * fork() * getpid() * xor instruction * exec() text/html 2007-12-12T19:14:46-07:00 Chris Clark http://www.read.cs.ucla.edu/111/notes/lec15?rev=1197515686&do=diff By Chang-Hung Chiang, Chris Clark, and Albert Chern Overview Last lecture we began discussing virtual memory. Let's recap and see how it works. The diagram below illustrates how a virtual address is stored and located in physical memory. We are given the virtual address of 0x00901050. The way we interpret this value is by dividing it into three distinct indices: