Path: utzoo!attcan!uunet!husc6!purdue!umd5!mimsy!chris From: chris@mimsy.UUCP (Chris Torek) Newsgroups: comp.unix.wizards Subject: Re: Is write(2) "atomic" ? Message-ID: <12424@mimsy.UUCP> Date: 12 Jul 88 21:18:45 GMT References: <11410005@eecs.nwu.edu> <23801@bu-cs.BU.EDU> Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742 Lines: 13 In article <23801@bu-cs.BU.EDU> bzs@bu-cs.BU.EDU (Barry Shein) writes: >I think the result is indeterminate (undefined), a few experiments >here on various systems came up with some even stranger results .... It is certainly not well-defined. 4BSD makes writes to regular files and block special files atomic by locking the inode across the write() call. Character devices like terminals tend to be written atomically only when the number of characters written fits in a cblock. Appending by lseek/write (rather than FAPPEND) has a race between the lseek and the write, and so forth. -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163) Domain: chris@mimsy.umd.edu Path: uunet!mimsy!chris