I don't think it's any more ill-behaved than any other high-level mechanism (like FileScriptingObject) when it comes to manipulating files when there may be contention from multiple sources. It really boils down to knowing who else needs access to the file, and how that interface functions.
----- Original Message ----- From: "Jim McAtee" <[EMAIL PROTECTED]> To: "CF-Talk" <[EMAIL PROTECTED]> Sent: Tuesday, January 08, 2002 12:06 PM Subject: Re: CFLOCK on files > I'm clear on the fact that CFLOCK and CFFILE are independent of one another. > Originally, I was hoping there was an outside chance that CF might enforce > system level file locking when a CFFILE operation was contained within a > CFLOCK. > > I'm also completely clear on the benefits of using CFLOCK's around CFFILE > operations and am aware that those locks are only recognized and for the > benefit of the CF application server itself. > > If CFFILE is really as ill-behaved as everyone says, then that has at a > least a few implications for its use and usefulness. > > Jim > > > ----- Original Message ----- > From: "Billy Cravens" <[EMAIL PROTECTED]> > To: "CF-Talk" <[EMAIL PROTECTED]> > Sent: Tuesday, January 08, 2002 10:32 AM > Subject: Re: CFLOCK on files > > > > Note that CFLock is totally indepedent of file locking. CFLock only locks > a > > block of code within a particular context within CF. I was under the > > impression that the other "service" Jim was referring to wasn't > necessarily > > a CF application, in which case CFLock would have absolutely ZERO affect > on > > access to the file. > > > > My recommendation: when dealing with files in use by third-party > > applications, things tend to get really messy. (I had a bad experience > > trashing a FoxPro database in use by a legacy POS system once) I'd > recommend > > forgoing CFFile altogether, and write a COM object that uses the Win32 API > > to look at the status of the file, and behaves accordingly. > > > > > > ----- Original Message ----- > > From: "Chris Norloff" <[EMAIL PROTECTED]> > > To: "CF-Talk" <[EMAIL PROTECTED]> > > Sent: Tuesday, January 08, 2002 11:12 AM > > Subject: Re: CFLOCK on files > > > > > > > I wouldn't count on there being any automatic file locking with > operations > > > like cffile. For our use of cffile, we use it inside named locks that > > prev > > > ent multiple simultaneous accesses to error log files we generate. This > > ha > > > s worked well, even with busy error logging with many users ...<sigh>. > > > > > > So you might be able to get by without an explicit lock, but it's one of > > th > > > e first places I'd look if there's problems with cfserver stability. > > > > > > best, > > > Chris Norloff > > > > > > BTW, we learned the hard way that when cffile does an action=append, it > a > > > ctually reads the ENTIRE file into memory, then appends the new info, > then > > > writes the entire file to the disk. So watch your file size and your > > avail > > > able memory ... > > > > > > > > > ---------- Original Message ---------------------------------- > > > from: Jim McAtee <[EMAIL PROTECTED]> > > > Reply-To: [EMAIL PROTECTED] > > > date: Tue, 8 Jan 2002 09:53:12 -0700 > > > > > > >Even if you can't explicitly lock a file during a CFFILE operation... > If > > C > > > F > > > >uses system-level function calls to read and write files (that must be > > why > > > > > > >it's capable of being locked out of a file when another application has > > it > > > > > > >locked), then you would think that during a CF file write operation, > the > > O > > > S > > > >must place a lock on the file. Or no? > > > > > > > >The reason I brought up the point in the first place is that I need to > > rea > > > d > > > >and write a large number of small text files that are in use by > another, > > > >very busy service. I'm hoping that by doing so, I wouldn't be causing > > > >problems for that application, or for CF itself. > > > > > > > >Jim > > > > > > > > > > > >----- Original Message ----- > > > >From: "Jochem van Dieten" <[EMAIL PROTECTED]> > > > >To: "CF-Talk" <[EMAIL PROTECTED]> > > > >Sent: Monday, January 07, 2002 5:24 PM > > > >Subject: Re: CFLOCK on files > > > > > > > > > > > >> Kelly Matthews wrote: > > > >> > > > >> > as far as I know it's not something that can be done. CFLOCK is > > strict > > > ly > > > >for > > > >> > sessions, etc. > > > >> > > > >> > > > >> CFLOCK is for single threading CF. Whatever you do inside that single > > > >> threaded application is not of CFs concern. > > > >> > > > >> > > > >> > CFFILE doesn't allow you to add a system level lock on a file nor > > > >release a > > > >> > lock. > > > >> > > > >> > > > >> Unfortunately not. > > > >> > > > >> Jochem > > > > > > > > > > ______________________________________________________________________ Get Your Own Dedicated Windows 2000 Server PIII 800 / 256 MB RAM / 40 GB HD / 20 GB MO/XFER Instant Activation · $99/Month · Free Setup http://www.pennyhost.com/redirect.cfm?adcode=coldfusionb FAQ: http://www.thenetprofits.co.uk/coldfusion/faq Archives: http://www.mail-archive.com/cf-talk@houseoffusion.com/ Unsubscribe: http://www.houseoffusion.com/index.cfm?sidebar=lists
