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/[email protected]/ Unsubscribe: http://www.houseoffusion.com/index.cfm?sidebar=lists
