Jason P Sage wrote: > I read an old thread about how to make temporary filenames (unique > filenames . . > My algorithm is platform independent but I know my technique may be > frowned > upon by many but it works. > > I create a file called something intuitive: counterlockfile.lock > > Each call to my unit TRIES to open the file for REWRITE - if it can't > (because another process has it - then it retries a few times with a > sleep/yield call and both the repeat attempts and sleep duration are > configurable. . .
Actually, I don't think your solution really is platform independent. The main reason for that is that file locking doesn't work the same way on different platforms, so in fact you can have 2 processes having the same file open for writing on some platforms. In addition to that, your approach doesn't seem to be very efficient from my point of view, because it implies additional disk accesses. Furthermore, it only works across programs created with the same unit, whereas other programs not using your unit (and possibly not created with FPC at all) could easily create files with the same name, thus uniqueness is not really guaranteed. SysUtils.GetTempFileName is supposed to provide you with such filename, but the appropriate platform specific implementation for GO32v2 is currently missing (i.e. only general version not necessarily guaranteeing uniqueness is in place). I guess I could fix that, because the appropriate API is provided by DOS, but I'd need to check the real implementation to make sure that it really works properly for multiple emulated DOS virtual DOS machines/sessions running under a different operating system. Tomas _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
