Ralf.Brown@B.GP.CS.CMU.EDU (08/01/90)
In article <jbf6cm79f@tmsoft.uucp>, mshiels@tmsoft.uucp (Michael A. Shiels) wrote: }Does DOS do it's own semaphoring with INT 2A AX=80xx/AX=81xx to ensure you }don't swap in the middle of a drive read/write? Not really. DOS protects a few sections of code that absolutely positively cannot be reentered. Much of the SHARE.EXE code consists of such critical sections--wouldn't want to interrupt the search whether a file is currently open with an open of that file, would we? However, DOS itself does not check the semaphores at all. That is left up to whatever software is doing the reentering (that software also has to maintain the semaphores itself). -- UUCP: {ucbvax,harvard}!cs.cmu.edu!ralf -=- 412-268-3053 (school) -=- FAX: ask ARPA: ralf@cs.cmu.edu BIT: ralf%cs.cmu.edu@CMUCCVMA FIDO: 1:129/3.1 Disclaimer? | I was gratified to be able to answer promptly, and I did. What's that? | I said I didn't know. --Mark Twain
mshiels@tmsoft.uucp (Michael A. Shiels) (08/02/90)
Does DOS do it's own semaphoring with INT 2A AX=80xx/AX=81xx to ensure you don't swap in the middle of a drive read/write?