Emacs 64-bit ahead of its time: clock skew

[Markus Hoenicka]

Hi,

once in a while make complains that some of my files have timestamps in 
the future. I've investigated a little, and it seems that this affecs 
only files which I save from Emacs. The following script reproduces the 
problem (run it in an empty directory, especially sample.txt must not 
exist):

#!/bin/sh
emacs -batch sample.txt -f save-buffer
touch sample2.txt
date
ls -al --full-time
uname -a

The emacs command simply creates an empty buffer and writes it to disk. 
This is comparable to what touch does if the file does not exist.
I get the following output:

$ ./clockskewtest.sh
Wrote 
/home/markus.hoenicka/workspace/emacs-bug/20140731clockskew/sample.txt
Thu, Jul 31, 2014  2:21:06 PM
total 18
drwxr-xr-x+ 1 markus.hoenicka Domänen-Benutzer   0 2014-07-31 
14:21:34.333524000 +0200 .
drwxr-xr-x+ 1 markus.hoenicka Domänen-Benutzer   0 2014-07-31 
14:15:24.354636000 +0200 ..
-rwxr--r--+ 1 markus.hoenicka Domänen-Benutzer 101 2014-07-31 
14:21:25.918416000 +0200 clockskewtest.sh
-rwxr--r--+ 1 markus.hoenicka Domänen-Benutzer  92 2014-07-31 
14:18:39.592771000 +0200 clockskewtest.sh~
-rw-r--r--+ 1 markus.hoenicka Domänen-Benutzer   0 2014-07-31 
14:21:34.265547000 +0200 sample.txt
-rw-r--r--+ 1 markus.hoenicka Domänen-Benutzer   0 2014-07-31 
14:21:06.315410800 +0200 sample2.txt
CYGWIN_NT-6.1 SBHC123 1.7.31s(0.273/5/3) 20140709 12:14:54 x86_64 Cygwin

Please note that the file created by Emacs is about 28 seconds in the 
future. These 28 s seem to be reproducible in consecutive runs of this 
script. I wonder if this is related in some way to the random and quite 
rare crashes which I reported previously, see this thread:

https://groups.google.com/forum/#!topic/gnu.emacs.bug/cR3wgNDxVzA

In many of those backtraces references to some function run_timers() in 
atime.c pop up. Just wondering.

regards,
Markus

-- 
Markus Hoenicka
http://www.mhoenicka.de
AQ score 38


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