On 4/11/2011 2:13 PM, Masayoshi Okutsu wrote:
Probably the difference isn't documented. I tried Solaris 10 and Ubuntu
10.03. The difference still exists.
Solaris 10:
$ unset TZ
$ date
Fri Nov 4 13:04:45 JST 2011
$ TZ="" date
Fri Nov 4 13:04:53 JST 2011
Ubuntu 10.04:
$ unset TZ
$ date
Fri Nov 4 13:05:50 JST 2011
$ TZ="" date
Fri Nov 4 04:05:55 UTC 2011
When the TZ value is an empty string, Ubuntu uses UTC while Solaris
still looks up the system default.
I have to take back my comment regarding this not seeming to be platform
specific code - it is highly platform specific! It seems that on Linux
we are happy to report a TZ of "" but not so on Solaris. I presume this
is an attempt to keep Java's use of TZ consistent with how other apps
handle it on that platform. (environ(5) gives a little insight on
Solaris as to how TZ is used.)
So the key thing here is to not disturb the existing behaviour on either
linux or Solaris - which suggests the original patch. That said I'm not
convinced - given this is so platform specific - that simply treating
non-linux the same as Solaris is a reasonable thing to do. I think it
would be useful to see what the BSD/OSX port(s) had to do with this code
- if anything.
David
-----
Thanks,
Masayoshi
On 11/3/2011 4:16 PM, Jonathan Lu wrote:
Hi Masayoshi,
I did find some references about date-time related functions / TZ
variables on Linux but got only a few about Solaris, so could not see
any differences between those two platforms about the changes
described in my patch. Have you got any links or references about
these differences? I'm interested in it and may update the patch again
after reading them.
Thanks a lot!
- Jonathan
On 11/02/2011 10:27 PM, Masayoshi Okutsu wrote:
Hi Jonathan,
IIRC, the difference came from some behavioral difference between the
Linux and Solaris libc date-time functions and/or the date command,
and TimeZone_md.c tries to follow the difference. But the code was
written looooong ago. The difference may no longer exist.
Thanks,
Masayoshi
On 11/2/2011 8:39 PM, Jonathan Lu wrote:
On 11/02/2011 07:00 PM, David Holmes wrote:
On 2/11/2011 7:01 PM, Jonathan Lu wrote:
On 11/02/2011 04:56 PM, Jonathan Lu wrote:
Hi core-libs-dev,
In jdk/src/solaris/native/java/util/TimeZone_md.c, starting from
line
626, I found that the scope of "#ifdef __solaris__" might be too
narrow, since it also works for some kind of OS which I'm currently
working on, such as AIX.
So I suggest to just remove the '#ifdef __solaris__' and leave the
"#else" to accommodate more conditions, see attachment
'patch.diff'. I
think this may enhance the cross-platform ability, any ideas about
this modification?
Regards
- Jonathan Lu
I'm not sure why the attachment got filtered, here paste it to the
mail
content directly.
diff -r 4788745572ef src/solaris/native/java/util/TimeZone_md.c
--- a/src/solaris/native/java/util/TimeZone_md.c Mon Oct 17 19:06:53
2011 -0700
+++ b/src/solaris/native/java/util/TimeZone_md.c Thu Oct 20 13:43:47
2011 +0800
@@ -626,10 +626,8 @@
#ifdef __linux__
if (tz == NULL) {
#else
-#ifdef __solaris__
if (tz == NULL || *tz == '\0') {
#endif
-#endif
tz = getPlatformTimeZoneID();
freetz = tz;
}
I'm unclear why any of that code needs to be platform specific - is
an empty TZ string somehow valid on linux? I would have thought the
following would be platform neutral:
if (tz == NULL || *tz == '\0') {
tz = getPlatformTimeZoneID();
freetz = tz;
}
Hi David,
getenv("TZ") returns NULL when TZ environment variable is not set at
all and returns '\0' when TZ was exported as empty string. After
more checking for both cases, I agree with you, nothing useful can
be retrieved from that environment variable.
So I changed the patch to this,
diff -r 7ab0d613cd1a src/solaris/native/java/util/TimeZone_md.c
--- a/src/solaris/native/java/util/TimeZone_md.c Thu Oct 20 10:32:47
2011 -0700
+++ b/src/solaris/native/java/util/TimeZone_md.c Wed Nov 02 19:34:51
2011 +0800
@@ -623,13 +623,7 @@
tz = getenv("TZ");
-#ifdef __linux__
- if (tz == NULL) {
-#else
-#ifdef __solaris__
if (tz == NULL || *tz == '\0') {
-#endif
-#endif
tz = getPlatformTimeZoneID();
freetz = tz;
}
David
-----
Regards
- Jonathan Lu
Regards
- Jonathan
