Commit Graph

20 Commits

Author SHA1 Message Date
Daniel P. Berrangé
600462834f Remove all Author(s): lines from source file headers
In many files there are header comments that contain an Author:
statement, supposedly reflecting who originally wrote the code.
In a large collaborative project like libvirt, any non-trivial
file will have been modified by a large number of different
contributors. IOW, the Author: comments are quickly out of date,
omitting people who have made significant contribitions.

In some places Author: lines have been added despite the person
merely being responsible for creating the file by moving existing
code out of another file. IOW, the Author: lines give an incorrect
record of authorship.

With this all in mind, the comments are useless as a means to identify
who to talk to about code in a particular file. Contributors will always
be better off using 'git log' and 'git blame' if they need to  find the
author of a particular bit of code.

This commit thus deletes all Author: comments from the source and adds
a rule to prevent them reappearing.

The Copyright headers are similarly misleading and inaccurate, however,
we cannot delete these as they have legal meaning, despite being largely
inaccurate. In addition only the copyright holder is permitted to change
their respective copyright statement.

Reviewed-by: Erik Skultety <eskultet@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2018-12-13 16:08:38 +00:00
Erik Skultety
9403b63102 internal: Move <stdio.h> include to internal.h
It doesn't really make sense for us to have stdlib.h and string.h but
not stdio.h in the internal.h header.

Signed-off-by: Erik Skultety <eskultet@redhat.com>
Acked-by: Michal Privoznik <mprivozn@redhat.com>
2018-09-20 10:16:38 +02:00
Michal Privoznik
67dcb797ed virTimeBackOffWait: Avoid long periods of sleep
While connecting to qemu monitor, the first thing we do is wait
for it to show up. However, we are doing it with some timeout to
avoid indefinite waits (e.g. when qemu doesn't create the monitor
socket at all). After beaa447a29 we are using exponential back
off timeout meaning, after the first connection attempt we wait
1ms, then 2ms, then 4 and so on.  This allows us to bring down
wait time for small domains where qemu initializes quickly.
However, on the other end of this scale are some domains with
huge amounts of guest memory. Now imagine that we've gotten up to
wait time of 15 seconds. The next one is going to be 30 seconds,
and the one after that whole minute. Well, okay - with current
code we are not going to wait longer than 30 seconds in total,
but this is going to change in the next commit.

The exponential back off is usable only for first few iterations.
Then it needs to be caped (one second was chosen as the limit)
and switch to constant wait time.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2017-03-16 09:21:39 +01:00
Richard W.M. Jones
beaa447a29 Add functions for handling exponential backoff loops.
In a few places in libvirt we busy-wait for events, for example qemu
creating a monitor socket.  This is problematic because:

 - We need to choose a sufficiently small polling period so that
   libvirt doesn't add unnecessary delays.

 - We need to choose a sufficiently large polling period so that
   the effect of busy-waiting doesn't affect the system.

The solution to this conflict is to use an exponential backoff.

This patch adds two functions to hide the details, and modifies a few
places where we currently busy-wait.

Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
2016-04-15 16:54:28 +01:00
Cédric Bosdonnat
90712bb5c0 Renamed internal __mon_yday into mon_yday to avoid conflicts
libc has another constant with the same name, which leads to
redefinition error when building against static libvirt
2014-10-28 14:44:18 -06:00
John Ferlan
f26e6397b3 virtime: Resolve Coverity DEADCODE
Coverity complains that because of how 'offset' is initialized to
0 (zero), the resulting math and comparison on rem is pointless.

According to the origin commit id '3ec128989', the code is a
replacement for gmtime(), but without the localtime() or GMT
calculations - so just remove this code and add a comment
indicating the removal
2014-09-15 10:44:27 -04:00
James
febfe83721 util: virTimeFieldsThenRaw never returns negative
virTimeFieldsThenRaw will never return negative result, so I clean up
the related meaningless judgements to make it better.

Signed-off-by: James <james.wangyufei@huawei.com>
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-07-25 12:06:07 +02:00
Laine Stump
26d43113a3 util: fix virTimeLocalOffsetFromUTC DST processing
The original version of virTimeLocalOffsetFromUTC() would fail for
certain times of the day if daylight savings time was active. This
could most easily be seen by uncommenting the TEST_LOCALOFFSET() cases
that include a DST setting.

After a lot of experimenting, I found that the way to solve it in
almost all test cases is to set tm_isdst = -1 in the struct tm prior
to calling mktime(). Once this is done, the correct offset is returned
for all test cases at all times except the two hours just after
00:00:00 Jan 1 UTC - during that time, any timezone that is *behind*
UTC, and that is supposed to always be in DST will not have DST
accounted for in its offset.

I believe that the code of virTimeLocalOffsetFromUTC() actually is
correct for all cases, but the problem still encountered is due to our
inability to come up with a TZ string that properly forces DST to
*always* be active. Since a modfication of the (currently fixed)
expected result data to account for this would necessarily use the
same functions that we're trying to test, I've instead just made the
test program conditionally bypass the problematic cases if the current
date is either December 31 or January 1. This way we get maximum
testing during 363 days of the year, but don't get false failures on
Dec 31 and Jan 1.
2014-05-29 10:37:49 +03:00
Laine Stump
1cddaea7ae util: new function virTimeLocalOffsetFromUTC
Since there isn't a single libc API to get this value, this patch
supplies one which gets the value by grabbing current time, then
converting that into a struct tm with gmtime_r(), then back to a
time_t using mktime.

The returned value is the difference between UTC and localtime in
seconds. If localtime is ahead of UTC (east) the offset will be a
positive number, and if localtime is behind UTC (west) the offset will
be negative.

This function should be POSIX-compliant, and is threadsafe, but not
async signal safe. If it was ever necessary to know this value in a
child process, we could cache it with a one-time init function when
libvirtd starts, then just supply the cached value, but that
complexity isn't needed for current usage; that would also have the
problem that it might not be accurate after a local daylight savings
boundary.

(If it weren't for DST, we could simply replace this entire function
with "-timezone"; timezone contains the offset of the current timezone
(negated from what we want) but doesn't account for DST. And in spite
of being guaranteed by POSIX, it isn't available on older versions of
mingw.)

Signed-off-by: Eric Blake <eblake@redhat.com>
2014-05-26 13:51:05 +03:00
Michal Privoznik
a2f8babc7d Adapt to VIR_ALLOC and virAsprintf in src/util/* 2013-07-10 11:07:33 +02:00
Michal Privoznik
7c9a2d88cd virutil: Move string related functions to virstring.c
The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.
2013-05-02 16:56:55 +02:00
Daniel P. Berrange
f24404a324 Rename virterror.c virterror_internal.h to virerror.{c,h} 2012-12-21 11:19:50 +00:00
Daniel P. Berrange
44f6ae27fe Rename util.{c,h} to virutil.{c,h} 2012-12-21 11:19:49 +00:00
Daniel P. Berrange
ab9b7ec2f6 Rename memory.{c,h} to viralloc.{c,h} 2012-12-21 11:17:14 +00:00
Daniel P. Berrange
1c04f99970 Remove spurious whitespace between function name & open brackets
The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-11-02 13:36:49 +00:00
Eric Blake
4ecb723b9e maint: fix up copyright notice inconsistencies
https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.

* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/;  If/.  If/
2012-09-20 16:30:55 -06:00
Eric Blake
d74e5a4dfc build: use correct libraries for clock_gettime
On OpenBSD, clock_gettime() exists in libc rather than librt, and
blindly linking with -lrt made the build fail.  Gnulib already
did the work for determining which libraries to use, so we should
reuse that work rather than doing it ourselves.

* bootstrap.conf (gnulib_modules): Pull in clock-time.
* configure.ac (RT_LIBS): Drop.
* src/Makefile.am (libvirt_util_la_LIBADD): Use gnulib variable
instead.
* src/util/virtime.c (includes): Simplify.
2012-09-04 10:57:25 -06:00
Osier Yang
f9ce7dad60 Desert the FSF address in copyright
Per the FSF address could be changed from time to time, and GNU
recommends the following now: (http://www.gnu.org/licenses/gpl-howto.html)

  You should have received a copy of the GNU General Public License
  along with Foobar.  If not, see <http://www.gnu.org/licenses/>.

This patch removes the explicit FSF address, and uses above instead
(of course, with inserting 'Lesser' before 'General').

Except a bunch of files for security driver, all others are changed
automatically, the copyright for securify files are not complete,
that's why to do it manually:

  src/security/security_selinux.h
  src/security/security_driver.h
  src/security/security_selinux.c
  src/security/security_apparmor.h
  src/security/security_apparmor.c
  src/security/security_driver.c
2012-07-23 10:50:50 +08:00
Daniel P. Berrange
b0ed12276e Don't use undocumented __isleap macro
The glibc time.h header has an undocumented __isleap macro
that we are using. Since it is undocumented & does not appear
on any other OS, stop using it and just define the macro in
libvirt code instead.

* src/util/virtime.c: Remove __isleap usage
2011-12-01 13:28:44 +00:00
Daniel P. Berrange
3ec1289896 Add internal APIs for dealing with time
The logging APIs need to be able to generate formatted timestamps
using only async signal safe functions. This rules out using
gmtime/localtime/malloc/gettimeday(!) and much more.

Introduce a new internal API which is async signal safe.

  virTimeMillisNowRaw replacement for gettimeofday. Uses clock_gettime
                      where available, otherwise falls back to the unsafe
                      gettimeofday

  virTimeFieldsNowRaw  replacements for gmtime(), convert a timestamp
  virTimeFieldsThenRaw into a broken out set of fields. No localtime()
                       replacement is provided, because converting to
                       local time is not practical with only async signal
                       safe APIs.

  virTimeStringNowRaw  replacements for strftime() which print a timestamp
  virTimeStringThenRaw into a string, using a pre-determined format, with
                       a fixed size buffer (VIR_TIME_STRING_BUFLEN)

For each of these there is also a version without the Raw postfix
which raises a full libvirt error. These versions are not async
signal safe

* src/Makefile.am, src/util/virtime.c, src/util/virtime.h: New files
* src/libvirt_private.syms: New APis
* configure.ac: Check for clock_gettime in -lrt
* tests/virtimetest.c, tests/Makefile.am: Test new APIs
2011-11-30 11:43:49 +00:00