This makes it possible to run tests that need access to installation
directories, such as the rundir, without having access to the actual
installation directories (/var/run is generally not world-writable), by
setting environment variables. This is not a good way to do things in
general--usually it would be better to choose the correct directories
at configure time--so for now this is undocumented.
If a process daemonizes itself, then it should be possible to control that
process's log levels with "ovs-appctl vlog/set" and related commands. The
vlog_init() function registers those commands. But vlog_init() doesn't
normally get called until the first log message is issued. This can take a
while, especially for ovs-controller, where I first noticed the problem.
This commit fixes the problem by calling vlog_init() from
daemonize_start(), which always gets called as a process daemonizes.
Commit 480ce8ab "vlog: Make the vlog module catalog program-specific."
accidentally inverted the logic in this function, which broke the "-v"
to various OVS programs as well as other mechanisms to set logging to
non-default levels.
Until now, the collection of vlog modules supported by a given OVS program
was not specific to that program. That means that, for example, even
though ovs-dpctl does not have anything to do with jsonrpc, it still has
a vlog module for it. This is confusing, at best.
This commit fixes the problem on some systems, in particular on ones that
use GCC and the GNU linker. It uses the feature of the GNU linker
described in its manual as:
If an orphaned section's name is representable as a C identifier then
the linker will automatically see PROVIDE two symbols: __start_SECNAME
and __end_SECNAME, where SECNAME is the name of the section. These
indicate the start address and end address of the orphaned section
respectively.
Systems that don't support these features retain the earlier behavior.
This commit also fixes the annoyance that modifying lib/vlog-modules.def
causes all sources files that #include "vlog.h" to recompile.
Adding a macro to define the vlog module in use adds a level of
indirection, which makes it easier to change how the vlog module must be
defined. A followup commit needs to do that, so getting these widespread
changes out of the way first should make that commit easier to review.
It's more convenient if clients don't have to initialize modules
explicitly.
The most important part of this change is to initialize the default
log levels statically. Previously, by initializing log levels only
from vlog_init(), all the log levels appeared to be VLL_EMER (0) if
vlog_init() was accidentally not called at all. This was not intended
behavior, so this commit fixes it.
This commit also fixes up a few test programs whose tests accidentally
depended on this behavior, by making them explicitly turn off log
messages that were implicitly turned off before.
Most of the timekeeping needs of OVS are simply to measure intervals,
which means that it is sensitive to changes in the clock. This commit
replaces the existing clocks with monotonic timers. An additional set
of wall clock timers are added and used in locations that need absolute
time.
Bug #1858
