Right now it only catches cases where we aren't initializing events,
or where we are re-initializing events without deleting them first.
These are however shockingly common.
Nothing in evrpc.c was using rpc_compat.h, so it's best to take it
out, especially since it polluted our build process with GCC variadic
macros.
While we're at it, this patch puts an extra restriction on when the
variadic macros in rpc_compat.h are defined. Not only must GCC be the
compiler, but GCC must not be running in -ansi mode.
The logic here is a little complex, since epoll_add must used called exactly
when no events were previously set, epoll_mod must be used when any events
were previously set, and epoll_del only called when the removing all events.
Most of these should be unable to fail, since adding a timeout
generally always works. Still, it's better not to try to be "too
smart for our own good here."
There are some remaining event_add() calls that I didn't add checks
for; I've marked those with "XXXX" comments.
Previously, we assumed that we would have setenv/unsetenv everywhere
but WIN32, where we could fake them with putenv. This isn't so: some
other non-windows systems lack setenv/unsetenv, and some of them lack
putenv too.
The first part of the solution, then, is to detect setenv/unsetenv/
putenv from configure.in, and to fake setenv/unsetenv with putenv
whenever we have the latter but not one of the former.
But what should we do when we don't even have putenv? We could do
elaborate tricks to manipulate the environ pointer, but since we're
only doing this for the unit tests, let's just skip the one test in
question that uses setenv/unsetenv.
If the user sets a bind address to use for nameservers, and a
nameserver happens to be on 127.0.0.1, the nameserver will generally
fail. This patch alters this behavior so that the bind address is
only applied when the nameserver is on a non-loopback address.
Once event_assign() or event_new() had been called, there was no way
to get at a copy of the event's callback, callback argument, or
configured events. This patch adds an accessor function for each, and
an all-fields accessor for code that wants to re-assign one field of
an event.
This patch also adds a function to return sizeof(struct event), so
that code with intense RAM needs can still retain ABI compatibility
between versions of Libevent without having to heap-allocate every
struct event individually.
The code here was first proposed by Pavel Pisa.
For what it's worth, we are aware that "Copyright $YEAR $NAME" is
sufficient notice of copyright on software under US law and
Internationally, and saying Copyright (c) $YEAR $NAME is a bit nutty.
The character sequence (c) has never been ruled to have the same force
in US law as the actual copyright symbol, and that neither of these
US-specific symbols adds anything of value beyond saying "Copyright"
since the Berne convention took effect in the US back in 1989.
Similarly, saying "all rights reserved" doesn't do anything magical
unless your software goes in a time-warp back to when the Buenos Aires
Convention was the general rule. (And what will they run it on back
then?) And what would even lead you to say "All Rights Reserved" when
you're explicitly granting most of those rights to anybody receiving
the work in accordance with the 3-clause BSD license?
But still the FOSS community retains these ritual notations out of a
kind of cargo-cult lawyering. Who knows? Perhaps one day, if we
write our copyright notices ineptly enough, John Frum will come and
give us a DFSG-compatible license that everybody can get behind.
(Also, I am not a lawyer. The above should not be taken as legal
advice. -- Nick)
Since we're no longer writing directly to it from add/del, we don't
need to worry about it changing as kq_dispatch releases the lock. We
would make it a local variable, except that we wouldn't want to malloc
and free it all the time.
This fixes a bug in kqueue identified by Charles Kerr and various
Transmission users, where adding and deleting an event in succession
would make the event get reported, even if we didn't actually want to
see it.
Of course, this also makes the array of changes passed to kevent
smaller, which could help performance.
This is necessary or useful for a few reasons:
1) Sometimes applications will add and delete the same event more
than once between calls to dispatch. Processing these changes
immediately is needless, and potentially expensive (especially
if we're on a system that makes one syscall per changed event).
Yes, this actually happens in practice for nonpathological
code, such as in cases where the user's callback conditionally
re-adds a non-persistent event, or where draining a buffer
turns off writing and invokes a user callback which adds more
data which in turn re-enabled writing.
2) Sometimes we can coalesce multiple changes on the same fd into
a single syscall if we know about them in advance. For
example, epoll can do an add and a delete at the same time, but
only if we have found out about both of them before we tell
epoll.
3) Sometimes adding an event that we immediately delete can cause
unintended consequences: in kqueue, this makes pending events
get reported spuriously.
Now that we have a generic listen-on-a-socket mechanism, there's no
longer any reason to have a separate listen-on-a-socket implementation
in http.c.
This also lets us use IOCP and AcceptEx() when they're enabled.
Possibly, we should have a new mechanism to add a socket given only a
listener.
This was as simple as using bufferevent_connect_hostname instead of
calling connect() ourself, which already knows how to use an
evdns_base if it gets one.
Untangling the bind code might be a little trickier.
Some systems have a version of /bin/sh whose builtin echo doesn't
support the -n option used in test/test.sh. /bin/echo, however,
usually does. This patch makes us use /bin/echo for echo -n whenever
it is present.
Also, our use of echo -n really only made sense when suppressing all
test output. Since test output isn't suppressed when logging to a
file, this pach makes us stop using echo -n when logging to a file.
This is a partial forward-port from 4fd2dd9d83a000b6. There's no need
to forward-port the bugfix, since the test passes with http.c as-is.
I believe we fixed this while we were porting evhttp to bufferevent.
--nickm
This is harder than it might initially seem, since the proper filename
depends on what the admin has decided to call the windows system directory,
which for all we know might be Q:\tralfamidore\slartibartfast. And of course,
this being windows, there are twelve ways to do it, where you can pick a
nice one or a portable one, but not a really nice portable one.
The regular blocking evutil_getaddrinfo() already supported /etc/hosts
by falling back to getaddrinfo() or gethostbyname(). But
evdns_getaddrinfo() had no such facility. Now it does.
The data structure here isn't very clever. I guess people with huge
/etc/hosts files will either need to get out of the 1980s, or submit a
patch to this code so that it uses a hashtable instead of a linked
list.
Includes basic unit tests.
Apparently some newer versions of mingw provide a fake pthreads api to
let applications work even if they don't know about windows threading.
That's nice, but we aren't one of those.
In many places throughout the code, we called _bufferevent_run_eventcb
without checking whether the eventcb was actually set. This would
work fine when the bufferevent's callbacks were deferred, but
otherwise the code would segfault. Strangely, we always remembered to
check before calling the _bufferevent_run_{read,write}cb functions.
To prevent similar errors in the future, all of
_buferevent_run_{read,write,event}cb now check to make sure the
callback is actually set before invoking or deferring the callback.
This patch also removes the now-redundant checks for {read,write}cb.
By default, the test.sh script still suppresses the output of all the
tests it invokes. Now, however, you can have that output written to
a file specified in the TEST_OUTPUT_FILE shell variable.
When we decide that a nameserver is down, we stop sending queries to
it, except to periodically probe it to see if it has come back up.
Our previous probe sechedule was an ad-hoc and hard-wired "10 seconds,
one minute, 5 minues, 15 minutes, 1 hour, 1 hour, 1 hour...". There
was nothing wrong with having it be ad-hoc, but making it hard-wired
served no good purpose.
Now the user can set the initial timeout via a new
"initial-probe-timeout:" option; future timeouts back off by a factor
of 3 on every failure to a maximum of 1 hour.
As a side-benefit, this lets us cut the runtime of the dns/retry test
from about 40 seconds to about 3 seconds. Faster unit tests are
always a good thing.
