Although bufferevent operations are threadsafe, sometimes you need
to make sure that a few operations on a single bufferevent will all
be executed with nothing intervening. That's what these functions
are for.
The different bufferevent implementations had different behavior for
their timeouts. Some of them kept re-triggering the timeouts
indefinitely; some disabled the event immediately the first time a
timeout triggered. Some of them made the timeouts only count when
the bufferevent was actively trying to read or write; some did not.
The new behavior is modeled after old socket bufferevents, since
they were here first and their behavior is relatively sane.
Basically, each timeout disables the bufferevent's corresponding
read or write operation when it fires. Timeouts are stopped
whenever we suspend writing or reading, and reset whenever we
unsuspend writing or reading. Calling bufferevent_enable resets a
timeout, as does changing the timeout value.
We need these for Tor, and other projects probably need them too. Uses
include:
- Checking whether bandwidth is mostly-used, and only taking some
actions when there's plenty of bandwidth.
- Deducting some non-bufferevent activities from a rate-limit group.
It turns out that absolutely everything that was including
windows.h was doing so needlessly; our headers don't need it,
so we should just include winsock2.h (since that's where
struct timeval is defined).
Pre-2.0 code will use the old headers, which include windows.h
for them, so we aren't breaking source compatibility with 1.4.
This solves the bug where we were leaving WIN32_LEAN_AND_MEAN
defined, in roughly the same way that buying an automobile
solves the question of what to give your coachman for boxing
day.
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.
The fairness algorithms are not the best, not every bufferevent type
is supported, and some of the locking tricks here are simply absurd.
Still, this code should be a good first step.
This function, bufferevent_socket_connect_hostname() can either use
evdns to do the resolve, or use a new function (evutil_resolve) that
uses getaddrinfo or gethostbyname, like http.c does now.
This function is meant to eventually replace the hostname resolution mess in
http.c.
svn:r1496
This makes our interfaces usable from C++, which doesn't believe
you can say "bufferevent_socket_nase(base, -1,
BEV_OPT_CLOSE_ON_FREE|BEV_OPT_DEFER_CALLBACKS)" but which instead
would demand "static_cast<bufferevent_options>(BEV_OPT_CLOSE_ON_FREE|
BEV_OPT_DEFER_CALLBACKS))" for the last argument.
Diagnosis and patch from Chris Davis.
svn:r1456
Original message from SF patch 2797966:
While commas at the end of enumerator lists are valid in c99, they
are not valid +in c89 nor in c++. When using gcc/g++ with the
-pedantic flag, users will +receive a warning (gcc) or an
error(g++) when including the event2/event.h and
+event2/bufferevent.h. The errors look something like
event2/event.h:159: error: comma at end of enumerator list
Patch from Akita Noek on Sourceforge.
svn:r1321
OpenSSL uses something like this to implement get/set access for
properties on its BIOs, so that it doesn't need to add a pair of
get/set functions to the vtable struct for every new abstract property
it provides an accessor for.
Doing this lets us make bufferevent_setfd abstract, and implement an
abstract bufferevent_getfd.
svn:r1284
This is a bit of an interface doozy, but it's really needed in order
to be able to document this stuff without apologizing it. This patch
does the following renamings:
evbuffercb -> bufferevent_data_cb
everrorcb -> bufferevent_event_cb
EVBUFFER_(READ,WRITE,...) -> BEV_EVENT_(...)
EVBUFFER_(INPUT,OUTPUT) -> bufferevent_get_(input,output)
All the old names are available in event2/bufferevent_compat.h
svn:r1283
This is stuff that it's easy to get wrong (as I noticed when writing
bench_http), and that takes up a fair amount of space (see http.c).
Also, it's something that we'll eventually want to abstract to use
IOCP, where available.
svn:r1272
The new bufferevent_pair abstraction works like a set of buferevent_sockets
connected by a socketpair, except that it doesn't require a socketpair,
and therefore doesn't need to get the kernel involved.
It's also a good way to make sure that deferred callbacks work. It's a good
use case for deferred callbacks: before I implemented them, the recursive
relationship between the evbuffer callback and the read callback would
make the unit tests overflow the stack.
svn:r1152
a) this is 2009
b) niels and nick have been comaintainers for a while
c) saying "all rights reserved" when you then go on to explicitly
disclaim some rights is sheer cargo-cultism.
svn:r1065
Stop pretending that u_char and u_short are standard types that win32 is dumb not to have. In fact, u_char can really just be spelled out, and u_short was usually just a bad way of saying ev_uint16_t.
svn:r808
