Previously, the be5_outcome field for the dns error would be set to
something dependent on our system resolver. It turns out that you
can't rely on nameservers to really give you an NEXIST answer for
xyz.example.com nowadays: too many of them are annoyingly broken and
like to redirect you to their locked-in portals. This patch changes
the bufferevent_connect_hostname test so that it makes sure that the
dns_error of be5_outcome is "whatever you would get from resolving
the target hostname"
Importantly, we don't actually want to call evbuffer_write() when
the buffer is empty. This makes it an error to ever get a -1 return
value from evbuffer_add_file(), which makes it safe for us to test
the return value.
The "current_base" symbol was never actually declared in an exported
header; it's hideously deprecated, and it was the one remaining
exported symbol (fwict) that was prefixed with neither ev nor
bufferevent nor _ev nor _bufferevent.
codesearch.google.com turns up no actual attempts to use our
current_base from outside libevent.
Of the backends that support edge-triggered IO, most (all?) do not
support attempts to mix edge-triggered and level-triggered IO on the
same FD. With debugging mode enabled, we now detect and refuse attempts
to add a level-triggered IO event to an fd that already has an
edge-triggered IO event, and vice versa.
The old logging code was littered with places where we stored messages in
static char[] fields. This is fine in a single-threaded program, but if you
ever tried to log evdns messages from two threads at once, you'd hit a race.
This patch also refactors evdns's debug_ntop function into a more useful
evutil_sockaddr_port_format() function, with unit tests.
The EVUTIL_CLOSESOCKET() macro required you to include unistd.h in your
source for POSIX. We might as well turn it into a function: an extra
function call is going to be cheap in comparison with the system call.
We retain the EVUTIL_CLOSESOCKET() macro as an alias for the new
evutil_closesocket() function.
(commit message from email by Nick and Sebastian)
The previous evbuffer_expand was not only incorrect; it was
inefficient too. On all questions of time vs memory tradeoffs, it
chose to burn time in order to avoid wasting memory. The new code
tries to be a little more balanced: it only resizes an existing chain
when doing so doesn't require too much copying, and when failing to do
so would waste a lot of the chain's space.
This patch also rewrites evbuffer_chain_insert to work properly with
last_with_datap, and adds a few convenience functions to buffer.c.
To implement evbuffer_expand() properly, you need to be able to
replace the last chunk that has data, which means that we need to keep
track of the the next pointer pointing to the last_with_data chunk,
not the last_with_data chunk itself.
Calling event_base_loop on a base from inside a callback invoked by
that same base, or from two threads at once, has long been a way to
get exceedingly hard-to-diagnose errors. This patch adds code to
detect such reentrant invocatinos, and exit quickly with a warning
that should explain what went wrong.
This is mainly intended to ensure that we don't get hung up on
the 64-handle limit that lots of O(n) Windows functions (but FWICT
not select) like to enforce.
We were using the same bufferevent as the child of two filtering parents,
orphaning another. This made one get freed twice, and the other not at all.
Possible fix for bug 2963306 spotted by Doug Cuthbertson.
This actually makes some of the code a lot simpler. The only
ones that actually used previous_to_last for anything were reserving
and committing space.
This is the first patch in a series to replace previous_to_last with
last_with_data. Currently, we can only use two partially empty chains
at the end of an evbuffer, so if we have one with 511 bytes free, and
another with 512 bytes free, and we try to do a 1024 byte read, we
can't just stick another chain on the end: we need to reallocate the
last one. That's stupid and inefficient.
Instead, this patch adds a last_with_data pointer to eventually
replace previous_to_last. Instead of pointing to the penultimated
chain (if any) as previous_to_last does, last_with_data points to the
last chain that has any data in it, if any. If all chains are empty,
last_with_data points to the first chain. If there are no chains,
last_with_data is NULL.
The next step is to start using last_with_data everywhere that we
currently use previous_to_last. When that's done, we can remove
previous_to_last and the code that maintains it.
Remeber, win32 has a socket type that's actually a handle, so if
there's a chance that code is run on win32, we can't use "int" as the
socket type.
This isn't a blind search-and-replace: sometimes an fd is really in
fact for a file, and not a socket at all.
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.
