Conventionally, ident for EVFILT_USER is set to 0 to avoid
collision of file descriptors, which is what other renowned
networking frameworks like netty(java), mio(rust), gnet(go),
swift-nio(swift), etc. do currently.
Co-authored-by: Azat Khuzhin <azat@libevent.org>
Found by oss-fuzz, after coverage had been improved in google/oss-fuzz#11257
v2: adjust test
v3: fix for windows (_get_osfhandle() crashes when called on closed fd)
v4: fix for EVENT__DISABLE_MM_REPLACEMENT
In buffer.c a variable "flags" and a label "done" are defined but
never used if "EVENT__HAVEMMAP" is not defined.
The code does not work on platforms which do not provide
the function `socketpair()`. Introduce EVENT__HAVE_SOCKETPAIR flag
which determines if `socketpair()` or `evutil_ersatz_socketpair()`
is used.
* evbuffer_add_reference_with_offset:
Add a comment for evbuffer_ref_cleanup_cb
tests: simplify test_evbuffer_add_reference_with_offset
Add function evbuffer_add_reference_with_offset()
report:
/src/le/libevent/sample/becat.c:304:29: warning: implicit truncation from 'int' to a one-bit wide bit-field changes value from 1 to -1 [-Wsingle-bit-bitfield-constant-conversion]
case 'k': o.extra.keep = 1; break;
This is the same as evbuffer_add_reference(), but allows to specify
offset in the @data
v2: rename evbuffer_add_reference_misalign() to evbuffer_add_reference_with_offset()
Replace evws_send with evws_send_text, and introduce new API -
evws_send_binary, that can be used to send binary frames.
But note, that this commit breaks the ABI compatibility, but it should be OK,
since there was only alpha release with evws_send, and nobody should rely on
this, and I hope nobody does (we decided to go this way to avoid supporting
deprecated API).
signalfd may behave differently to sigaction/signal, so to avoid
breaking libevent users (like [1], [2]) disable it by default.
[1]: https://github.com/tmux/tmux/pull/3621
[2]: https://github.com/tmux/tmux/pull/3626
Also signalfd is not that perfect:
- you need to SIG_BLOCK the signal before
- blocked signals are not reset on exec
- blocked signals are allowed to coalesce - so in case of multiple
signals sent you may get the signal only once (ok for most of the
signals, but may be a problem for SIGCHLD, though you may call
waitpid() in a loop or use pidfd)
- and also one implementation problem -
sigprocmask is unspecified in a multithreaded process
Refs:
- https://lwn.net/Articles/415684/
- https://ldpreload.com/blog/signalfd-is-useless
Refs: https://github.com/libevent/libevent/issues/1460
Refs: #1342 (cc @dmantipov)
I faced with strange problem: event loop doesn't exit after dns resolving with
`EVDNS_BASE_DISABLE_WHEN_INACTIVE`.
Stand:
- Ubuntu 22;
- libevent release-2.1.12-stable
- `resolve.conf` contains 2 nameservers;
- I use `evdns_base_new` with `EVDNS_BASE_DISABLE_WHEN_INACTIVE | EVDNS_BASE_INITIALIZE_NAMESERVERS` to avoid OS specific code.
After small investigation, look like events related with dns sockets added to
event_base before `evdns->disable_when_inactive` was initialized. `libevent`
did epoll_ctl(DEL) after resolving completed on the first socket, but the
second socket remained in the `epoll` interest list.
compiler warning:
test/regress_http.c:968:38: warning: result of comparison of constant 65536 with expression of type 'enum evhttp_cmd_type' is always true [-Wtautological-constant-out-of-range-compare]
if (evhttp_request_get_command(req) != EVHTTP_REQ_CUSTOM) {
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~
It is not a thankless task to fix such issues on and on, let's just
prohibit this cases, and our build with -Werror on CI will show new
issues from now on.
Fixes: #1434
- -Wdeprecated-non-prototype
/src/le/libevent/strlcpy.c:48:1: warning: a function definition without a prototype is deprecated in all versions of C and is not supported in C2x [-Wdeprecated-non-prototype]
event_strlcpy_(dst, src, siz)
- -Wstrict-prototypes
/src/le/libevent/evthread.c:82:70: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
struct evthread_condition_callbacks *evthread_get_condition_callbacks()
- -Wunused-but-set-variable
/src/le/libevent/test/regress_buffer.c:130:6: warning: variable 'n' set but not used [-Wunused-but-set-variable]
int n = 0;
^
