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)
This adds few functions to use evhttp-based webserver to handle incoming
WebSockets connections. We've tried to use both libevent and libwebsockets in
our application, but found that we need to have different ports at the same
time to handle standard HTTP and WebSockets traffic. This change can help to
stick only with libevent library.
Implementation was inspired by modified Libevent source code in ipush project
[1].
[1]: https://github.com/sqfasd/ipush/tree/master/deps/libevent-2.0.21-stable
Also, WebSocket-based chat server was added as a sample.
libevent is lacking a scalable backend on Windows. Let's leverage the wepoll
library until Windows comes up with an epoll/kqueue compete user mode API.
- All regress tests pass for standard wepoll
- These 2 tests fail intermittently for changelist wepoll, so disabling
changelist wepoll for now
http/cancel_inactive_server
http/stream_in
- verify target on Windows runs tests for both wepoll and win32 backends
- wepoll backend preferred over win32 backend
- wepoll version 1.5.6
v2: cleaner backend abstraction. Disallow wepoll on MinGW/Cygwin.
v3: Add wepoll.h to dist
v4: Make sure wepoll source files are excluded from cygwin/mingw builds
v5: Keep win32 as default backend on windows.
v6: Include wepoll in mingw builds. Verified that regress tests pass w/ WEPOLL backend.
v7: Enable wepoll on mingw when building with cmake
v8: Add wepoll testrunner for autotools test target
Adds two new callbacks: "prepare" watchers, which fire immediately
before we poll for I/O, and "check" watchers, which fire immediately
after we finish polling and before we process events. This allows other
event loops to be embedded into libevent's, and enables certain
performance monitoring.
Closes: #710
Due to regress linked with event and event_core (both of them includes
evthread.c) there will be two different evthread_id_fn_ variables under
mingw64:
evthread_id_fn_: &0x5294f20a8
evthread_id_fn_: &0x4ba0030a8
And because of this evthread_use_pthreads() can/will set one copy of
variables while evthread*() functions will access another, which will
break a lot of things (for example main/del_notify test).
Fixes: #792
Before this patch we have one test.sh (well test-script.sh), and tooks
very long to run it sequentially, but they are pretty lightweight, so we
should run then in parallel.
Currently an out-of-tree build will either write to the src dir or reuse
the existing regress.gen.[c,h]. But if building from a read-only git
tree (or if the git dir is cleaned), these files will not exist and the
build fails. So write the files to the build dir. If the system does
not have python, the regress.gen.[c,h] will be used from the src dir if
they exist.
