With SMP + event lib, extra locking is required when dealing with cross-thread
adoption case, and cross-vhost cases like wsi close, we need to hold the pt or
context lock.
These lock apis are NOPs when LWS_MAX_SMP == 1 which is the default.
The per-pt priv for event libs ended up overallocated at the context,
and pointed-to by a single pointer composed into each pt. That means
we can't do pointer arithmetic on it any more.
Update a couple of stragglers in libuv event lib to use a pointer in
the pt-priv for the event lib back to the pt instead.
Also in foreign case if we start idle, there may not be anything
happening to trigger the initial idle. So let each pt start with
its idle active.
Event lib support as it has been isn't scaling well, at the low level
libevent and libev headers have a namespace conflict so they can't
both be built into the same image, and at the distro level, binding
all the event libs to libwebsockets.so makes a bloaty situation for
packaging, lws will drag in all the event libs every time.
This patch implements the plan discussed here
https://github.com/warmcat/libwebsockets/issues/1980
and refactors the event lib support so they are built into isolated
plugins and bound at runtime according to what the application says
it wants to use. The event lib plugins can be packaged individually
so that only the needed sets of support are installed (perhaps none
of them if the user code is OK with the default poll() loop). And
dependent user code can mark the specific event loop plugin package
as required so pieces are added as needed.
The eventlib-foreign example is also refactored to build the selected
lib support isolated.
A readme is added detailing the changes and how to use them.
https://libwebsockets.org/git/libwebsockets/tree/READMEs/README.event-libs.md
Move the common plugin scanning dir stuff to be based on lws_dir, which
already builds for windows. Previously this was done via dirent for unix
and libuv for windows.
Reduce the dl plat stuff to just wrap instantiation and destruction of
dynlibs, establish common code in lib/misc/dir.c for plugin scanning
itself.
Migrate the libuv windows dl stuff to windows-plugins.c, so that he's
available even if later libuv loop support becomes and event lib plugin.
Remove the existing api exports scheme for plugins, just export a const struct
now which has a fixed header type but then whatever you want afterwards depending
on the class / purpose of the plugin. Place a "class" string in the header so
there can be different kinds of plugins implying different types exported.
Make the plugin apis public and add support for filter by class string, and
per instantation / destruction callbacks so the subclassed header type can
do its thing for the plugin class. The user provides a linked-list base
for his class of plugins, so he can manage them completely separately and
in user code / user export types.
Rip out some last hangers-on from generic sessions / tables.
This is all aimed at making the plugins support general enough so it can
provide event lib plugins later.
Currently we always reserve a fakewsi per pt so events that don't have a related actual
wsi, like vhost-protocol-init or vhost cert init via protocol callback can make callbacks
that look reasonable to user protocol handler code expecting a valid wsi every time.
This patch splits out stuff that user callbacks often unconditionally expect to be in
a wsi, like context pointer, vhost pointer etc into a substructure, which is composed
into struct lws at the top of it. Internal references (struct lws is opaque, so there
are only internal references) are all updated to go via the substructre, the compiler
should make that a NOP.
Helpers are added when fakewsi is used and referenced.
If not PLAT_FREERTOS, we continue to provide a full fakewsi in the pt as before,
although the helpers improve consistency by zeroing down the substructure. There is
a huge amount of user code out there over the last 10 years that did not always have
the minimal examples to follow, some of it does some unexpected things.
If it is PLAT_FREERTOS, that is a newer thing in lws and users have the benefit of
being able to follow the minimal examples' approach. For PLAT_FREERTOS we don't
reserve the fakewsi in the pt any more, saving around 800 bytes. The helpers then
create a struct lws_a (the substructure) on the stack, zero it down (but it is only
like 4 pointers) and prepare it with whatever we know like the context.
Then we cast it to a struct lws * and use it in the user protocol handler call.
In this case, the remainder of the struct lws is undefined. However the amount of
old protocol handlers that might touch things outside of the substructure in
PLAT_FREERTOS is very limited compared to legacy lws user code and the saving is
significant on constrained devices.
User handlers should not be touching everything in a wsi every time anyway, there
are several cases where there is no valid wsi to do the call with. Dereference of
things outside the substructure should only happen when the callback reason shows
there is a valid wsi bound to the activity (as in all the minimal examples).
This gives a valgrind result for lws-minimal-http-server-event-lib-foreign
that's clean for lws pieces, although glib is always dirty wrt thread local
storage and hashtable.
Adapt the pt sul owner list to be an array, and define two different lists,
one that acts like before and is the default for existing users, and another
that has the ability to cooperate with systemwide suspend to restrict the
interval spent suspended so that it will wake in time for the earliest
thing on this wake-suspend sul list.
Clean the api a bit and add lws_sul_cancel() that only needs the sul as the
argument.
Add a flag for client creation info to indicate that this client connection
is important enough that, eg, validity checking it to detect silently dead
connections should go on the wake-suspend sul list. That flag is exposed in
secure streams policy so it can be added to a streamtype with
"swake_validity": true
Deprecate out the old vhost timer stuff that predates sul. Add a flag
LWS_WITH_DEPRECATED_THINGS in cmake so users can get it back temporarily
before it will be removed in a v4.2.
Adapt all remaining in-tree users of it to use explicit suls.
Establish a new distributed CMake architecture with CMake code related to
a source directory moving to be in the subdir in its own CMakeLists.txt.
In particular, there's now one in ./lib which calls through to ones
further down the directory tree like ./lib/plat/xxx, ./lib/roles/xxx etc.
This cuts the main CMakelists.txt from 98KB -> 33KB, about a 66% reduction,
and it's much easier to maintain sub-CMakeLists.txt that are in the same
directory as the sources they manage, and conceal all the details that that
level.
Child CMakelists.txt become responsible for:
- include_directories() definition (this is not supported by CMake
directly, it passes it back up via PARENT_SCOPE vars in helper
macros)
- Addition child CMakeLists.txt inclusion, for example toplevel ->
role -> role subdir
- Source file addition to the build
- Dependent library path resolution... this is now a private thing
in the child CMakeLists.txt, it just passes back any adaptations
to include_directories() and the LIB_LIST without filling the
parent namespace with the details
Replace the bash selftest plumbing with CTest.
To use the selftests, build with -DLWS_WITH_MINIMAL_EXAMPLES=1
and `CTEST_OUTPUT_ON_FAILURE=1 make test` or just
`make test`.
To disable tests that require internet access, also give
-DLWS_CTEST_INTERNET_AVAILABLE=0
Remove travis and appveyor scripts on master.
Remove travis and appveyor decals on README.md.
Add selectable event lib support to minimal-http-client-multi and
clean up context destroy flow so we can use lws_destroy_context() from
inside the callback to indicate we want to end the event loop, without
using the traditional "interrupted" flag and in a way that works no
matter which event loop backend is being used.
Pre-sul, checking for interval to next pending scheduled event was expensive and
iterative, so the service avoided it if the wait was already 0.
With sul though, the internal "check" function also services ripe events and
removes them, and finding the interval to the next one is really cheap.
Rename the "check" function to __lws_sul_service_ripe() to make it clear it's
not just about returning the interval to the next pending one. And call it
regardless of if we already decided we are not going to wait in the poll.
After https://github.com/warmcat/libwebsockets/pull/1745
There's no longer any reason to come out of sleep for periodic service
which has been eliminated by lws_sul.
With event libs, there is no opportunity to do it anyway since their
event loop is atomic and makes callbacks and sleeps until it is stopped.
But some users are relying on the old poll() service loop as
glue that's difficult to replace. So for now help that happen by
accepting the timeout_ms of -1 as meaning sample poll and service
what's there without any wait.
wsi timeout, wsi hrtimer, sequencer timeout and vh-protocol timer
all now participate on a single sorted us list.
The whole idea of polling wakes is thrown out, poll waits ignore the
timeout field and always use infinite timeouts.
Introduce a public api that can schedule its own callback from the event
loop with us resolution (usually ms is all the platform can do).
Upgrade timeouts and sequencer timeouts to also be able to use us resolution.
Introduce a prepared fakewsi in the pt, so we don't have to allocate
one on the heap when we need it.
Directly handle vh-protocol timer if LWS_MAX_SMP == 1
There are quite a few linked-lists of things that want events after
some period. This introduces a type binding an lws_dll2 for the
list and a lws_usec_t for the duration.
The wsi timeouts, the hrtimer and the sequencer timeouts are converted
to use these, also in the common event wait calculation.
Adapt service loops and event libs to use microsecond waits
internally, for hrtimer and sequencer. Reduce granularity
according to platform / event lib wait.
Add a helper so there's a single place to extend it.
Generic sessions has been overdue some love to align it with
the progress in the rest of lws.
1) Strict Content Security Policy
2) http2 compatibility
3) fixes and additions for use in a separate process via unix domain socket
4) work on ws and http proxying in lws
5) add minimal example
This seen in the wild...
==20578== Invalid read of size 1
==20578== at 0x4D2E018: uv_poll_stop (poll.c:112)
==20578== by 0x48BC159: elops_io_uv (libuv.c:684)
==20578== by 0x4872F55: __remove_wsi_socket_from_fds (pollfd.c:326)
==20578== by 0x486EF1B: __lws_close_free_wsi (close.c:425)
==20578== by 0x486F3E2: lws_close_free_wsi (close.c:518)
==20578== by 0x487564C: lws_service_fd_tsi (service.c:1033)
==20578== by 0x48BAEA9: lws_io_cb (libuv.c:117)
==20578== by 0x4D3606F: uv__io_poll (linux-core.c:379)
==20578== by 0x4D27714: uv_run (core.c:361)
==20578== by 0x48BC347: elops_run_pt_uv (libuv.c:735)
==20578== by 0x4875746: lws_service (service.c:1080)
==20578== by 0x401A51: main (main.c:309)
==20578== Address 0x58 is not stack'd, malloc'd or (recently) free'd
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Setting m to 0 by default will prevent "error: ‘m’ may be used uninitialized in this function"
while compiling with the option -DLWS_WITH_LIBUV=ON.
Until now the uv watcher has been composed in the wsi.
This works fine except in the case of a client wsi that
meets a redirect when the event loop is libuv with its
requirement for handle close via the event loop.
We want to reuse the wsi, since the originator of it has
a copy of the wsi pointer, and we want to conceal the
redirect. Since the redirect is commonly to a different
IP, we want to keep the wsi alive while closing its
socket cleanly. That's not too difficult, unless you are
using uv.
With UV the comoposed watcher is a disaster, since after
the close is requested the wsi will start to reconnect.
We tried to deal with that by copying the uv handle and
freeing it when the handle close finalizes. But it turns
out the handle is in a linked-list scheme in uv.
This patch hopefully finally solves it by giving the uv
handle its own allocation from the start. When we want
to close the socket and reuse the wsi, we simply take
responsibility for freeing the handle and set the wsi
watcher pointer to NULL.
