This replaces the existing, unreleased lws_set_timer(wsi, secs) with
lws_set_timer_usecs(wsi, usecs).
wsi with a timer waiting are added to a linked-list sorted by the
timer trigger time.
1) poll() timeout (ie, poll wait) is trimmed to the nearest ms of the
first waiting timer if the default poll wait is longer than the
interval until the first waiting timer.
The linked-list of waiting timers is checked every entry and exit
from poll()... if no timers waiting or none reached their time
this costs almost nothing.
2) libuv: the earliest hrtimer is checked after every IO, again this
is costing nothing if the list head is NULL. If the case there
are hrtimers on the list, it costs a getimeofday (a VDSO in linux)
and more only if any of the timers have fired.
In addition on entry to libuv idle, if there are any waiting hrtimers
on the list, a libuv timer is used to force a wake in case we stay
idle (the libuv timer has ms resolution).
3) libev: not implemented
4) libevent: not implemented
Warnings are logged in the api is used on an event backend without
support. Patches welcome to add support similarly to libuv.
- Add platform helpers for pipe creation.
- Change the direct-to-fds implementation to create a wsi for each
pt and use the normal apis to bind it to the event loop.
- Modifiy context creation and destroy to create and remove the
event pipe wsis.
- Create the event pipe wsis during context create if using the
default poll() event loop, or when the other event loops start
otherwise.
- Add handler that calls back user code with
LWS_CALLBACK_EVENT_WAIT_CANCELLED
This patch allows you to call `lws_cancel_service(struct lws_context *context)`
from another thread.
It's very cheap for the other thread to call and is safe without
locking.
Every use protocol receives a LWS_CALLBACK_EVENT_WAIT_CANCELLED from
the main thread serialized normally in the event loop.
This enables selected things from -Wextra, can't use -Wextra because it is
fussy enough to complain about unused params on functions... they are
there for a reason.
-Wsign-compare
-Wignored-qualifiers
not -Wimplicit-fallthrough=3 ... only on gcc 7
-Wtype-limits
-Wuninitialized
not -Wclobbered ... only on gcc 7ish
fix the warnings everywhere they were found.
