This PR changes the `janet_gettime` implementation for OSX <10.12 to
read the system clock for `(os/clock :monotonic)`. As far as I was able
to find online this is _a_ monotonic clock, although it produces
different values from `clock_gettime(CLOCK_MONOTONIC, ...)` on the same
system. I can speculate that this is related to `SYSTEM_CLOCK` monotonic
time being implemented with `mach_absolute_time` which is documented to
_not advance during sleep_, and I suspect that
`clock_gettime(CLOCK_MONOTONIC, ...)` does.
**Resources**:
- `clock_get_time` implementation for the `SYSTEM_CLOCK`:
<e3723e1f17/osfmk/kern/clock_oldops.c (L284-L296)>
<2ff845c2e0/osfmk/arm/rtclock.c (L248-L260)>
- `mach_absolute_time` and `mach_continuous_time` definitions:
<e3723e1f17/osfmk/mach/mach_time.h (L55-L68)>
- Stack overflow post for implementing `clock_gettime` on OS X before 10.12:
<https://stackoverflow.com/questions/11680461/monotonic-clock-on-osx>
Since it is invalid to call accept on a datagram socket, net/server
always errors if handler is truthy and type is :datagram.
Add an assert to give a better error message in this case and clarify
the documentation.
References: https://github.com/janet-lang/janet/issues/1614
Call pthread_join on all worker threads for timeouts. Previously, we
were leaking some threads, as well as creating a timeout and leaving
has_worker unset on certain timeouts.
Fix some issue with clang sanitizers, name -fsanitize=thread and
-fsanitize=undefined. The threading issue arose from the implementation
of ev/deadlock when allowing for interpreter intrerrupts, as this is
implemented by racing a timeout thread with a worker thread.
The undefined behavior issue arose in some very old code in corelib.c that will
actually work as expected for most compilers, but was both undefined and
unecessary as we have a correct implemenation in util.c.
This is to better allow configuration on various, unknown compilers.
Previously, we hardcoded how thread local storage was specified for a
few different compilers, but we were not following and C standard. In
C11, there is a standardized storage specifier _Thread_local for this
storage class, however this is now deprecated in various C++ compilers
for a new keyword, confusingly. Janet also does not claim to require the
C11 standard, so for maximum flexibilty, the storage specifier must be
specified at configure time.
