Relax check that number of closure environments in a function matches
that of the def.
The def could be partially constructed, and so there may be a false
negative. The runtime will check that this is consistent, and the
garbage collector should handle when this constraint is not kept.
A threaded abstract is an abstract type that can be freely shared
between threads. While no synchronization is provided, refcounting
and transport between threads is. This will let implementers more easily
exploit OS-level parallelism in C library code. The caveat with these
types is that they need to be careful in how they interact with objects
on other heaps.
Some pointer casting with abstract types was incorrect, resulting
in strange behavior when trying to use supervisor channels that were
threaded. This fix also adds the ability to supply a supervisor channel
directly when creating a thread.
Also fix marshalling functions without full
sourcemapping information, as well as thread/receive
ignoring bad messages. Instead, thread/receive will error
on bad messages.
This allows unmarshal to optional marshal raw
pointers and cfunctions and send them across threads.
This flag is only exposed in the C API as it is very easy
to misuse and cause segfaults.
Lazy verification makes it easier to not leave funcenvs
in an invalid state, as well as be more precise with the validation.
We needed to verify the FuncEnvs actually pointed to a stack frame if
they were of the "on-stack" variant. There was some minor checking
before, but it was not enough to prevent func envs from pointing to
memory that was off of the fiber stack, overlapping stack frames, etc.
Using a bitset to indicate which stack values are upvalues, we
can more accurately track when a reference to a stack value
persists after the stack frame exits.
If possible, this will reduce the need to marshal fibers
in many cases. Also add this logic to the GC so holding a closure
that originally came from a fiber that crashed does not cause that fiber
to hang around forever.
This way we can support fewer build configurations. Also, remove
all undefined behavior due to use of memcpy with NULL pointers. GCC
was exploiting this to remove NULL checks in some builds.
Also make integer to size_t casts explicit rather than relying on
int32_t * sizeof(x) = size_t. This is kind of a personal preference for
this problem.
Because we use an amalgated build, feature
test macros should be set in a single file that
is included before any other headers, and is placed
at the top of the amalgamated build.
Gives more control over unmarshalling
abstract types. This should also
make it possible/easy to write abstract types that cannot
cause unmarshal to segfault.
