.. seeing an occasional valgrind/barf spew on some invalid read/writes..
need to investigate further.. i think its related to my poor citizen
conduct, re: pointers stashed in rust_kernel..
The runtime is in an uncertain state here and, instead of thinking
about how to make the logger work correctly, let's just avoid it.
Currently, it ends up hitting an assert saying that we can't log on
the rust stack.
.. up next: windows!
.. impl'd uv::direct::read_stop() and uv::direct::close() to wrap things up
.. demonstrated sending data out of the uv_read_cb via a channel (which
we block on to recv all of it, complete w/ EOF notification) that is
read from after the loop exits.
.. helpers to read the guts of a uv_buf_t
.. an idea im kicking around: starting to pile up all of these hideous
data accessor functions in uv::direct .. I might make impl/iface pairs
for the various uv_* types that I'm using, in order to encapsulate those
data access functions and, perhaps, make the access look a little cleaner
(it still won't be straight field access, but it'll be a lot better)
.. formatting cleanup to satisfy make check
so we're now adhering the libuv C api and passing structs by-val where
it is expected, instead of pulling pointer trickery (or worse having to
malloc structs in c++ to be passed back to rust and then into C again)
have to use ++ sigil in rust-side extern fn decls in order to have rust
actually copy the struct, by value, onto the C stack. gotcha, indeed.
also adding a helper method to verify/remind how to pass a struct by-val
into C... check out the rust fn sig for rust_uv_ip4_test_verify_port_val()
for more infos
.. but passing sockaddr_in by val back to C is broken, still passing by
ptr
.. the uv_write_cb is processed, but we have a status -1.. there is
also valgrind spew.. so buf passing is broken, still.
lots of changes, here.. should've commited sooner.
- added uv::direct module that contains rust fns that map, neatly, to
the libuv c library as much as possible. they operate on ptrs to libuv
structs mapped in rust, as much as possible (there are some notable
exceptions). these uv::direct fns should only take inputs from rust and,
as neccesary, translate them into C-friendly types and then pass to the
C functions. We want to them to return ints, as the libuv functions do,
so we can start tracking status.
- the notable exceptions for structs above is due to ref gh-1402, which
prevents us from passing structs, by value, across the Rust<->C barrier
(they turn to garbage, pretty much). So in the cases where we get back
by-val structs from C (uv_buf_init(), uv_ip4_addr(), uv_err_t in callbacks)
, we're going to use *ctypes::void (or just errnum ints for uv_err_t) until
gh-1402 is resolved.
- using crust functions, in these uv::direct fns, for callbacks from libuv,
will eschew uv_err_t, if possible, in favor a struct int.. if at all
possible (probably isn't.. hm.. i know libuv wants to eventually move to
replace uv_err_t with an int, as well.. so hm).
- started flushing out a big, gnarly test case to exercise the tcp request
side of the uv::direct functions. I'm at the point where, after the
connection is established, we write to the stream... when the writing is
done, we will read from it, then tear the whole thing down.
overall, it turns out that doing "close to the metal" interaction with
c libraries is painful (and more chatty) when orchestrated from rust. My
understanding is that not much, at all, is written in this fashion in the
existant core/std codebase.. malloc'ing in C has been preferred, from what
I've gathered. So we're treading new ground, here!
It's possible to have negative times if expressing time before 1970, so
we should use signed types. Other platforms can return times at a higher
resolution, so we should use 64 bits.
This is a workaround for #1815. libev uses realloc(0) to
free the loop, which valgrind doesn't like. We have suppressions
to make valgrind ignore them.
Valgrind also has a sanity check when collecting allocation backtraces
that the stack pointer must be at least 512 bytes into the stack (at
least 512 bytes of frames must have come before). When this is not
the case it doesn't collect the backtrace.
Unfortunately, with our spaghetti stacks that valgrind check triggers
sometimes and we don't get the backtrace for the realloc(0), it
fails to be suppressed, and it gets reported as 0 bytes lost
from a malloc with no backtrace.
This fixes the issue by alloca'ing 512 bytes before calling uv_loop_delete
