Previously we were locking the spawning task's scheduler. I couldn't
see that that was protecting anything. The newborn_task list in the new task's
scheduler though was unprotected from concurrent access. So now we're locking
the new task's scheduler.
This still looks a bit sketchy to me (why isn't there locking in
port::destroy?) but this manages to get rid of a problem with channels
accessing their task after it's NULL.
getenv is not threadsafe and (maybe as a result) it's randomly crashing with
CFLAGS=-g and RUST_THREADS=32. Calls from rust code are still on their
own.
that absolutely will not succeed with a large default stack. This
should be removed once we have stack grown working.
Also updated word-count to succeed under the new test framework.
Tasks are spawned on a random thread. Currently they stay there, but
we should add task migration and load balancing in the future. This
should drammatically improve our task performance benchmarks.
Updated the MapReduce protocol so that it's correct more often. It's
still not perfect, but the bugs repro less often now.
Also found a race condition in channel sending. The problem is that
send and receive both need to refer to the _unread field in
circular_buffer. For now I just grabbed the port lock to send. We can
probably get around this by using atomics instead.
We're trying to get closer to doing correct move semantics for channel
operations. This involves a lot of cleanup (such as removing the
unused sched parameter from rust_vec constructor) and making
circular_buffer kernel_owned.
Added tagging for memory allocations. This means we give a string tag
to everything we allocate. If we leak something and TRACK_ALLOCATIONS
is enabled, then it's much easier now to tell exactly what is leaking.
This is just until unwinding works. Adds a flag to the runtime to turn
the memory leak checks on task destruction into warnings instead of fatal
errors. I am so sorry.
Issue #428
When the root task fails the process fails. Failures on other tasks propagate
up the task tree. Failures on non-root tasks without parents just
(theoretically) unwind and disappear.
