old design the TLS held the scheduler struct, and the scheduler struct
held the active task. This posed all sorts of weird problems due to
how we wanted to use the contents of TLS. The cleaner approach is to
leave the active task in TLS and have the task hold the scheduler. To
make this work out the scheduler has to run inside a regular task, and
then once that is the case the context switching code is massively
simplified, as instead of three possible paths there is only one. The
logical flow is also easier to follow, as the scheduler struct acts
somewhat like a "token" indicating what is active.
These changes also necessitated changing a large number of runtime
tests, and rewriting most of the runtime testing helpers.
Polish level is "low", as I will very soon start on more scheduler
changes that will require wiping the polish off. That being said there
should be sufficient comments around anything complex to make this
entirely respectable as a standalone commit.
Hello,
While looking at `tests.mk` I noticed two errors:
- there's a `srcrustllvm` instead of `src/rustllvm`
- some filtered out files don't exist anymore
These two commits fix these issues. Thanks!
Change the former repetition::
for 5.times { }
to::
do 5.times { }
.times() cannot be broken with `break` or `return` anymore; for those
cases, use a numerical range loop instead.
Change all users of old-style for with internal iterators to using
`do`-loops.
The code in stackwalk.rs does not actually implement the
looping protocol (no break on return false).
The code in gc.rs does not use loop breaks, nor does any code using it.
We remove the capacity to break from the loops in std::gc and implement
the walks using `do { .. }` expressions.
No behavior change.
.intersection(), .union() etc methods in trait std::container::Set use
internal iters. Remove these methods from the trait.
I reported issue #8154 for the reinstatement of iterator-based set algebra
methods to the Set trait.
For bitv and treemap, that lack Iterator implementations of set
operations, preserve them as methods directly on the types themselves.
For HashSet, these methods are replaced by the present .union_iter()
etc.
Assertions without a message get a generated message that consists of a
prefix plus the stringified expression that is being asserted. That
prefix is currently a unique string, while a static string would be
sufficient and needs less code.
Builds are considerably faster without assertions, so when working on
e.g. libstd, which doesn't directly interact with LLVM, one might want
to disable them.
This is a preliminary implementation of `for ... in ... { ...}` using a transitionary keyword `foreach`. Codesize seems to be a little bit down (10% or less non-opt) and otherwise it seems quite trivial to rewrite lambda-based loops to use it. Once we've rewritten the codebase away from lambda-based `for` we can retarget that word at the same production, snapshot, rewrite the keywords in one go, and expire `foreach`.
Feedback welcome. It's a desugaring-based approach which is arguably something we should have been doing for other constructs before. I apologize both for the laziness associated with doing it this way and with any sense that I'm bending rules I put in place previously concerning "never doing desugarings". I put the expansion in `expand.rs` and would be amenable to the argument that the code there needs better factoring / more helpers / to move to a submodule or helper function. It does seem to work at this point, though, and I gather we'd like to get the shift done relatively quickly.
This removes a bunch of options from the task builder interface that are irrelevant to the new scheduler and were generally unused anyway. It also bumps the stack size of new scheduler tasks so that there's enough room to run rustc and changes the interface to `Thread` to not implicitly join threads on destruction, but instead require an explicit, and mandatory, call to `join`.
Assertions without a message get a generated message that consists of a
prefix plus the stringified expression that is being asserted. That
prefix is currently a unique string, while a static string would be
sufficient and needs less code.
Builds are considerably faster without assertions, so when working on
e.g. libstd, which doesn't directly interact with LLVM, one might want
to disable them.
