There are a few reasons that this is a desirable move to take:
1. Proof of concept that a third party event loop is possible
2. Clear separation of responsibility between rt::io and the uv-backend
3. Enforce in the future that the event loop is "pluggable" and replacable
Here's a quick summary of the points of this pull request which make this
possible:
* Two new lang items were introduced: event_loop, and event_loop_factory.
The idea of a "factory" is to define a function which can be called with no
arguments and will return the new event loop as a trait object. This factory
is emitted to the crate map when building an executable. The factory doesn't
have to exist, and when it doesn't then an empty slot is in the crate map and
a basic event loop with no I/O support is provided to the runtime.
* When building an executable, then the rustuv crate will be linked by default
(providing a default implementation of the event loop) via a similar method to
injecting a dependency on libstd. This is currently the only location where
the rustuv crate is ever linked.
* There is a new #[no_uv] attribute (implied by #[no_std]) which denies
implicitly linking to rustuv by default
Closes#5019
Some code cleanup, sorting of import blocks
Removed std::unstable::UnsafeArc's use of Either
Added run-fail tests for the new FailWithCause impls
Changed future_result and try to return Result<(), ~Any>.
- Internally, there is an enum of possible fail messages passend around.
- In case of linked failure or a string message, the ~Any gets
lazyly allocated in future_results recv method.
- For that, future result now returns a wrapper around a Port.
- Moved and renamed task::TaskResult into rt::task::UnwindResult
and made it an internal enum.
- Introduced a replacement typedef `type TaskResult = Result<(), ~Any>`.
It's not guaranteed that there will always be an event loop to run, and this
implementation will serve as an incredibly basic one which does not provide any
I/O, but allows the scheduler to still run.
cc #9128
This involved changing a fair amount of code, rooted in how we access the local
IoFactory instance. I added a helper method to the rtio module to access the
optional local IoFactory. This is different than before in which it was assumed
that a local IoFactory was *always* present. Now, a separate io_error is raised
when an IoFactory is not present, yet I/O is requested.
Remove the old path.
Rename path2 to path.
Update all clients for the new path.
Also make some miscellaneous changes to the Path APIs to help the
adoption process.
Remove these in favor of the two traits themselves and the wrapper
function std::from_str::from_str.
Add the function std::num::from_str_radix in the corresponding role for
the FromStrRadix trait.
The trait will keep the `Iterator` naming, but a more concise module
name makes using the free functions less verbose. The module will define
iterables in addition to iterators, as it deals with iteration in
general.
We already do this for libstd tests automatically, and compiletest runs into the
same problems where when forking lots of processes lots of file descriptors are
created. On OSX we can use specific syscalls to raise the limits, in this
situation, though.
Closes#8904
- Made naming schemes consistent between Option, Result and Either
- Changed Options Add implementation to work like the maybe monad (return None if any of the inputs is None)
- Removed duplicate Option::get and renamed all related functions to use the term `unwrap` instead
multicast functions now take IpAddr (without port), because they dont't
need port.
Uv* types renamed:
* UvIpAddr -> UvSocketAddr
* UvIpv4 -> UvIpv4SocketAddr
* UvIpv6 -> UvIpv6SocketAddr
"Socket address" is a common name for (ip-address, port) pair (e.g. in
sockaddr_in struct).
P. S. Are there any backward compatibility concerns? What is std::rt module, is it a part of public API?
OS X defaults the ulimit for open files to 256 for programs launched
from the Terminal (GUI apps get a higher default). Unfortunately this is
too low for the rt tests, which deliberately overcommit and create a lot
of threads (which means a lot of schedulers, and each scheduler needs at
least 2 fds).
By calling sysctl() and setrlimit() we can bump the fd limit up to the
maximum allowed (on stock OS X it's 10240).
Fixes#7772.
multicast functions now take IpAddr (without port), because they dont't
need port.
Uv* types renamed:
* UvIpAddr -> UvSocketAddr
* UvIpv4 -> UvIpv4SocketAddr
* UvIpv6 -> UvIpv6SocketAddr
"Socket address" is a common name for (ip-address, port) pair (e.g. in
sockaddr_in struct).
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.
Some notes about the commits.
Exit code propagation commits:
* ```Reimplement unwrap()``` has the same old code from ```arc::unwrap``` ported to use modern atomic types and finally (it's considerably nicer this way)
* ```Add try_unwrap()``` has some new slightly-tricky (but pretty simple) concurrency primitive code
* ```Add KillHandle``` and ```Add kill::Death``` are the bulk of the logic.
Task killing commits:
* ```Implement KillHandle::kill() and friends```, ```Do a task-killed check```, and ```Add BlockedTask``` implement the killing logic;
* ```Change the HOF context switchers``` turns said logic on
Linked failure commits:
* ```Replace *rust_task ptrs``` adapts the taskgroup code to work for both runtimes
* ```Enable taskgroup code``` does what it says on the tin.
r? @brson
