Similarly to the recent commit to do this for networking, there's no reason that
a read on a file descriptor should continue reading until the entire buffer is
full. This makes sense when dealing with literal files, but when dealing with
things like stdin this doesn't make sense.
This will allow capturing of common things like logging messages, stdout prints
(using stdio println), and failure messages (printed to stderr). Any new prints
added to libstd should be funneled through these task handles to allow capture
as well.
Additionally, this commit redirects logging back through a `Logger` trait so the
log level can be usefully consumed by an arbitrary logger.
This commit also introduces methods to set the task-local stdout handles:
* std::io::stdio::set_stdout
* std::io::stdio::set_stderr
* std::io::logging::set_logger
These methods all return the previous logger just in case it needs to be used
for inspection.
I plan on using this infrastructure for extra::test soon, but we don't quite
have the primitives that I'd like to use for it, so it doesn't migrate
extra::test at this time.
Closes#6369
libnative erroneously would attempt to fill the entire buffer in a call to
`read` before returning, when rather it should return immediately because
there's not guaranteed to be any data that will ever be received again.
Close#11328
There was a scheduling race where a child may not increment the global task
count before the parent exits, and the parent would then think that there are no
more tasks left.
Closes#11039
libnative erroneously would attempt to fill the entire buffer in a call to
`read` before returning, when rather it should return immediately because
there's not guaranteed to be any data that will ever be received again.
Close#11328
There was a scheduling race where a child may not increment the global task
count before the parent exits, and the parent would then think that there are no
more tasks left.
If the main closure failed, then the `exit_code` variable would still be `None`,
and the `unwrap()` was failing (triggering a process abort). This changes the
`unwrap()` to an `unwrap_or()` in order to prevent process abort and detect when
the native task failed.
This patchset adds intrinsics similar to the to_[be|le][16|32|64] intrinsics but for going in the reverse direction, e.g. from big/little endian to host endian. Implementation wise they do exactly the same as the corresponding to_* functions but I think it anyway make sense to have them since using the to_* functions in the reverse direction is not entirely intuitive.
The first patch adds the intrinsics and the two following changes instances of bswap* to use the [to|from]_* intrinsics instead.
For libgreen, bookeeping should not be global but rather on a per-pool basis.
Inside libnative, it's known that there must be a global counter with a
mutex/cvar.
The benefit of taking this strategy is to remove this functionality from libstd
to allow fine-grained control of it through libnative/libgreen. Notably, helper
threads in libnative can manually decrement the global count so they don't count
towards the global count of threads. Also, the shutdown process of *all* sched
pools is now dependent on the number of tasks in the pool being 0 rather than
this only being a hardcoded solution for the initial sched pool in libgreen.
This involved adding a Local::try_take() method on the Local trait in order for
the channel wakeup to work inside of libgreen. The channel send was happening
from a SchedTask when there is no Task available in TLS, and now this is
possible to work (remote wakeups are always possible, just a little slower).
For libgreen, bookeeping should not be global but rather on a per-pool basis.
Inside libnative, it's known that there must be a global counter with a
mutex/cvar.
The benefit of taking this strategy is to remove this functionality from libstd
to allow fine-grained control of it through libnative/libgreen. Notably, helper
threads in libnative can manually decrement the global count so they don't count
towards the global count of threads. Also, the shutdown process of *all* sched
pools is now dependent on the number of tasks in the pool being 0 rather than
this only being a hardcoded solution for the initial sched pool in libgreen.
This involved adding a Local::try_take() method on the Local trait in order for
the channel wakeup to work inside of libgreen. The channel send was happening
from a SchedTask when there is no Task available in TLS, and now this is
possible to work (remote wakeups are always possible, just a little slower).
Move the tests into libstd, use the `iotest!` macro to test both native and uv
bindings, and use the cloexec trick to figure out when the child process fails
in exec.
* vec::raw::to_ptr is gone
* Pausible => Pausable
* Removing @
* Calling the main task "<main>"
* Removing unused imports
* Removing unused mut
* Bringing some libextra tests up to date
* Allowing compiletest to work at stage0
* Fixing the bootstrap-from-c rmake tests
* assert => rtassert in a few cases
* printing to stderr instead of stdout in fail!()
This is a very real problem with cvars on normal systems, and all of channels
will not work if spurious wakeups are accepted. This problem is just solved with
a synchronized flag (accessed in the cvar's lock) to see whether a signal()
actually happened or whether it's spurious.
There was a race in the code previously where schedulers would *immediately*
shut down after spawning the main task (because the global task count would
still be 0). This fixes the logic by blocking the sched pool task in receving on
a port instead of spawning a task into the pool to receive on a port.
The modifications necessary were to have a "simple task" running by the time the
code is executing, but this is a simple enough thing to implement and I forsee
this being necessary to have implemented in the future anyway.
Note that this removes a number of run-pass tests which are exercising behavior
of the old runtime. This functionality no longer exists and is thoroughly tested
inside of libgreen and libnative. There isn't really the notion of "starting the
runtime" any more. The major notion now is "bootstrapping the initial task".
The scheduler pool now has a much more simplified interface. There is now a
clear distinction between creating the pool and then interacting the pool. When
a pool is created, all schedulers are not active, and only later if a spawn is
done does activity occur.
There are four operations that you can do on a pool:
1. Create a new pool. The only argument to this function is the configuration
for the scheduler pool. Currently the only configuration parameter is the
number of threads to initially spawn.
2. Spawn a task into this pool. This takes a procedure and task configuration
options and spawns a new task into the pool of schedulers.
3. Spawn a new scheduler into the pool. This will return a handle on which to
communicate with the scheduler in order to do something like a pinned task.
4. Shut down the scheduler pool. This will consume the scheduler pool, request
all of the schedulers to shut down, and then wait on all the scheduler
threads. Currently this will block the invoking OS thread, but I plan on
making 'Thread::join' not a thread-blocking call.
These operations can be used to encode all current usage of M:N schedulers, as
well as providing a simple interface through which a pool can be modified. There
is currently no way to remove a scheduler from a pool of scheduler, as there's
no way to guarantee that a scheduler has exited. This may be added in the
future, however (as necessary).
This adds a few smoke tests associated with libnative tasks (not much code to
test here anyway), and cleans up the entry points a little bit to be a little
more like libgreen.
The I/O code doesn't need much testing because that's all tested in libstd (with
the iotest! macro).
This commit introduces a new crate called "native" which will be the crate that
implements the 1:1 runtime of rust. This currently entails having an
implementation of std::rt::Runtime inside of libnative as well as moving all of
the native I/O implementations to libnative.
The current snag is that the start lang item must currently be defined in
libnative in order to start running, but this will change in the future.
Cool fact about this crate, there are no extra features that are enabled.
Note that this commit does not include any makefile support necessary for
building libnative, that's all coming in a later commit.
