The `walk_dir` iterator was simulating a queue using a vector (in particular, using `shift`),
leading to O(n^2) performance. Since the order was not well-specified (see issue #13411),
the simplest fix is to use the vector as a stack (and thus yield a depth-first traversal).
This patch does exactly that. It leaves the order as originally specified -- "some top-down
order" -- and adds a test to ensure a top-down traversal.
Note that the underlying `readdir` function does not specify any particular order, nor
does the system call it uses.
Closes#13411.
This adds experimental support for timeouts when accepting sockets through
`TcpAcceptor::accept`. This does not add a separate `accept_timeout` function,
but rather it adds a `set_timeout` function instead. This second function is
intended to be used as a hard deadline after which all accepts will never block
and fail immediately.
This idea was derived from Go's SetDeadline() methods. We do not currently have
a robust time abstraction in the standard library, so I opted to have the
argument be a relative time in millseconds into the future. I believe a more
appropriate argument type is an absolute time, but this concept does not exist
yet (this is also why the function is marked #[experimental]).
The native support is built on select(), similarly to connect_timeout(), and the
green support is based on channel select and a timer.
cc #13523
This adds experimental support for timeouts when accepting sockets through
`TcpAcceptor::accept`. This does not add a separate `accept_timeout` function,
but rather it adds a `set_timeout` function instead. This second function is
intended to be used as a hard deadline after which all accepts will never block
and fail immediately.
This idea was derived from Go's SetDeadline() methods. We do not currently have
a robust time abstraction in the standard library, so I opted to have the
argument be a relative time in millseconds into the future. I believe a more
appropriate argument type is an absolute time, but this concept does not exist
yet (this is also why the function is marked #[experimental]).
The native support is built on select(), similarly to connect_timeout(), and the
green support is based on channel select and a timer.
cc #13523
This alters the borrow checker's requirements on invoking closures from
requiring an immutable borrow to requiring a unique immutable borrow. This means
that it is illegal to invoke a closure through a `&` pointer because there is no
guarantee that is not aliased. This does not mean that a closure is required to
be in a mutable location, but rather a location which can be proven to be
unique (often through a mutable pointer).
For example, the following code is unsound and is no longer allowed:
type Fn<'a> = ||:'a;
fn call(f: |Fn|) {
f(|| {
f(|| {})
});
}
fn main() {
call(|a| {
a();
});
}
There is no replacement for this pattern. For all closures which are stored in
structures, it was previously allowed to invoke the closure through `&self` but
it now requires invocation through `&mut self`.
The standard library has a good number of violations of this new rule, but the
fixes will be separated into multiple breaking change commits.
Closes#12224
This adds a `TcpStream::connect_timeout` function in order to assist opening
connections with a timeout (cc #13523). There isn't really much design space for
this specific operation (unlike timing out normal blocking reads/writes), so I
am fairly confident that this is the correct interface for this function.
The function is marked #[experimental] because it takes a u64 timeout argument,
and the u64 type is likely to change in the future.
This removes all resizability support for ~[T] vectors in preparation of DST.
The only growable vector remaining is Vec<T>. In summary, the following methods
from ~[T] and various functions were removed. Each method/function has an
equivalent on the Vec type in std::vec unless otherwise stated.
* slice::OwnedCloneableVector
* slice::OwnedEqVector
* slice::append
* slice::append_one
* slice::build (no replacement)
* slice::bytes::push_bytes
* slice::from_elem
* slice::from_fn
* slice::with_capacity
* ~[T].capacity()
* ~[T].clear()
* ~[T].dedup()
* ~[T].extend()
* ~[T].grow()
* ~[T].grow_fn()
* ~[T].grow_set()
* ~[T].insert()
* ~[T].pop()
* ~[T].push()
* ~[T].push_all()
* ~[T].push_all_move()
* ~[T].remove()
* ~[T].reserve()
* ~[T].reserve_additional()
* ~[T].reserve_exect()
* ~[T].retain()
* ~[T].set_len()
* ~[T].shift()
* ~[T].shrink_to_fit()
* ~[T].swap_remove()
* ~[T].truncate()
* ~[T].unshift()
* ~str.clear()
* ~str.set_len()
* ~str.truncate()
Note that no other API changes were made. Existing apis that took or returned
~[T] continue to do so.
[breaking-change]
Exposing ctpop, ctlz, cttz and bswap as taking signed i8/i16/... is just
exposing the internal LLVM names pointlessly (LLVM doesn't have "signed
integers" or "unsigned integers", it just has sized integer types
with (un)signed *operations*).
These operations are semantically working with raw bytes, which the
unsigned types model better.
There are currently a number of return values from the std::comm methods, not
all of which are necessarily completely expressive:
* `Sender::try_send(t: T) -> bool`
This method currently doesn't transmit back the data `t` if the send fails
due to the other end having disconnected. Additionally, this shares the name
of the synchronous try_send method, but it differs in semantics in that it
only has one failure case, not two (the buffer can never be full).
* `SyncSender::try_send(t: T) -> TrySendResult<T>`
This method accurately conveys all possible information, but it uses a
custom type to the std::comm module with no convenience methods on it.
Additionally, if you want to inspect the result you're forced to import
something from `std::comm`.
* `SyncSender::send_opt(t: T) -> Option<T>`
This method uses Some(T) as an "error value" and None as a "success value",
but almost all other uses of Option<T> have Some/None the other way
* `Receiver::try_recv(t: T) -> TryRecvResult<T>`
Similarly to the synchronous try_send, this custom return type is lacking in
terms of usability (no convenience methods).
With this number of drawbacks in mind, I believed it was time to re-work the
return types of these methods. The new API for the comm module is:
Sender::send(t: T) -> ()
Sender::send_opt(t: T) -> Result<(), T>
SyncSender::send(t: T) -> ()
SyncSender::send_opt(t: T) -> Result<(), T>
SyncSender::try_send(t: T) -> Result<(), TrySendError<T>>
Receiver::recv() -> T
Receiver::recv_opt() -> Result<T, ()>
Receiver::try_recv() -> Result<T, TryRecvError>
The notable changes made are:
* Sender::try_send => Sender::send_opt. This renaming brings the semantics in
line with the SyncSender::send_opt method. An asychronous send only has one
failure case, unlike the synchronous try_send method which has two failure
cases (full/disconnected).
* Sender::send_opt returns the data back to the caller if the send is guaranteed
to fail. This method previously returned `bool`, but then it was unable to
retrieve the data if the data was guaranteed to fail to send. There is still a
race such that when `Ok(())` is returned the data could still fail to be
received, but that's inherent to an asynchronous channel.
* Result is now the basis of all return values. This not only adds lots of
convenience methods to all return values for free, but it also means that you
can inspect the return values with no extra imports (Ok/Err are in the
prelude). Additionally, it's now self documenting when something failed or not
because the return value has "Err" in the name.
Things I'm a little uneasy about:
* The methods send_opt and recv_opt are not returning options, but rather
results. I felt more strongly that Option was the wrong return type than the
_opt prefix was wrong, and I coudn't think of a much better name for these
methods. One possible way to think about them is to read the _opt suffix as
"optionally".
* Result<T, ()> is often better expressed as Option<T>. This is only applicable
to the recv_opt() method, but I thought it would be more consistent for
everything to return Result rather than one method returning an Option.
Despite my two reasons to feel uneasy, I feel much better about the consistency
in return values at this point, and I think the only real open question is if
there's a better suffix for {send,recv}_opt.
Closes#11527
Add more type signatures to the docs; tweak a few of them.
Someone reading the docs won't know what the types of various things
are, so this adds them in a few meaningful places to help with
comprehension.
cc #13423.
Someone reading the docs won't know what the types of various things
are, so this adds them in a few meaningful places to help with
comprehension.
cc #13423.
There are currently a number of return values from the std::comm methods, not
all of which are necessarily completely expressive:
Sender::try_send(t: T) -> bool
This method currently doesn't transmit back the data `t` if the send fails
due to the other end having disconnected. Additionally, this shares the name
of the synchronous try_send method, but it differs in semantics in that it
only has one failure case, not two (the buffer can never be full).
SyncSender::try_send(t: T) -> TrySendResult<T>
This method accurately conveys all possible information, but it uses a
custom type to the std::comm module with no convenience methods on it.
Additionally, if you want to inspect the result you're forced to import
something from `std::comm`.
SyncSender::send_opt(t: T) -> Option<T>
This method uses Some(T) as an "error value" and None as a "success value",
but almost all other uses of Option<T> have Some/None the other way
Receiver::try_recv(t: T) -> TryRecvResult<T>
Similarly to the synchronous try_send, this custom return type is lacking in
terms of usability (no convenience methods).
With this number of drawbacks in mind, I believed it was time to re-work the
return types of these methods. The new API for the comm module is:
Sender::send(t: T) -> ()
Sender::send_opt(t: T) -> Result<(), T>
SyncSender::send(t: T) -> ()
SyncSender::send_opt(t: T) -> Result<(), T>
SyncSender::try_send(t: T) -> Result<(), TrySendError<T>>
Receiver::recv() -> T
Receiver::recv_opt() -> Result<T, ()>
Receiver::try_recv() -> Result<T, TryRecvError>
The notable changes made are:
* Sender::try_send => Sender::send_opt. This renaming brings the semantics in
line with the SyncSender::send_opt method. An asychronous send only has one
failure case, unlike the synchronous try_send method which has two failure
cases (full/disconnected).
* Sender::send_opt returns the data back to the caller if the send is guaranteed
to fail. This method previously returned `bool`, but then it was unable to
retrieve the data if the data was guaranteed to fail to send. There is still a
race such that when `Ok(())` is returned the data could still fail to be
received, but that's inherent to an asynchronous channel.
* Result is now the basis of all return values. This not only adds lots of
convenience methods to all return values for free, but it also means that you
can inspect the return values with no extra imports (Ok/Err are in the
prelude). Additionally, it's now self documenting when something failed or not
because the return value has "Err" in the name.
Things I'm a little uneasy about:
* The methods send_opt and recv_opt are not returning options, but rather
results. I felt more strongly that Option was the wrong return type than the
_opt prefix was wrong, and I coudn't think of a much better name for these
methods. One possible way to think about them is to read the _opt suffix as
"optionally".
* Result<T, ()> is often better expressed as Option<T>. This is only applicable
to the recv_opt() method, but I thought it would be more consistent for
everything to return Result rather than one method returning an Option.
Despite my two reasons to feel uneasy, I feel much better about the consistency
in return values at this point, and I think the only real open question is if
there's a better suffix for {send,recv}_opt.
Closes#11527
Previously, a private use statement would shadow a public use statement, all of
a sudden publicly exporting the privately used item. The correct behavior here
is to only shadow the use for the module in question, but for now it just
reverts the entire name to private so the pub use doesn't have much effect.
The behavior isn't exactly what we want, but this no longer has backwards
compatibility hazards.
Apparently windows doesn't like reading from stdin with a large buffer size, and
it also apparently is ok with a smaller buffer size. This changes the reader
returned by stdin() to return an 8k buffered reader for stdin rather than a 64k
buffered reader.
Apparently libuv has run into this before, taking a peek at their code, with a
specific comment in their console code saying that "ReadConsole can't handle big
buffers", which I presume is related to invoking ReadFile as if it were a file
descriptor.
Closes#13304
`Reader`, `Writer`, `MemReader`, `MemWriter`, and `MultiWriter` now work with `Vec<u8>` instead of `~[u8]`. This does introduce some extra copies since `from_utf8_owned` isn't usable anymore, but I think that can't be helped until `~str`'s representation changes.
move errno -> IoError converter into std, bubble up OSRng errors
Also adds a general errno -> `~str` converter to `std::os`, and makes the failure messages for the things using `OSRng` (e.g. (transitively) the task-local RNG, meaning hashmap initialisation failures aren't such a black box).
The various ...Rng::new() methods can hit IO errors from the OSRng they use,
and it seems sensible to expose them at a higher level. Unfortunately, writing
e.g. `StdRng::new().unwrap()` gives a much poorer error message than if it
failed internally, but this is a problem with all `IoResult`s.
This removes the `attr` matcher and adds a `meta` matcher. The previous `attr`
matcher is now ambiguous because it doesn't disambiguate whether it means inner
attribute or outer attribute.
The new behavior can still be achieved by taking an argument of the form
`#[$foo:meta]` (the brackets are part of the macro pattern).
Closes#13067
It turns out that on linux, and possibly other platforms, child processes will
continue to accept signals until they have been *reaped*. This means that once
the child has exited, it will succeed to receive signals until waitpid() has
been invoked on it.
This is unfortunate behavior, and differs from what is seen on OSX and windows.
This commit changes the behavior of Process::signal() to be the same across
platforms, and updates the documentation of Process::kill() to note that when
signaling a foreign process it may accept signals until reaped.
Implementation-wise, this invokes waitpid() with WNOHANG before each signal to
the child to ensure that if the child has exited that we will reap it. Other
possibilities include installing a SIGCHLD signal handler, but at this time I
believe that that's too complicated.
Closes#13124
This commit contains an implementation of synchronous, bounded channels for
Rust. This is an implementation of the proposal made last January [1]. These
channels are built on mutexes, and currently focus on a working implementation
rather than speed. Receivers for sync channels have select() implemented for
them, but there is currently no implementation of select() for sync senders.
Rust will continue to provide both synchronous and asynchronous channels as part
of the standard distribution, there is no intent to remove asynchronous
channels. This flavor of channels is meant to provide an alternative to
asynchronous channels because like green tasks, asynchronous channels are not
appropriate for all situations.
[1] - https://mail.mozilla.org/pipermail/rust-dev/2014-January/007924.html
