The new semantics of this function are that the callbacks are run when the *main
thread* exits, not when all threads have exited. This implies that other threads
may still be running when the `at_exit` callbacks are invoked and users need to
be prepared for this situation.
Users in the standard library have been audited in accordance to these new rules
as well.
Closes#20012
I've created a patch for #20226, which maps `EEXIST` to the `PathAlreadyExists` error on Unix. To test this, I use `mkdir`, which raises `EEXIST` if the directory already exists.
On Windows, I map `ERROR_ALREADY_EXISTS` to `PathAlreadyExist`, but I am note sure if `mkdir` on Windows raises `ERROR_ALREADY_EXISTS` and do not have a Windows installation handy for testing.
And I noticed another thing. No error seems to map to `IoErrorKind::PathDoesntExist` and I am wondering what the difference to `FileNotFound` is?
This commit performs a second pass for stabilization over the `std::ptr` module.
The specific actions taken were:
* The `RawPtr` trait was renamed to `PtrExt`
* The `RawMutPtr` trait was renamed to `PtrMutExt`
* The module name `ptr` is now stable.
* These functions were all marked `#[stable]` with no modification:
* `null`
* `null_mut`
* `swap`
* `replace`
* `read`
* `write`
* `PtrExt::is_null`
* `PtrExt::is_not_null`
* `PtrExt::offset`
* These functions remain unstable:
* `as_ref`, `as_mut` - the return value of an `Option` is not fully expressive
as null isn't the only bad value, and it's unclear
whether we want to commit to these functions at this
time. The reference/lifetime semantics as written are
also problematic in how they encourage arbitrary
lifetimes.
* `zero_memory` - This function is currently not used at all in the
distribution, and in general it plays a broader role in the
"working with unsafe pointers" story. This story is not yet
fully developed, so at this time the function remains
unstable for now.
* `read_and_zero` - This function remains unstable for largely the same
reasons as `zero_memory`.
* These functions are now all deprecated:
* `PtrExt::null` - call `ptr::null` or `ptr::null_mut` instead.
* `PtrExt::to_uint` - use an `as` expression instead.
This commit performs a second pass for stabilization over the `std::ptr` module.
The specific actions taken were:
* The `RawPtr` trait was renamed to `PtrExt`
* The `RawMutPtr` trait was renamed to `MutPtrExt`
* The module name `ptr` is now stable.
* These functions were all marked `#[stable]` with no modification:
* `null`
* `null_mut`
* `swap`
* `replace`
* `read`
* `write`
* `PtrExt::is_null`
* `PtrExt::offset`
* These functions remain unstable:
* `as_ref`, `as_mut` - the return value of an `Option` is not fully expressive
as null isn't the only bad value, and it's unclear
whether we want to commit to these functions at this
time. The reference/lifetime semantics as written are
also problematic in how they encourage arbitrary
lifetimes.
* `zero_memory` - This function is currently not used at all in the
distribution, and in general it plays a broader role in the
"working with unsafe pointers" story. This story is not yet
fully developed, so at this time the function remains
unstable for now.
* `read_and_zero` - This function remains unstable for largely the same
reasons as `zero_memory`.
* These functions are now all deprecated:
* `PtrExt::null` - call `ptr::null` or `ptr::null_mut` instead.
* `PtrExt::to_uint` - use an `as` expression instead.
* `PtrExt::is_not_null` - use `!p.is_null()` instead.
All of the current std::sync primitives have poisoning enable which means that
when a task fails inside of a write-access lock then all future attempts to
acquire the lock will fail. This strategy ensures that stale data whose
invariants are possibly not upheld are never viewed by other tasks to help
propagate unexpected panics (bugs in a program) among tasks.
Currently there is no way to test whether a mutex or rwlock is poisoned. One
method would be to duplicate all the methods with a sister foo_catch function,
for example. This pattern is, however, against our [error guidelines][errors].
As a result, this commit exposes the fact that a task has failed internally
through the return value of a `Result`.
[errors]: https://github.com/rust-lang/rfcs/blob/master/text/0236-error-conventions.md#do-not-provide-both-result-and-fail-variants
All methods now return a `LockResult<T>` or a `TryLockResult<T>` which
communicates whether the lock was poisoned or not. In a `LockResult`, both the
`Ok` and `Err` variants contains the `MutexGuard<T>` that is being returned in
order to allow access to the data if poisoning is not desired. This also means
that the lock is *always* held upon returning from `.lock()`.
A new type, `PoisonError`, was added with one method `into_guard` which can
consume the assertion that a lock is poisoned to gain access to the underlying
data.
This is a breaking change because the signatures of these methods have changed,
often incompatible ways. One major difference is that the `wait` methods on a
condition variable now consume the guard and return it in as a `LockResult` to
indicate whether the lock was poisoned while waiting. Most code can be updated
by calling `.unwrap()` on the return value of `.lock()`.
[breaking-change]
This commit starts out by consolidating all `str` extension traits into one
`StrExt` trait to be included in the prelude. This means that
`UnicodeStrPrelude`, `StrPrelude`, and `StrAllocating` have all been merged into
one `StrExt` exported by the standard library. Some functionality is currently
duplicated with the `StrExt` present in libcore.
This commit also currently avoids any methods which require any form of pattern
to operate. These functions will be stabilized via a separate RFC.
Next, stability of methods and structures are as follows:
Stable
* from_utf8_unchecked
* CowString - after moving to std::string
* StrExt::as_bytes
* StrExt::as_ptr
* StrExt::bytes/Bytes - also made a struct instead of a typedef
* StrExt::char_indices/CharIndices - CharOffsets was renamed
* StrExt::chars/Chars
* StrExt::is_empty
* StrExt::len
* StrExt::lines/Lines
* StrExt::lines_any/LinesAny
* StrExt::slice_unchecked
* StrExt::trim
* StrExt::trim_left
* StrExt::trim_right
* StrExt::words/Words - also made a struct instead of a typedef
Unstable
* from_utf8 - the error type was changed to a `Result`, but the error type has
yet to prove itself
* from_c_str - this function will be handled by the c_str RFC
* FromStr - this trait will have an associated error type eventually
* StrExt::escape_default - needs iterators at least, unsure if it should make
the cut
* StrExt::escape_unicode - needs iterators at least, unsure if it should make
the cut
* StrExt::slice_chars - this function has yet to prove itself
* StrExt::slice_shift_char - awaiting conventions about slicing and shifting
* StrExt::graphemes/Graphemes - this functionality may only be in libunicode
* StrExt::grapheme_indices/GraphemeIndices - this functionality may only be in
libunicode
* StrExt::width - this functionality may only be in libunicode
* StrExt::utf16_units - this functionality may only be in libunicode
* StrExt::nfd_chars - this functionality may only be in libunicode
* StrExt::nfkd_chars - this functionality may only be in libunicode
* StrExt::nfc_chars - this functionality may only be in libunicode
* StrExt::nfkc_chars - this functionality may only be in libunicode
* StrExt::is_char_boundary - naming is uncertain with container conventions
* StrExt::char_range_at - naming is uncertain with container conventions
* StrExt::char_range_at_reverse - naming is uncertain with container conventions
* StrExt::char_at - naming is uncertain with container conventions
* StrExt::char_at_reverse - naming is uncertain with container conventions
* StrVector::concat - this functionality may be replaced with iterators, but
it's not certain at this time
* StrVector::connect - as with concat, may be deprecated in favor of iterators
Deprecated
* StrAllocating and UnicodeStrPrelude have been merged into StrExit
* eq_slice - compiler implementation detail
* from_str - use the inherent parse() method
* is_utf8 - call from_utf8 instead
* replace - call the method instead
* truncate_utf16_at_nul - this is an implementation detail of windows and does
not need to be exposed.
* utf8_char_width - moved to libunicode
* utf16_items - moved to libunicode
* is_utf16 - moved to libunicode
* Utf16Items - moved to libunicode
* Utf16Item - moved to libunicode
* Utf16Encoder - moved to libunicode
* AnyLines - renamed to LinesAny and made a struct
* SendStr - use CowString<'static> instead
* str::raw - all functionality is deprecated
* StrExt::into_string - call to_string() instead
* StrExt::repeat - use iterators instead
* StrExt::char_len - use .chars().count() instead
* StrExt::is_alphanumeric - use .chars().all(..)
* StrExt::is_whitespace - use .chars().all(..)
Pending deprecation -- while slicing syntax is being worked out, these methods
are all #[unstable]
* Str - while currently used for generic programming, this trait will be
replaced with one of [], deref coercions, or a generic conversion trait.
* StrExt::slice - use slicing syntax instead
* StrExt::slice_to - use slicing syntax instead
* StrExt::slice_from - use slicing syntax instead
* StrExt::lev_distance - deprecated with no replacement
Awaiting stabilization due to patterns and/or matching
* StrExt::contains
* StrExt::contains_char
* StrExt::split
* StrExt::splitn
* StrExt::split_terminator
* StrExt::rsplitn
* StrExt::match_indices
* StrExt::split_str
* StrExt::starts_with
* StrExt::ends_with
* StrExt::trim_chars
* StrExt::trim_left_chars
* StrExt::trim_right_chars
* StrExt::find
* StrExt::rfind
* StrExt::find_str
* StrExt::subslice_offset
This flag is somewhat tied to the `unwind` module rather than the `thread_info`
module, so this commit moves it into that module as well as allowing the same OS
thread to call `unwind::try` multiple times. Previously once a thread panicked
its panic flag was never reset, even after exiting the panic handler.
The current implementations use `std::sync` primitives, but these primitives
currently end up relying on `thread_info` and a local `Thread` being available
(mainly for checking the panicking flag).
To get around this, this commit lowers the abstractions used by the windows
thread_local implementation as well as the at_exit_imp module. Both of these
modules now use a `sys::Mutex` and a `static mut` and manage the
allocation/locking manually.
This commit is part of a series that introduces a `std::thread` API to
replace `std::task`.
In the new API, `spawn` returns a `JoinGuard`, which by default will
join the spawned thread when dropped. It can also be used to join
explicitly at any time, returning the thread's result. Alternatively,
the spawned thread can be explicitly detached (so no join takes place).
As part of this change, Rust processes now terminate when the main
thread exits, even if other detached threads are still running, moving
Rust closer to standard threading models. This new behavior may break code
that was relying on the previously implicit join-all.
In addition to the above, the new thread API also offers some built-in
support for building blocking abstractions in user space; see the module
doc for details.
Closes#18000
[breaking-change]
This commit removes the runtime bookkeeping previously used to ensure
that all Rust tasks were joined before the runtime was shut down.
This functionality will be replaced by an RAII style `Thread` API, that
will also offer a detached mode.
Since this changes the semantics of shutdown, it is a:
[breaking-change]
This commit merges the `rustrt` crate into `std`, undoing part of the
facade. This merger continues the paring down of the runtime system.
Code relying on the public API of `rustrt` will break; some of this API
is now available through `std::rt`, but is likely to change and/or be
removed very soon.
[breaking-change]
followed by a semicolon.
This allows code like `vec![1i, 2, 3].len();` to work.
This breaks code that uses macros as statements without putting
semicolons after them, such as:
fn main() {
...
assert!(a == b)
assert!(c == d)
println(...);
}
It also breaks code that uses macros as items without semicolons:
local_data_key!(foo)
fn main() {
println("hello world")
}
Add semicolons to fix this code. Those two examples can be fixed as
follows:
fn main() {
...
assert!(a == b);
assert!(c == d);
println(...);
}
local_data_key!(foo);
fn main() {
println("hello world")
}
RFC #378.
Closes#18635.
[breaking-change]
