Commit Graph

59 Commits

Author SHA1 Message Date
Peter Atashian
dd11d3c619 Add error kind handling for ERROR_PATH_NOT_FOUND
Fixes #29150

Signed-off-by: Peter Atashian <retep998@gmail.com>
2015-10-19 00:54:51 -04:00
Cristi Cobzarenco
4b308b44e1 typos: fix a grabbag of typos all over the place 2015-10-08 19:49:31 +01:00
Alex Crichton
f4be2026df std: Internalize almost all of std::rt
This commit does some refactoring to make almost all of the `std::rt` private.
Specifically, the following items are no longer part of its API:

* DEFAULT_ERROR_CODE
* backtrace
* unwind
* args
* at_exit
* cleanup
* heap (this is just alloc::heap)
* min_stack
* util

The module is now tagged as `#[doc(hidden)]` as the only purpose it's serve is
an entry point for the `panic!` macro via the `begin_unwind` and
`begin_unwind_fmt` reexports.
2015-09-11 11:19:20 -07:00
Alex Crichton
8d90d3f368 Remove all unstable deprecated functionality
This commit removes all unstable and deprecated functions in the standard
library. A release was recently cut (1.3) which makes this a good time for some
spring cleaning of the deprecated functions.
2015-08-12 14:55:17 -07:00
Steven Fackler
999bdeca88 Stabilize the Duration API
This commit stabilizes the `std::time` module and the `Duration` type.
`Duration::span` remains unstable, and the `Display` implementation for
`Duration` has been removed as it is still being reworked and all trait
implementations for stable types are de facto stable.

This is a [breaking-change] to those using `Duration`'s `Display`
implementation.
2015-08-10 20:04:18 -04:00
Alex Crichton
10b103af48 std: Fix Windows XP compatibility
This commit enables executables linked against the standard library to run on
Windows XP. There are two main components of this commit:

* APIs not available on XP are shimmed to have a fallback implementation and use
  runtime detection to determine if they are available.
* Mutexes on Windows were reimplemented to use critical sections on XP where
  rwlocks are not available.

The APIs which are not available on XP are:

* SetFileInformationByHandle - this is just used by `File::truncate` and that
  function just returns an error now.
* SetThreadStackGuarantee - this is used by the stack overflow support on
  windows, but if this isn't available then it's just ignored (it seems
  non-critical).
* All condition variable APIs are missing - the shims added for these apis
  simply always panic for now. We may eventually provide a fallback
  implementation, but for now the standard library does not rely on condition
  variables for normal use.
* RWLocks, like condition variables, are missing entirely. The same story for
  condition variables is taken here. These APIs are all now panicking stubs as
  the standard library doesn't rely on RWLocks for normal use.

Currently, as an optimization, we use SRWLOCKs for the standard `sync::Mutex`
implementation on Windows, which is indeed required for normal operation of the
standard library. To allow the standard library to run on XP, this commit
reimplements mutexes on Windows to use SRWLOCK instances *if available* and
otherwise a CriticalSection is used (with some checking for recursive
locking).

With all these changes put together, a 32-bit MSVC-built executable can run on
Windows XP and print "hello world"

Closes #12842
Closes #19992
Closes #24776
2015-06-27 19:45:24 -07:00
Steven Fackler
69a0e1af95 Implement RFC 1047 - socket timeouts
Closes #25619
2015-05-28 20:03:20 -07:00
bors
dd4dad8c86 Auto merge of #24920 - alexcrichton:duration, r=aturon
This commit is an implementation of [RFC 1040][rfc] which is a redesign of the
currently-unstable `Duration` type. The API of the type has been scaled back to
be more conservative and it also no longer supports negative durations.

[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/1040-duration-reform.md

The inner `duration` module of the `time` module has now been hidden (as
`Duration` is reexported) and the feature name for this type has changed from
`std_misc` to `duration`. All APIs accepting durations have also been audited to
take a more flavorful feature name instead of `std_misc`.

Closes #24874
2015-05-14 18:18:39 +00:00
Alex Crichton
556e76bb78 std: Redesign Duration, implementing RFC 1040
This commit is an implementation of [RFC 1040][rfc] which is a redesign of the
currently-unstable `Duration` type. The API of the type has been scaled back to
be more conservative and it also no longer supports negative durations.

[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/1040-duration-reform.md

The inner `duration` module of the `time` module has now been hidden (as
`Duration` is reexported) and the feature name for this type has changed from
`std_misc` to `duration`. All APIs accepting durations have also been audited to
take a more flavorful feature name instead of `std_misc`.

Closes #24874
2015-05-13 17:50:58 -07:00
Alex Crichton
377b1adc36 std: Rename sys::foo2 modules to sys::foo
Now that `std::old_io` has been removed for quite some time the naming real
estate here has opened up to allow these modules to move back to their proper
names.
2015-05-07 09:30:00 -07:00
Alex Crichton
a568a7f9f2 std: Bring back f32::from_str_radix as an unstable API
This API was exercised in a few tests and mirrors the `from_str_radix`
functionality of the integer types.
2015-04-21 15:23:54 -07:00
Alex Crichton
bf4e77d4b5 std: Remove old_io/old_path/rand modules
This commit entirely removes the old I/O, path, and rand modules. All
functionality has been deprecated and unstable for quite some time now!
2015-04-14 10:14:11 -07:00
Aaron Turon
232424d995 Stabilize std::num
This commit stabilizes the `std::num` module:

* The `Int` and `Float` traits are deprecated in favor of (1) the
  newly-added inherent methods and (2) the generic traits available in
  rust-lang/num.

* The `Zero` and `One` traits are reintroduced in `std::num`, which
  together with various other traits allow you to recover the most
  common forms of generic programming.

* The `FromStrRadix` trait, and associated free function, is deprecated
  in favor of inherent implementations.

* A wide range of methods and constants for both integers and floating
  point numbers are now `#[stable]`, having been adjusted for integer
  guidelines.

* `is_positive` and `is_negative` are renamed to `is_sign_positive` and
  `is_sign_negative`, in order to address #22985

* The `Wrapping` type is moved to `std::num` and stabilized;
  `WrappingOps` is deprecated in favor of inherent methods on the
  integer types, and direct implementation of operations on
  `Wrapping<X>` for each concrete integer type `X`.

Closes #22985
Closes #21069

[breaking-change]
2015-03-31 07:50:25 -07:00
Alex Crichton
29b54387b8 Test fixes and rebase conflicts, round 2 2015-03-23 17:10:19 -07:00
Alex Crichton
dedac5eb3c std: Stablize io::ErrorKind
This commit stabilizes the `ErrorKind` enumeration which is consumed by and
generated by the `io::Error` type. The purpose of this type is to serve as a
cross-platform namespace to categorize errors into. Two specific issues are
addressed as part of this stablization:

* The naming of each variant was scrutinized and some were tweaked. An example
  is how `FileNotFound` was renamed to simply `NotFound`. These names should not
  show either a Unix or Windows bias and the set of names is intended to grow
  over time. For now the names will likely largely consist of those errors
  generated by the I/O APIs in the standard library.

* The mapping of OS error codes onto kinds has been altered. Coalescing no
  longer occurs (multiple error codes become one kind). It is intended that each
  OS error code, if bound, corresponds to only one `ErrorKind`. The current set
  of error kinds was expanded slightly to include some networking errors.

This commit also adds a `raw_os_error` function which returns an `Option<i32>`
to extract the underlying raw error code from the `Error`.
2015-03-19 09:59:21 -07:00
Alex Crichton
1f5f76adc3 std: Stabilize portions of std::os::$platform
This commit starts to organize the `std::os::$platform` modules and in the
process stabilizes some of the functionality contained within. The organization
of these modules will reflect the organization of the standard library itself
with extension traits for primitives in the same corresponding module.

The OS-specific modules will grow more functionality over time including
concrete types that are not extending functionality of other structures, and
these will either go into the closest module in `std::os::$platform` or they
will grow a new module in the hierarchy.

The following items are now stable:

* `os::{unix, windows}`
* `unix::ffi`
* `unix::ffi::OsStrExt`
* `unix::ffi::OsStrExt::{from_bytes, as_bytes, to_cstring}`
* `unix::ffi::OsString`
* `unix::ffi::OsStringExt::{from_vec, into_vec}`
* `unix::process`
* `unix::process::CommandExt`
* `unix::process::CommandExt::{uid, gid}`
* `unix::process::ExitStatusExt`
* `unix::process::ExitStatusExt::signal`
* `unix::prelude`
* `windows::ffi`
* `windows::ffi::OsStringExt`
* `windows::ffi::OsStringExt::from_wide`
* `windows::ffi::OsStrExt`
* `windows::ffi::OsStrExt::encode_wide`
* `windows::prelude`

The following items remain unstable:

* `unix::io`
* `unix::io::{Fd, AsRawFd}`
* `unix::fs::{PermissionsExt, OpenOptionsExt}`
* `windows::io`
* `windows::io::{Handle, AsRawHandle}`
* `windows::io::{Socket, AsRawSocket}`
* `windows::fs`
* `windows::fs::OpenOptionsExt`

Due to the reorgnization of the platform extension modules, this commit is a
breaking change. Most imports can be fixed by adding the relevant libstd module
in the `use` path (such as `ffi` or `fs`).

[breaking-change]
2015-03-15 10:28:34 -07:00
Alex Crichton
981bf5f690 Fallout of std::old_io deprecation 2015-03-13 10:00:28 -07:00
Alex Crichton
c933d44f7b std: Remove #[allow] directives in sys modules
These were suppressing lots of interesting warnings! Turns out there was also
quite a bit of dead code.
2015-03-12 10:23:27 -07:00
Alex Crichton
94d71f8836 std: Implement stdio for std::io
This is an implementation of RFC 899 and adds stdio functionality to the new
`std::io` module. Details of the API can be found on the RFC, but from a high
level:

* `io::{stdin, stdout, stderr}` constructors are now available. There are also
  `*_raw` variants for unbuffered and unlocked access.
* All handles are globally shared (excluding raw variants).
* The stderr handle is no longer buffered.
* All handles can be explicitly locked (excluding the raw variants).

The `print!` and `println!` machinery has not yet been hooked up to these
streams just yet. The `std::fmt::output` module has also not yet been
implemented as part of this commit.
2015-02-28 23:13:02 -08:00
Manish Goregaokar
e61a790495 Fix type inference error (fixup #22739) 2015-02-25 13:58:58 +05:30
Manish Goregaokar
b18584cbd9 Rollup merge of #22727 - alexcrichton:prep-env, r=aturon
This commit moves `std::env` away from the `std::old_io` error type as well as
the `std::old_path` module. Methods returning an error now return `io::Error`
and methods consuming or returning paths use `std::path` instead of
`std::old_path`. This commit does not yet mark these APIs as `#[stable]`.

This commit also migrates `std::old_io::TempDir` to `std::fs::TempDir` with
essentially the exact same API. This type was added to interoperate with the new
path API and has its own `tempdir` feature.

Finally, this commit reverts the deprecation of `std::os` APIs returning the old
path API types. This deprecation can come back once the entire `std::old_path`
module is deprecated.

[breaking-change]
2015-02-25 10:29:39 +05:30
Alex Crichton
2d200c9c8b std: Move std::env to the new I/O APIs
This commit moves `std::env` away from the `std::old_io` error type as well as
the `std::old_path` module. Methods returning an error now return `io::Error`
and methods consuming or returning paths use `std::path` instead of
`std::old_path`. This commit does not yet mark these APIs as `#[stable]`.

This commit also migrates `std::old_io::TempDir` to `std::fs::TempDir` with
essentially the exact same API. This type was added to interoperate with the new
path API and has its own `tempdir` feature.

Finally, this commit reverts the deprecation of `std::os` APIs returning the old
path API types. This deprecation can come back once the entire `std::old_path`
module is deprecated.

[breaking-change]
2015-02-24 15:27:42 -08:00
Tobias Bucher
0fc1a7da93 Improve readability of an error check in set_non_blocking 2015-02-24 18:03:01 +01:00
Tobias Bucher
d0c589d5ce Hide unnecessary error checking from the user
This affects the `set_non_blocking` function which cannot fail for Unix or
Windows, given correct parameters. Additionally, the short UDP write error case
has been removed as there is no such thing as "short UDP writes", instead, the
operating system will error out if the application tries to send a packet
larger than the MTU of the network path.
2015-02-23 23:52:24 +01:00
Niko Matsakis
9ea84aeed4 Replace all uses of &foo[] with &foo[..] en masse. 2015-02-18 17:36:03 -05:00
Aaron Turon
4175f1ce2f Add std::process
Per [RFC 579](https://github.com/rust-lang/rfcs/pull/579), this commit
adds a new `std::process` module. This module is largely based on the
existing `std::old_io::process` module, but refactors the API to use
`OsStr` and other new standards set out by IO reform.

The existing module is not yet deprecated, to allow for the new API to
get a bit of testing before a mass migration to it.
2015-02-13 23:21:08 -08:00
Alex Crichton
395709ca6d std: Add a net module for TCP/UDP
This commit is an implementation of [RFC 807][rfc] which adds a `std::net`
module for basic neworking based on top of `std::io`. This module serves as a
replacement for the `std::old_io::net` module and networking primitives in
`old_io`.

[rfc]: fillmein

The major focus of this redesign is to cut back on the level of abstraction to
the point that each of the networking types is just a bare socket. To this end
functionality such as timeouts and cloning has been removed (although cloning
can be done through `duplicate`, it may just yield an error).

With this `net` module comes a new implementation of `SocketAddr` and `IpAddr`.
This work is entirely based on #20785 and the only changes were to alter the
in-memory representation to match the `libc`-expected variants and to move from
public fields to accessors.
2015-02-11 15:23:34 -08:00
Alex Crichton
6bfbad937b std: Add a new fs module
This commit is an implementation of [RFC 739][rfc] which adds a new `std::fs`
module to the standard library. This module provides much of the same
functionality as `std::old_io::fs` but it has many tweaked APIs as well as uses
the new `std::path` module.

[rfc]: https://github.com/rust-lang/rfcs/pull/739
2015-02-09 18:43:12 -08:00
Alex Crichton
5cf9905e25 std: Add io module again
This commit is an implementation of [RFC 576][rfc] which adds back the `std::io`
module to the standard library. No functionality in `std::old_io` has been
deprecated just yet, and the new `std::io` module is behind the same `io`
feature gate.

[rfc]: https://github.com/rust-lang/rfcs/pull/576

A good bit of functionality was copied over from `std::old_io`, but many tweaks
were required for the new method signatures. Behavior such as precisely when
buffered objects call to the underlying object may have been tweaked slightly in
the transition. All implementations were audited to use composition wherever
possible. For example the custom `pos` and `cap` cursors in `BufReader` were
removed in favor of just using `Cursor<Vec<u8>>`.

A few liberties were taken during this implementation which were not explicitly
spelled out in the RFC:

* The old `LineBufferedWriter` is now named `LineWriter`
* The internal representation of `Error` now favors OS error codes (a
  0-allocation path) and contains a `Box` for extra semantic data.
* The io prelude currently reexports `Seek` as `NewSeek` to prevent conflicts
  with the real prelude reexport of `old_io::Seek`
* The `chars` method was moved from `BufReadExt` to `ReadExt`.
* The `chars` iterator returns a custom error with a variant that explains that
  the data was not valid UTF-8.
2015-02-03 12:51:12 -08:00
Alex Crichton
70ed3a48df std: Add a new env module
This is an implementation of [RFC 578][rfc] which adds a new `std::env` module
to replace most of the functionality in the current `std::os` module. More
details can be found in the RFC itself, but as a summary the following methods
have all been deprecated:

[rfc]: https://github.com/rust-lang/rfcs/pull/578

* `os::args_as_bytes`   => `env::args`
* `os::args`            => `env::args`
* `os::consts`          => `env::consts`
* `os::dll_filename`    => no replacement, use `env::consts` directly
* `os::page_size`       => `env::page_size`
* `os::make_absolute`   => use `env::current_dir` + `join` instead
* `os::getcwd`          => `env::current_dir`
* `os::change_dir`      => `env::set_current_dir`
* `os::homedir`         => `env::home_dir`
* `os::tmpdir`          => `env::temp_dir`
* `os::join_paths`      => `env::join_paths`
* `os::split_paths`     => `env::split_paths`
* `os::self_exe_name`   => `env::current_exe`
* `os::self_exe_path`   => use `env::current_exe` + `pop`
* `os::set_exit_status` => `env::set_exit_status`
* `os::get_exit_status` => `env::get_exit_status`
* `os::env`             => `env::vars`
* `os::env_as_bytes`    => `env::vars`
* `os::getenv`          => `env::var` or `env::var_string`
* `os::getenv_as_bytes` => `env::var`
* `os::setenv`          => `env::set_var`
* `os::unsetenv`        => `env::remove_var`

Many function signatures have also been tweaked for various purposes, but the
main changes were:

* `Vec`-returning APIs now all return iterators instead
* All APIs are now centered around `OsString` instead of `Vec<u8>` or `String`.
  There is currently on convenience API, `env::var_string`, which can be used to
  get the value of an environment variable as a unicode `String`.

All old APIs are `#[deprecated]` in-place and will remain for some time to allow
for migrations. The semantics of the APIs have been tweaked slightly with regard
to dealing with invalid unicode (panic instead of replacement).

The new `std::env` module is all contained within the `env` feature, so crates
must add the following to access the new APIs:

    #![feature(env)]

[breaking-change]
2015-02-01 11:08:15 -08:00
Alex Crichton
5d836cdf86 std: Rename Writer::write to Writer::write_all
In preparation for upcoming changes to the `Writer` trait (soon to be called
`Write`) this commit renames the current `write` method to `write_all` to match
the semantics of the upcoming `write_all` method. The `write` method will be
repurposed to return a `usize` indicating how much data was written which
differs from the current `write` semantics. In order to head off as much
unintended breakage as possible, the method is being deprecated now in favor of
a new name.

[breaking-change]
2015-01-26 16:01:58 -08:00
Aaron Turon
c5369ebc7f Add ffi::OsString and OsStr
Per [RFC 517](https://github.com/rust-lang/rfcs/pull/575/), this commit
introduces platform-native strings. The API is essentially as described
in the RFC.

The WTF-8 implementation is adapted from @SimonSapin's
[implementation](https://github.com/SimonSapin/rust-wtf8). To make this
work, some encodign and decoding functionality in `libcore` is now
exported in a "raw" fashion reusable for WTF-8. These exports are *not*
reexported in `std`, nor are they stable.
2015-01-24 10:21:30 -08:00
Steven Fackler
08f6380a9f Rewrite Condvar::wait_timeout and make it public
**The implementation is a direct adaptation of libcxx's
condition_variable implementation.**

pthread_cond_timedwait uses the non-monotonic system clock. It's
possible to change the clock to a monotonic via pthread_cond_attr, but
this is incompatible with static initialization. To deal with this, we
calculate the timeout using the system clock, and maintain a separate
record of the start and end times with a monotonic clock to be used for
calculation of the return value.
2015-01-16 09:17:37 -08:00
Jorge Aparicio
56dcbd17fd sed -i -s 's/\bmod,/self,/g' **/*.rs 2015-01-03 22:42:21 -05:00
Alex Crichton
e921e3f045 Rollup test fixes and rebase conflicts 2015-01-02 10:50:13 -08:00
Alex Crichton
009ec5d2b0 rollup merge of #20315: alexcrichton/std-sync
Conflicts:
	src/libstd/rt/exclusive.rs
	src/libstd/sync/barrier.rs
	src/libstd/sys/unix/pipe.rs
	src/test/bench/shootout-binarytrees.rs
	src/test/bench/shootout-fannkuch-redux.rs
2015-01-02 09:19:00 -08:00
Alex Crichton
56290a0044 std: Stabilize the prelude module
This commit is an implementation of [RFC 503][rfc] which is a stabilization
story for the prelude. Most of the RFC was directly applied, removing reexports.
Some reexports are kept around, however:

* `range` remains until range syntax has landed to reduce churn.
* `Path` and `GenericPath` remain until path reform lands. This is done to
  prevent many imports of `GenericPath` which will soon be removed.
* All `io` traits remain until I/O reform lands so imports can be rewritten all
  at once to `std::io::prelude::*`.

This is a breaking change because many prelude reexports have been removed, and
the RFC can be consulted for the exact list of removed reexports, as well as to
find the locations of where to import them.

[rfc]: https://github.com/rust-lang/rfcs/blob/master/text/0503-prelude-stabilization.md
[breaking-change]

Closes #20068
2015-01-02 08:54:06 -08:00
Alex Crichton
f3a7ec7028 std: Second pass stabilization of sync
This pass performs a second pass of stabilization through the `std::sync`
module, avoiding modules/types that are being handled in other PRs (e.g.
mutexes, rwlocks, condvars, and channels).

The following items are now stable

* `sync::atomic`
* `sync::atomic::ATOMIC_BOOL_INIT` (was `INIT_ATOMIC_BOOL`)
* `sync::atomic::ATOMIC_INT_INIT` (was `INIT_ATOMIC_INT`)
* `sync::atomic::ATOMIC_UINT_INIT` (was `INIT_ATOMIC_UINT`)
* `sync::Once`
* `sync::ONCE_INIT`
* `sync::Once::call_once` (was `doit`)
  * C == `pthread_once(..)`
  * Boost == `call_once(..)`
  * Windows == `InitOnceExecuteOnce`
* `sync::Barrier`
* `sync::Barrier::new`
* `sync::Barrier::wait` (now returns a `bool`)
* `sync::Semaphore::new`
* `sync::Semaphore::acquire`
* `sync::Semaphore::release`

The following items remain unstable

* `sync::SemaphoreGuard`
* `sync::Semaphore::access` - it's unclear how this relates to the poisoning
                              story of mutexes.
* `sync::TaskPool` - the semantics of a failing task and whether a thread is
                     re-attached to a thread pool are somewhat unclear, and the
                     utility of this type in `sync` is question with respect to
                     the jobs of other primitives. This type will likely become
                     stable or move out of the standard library over time.
* `sync::Future` - futures as-is have yet to be deeply re-evaluated with the
                   recent core changes to Rust's synchronization story, and will
                   likely become stable in the future but are unstable until
                   that time comes.

[breaking-change]
2015-01-01 22:02:59 -08:00
Alex Crichton
aec67c2ee0 Revert "std: Re-enable at_exit()"
This reverts commit 9e224c2bf1.

Conflicts:
	src/libstd/sys/windows/os.rs
2014-12-31 10:20:31 -08:00
Alex Crichton
b936fb3d16 rollup merge of #20286: murarth/get-address-name 2014-12-30 16:26:02 -08:00
Alex Crichton
9e224c2bf1 std: Re-enable at_exit()
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
2014-12-30 14:33:59 -08:00
Murarth
e6c8b8f480 Added get_address_name, an interface to getnameinfo 2014-12-28 15:45:43 -07:00
Florian Hahn
eb4b20288e Map EEXIST to PathAlreadyExists error, closes #20226 2014-12-25 22:22:44 +01:00
Aaron Turon
2b3477d373 libs: merge librustrt into libstd
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]
2014-12-18 23:31:34 -08:00
Patrick Walton
ddb2466f6a librustc: Always parse macro!()/macro![] as expressions if not
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]
2014-12-18 12:09:07 -05:00
Jorge Aparicio
cdbb3ca9b7 libstd: use unboxed closures 2014-12-13 17:03:47 -05:00
Alex Crichton
c3adbd34c4 Fall out of the std::sync rewrite 2014-12-05 09:12:25 -08:00
Alex Crichton
71d4e77db8 std: Rewrite the sync module
This commit is a reimplementation of `std::sync` to be based on the
system-provided primitives wherever possible. The previous implementation was
fundamentally built on top of channels, and as part of the runtime reform it has
become clear that this is not the level of abstraction that the standard level
should be providing. This rewrite aims to provide as thin of a shim as possible
on top of the system primitives in order to make them safe.

The overall interface of the `std::sync` module has in general not changed, but
there are a few important distinctions, highlighted below:

* The condition variable type, `Condvar`, has been separated out of a `Mutex`.
  A condition variable is now an entirely separate type. This separation
  benefits users who only use one mutex, and provides a clearer distinction of
  who's responsible for managing condition variables (the application).

* All of `Condvar`, `Mutex`, and `RWLock` are now directly built on top of
  system primitives rather than using a custom implementation. The `Once`,
  `Barrier`, and `Semaphore` types are still built upon these abstractions of
  the system primitives.

* The `Condvar`, `Mutex`, and `RWLock` types all have a new static type and
  constant initializer corresponding to them. These are provided primarily for C
  FFI interoperation, but are often useful to otherwise simply have a global
  lock. The types, however, will leak memory unless `destroy()` is called on
  them, which is clearly documented.

* The `Condvar` implementation for an `RWLock` write lock has been removed. This
  may be added back in the future with a userspace implementation, but this
  commit is focused on exposing the system primitives first.

* The fundamental architecture of this design is to provide two separate layers.
  The first layer is that exposed by `sys_common` which is a cross-platform
  bare-metal abstraction of the system synchronization primitives. No attempt is
  made at making this layer safe, and it is quite unsafe to use! It is currently
  not exported as part of the API of the standard library, but the stabilization
  of the `sys` module will ensure that these will be exposed in time. The
  purpose of this layer is to provide the core cross-platform abstractions if
  necessary to implementors.

  The second layer is the layer provided by `std::sync` which is intended to be
  the thinnest possible layer on top of `sys_common` which is entirely safe to
  use. There are a few concerns which need to be addressed when making these
  system primitives safe:

    * Once used, the OS primitives can never be **moved**. This means that they
      essentially need to have a stable address. The static primitives use
      `&'static self` to enforce this, and the non-static primitives all use a
      `Box` to provide this guarantee.

    * Poisoning is leveraged to ensure that invalid data is not accessible from
      other tasks after one has panicked.

  In addition to these overall blanket safety limitations, each primitive has a
  few restrictions of its own:

    * Mutexes and rwlocks can only be unlocked from the same thread that they
      were locked by. This is achieved through RAII lock guards which cannot be
      sent across threads.

    * Mutexes and rwlocks can only be unlocked if they were previously locked.
      This is achieved by not exposing an unlocking method.

    * A condition variable can only be waited on with a locked mutex. This is
      achieved by requiring a `MutexGuard` in the `wait()` method.

    * A condition variable cannot be used concurrently with more than one mutex.
      This is guaranteed by dynamically binding a condition variable to
      precisely one mutex for its entire lifecycle. This restriction may be able
      to be relaxed in the future (a mutex is unbound when no threads are
      waiting on the condvar), but for now it is sufficient to guarantee safety.

* Condvars now support timeouts for their blocking operations. The
  implementation for these operations is provided by the system.

Due to the modification of the `Condvar` API, removal of the `std::sync::mutex`
API, and reimplementation, this is a breaking change. Most code should be fairly
easy to port using the examples in the documentation of these primitives.

[breaking-change]

Closes #17094
Closes #18003
2014-12-05 00:53:22 -08:00
bors
61af402789 auto merge of #19169 : aturon/rust/fds, r=alexcrichton
This PR adds some internal infrastructure to allow the private `std::sys` module to access internal representation details of `std::io`.

It then exposes those details in two new, platform-specific API surfaces: `std::os::unix` and `std::os::windows`.

To start with, these will provide the ability to extract file descriptors, HANDLEs, SOCKETs, and so on from `std::io` types.

More functionality, and more specific platforms (e.g. `std::os::linux`) will be added over time.

Closes #18897
2014-11-26 08:42:09 +00:00
Alex Crichton
a9c1152c4b std: Add a new top-level thread_local module
This commit removes the `std::local_data` module in favor of a new
`std::thread_local` module providing thread local storage. The module provides
two variants of TLS: one which owns its contents and one which is based on
scoped references. Each implementation has pros and cons listed in the
documentation.

Both flavors have accessors through a function called `with` which yield a
reference to a closure provided. Both flavors also panic if a reference cannot
be yielded and provide a function to test whether an access would panic or not.
This is an implementation of [RFC 461][rfc] and full details can be found in
that RFC.

This is a breaking change due to the removal of the `std::local_data` module.
All users can migrate to the new thread local system like so:

    thread_local!(static FOO: Rc<RefCell<Option<T>>> = Rc::new(RefCell::new(None)))

The old `local_data` module inherently contained the `Rc<RefCell<Option<T>>>` as
an implementation detail which must now be explicitly stated by users.

[rfc]: https://github.com/rust-lang/rfcs/pull/461
[breaking-change]
2014-11-23 23:37:16 -08:00