1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Platform-independent platform abstraction
13 //! This is the platform-independent portion of the standard library's
14 //! platform abstraction layer, whereas `std::sys` is the
15 //! platform-specific portion.
17 //! The relationship between `std::sys_common`, `std::sys` and the
18 //! rest of `std` is complex, with dependencies going in all
19 //! directions: `std` depending on `sys_common`, `sys_common`
20 //! depending on `sys`, and `sys` depending on `sys_common` and `std`.
21 //! Ideally `sys_common` would be split into two and the dependencies
22 //! between them all would form a dag, facilitating the extraction of
23 //! `std::sys` from the standard library.
25 #![allow(missing_docs)]
26 #![allow(missing_debug_implementations)]
32 #[cfg(any(not(cargobuild), feature = "backtrace"))]
47 #[cfg(target_os = "redox")]
50 #[cfg(not(target_os = "redox"))]
53 #[cfg(any(not(cargobuild), feature = "backtrace"))]
54 #[cfg(any(all(unix, not(any(target_os = "macos", target_os = "ios", target_os = "emscripten"))),
55 all(windows, target_env = "gnu")))]
58 // common error constructors
60 /// A trait for viewing representations from std types
62 pub trait AsInner<Inner: ?Sized> {
63 fn as_inner(&self) -> &Inner;
66 /// A trait for viewing representations from std types
68 pub trait AsInnerMut<Inner: ?Sized> {
69 fn as_inner_mut(&mut self) -> &mut Inner;
72 /// A trait for extracting representations from std types
74 pub trait IntoInner<Inner> {
75 fn into_inner(self) -> Inner;
78 /// A trait for creating std types from internal representations
80 pub trait FromInner<Inner> {
81 fn from_inner(inner: Inner) -> Self;
84 /// Enqueues a procedure to run when the main thread exits.
86 /// Currently these closures are only run once the main *Rust* thread exits.
87 /// Once the `at_exit` handlers begin running, more may be enqueued, but not
88 /// infinitely so. Eventually a handler registration will be forced to fail.
90 /// Returns `Ok` if the handler was successfully registered, meaning that the
91 /// closure will be run once the main thread exits. Returns `Err` to indicate
92 /// that the closure could not be registered, meaning that it is not scheduled
94 pub fn at_exit<F: FnOnce() + Send + 'static>(f: F) -> Result<(), ()> {
95 if at_exit_imp::push(Box::new(f)) {Ok(())} else {Err(())}
98 macro_rules! rtabort {
99 ($($t:tt)*) => (::sys_common::util::abort(format_args!($($t)*)))
102 /// One-time runtime cleanup.
104 static CLEANUP: Once = Once::new();
105 CLEANUP.call_once(|| unsafe {
106 sys::args::cleanup();
107 sys::stack_overflow::cleanup();
108 at_exit_imp::cleanup();
112 // Computes (value*numer)/denom without overflow, as long as both
113 // (numer*denom) and the overall result fit into i64 (which is the case
114 // for our time conversions).
115 #[allow(dead_code)] // not used on all platforms
116 pub fn mul_div_u64(value: u64, numer: u64, denom: u64) -> u64 {
117 let q = value / denom;
118 let r = value % denom;
119 // Decompose value as (value/denom*denom + value%denom),
120 // substitute into (value*numer)/denom and simplify.
121 // r < denom, so (denom*numer) is the upper bound of (r*numer)
122 q * numer + r * numer / denom
127 assert_eq!(mul_div_u64( 1_000_000_000_001, 1_000_000_000, 1_000_000),
128 1_000_000_000_001_000);