src/libstd/sys/common/mod.rs

   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.
   4 //
   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.
  10
  11 #![allow(missing_docs)]
  12
  13 use boxed::Box;
  14 use sync::Once;
  15 use sys;
  16
  17 macro_rules! rtabort {
  18     ($($t:tt)*) => (::sys_common::util::abort(format_args!($($t)*)))
  19 }
  20
  21 macro_rules! rtassert {
  22     ($e:expr) => ({
  23         if !$e {
  24             rtabort!(concat!("assertion failed: ", stringify!($e)))
  25         }
  26     })
  27 }
  28
  29 pub mod args;
  30 pub mod at_exit_imp;
  31 pub mod backtrace;
  32 pub mod condvar;
  33 pub mod dwarf;
  34 pub mod io;
  35 pub mod libunwind;
  36 pub mod mutex;
  37 pub mod net;
  38 pub mod poison;
  39 pub mod remutex;
  40 pub mod rwlock;
  41 pub mod thread;
  42 pub mod thread_info;
  43 pub mod thread_local;
  44 pub mod unwind;
  45 pub mod util;
  46 pub mod wtf8;
  47
  48 #[cfg(any(all(unix, not(any(target_os = "macos", target_os = "ios"))),
  49           all(windows, target_env = "gnu")))]
  50 pub mod gnu;
  51
  52 // common error constructors
  53
  54 /// A trait for viewing representations from std types
  55 #[doc(hidden)]
  56 pub trait AsInner<Inner: ?Sized> {
  57     fn as_inner(&self) -> &Inner;
  58 }
  59
  60 /// A trait for viewing representations from std types
  61 #[doc(hidden)]
  62 pub trait AsInnerMut<Inner: ?Sized> {
  63     fn as_inner_mut(&mut self) -> &mut Inner;
  64 }
  65
  66 /// A trait for extracting representations from std types
  67 #[doc(hidden)]
  68 pub trait IntoInner<Inner> {
  69     fn into_inner(self) -> Inner;
  70 }
  71
  72 /// A trait for creating std types from internal representations
  73 #[doc(hidden)]
  74 pub trait FromInner<Inner> {
  75     fn from_inner(inner: Inner) -> Self;
  76 }
  77
  78 /// Enqueues a procedure to run when the main thread exits.
  79 ///
  80 /// Currently these closures are only run once the main *Rust* thread exits.
  81 /// Once the `at_exit` handlers begin running, more may be enqueued, but not
  82 /// infinitely so. Eventually a handler registration will be forced to fail.
  83 ///
  84 /// Returns `Ok` if the handler was successfully registered, meaning that the
  85 /// closure will be run once the main thread exits. Returns `Err` to indicate
  86 /// that the closure could not be registered, meaning that it is not scheduled
  87 /// to be run.
  88 pub fn at_exit<F: FnOnce() + Send + 'static>(f: F) -> Result<(), ()> {
  89     if at_exit_imp::push(Box::new(f)) {Ok(())} else {Err(())}
  90 }
  91
  92 /// One-time runtime cleanup.
  93 pub fn cleanup() {
  94     static CLEANUP: Once = Once::new();
  95     CLEANUP.call_once(|| unsafe {
  96         args::cleanup();
  97         sys::stack_overflow::cleanup();
  98         at_exit_imp::cleanup();
  99     });
 100 }
 101
 102 // Computes (value*numer)/denom without overflow, as long as both
 103 // (numer*denom) and the overall result fit into i64 (which is the case
 104 // for our time conversions).
 105 #[allow(dead_code)] // not used on all platforms
 106 pub fn mul_div_u64(value: u64, numer: u64, denom: u64) -> u64 {
 107     let q = value / denom;
 108     let r = value % denom;
 109     // Decompose value as (value/denom*denom + value%denom),
 110     // substitute into (value*numer)/denom and simplify.
 111     // r < denom, so (denom*numer) is the upper bound of (r*numer)
 112     q * numer + r * numer / denom
 113 }
 114
 115 #[test]
 116 fn test_muldiv() {
 117     assert_eq!(mul_div_u64( 1_000_000_000_001, 1_000_000_000, 1_000_000),
 118                1_000_000_000_001_000);
 119 }