src/libstd/sys/windows/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, bad_style)]
  12
  13 use prelude::v1::*;
  14
  15 use ffi::{OsStr, OsString};
  16 use io::{self, ErrorKind};
  17 use num::Zero;
  18 use os::windows::ffi::{OsStrExt, OsStringExt};
  19 use path::PathBuf;
  20 use time::Duration;
  21
  22 #[macro_use] pub mod compat;
  23
  24 pub mod backtrace;
  25 pub mod c;
  26 pub mod condvar;
  27 pub mod dynamic_lib;
  28 pub mod ext;
  29 pub mod fs;
  30 pub mod handle;
  31 pub mod mutex;
  32 pub mod net;
  33 pub mod os;
  34 pub mod os_str;
  35 pub mod pipe;
  36 pub mod process;
  37 pub mod rand;
  38 pub mod rwlock;
  39 pub mod stack_overflow;
  40 pub mod thread;
  41 pub mod thread_local;
  42 pub mod time;
  43 pub mod stdio;
  44
  45 #[cfg(not(test))]
  46 pub fn init() {
  47     ::alloc::oom::set_oom_handler(oom_handler);
  48
  49     // See comment in sys/unix/mod.rs
  50     fn oom_handler() -> ! {
  51         use intrinsics;
  52         use ptr;
  53         let msg = "fatal runtime error: out of memory\n";
  54         unsafe {
  55             // WriteFile silently fails if it is passed an invalid handle, so
  56             // there is no need to check the result of GetStdHandle.
  57             c::WriteFile(c::GetStdHandle(c::STD_ERROR_HANDLE),
  58                          msg.as_ptr() as c::LPVOID,
  59                          msg.len() as c::DWORD,
  60                          ptr::null_mut(),
  61                          ptr::null_mut());
  62             intrinsics::abort();
  63         }
  64     }
  65 }
  66
  67 pub fn decode_error_kind(errno: i32) -> ErrorKind {
  68     match errno as c::DWORD {
  69         c::ERROR_ACCESS_DENIED => return ErrorKind::PermissionDenied,
  70         c::ERROR_ALREADY_EXISTS => return ErrorKind::AlreadyExists,
  71         c::ERROR_BROKEN_PIPE => return ErrorKind::BrokenPipe,
  72         c::ERROR_FILE_NOT_FOUND => return ErrorKind::NotFound,
  73         c::ERROR_PATH_NOT_FOUND => return ErrorKind::NotFound,
  74         c::ERROR_NO_DATA => return ErrorKind::BrokenPipe,
  75         c::ERROR_OPERATION_ABORTED => return ErrorKind::TimedOut,
  76         _ => {}
  77     }
  78
  79     match errno {
  80         c::WSAEACCES => ErrorKind::PermissionDenied,
  81         c::WSAEADDRINUSE => ErrorKind::AddrInUse,
  82         c::WSAEADDRNOTAVAIL => ErrorKind::AddrNotAvailable,
  83         c::WSAECONNABORTED => ErrorKind::ConnectionAborted,
  84         c::WSAECONNREFUSED => ErrorKind::ConnectionRefused,
  85         c::WSAECONNRESET => ErrorKind::ConnectionReset,
  86         c::WSAEINVAL => ErrorKind::InvalidInput,
  87         c::WSAENOTCONN => ErrorKind::NotConnected,
  88         c::WSAEWOULDBLOCK => ErrorKind::WouldBlock,
  89         c::WSAETIMEDOUT => ErrorKind::TimedOut,
  90
  91         _ => ErrorKind::Other,
  92     }
  93 }
  94
  95 pub fn to_u16s<S: AsRef<OsStr>>(s: S) -> io::Result<Vec<u16>> {
  96     fn inner(s: &OsStr) -> io::Result<Vec<u16>> {
  97         let mut maybe_result: Vec<u16> = s.encode_wide().collect();
  98         if maybe_result.iter().any(|&u| u == 0) {
  99             return Err(io::Error::new(io::ErrorKind::InvalidInput,
 100                                       "strings passed to WinAPI cannot contain NULs"));
 101         }
 102         maybe_result.push(0);
 103         Ok(maybe_result)
 104     }
 105     inner(s.as_ref())
 106 }
 107
 108 // Many Windows APIs follow a pattern of where we hand a buffer and then they
 109 // will report back to us how large the buffer should be or how many bytes
 110 // currently reside in the buffer. This function is an abstraction over these
 111 // functions by making them easier to call.
 112 //
 113 // The first callback, `f1`, is yielded a (pointer, len) pair which can be
 114 // passed to a syscall. The `ptr` is valid for `len` items (u16 in this case).
 115 // The closure is expected to return what the syscall returns which will be
 116 // interpreted by this function to determine if the syscall needs to be invoked
 117 // again (with more buffer space).
 118 //
 119 // Once the syscall has completed (errors bail out early) the second closure is
 120 // yielded the data which has been read from the syscall. The return value
 121 // from this closure is then the return value of the function.
 122 fn fill_utf16_buf<F1, F2, T>(mut f1: F1, f2: F2) -> io::Result<T>
 123     where F1: FnMut(*mut u16, c::DWORD) -> c::DWORD,
 124           F2: FnOnce(&[u16]) -> T
 125 {
 126     // Start off with a stack buf but then spill over to the heap if we end up
 127     // needing more space.
 128     let mut stack_buf = [0u16; 512];
 129     let mut heap_buf = Vec::new();
 130     unsafe {
 131         let mut n = stack_buf.len();
 132         loop {
 133             let buf = if n <= stack_buf.len() {
 134                 &mut stack_buf[..]
 135             } else {
 136                 let extra = n - heap_buf.len();
 137                 heap_buf.reserve(extra);
 138                 heap_buf.set_len(n);
 139                 &mut heap_buf[..]
 140             };
 141
 142             // This function is typically called on windows API functions which
 143             // will return the correct length of the string, but these functions
 144             // also return the `0` on error. In some cases, however, the
 145             // returned "correct length" may actually be 0!
 146             //
 147             // To handle this case we call `SetLastError` to reset it to 0 and
 148             // then check it again if we get the "0 error value". If the "last
 149             // error" is still 0 then we interpret it as a 0 length buffer and
 150             // not an actual error.
 151             c::SetLastError(0);
 152             let k = match f1(buf.as_mut_ptr(), n as c::DWORD) {
 153                 0 if c::GetLastError() == 0 => 0,
 154                 0 => return Err(io::Error::last_os_error()),
 155                 n => n,
 156             } as usize;
 157             if k == n && c::GetLastError() == c::ERROR_INSUFFICIENT_BUFFER {
 158                 n *= 2;
 159             } else if k >= n {
 160                 n = k;
 161             } else {
 162                 return Ok(f2(&buf[..k]))
 163             }
 164         }
 165     }
 166 }
 167
 168 fn os2path(s: &[u16]) -> PathBuf {
 169     PathBuf::from(OsString::from_wide(s))
 170 }
 171
 172 pub fn truncate_utf16_at_nul<'a>(v: &'a [u16]) -> &'a [u16] {
 173     match v.iter().position(|c| *c == 0) {
 174         // don't include the 0
 175         Some(i) => &v[..i],
 176         None => v
 177     }
 178 }
 179
 180 fn cvt<I: PartialEq + Zero>(i: I) -> io::Result<I> {
 181     if i == I::zero() {
 182         Err(io::Error::last_os_error())
 183     } else {
 184         Ok(i)
 185     }
 186 }
 187
 188 fn dur2timeout(dur: Duration) -> c::DWORD {
 189     // Note that a duration is a (u64, u32) (seconds, nanoseconds) pair, and the
 190     // timeouts in windows APIs are typically u32 milliseconds. To translate, we
 191     // have two pieces to take care of:
 192     //
 193     // * Nanosecond precision is rounded up
 194     // * Greater than u32::MAX milliseconds (50 days) is rounded up to INFINITE
 195     //   (never time out).
 196     dur.as_secs().checked_mul(1000).and_then(|ms| {
 197         ms.checked_add((dur.subsec_nanos() as u64) / 1_000_000)
 198     }).and_then(|ms| {
 199         ms.checked_add(if dur.subsec_nanos() % 1_000_000 > 0 {1} else {0})
 200     }).map(|ms| {
 201         if ms > <c::DWORD>::max_value() as u64 {
 202             c::INFINITE
 203         } else {
 204             ms as c::DWORD
 205         }
 206     }).unwrap_or(c::INFINITE)
 207 }