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// Copyright 2016 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your // option. This file may not be copied, modified, or distributed // except according to those terms. use io; use sys::{cvt, syscall}; use sys::fd::FileDesc; //////////////////////////////////////////////////////////////////////////////// // Anonymous pipes //////////////////////////////////////////////////////////////////////////////// pub struct AnonPipe(FileDesc); pub fn anon_pipe() -> io::Result<(AnonPipe, AnonPipe)> { let mut fds = [0; 2]; cvt(syscall::pipe2(&mut fds, syscall::O_CLOEXEC))?; Ok((AnonPipe(FileDesc::new(fds[0])), AnonPipe(FileDesc::new(fds[1])))) } impl AnonPipe { pub fn from_fd(fd: FileDesc) -> io::Result<AnonPipe> { fd.set_cloexec()?; Ok(AnonPipe(fd)) } pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> { self.0.read(buf) } pub fn write(&self, buf: &[u8]) -> io::Result<usize> { self.0.write(buf) } pub fn fd(&self) -> &FileDesc { &self.0 } pub fn into_fd(self) -> FileDesc { self.0 } } pub fn read2(p1: AnonPipe, v1: &mut Vec<u8>, p2: AnonPipe, v2: &mut Vec<u8>) -> io::Result<()> { //FIXME: Use event based I/O multiplexing //unimplemented!() p1.0.read_to_end(v1)?; p2.0.read_to_end(v2)?; Ok(()) /* // Set both pipes into nonblocking mode as we're gonna be reading from both // in the `select` loop below, and we wouldn't want one to block the other! let p1 = p1.into_fd(); let p2 = p2.into_fd(); p1.set_nonblocking(true)?; p2.set_nonblocking(true)?; loop { // wait for either pipe to become readable using `select` cvt_r(|| unsafe { let mut read: libc::fd_set = mem::zeroed(); libc::FD_SET(p1.raw(), &mut read); libc::FD_SET(p2.raw(), &mut read); libc::select(max + 1, &mut read, ptr::null_mut(), ptr::null_mut(), ptr::null_mut()) })?; // Read as much as we can from each pipe, ignoring EWOULDBLOCK or // EAGAIN. If we hit EOF, then this will happen because the underlying // reader will return Ok(0), in which case we'll see `Ok` ourselves. In // this case we flip the other fd back into blocking mode and read // whatever's leftover on that file descriptor. let read = |fd: &FileDesc, dst: &mut Vec<u8>| { match fd.read_to_end(dst) { Ok(_) => Ok(true), Err(e) => { if e.raw_os_error() == Some(libc::EWOULDBLOCK) || e.raw_os_error() == Some(libc::EAGAIN) { Ok(false) } else { Err(e) } } } }; if read(&p1, v1)? { p2.set_nonblocking(false)?; return p2.read_to_end(v2).map(|_| ()); } if read(&p2, v2)? { p1.set_nonblocking(false)?; return p1.read_to_end(v1).map(|_| ()); } } */ }