use prelude::v1::*;
use io::prelude::*;
+use cell::RefCell;
use cmp;
use fmt;
use io::lazy::Lazy;
use sync::{Arc, Mutex, MutexGuard};
use sys::stdio;
+/// Stdout used by print! and println! macros
+thread_local! {
+ static LOCAL_STDOUT: RefCell<Option<Box<Write + Send>>> = {
+ RefCell::new(None)
+ }
+}
+
/// A handle to a raw instance of the standard input stream of this process.
///
/// This handle is not synchronized or buffered in any fashion. Constructed via
-/// the `std::io::stdin_raw` function.
-pub struct StdinRaw(stdio::Stdin);
+/// the `std::io::stdio::stdin_raw` function.
+struct StdinRaw(stdio::Stdin);
/// A handle to a raw instance of the standard output stream of this process.
///
/// This handle is not synchronized or buffered in any fashion. Constructed via
-/// the `std::io::stdout_raw` function.
-pub struct StdoutRaw(stdio::Stdout);
+/// the `std::io::stdio::stdout_raw` function.
+struct StdoutRaw(stdio::Stdout);
/// A handle to a raw instance of the standard output stream of this process.
///
/// This handle is not synchronized or buffered in any fashion. Constructed via
-/// the `std::io::stderr_raw` function.
-pub struct StderrRaw(stdio::Stderr);
+/// the `std::io::stdio::stderr_raw` function.
+struct StderrRaw(stdio::Stderr);
/// Construct a new raw handle to the standard input of this process.
///
/// handles is **not** available to raw handles returned from this function.
///
/// The returned handle has no external synchronization or buffering.
-pub fn stdin_raw() -> StdinRaw { StdinRaw(stdio::Stdin::new()) }
+fn stdin_raw() -> StdinRaw { StdinRaw(stdio::Stdin::new()) }
/// Construct a new raw handle to the standard input stream of this process.
///
///
/// The returned handle has no external synchronization or buffering layered on
/// top.
-pub fn stdout_raw() -> StdoutRaw { StdoutRaw(stdio::Stdout::new()) }
+fn stdout_raw() -> StdoutRaw { StdoutRaw(stdio::Stdout::new()) }
/// Construct a new raw handle to the standard input stream of this process.
///
///
/// The returned handle has no external synchronization or buffering layered on
/// top.
-pub fn stderr_raw() -> StderrRaw { StderrRaw(stdio::Stderr::new()) }
+fn stderr_raw() -> StderrRaw { StderrRaw(stdio::Stderr::new()) }
impl Read for StdinRaw {
fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> { self.0.read(buf) }
/// The `Read` trait is implemented for the returned value but the `BufRead`
/// trait is not due to the global nature of the standard input stream. The
/// locked version, `StdinLock`, implements both `Read` and `BufRead`, however.
-///
-/// To avoid locking and buffering altogether, it is recommended to use the
-/// `stdin_raw` constructor.
#[stable(feature = "rust1", since = "1.0.0")]
pub fn stdin() -> Stdin {
static INSTANCE: Lazy<Mutex<BufReader<StdinRaw>>> = lazy_init!(stdin_init);
/// provided via the `lock` method.
///
/// The returned handle implements the `Write` trait.
-///
-/// To avoid locking and buffering altogether, it is recommended to use the
-/// `stdout_raw` constructor.
#[stable(feature = "rust1", since = "1.0.0")]
pub fn stdout() -> Stdout {
static INSTANCE: Lazy<Mutex<LineWriter<StdoutRaw>>> = lazy_init!(stdout_init);
/// this function. No handles are buffered, however.
///
/// The returned handle implements the `Write` trait.
-///
-/// To avoid locking altogether, it is recommended to use the `stderr_raw`
-/// constructor.
#[stable(feature = "rust1", since = "1.0.0")]
pub fn stderr() -> Stderr {
static INSTANCE: Lazy<Mutex<StderrRaw>> = lazy_init!(stderr_init);
}
fn flush(&mut self) -> io::Result<()> { self.inner.flush() }
}
+
+/// Resets the task-local stderr handle to the specified writer
+///
+/// This will replace the current task's stderr handle, returning the old
+/// handle. All future calls to `panic!` and friends will emit their output to
+/// this specified handle.
+///
+/// Note that this does not need to be called for all new tasks; the default
+/// output handle is to the process's stderr stream.
+#[unstable(feature = "set_stdio",
+ reason = "this function may disappear completely or be replaced \
+ with a more general mechanism")]
+#[doc(hidden)]
+pub fn set_panic(sink: Box<Write + Send>) -> Option<Box<Write + Send>> {
+ use panicking::LOCAL_STDERR;
+ use mem;
+ LOCAL_STDERR.with(move |slot| {
+ mem::replace(&mut *slot.borrow_mut(), Some(sink))
+ }).and_then(|mut s| {
+ let _ = s.flush();
+ Some(s)
+ })
+}
+
+/// Resets the task-local stdout handle to the specified writer
+///
+/// This will replace the current task's stdout handle, returning the old
+/// handle. All future calls to `print!` and friends will emit their output to
+/// this specified handle.
+///
+/// Note that this does not need to be called for all new tasks; the default
+/// output handle is to the process's stdout stream.
+#[unstable(feature = "set_stdio",
+ reason = "this function may disappear completely or be replaced \
+ with a more general mechanism")]
+#[doc(hidden)]
+pub fn set_print(sink: Box<Write + Send>) -> Option<Box<Write + Send>> {
+ use mem;
+ LOCAL_STDOUT.with(move |slot| {
+ mem::replace(&mut *slot.borrow_mut(), Some(sink))
+ }).and_then(|mut s| {
+ let _ = s.flush();
+ Some(s)
+ })
+}
+
+#[unstable(feature = "print",
+ reason = "implementation detail which may disappear or be replaced at any time")]
+#[doc(hidden)]
+pub fn _print(args: fmt::Arguments) {
+ if let Err(e) = LOCAL_STDOUT.with(|s| match s.borrow_mut().as_mut() {
+ Some(w) => w.write_fmt(args),
+ None => stdout().write_fmt(args)
+ }) {
+ panic!("failed printing to stdout: {}", e);
+ }
+}
projects / rust.git / blobdiff