std: Second pass stabilization for `comm`

This commit is a second pass stabilization for the `std::comm` module,
performing the following actions:

* The entire `std::comm` module was moved under `std::sync::mpsc`. This movement
  reflects that channels are just yet another synchronization primitive, and
  they don't necessarily deserve a special place outside of the other
  concurrency primitives that the standard library offers.
* The `send` and `recv` methods have all been removed.
* The `send_opt` and `recv_opt` methods have been renamed to `send` and `recv`.
  This means that all send/receive operations return a `Result` now indicating
  whether the operation was successful or not.
* The error type of `send` is now a `SendError` to implement a custom error
  message and allow for `unwrap()`. The error type contains an `into_inner`
  method to extract the value.
* The error type of `recv` is now `RecvError` for the same reasons as `send`.
* The `TryRecvError` and `TrySendError` types have had public reexports removed
  of their variants and the variant names have been tweaked with enum
  namespacing rules.
* The `Messages` iterator is renamed to `Iter`

This functionality is now all `#[stable]`:

* `Sender`
* `SyncSender`
* `Receiver`
* `std::sync::mpsc`
* `channel`
* `sync_channel`
* `Iter`
* `Sender::send`
* `Sender::clone`
* `SyncSender::send`
* `SyncSender::try_send`
* `SyncSender::clone`
* `Receiver::recv`
* `Receiver::try_recv`
* `Receiver::iter`
* `SendError`
* `RecvError`
* `TrySendError::{mod, Full, Disconnected}`
* `TryRecvError::{mod, Empty, Disconnected}`
* `SendError::into_inner`
* `TrySendError::into_inner`

This is a breaking change due to the modification of where this module is
located, as well as the changing of the semantics of `send` and `recv`. Most
programs just need to rename imports of `std::comm` to `std::sync::mpsc` and
add calls to `unwrap` after a send or a receive operation.

[breaking-change]

1 files changed, 5 insertions, 5 deletions

diff --git a/src/libstd/sys/unix/timer.rs b/src/libstd/sys/unix/timer.rs
index 903c4954f6f..4afe13d8735 100644
--- a/src/libstd/sys/unix/timer.rs
+++ b/src/libstd/sys/unix/timer.rs
@@ -49,13 +49,13 @@
 use prelude::v1::*;
 use self::Req::*;
 
-use comm::{mod, channel, Sender, Receiver};
 use io::IoResult;
 use libc;
 use mem;
 use os;
 use ptr;
 use sync::atomic;
+use sync::mpsc::{channel, Sender, Receiver, TryRecvError};
 use sys::c;
 use sys::fs::FileDesc;
 use sys_common::helper_thread::Helper;
@@ -168,7 +168,7 @@ fn helper(input: libc::c_int, messages: Receiver<Req>, _: ()) {
             1 => {
                 loop {
                     match messages.try_recv() {
-                        Err(comm::Disconnected) => {
+                        Err(TryRecvError::Disconnected) => {
                             assert!(active.len() == 0);
                             break 'outer;
                         }
@@ -179,7 +179,7 @@ fn helper(input: libc::c_int, messages: Receiver<Req>, _: ()) {
                             match dead.iter().position(|&(i, _)| id == i) {
                                 Some(i) => {
                                     let (_, i) = dead.remove(i).unwrap();
-                                    ack.send(i);
+                                    ack.send(i).unwrap();
                                     continue
                                 }
                                 None => {}
@@ -187,7 +187,7 @@ fn helper(input: libc::c_int, messages: Receiver<Req>, _: ()) {
                             let i = active.iter().position(|i| i.id == id);
                             let i = i.expect("no timer found");
                             let t = active.remove(i).unwrap();
-                            ack.send(t);
+                            ack.send(t).unwrap();
                         }
                         Err(..) => break
                     }
@@ -271,7 +271,7 @@ impl Timer {
             None => {
                 let (tx, rx) = channel();
                 HELPER.send(RemoveTimer(self.id, tx));
-                rx.recv()
+                rx.recv().unwrap()
             }
         }
     }