---

yaml
---
r: 12735
b: refs/heads/master
c: beb1a59
h: refs/heads/master
i:
  12733: d634511
  12731: 52258cc
  12727: 59774e7
  12719: a26ee9f
  12703: b5cb19f
  12671: 7820964
v: v3

Author: brson

[refs]

@@ -1,5 +1,5 @@
 ---
-refs/heads/master: 29b807be2a0d060e4321b28849e68596dc1a6b45
+refs/heads/master: beb1a59f82e7689b72bf10d2a86d0d1b6060983e
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: 4a81779abd786ff22d71434c6d9a5917ea4cdfff
 refs/heads/try: 2898dcc5d97da9427ac367542382b6239d9c0bbf

trunk/src/libcore/comm.rs

@@ -28,6 +28,7 @@ import either::either;
 
 export send;
 export recv;
+export recv_chan;
 export peek;
 export select2;
 export chan::{};
@@ -52,6 +53,10 @@ native mod rustrt {
     fn rust_port_select(dptr: **rust_port, ports: **rust_port,
                         n_ports: libc::size_t,
                         yield: *libc::uintptr_t);
+    fn rust_port_take(port_id: port_id) -> *rust_port;
+    fn rust_port_drop(p: *rust_port);
+    fn rust_port_task(p: *rust_port) -> libc::uintptr_t;
+    fn get_task_id() -> libc::uintptr_t;
 }
 
 #[abi = "rust-intrinsic"]
@@ -132,6 +137,25 @@ task will block until data becomes available.
 "]
 fn recv<T: send>(p: port<T>) -> T { recv_(***p) }
 
+#[doc(hidden)]
+fn recv_chan<T: send>(ch: comm::chan<T>) -> T {
+    resource portref(p: *rust_port) {
+        if !ptr::is_null(p) {
+            rustrt::rust_port_drop(p);
+        }
+    }
+
+    let p = portref(rustrt::rust_port_take(*ch));
+
+    if ptr::is_null(*p) {
+        fail "unable to locate port for channel"
+    } else if rustrt::get_task_id() != rustrt::rust_port_task(*p) {
+        fail "attempting to receive on unowned channel"
+    }
+
+    recv_(*p)
+}
+
 #[doc = "Receive on a raw port pointer"]
 fn recv_<T: send>(p: *rust_port) -> T {
     let yield = 0u;
@@ -327,3 +351,31 @@ fn test_select2_stress() {
     assert as == 400;
     assert bs == 400;
 }
+
+#[test]
+fn test_recv_chan() {
+    let po = port();
+    let ch = chan(po);
+    send(ch, "flower");
+    assert recv_chan(ch) == "flower";
+}
+
+#[test]
+#[should_fail]
+#[ignore(cfg(target_os = "win32"))]
+fn test_recv_chan_dead() {
+    let ch = chan(port());
+    send(ch, "flower");
+    recv_chan(ch);
+}
+
+#[test]
+#[ignore(cfg(target_os = "win32"))]
+fn test_recv_chan_wrong_task() {
+    let po = port();
+    let ch = chan(po);
+    send(ch, "flower");
+    assert result::is_failure(task::try {||
+        recv_chan(ch)
+    })
+}

trunk/src/rt/rust_builtin.cpp

@@ -630,6 +630,24 @@ sched_threads() {
     return task->sched->number_of_threads();
 }
 
+extern "C" CDECL rust_port*
+rust_port_take(rust_port_id id) {
+    rust_task *task = rust_get_current_task();
+    return task->kernel->get_port_by_id(id);
+}
+
+extern "C" CDECL void
+rust_port_drop(rust_port *p) {
+    assert(p != NULL);
+    p->deref();
+}
+
+extern "C" CDECL rust_task_id
+rust_port_task(rust_port *p) {
+    assert(p != NULL);
+    return p->task->id;
+}
+
 extern "C" CDECL rust_port*
 new_port(size_t unit_sz) {
     rust_task *task = rust_get_current_task();

trunk/src/rt/rustrt.def.in

@@ -149,3 +149,6 @@ rust_dbg_call
 rust_osmain_sched_id
 rust_compare_and_swap_ptr
 rust_global_env_chan_ptr
+rust_port_take
+rust_port_drop
+rust_port_task