Move channel cloning logic into a method on rust_chan.

This will allow us to more easily clone channels from native code.

Author: robarnold

src/rt/rust_chan.cpp

@@ -97,6 +97,25 @@ void rust_chan::send(void *sptr) {
 
     return;
 }
+
+rust_chan *rust_chan::clone(maybe_proxy<rust_task> *target) {
+    size_t unit_sz = buffer.unit_sz;
+    maybe_proxy<rust_port> *port = this->port;
+    rust_task *target_task = NULL;
+    if (target->is_proxy() == false) {
+        port = this->port;
+        target_task = target->referent();
+    } else {
+        rust_handle<rust_port> *handle =
+            task->sched->kernel->get_port_handle(port->as_referent());
+        maybe_proxy<rust_port> *proxy = new rust_proxy<rust_port> (handle);
+        LOG(task, mem, "new proxy: " PTR, proxy);
+        port = proxy;
+        target_task = target->as_proxy()->handle()->referent();
+    }
+    return new (target_task) rust_chan(target_task, port, unit_sz);
+}
+
 //
 // Local Variables:
 // mode: C++

src/rt/rust_chan.h

@@ -19,6 +19,8 @@ class rust_chan : public rc_base<rust_chan>,
     bool is_associated();
 
     void send(void *sptr);
+
+    rust_chan *clone(maybe_proxy<rust_task> *target);
 };
 
 //

src/rt/rust_upcall.cpp

@@ -166,21 +166,7 @@ upcall_clone_chan(rust_task *task, maybe_proxy<rust_task> *target,
                   rust_chan *chan) {
     LOG_UPCALL_ENTRY(task);
     scoped_lock with(task->kernel->scheduler_lock);
-    size_t unit_sz = chan->buffer.unit_sz;
-    maybe_proxy<rust_port> *port = chan->port;
-    rust_task *target_task = NULL;
-    if (target->is_proxy() == false) {
-        port = chan->port;
-        target_task = target->referent();
-    } else {
-        rust_handle<rust_port> *handle =
-            task->sched->kernel->get_port_handle(port->as_referent());
-        maybe_proxy<rust_port> *proxy = new rust_proxy<rust_port> (handle);
-        LOG(task, mem, "new proxy: " PTR, proxy);
-        port = proxy;
-        target_task = target->as_proxy()->handle()->referent();
-    }
-    return new (target_task) rust_chan(target_task, port, unit_sz);
+    return chan->clone(target);
 }
 
 extern "C" CDECL void