rt: Perform task notification before killing the parent task

Author: brson

src/lib/comm.rs

@@ -81,7 +81,7 @@ resource port_ptr<uniq T>(po: *rustrt::rust_port) {
     while rustrt::rust_port_size(po) > 0u {
         // FIXME: For some reason if we don't assign to something here
         // we end up with invalid reads in the drop glue.
-        let t = rusti::recv::<T>(po);
+        let _t = rusti::recv::<T>(po);
     }
     rustrt::del_port(po);
 }

src/rt/rust_task.cpp

@@ -126,24 +126,6 @@ rust_task::~rust_task()
     DLOG(sched, task, "~rust_task %s @0x%" PRIxPTR ", refcnt=%d",
          name, (uintptr_t)this, ref_count);
 
-    if(user.notify_enabled) {
-        rust_task *target_task = kernel->get_task_by_id(user.notify_chan.task);
-        if (target_task) {
-            rust_port *target_port =
-                target_task->get_port_by_id(user.notify_chan.port);
-            if(target_port) {
-                task_notification msg;
-                msg.id = user.id;
-                msg.result = failed ? tr_failure : tr_success;
-
-                target_port->send(&msg);
-                scoped_lock with(target_task->lock);
-                target_port->deref();
-            }
-            target_task->deref();
-        }
-    }
-
     if (supervisor) {
         supervisor->deref();
     }
@@ -203,6 +185,8 @@ void task_start_wrapper(spawn_args *a)
         failed = true;
     }
 
+    task->notify(!failed);
+
     if (failed) {
 #ifndef __WIN32__
         task->conclude_failure();
@@ -605,6 +589,28 @@ rust_task::claim_alloc(void *alloc, const type_desc *tydesc) {
     lock.unlock();
 }
 
+void
+rust_task::notify(bool success) {
+    // FIXME (1078) Do this in rust code
+    if(user.notify_enabled) {
+        rust_task *target_task = kernel->get_task_by_id(user.notify_chan.task);
+        if (target_task) {
+            rust_port *target_port =
+                target_task->get_port_by_id(user.notify_chan.port);
+            if(target_port) {
+                task_notification msg;
+                msg.id = user.id;
+                msg.result = !success ? tr_failure : tr_success;
+
+                target_port->send(&msg);
+                scoped_lock with(target_task->lock);
+                target_port->deref();
+            }
+            target_task->deref();
+        }
+    }
+}
+
 //
 // Local Variables:
 // mode: C++

src/rt/rust_task.h

@@ -213,6 +213,8 @@ rust_task : public kernel_owned<rust_task>, rust_cond
     // ground. We should never be migrating shared boxes between tasks.
     const type_desc *release_alloc(void *alloc);
     void claim_alloc(void *alloc, const type_desc *tydesc);
+
+    void notify(bool success);
 };
 
 //