Adding test case dealing with communication and hashmaps.

src/test/run-pass/hashmap-memory.rs

@@ -0,0 +1,108 @@
+/**
+   A somewhat reduced test case to expose some Valgrind issues.
+
+   This originally came from the word-count benchmark.
+*/
+
+use std;
+
+import std::io;
+import option = std::option::t;
+import std::option::some;
+import std::option::none;
+import std::str;
+import std::vec;
+import std::map;
+
+fn map(str filename, map_reduce::putter emit) {
+    emit(filename, "1");
+}
+
+mod map_reduce {
+    export putter;
+    export mapper;
+    export map_reduce;
+
+    type putter = fn(str, str) -> ();
+
+    type mapper = fn(str, putter);
+
+    tag ctrl_proto {
+        find_reducer(str, chan[int]);
+        mapper_done;
+    }
+
+    fn start_mappers(chan[ctrl_proto] ctrl,
+                     vec[str] inputs) {
+        for(str i in inputs) {
+            spawn map_task(ctrl, i);
+        }
+    }
+
+    fn map_task(chan[ctrl_proto] ctrl,
+                str input) {
+        
+        auto intermediates = map::new_str_hash();
+
+        fn emit(&map::hashmap[str, int] im,
+                chan[ctrl_proto] ctrl,
+                str key, str val) {
+            auto c;
+            alt(im.find(key)) {
+                case(some(?_c)) {
+                    c = _c
+                }
+                case(none) {
+                    auto p = port();
+                    log_err "sending find_reducer";
+                    ctrl <| find_reducer(key, chan(p));
+                    log_err "receiving";
+                    p |> c;
+                    log_err c;
+                    im.insert(key, c);
+                }
+            }
+        }
+
+        map(input, bind emit(intermediates, ctrl, _, _));
+        ctrl <| mapper_done;
+    }
+
+    fn map_reduce (vec[str] inputs) {
+        auto ctrl = port[ctrl_proto]();
+
+        // This task becomes the master control task. It spawns others
+        // to do the rest.
+
+        let map::hashmap[str, int] reducers;
+
+        reducers = map::new_str_hash();
+
+        start_mappers(chan(ctrl), inputs);
+
+        auto num_mappers = vec::len(inputs) as int;
+
+        while(num_mappers > 0) {
+            auto m;
+            ctrl |> m;
+            
+            alt(m) {
+                case(mapper_done) { num_mappers -= 1; }
+                case(find_reducer(?k, ?cc)) {
+                    auto c;
+                    alt(reducers.find(k)) {
+                        case(some(?_c)) { c = _c; }
+                        case(none) {
+                            c = 0;
+                        }
+                    }
+                    cc <| c;
+                }
+            }
+        }
+    }
+}
+
+fn main(vec[str] argv) {
+    map_reduce::map_reduce(["../src/test/run-pass/hashmap-memory.rs"]);
+}