tasks a-s

Task/Nautical-bell/D/nautical-bell.d

@@ -0,0 +1,50 @@
+import std.stdio, core.thread, std.datetime;
+
+class NauticalBell : Thread {
+    private shared bool stopped;
+
+    this() {
+        super(&run);
+    }
+
+    void run() {
+        uint numBells;
+        auto time = cast(TimeOfDay)Clock.currTime();
+        auto next = TimeOfDay();
+
+        void setNextBellTime() {
+            next += minutes(30);
+            numBells = 1 + (numBells % 8);
+        }
+
+        while (next < time)
+            setNextBellTime();
+
+        while (!this.stopped) {
+            time = cast(TimeOfDay)Clock.currTime();
+            if (next.minute == time.minute &&
+                    next.hour == time.hour) {
+                immutable bells = numBells == 1 ? "bell" : "bells";
+                writefln("%s : %d %s", time, numBells, bells);
+                setNextBellTime();
+            }
+            sleep(dur!"msecs"(100));
+            yield();
+         }
+     }
+
+     void stop() {
+        this.stopped = true;
+     }
+}
+
+void main() {
+    auto bells = new NauticalBell();
+    bells.isDaemon(true);
+    bells.start();
+    try {
+        bells.join();
+    } catch (ThreadException e) {
+        writeln(e.msg);
+    }
+}