add jtk.event.wait_event()

src/jtk/event.d

@@ -2,6 +2,7 @@ module jtk.event;
 
 import core.thread;
 import core.sync.mutex;
+import core.sync.condition;
 import std.container.dlist;
 import jtk.timer;
 
@@ -54,18 +55,41 @@ private extern(C) void jtk_wait_event(Event * event, ulong time_to_wait);
 
 private __gshared DList!(Event *) * event_list;
 private __gshared Mutex event_list_mutex;
+private __gshared Mutex wait_event_mutex;
+private __gshared Condition wait_event_condition;
 
 Event * check_event()
 {
-    Event * rv = null;
-    event_list_mutex.lock_nothrow();
-    if (!event_list.empty)
+    synchronized(event_list_mutex)
     {
-        rv = event_list.front;
-        event_list.removeFront();
+        if (!event_list.empty)
+        {
+            Event * rv = event_list.front;
+            event_list.removeFront();
+            return rv;
+        }
+    }
+    return null;
+}
+
+Event * wait_event()
+{
+    synchronized(wait_event_mutex)
+    {
+        for (;;)
+        {
+            synchronized(event_list_mutex)
+            {
+                if (!event_list.empty)
+                {
+                    Event * rv = event_list.front;
+                    event_list.removeFront();
+                    return rv;
+                }
+            }
+            wait_event_condition.wait();
+        }
     }
-    event_list_mutex.unlock_nothrow();
-    return rv;
 }
 
 private void event_thread()
@@ -73,12 +97,16 @@ private void event_thread()
     for (;;)
     {
         Event * event = new Event;
-        ulong time_until_next_timer_expiry =
-            jtk.timer.Timer.time_to_next_timer_expiration();
+        ulong time_until_next_timer_expiry = Timer.time_to_next_timer_expiration();
         jtk_wait_event(event, time_until_next_timer_expiry);
-        event_list_mutex.lock_nothrow();
-        event_list.insertBack(event);
-        event_list_mutex.unlock_nothrow();
+        synchronized(event_list_mutex)
+        {
+            event_list.insertBack(event);
+        }
+        synchronized(wait_event_mutex)
+        {
+            wait_event_condition.notifyAll();
+        }
     }
 }
 
@@ -86,5 +114,7 @@ package void event_init()
 {
     event_list = new DList!(Event *);
     event_list_mutex = new Mutex;
+    wait_event_mutex = new Mutex;
+    wait_event_condition = new Condition(wait_event_mutex);
     new Thread(&event_thread).start();
 }