add Event.waiting_on()

src/core/chuck_lang.cpp

@@ -412,7 +412,12 @@ t_CKBOOL init_class_event( Chuck_Env * env, Chuck_Type * type )
 
     // add can_wait()
     func = make_new_mfun( "int", "can_wait", event_can_wait );
-    func->doc = "can the event can be waited on? Internally used by virtual machine for synthronization.";
+    func->doc = "can the event can be waited on? (internal) used by virtual machine for synchronization.";
+    if( !type_engine_import_mfun( env, func ) ) goto error;
+
+    // add waiting_on()
+    func = make_new_mfun( "void", "waiting_on", event_waiting_on );
+    func->doc = "(internal) used by virtual machine to be notified when a shred starts waiting on this Event.";
     if( !type_engine_import_mfun( env, func ) ) goto error;
 
     // add examples
@@ -441,6 +446,13 @@ t_CKBOOL init_class_event( Chuck_Env * env, Chuck_Type * type )
     // remember it
     Chuck_Event::our_can_wait = value->func_ref->vt_index;
 
+    // find the offset for waiting_on
+    value = type_engine_find_value( type, "waiting_on" );
+    assert( value != NULL );
+    assert( value->func_ref != NULL );
+    // remember it
+    Chuck_Event::our_waiting_on = value->func_ref->vt_index;
+
     return TRUE;
 
 error:
@@ -2051,11 +2063,19 @@ CK_DLL_MFUN( event_wait )
     assert( FALSE );
 }
 
+// default implementation
 CK_DLL_MFUN( event_can_wait )
 {
     RETURN->v_int = TRUE;
 }
 
+// 1.5.1.4 (ge/andrew) added; default implementation
+CK_DLL_MFUN( event_waiting_on )
+{
+    // do nothing here; this function could be overridden as needed
+    // FYI get the calling shred with 'SHRED' parameter to this function
+}
+
 
 //-----------------------------------------------------------------------------
 // vec3 API

src/core/chuck_lang.h

@@ -211,6 +211,7 @@ CK_DLL_MFUN( event_signal );
 CK_DLL_MFUN( event_broadcast );
 CK_DLL_MFUN( event_wait );
 CK_DLL_MFUN( event_can_wait );
+CK_DLL_MFUN( event_waiting_on );
 
 
 //-----------------------------------------------------------------------------

src/core/chuck_oo.cpp

@@ -2919,6 +2919,7 @@ void Chuck_Array32::sort()
 
 // Chuck_Event static instantiation
 t_CKUINT Chuck_Event::our_can_wait = 0;
+t_CKUINT Chuck_Event::our_waiting_on = 0;
 
 //-----------------------------------------------------------------------------
 // name: signal_local()
@@ -3442,6 +3443,11 @@ void Chuck_Event::wait( Chuck_VM_Shred * shred, Chuck_VM * vm )
 
         // add shred to shreduler
         vm->shreduler()->add_blocked( shred );
+
+        // get the virtual function for waiting_on()
+        f_mfun waiting_on = (f_mfun)this->vtable->funcs[our_waiting_on]->code->native_func;
+        // call to nofify event that a shred has starting waiting on it
+        waiting_on( this, NULL, &RETURN, vm, shred, Chuck_DL_Api::Api::instance() );
     }
     else // can't wait
     {

src/core/chuck_oo.h

@@ -750,7 +750,10 @@ struct Chuck_Event : public Chuck_Object
     void queue_broadcast( CBufferSimple * event_buffer = NULL );
 
 public:
+    // virtual table offset for can_wait()
     static t_CKUINT our_can_wait;
+    // virtual table offset for waiting_on() | 1.5.1.4 (ge/andrew) added
+    static t_CKUINT our_waiting_on;
 
 protected:
     std::queue<Chuck_VM_Shred *> m_queue;