void asCGarbageCollector::ReportUndestroyedObjects()
{
for( asUINT n = 0; n < gcOldObjects.GetLength(); n++ )
{
asSObjTypePair gcObj = GetOldObjectAtIdx(n);
asCString msg;
msg.Format(TXT_GC_CANNOT_FREE_OBJ_OF_TYPE_s, gcObj.type->name.AddressOf());
engine->WriteMessage("", 0, 0, asMSGTYPE_ERROR, msg.AddressOf());
}
}
int asCGarbageCollector::ReportAndReleaseUndestroyedObjects()
{
// This function will only be called as the engine is shutting down
int items = 0;
for( asUINT n = 0; n < gcOldObjects.GetLength(); n++ )
{
asSObjTypePair gcObj = GetOldObjectAtIdx(n);
int refCount = 0;
if( gcObj.type->beh.gcGetRefCount && engine->scriptFunctions[gcObj.type->beh.gcGetRefCount] )
refCount = engine->CallObjectMethodRetInt(gcObj.obj, gcObj.type->beh.gcGetRefCount);
// Report the object as not being properly destroyed
asCString msg;
msg.Format(TXT_d_GC_CANNOT_FREE_OBJ_OF_TYPE_s_REF_COUNT_d, gcObj.seqNbr, gcObj.type->name.AddressOf(), refCount - 1);
engine->WriteMessage("", 0, 0, asMSGTYPE_ERROR, msg.AddressOf());
// Add additional info for builtin types
if( gcObj.type->name == "_builtin_function_" )
{
// Unfortunately we can't show the function declaration here, because the engine may have released the parameter list already so the declaration would only be misleading
// We need to show the function type too as for example delegates do not have a name
msg.Format(TXT_PREV_FUNC_IS_NAMED_s_TYPE_IS_d, reinterpret_cast<asCScriptFunction*>(gcObj.obj)->GetName(), reinterpret_cast<asCScriptFunction*>(gcObj.obj)->GetFuncType());
engine->WriteMessage("", 0, 0, asMSGTYPE_INFORMATION, msg.AddressOf());
}
else if( gcObj.type->name == "_builtin_objecttype_" )
{
msg.Format(TXT_PREV_TYPE_IS_NAMED_s, reinterpret_cast<asCObjectType*>(gcObj.obj)->GetName());
engine->WriteMessage("", 0, 0, asMSGTYPE_INFORMATION, msg.AddressOf());
}
else if( gcObj.type->name == "_builtin_globalprop_" )
{
msg.Format(TXT_PREV_TYPE_IS_NAMED_s, reinterpret_cast<asCGlobalProperty*>(gcObj.obj)->name.AddressOf());
engine->WriteMessage("", 0, 0, asMSGTYPE_INFORMATION, msg.AddressOf());
}
// Release the reference that the GC holds if the release functions is still available
if( gcObj.type->beh.release && engine->scriptFunctions[gcObj.type->beh.release] )
engine->CallObjectMethod(gcObj.obj, gcObj.type->beh.release);
items++;
}
return items;
}
int asCGarbageCollector::ReportAndReleaseUndestroyedObjects()
{
int items = 0;
for( asUINT n = 0; n < gcOldObjects.GetLength(); n++ )
{
asSObjTypePair gcObj = GetOldObjectAtIdx(n);
// Report the object as not being properly destroyed
asCString msg;
msg.Format(TXT_GC_CANNOT_FREE_OBJ_OF_TYPE_s, gcObj.type->name.AddressOf());
engine->WriteMessage("", 0, 0, asMSGTYPE_ERROR, msg.AddressOf());
// Release the reference that the GC holds if the release functions is still available
if( gcObj.type->beh.release && engine->scriptFunctions[gcObj.type->beh.release] )
engine->CallObjectMethod(gcObj.obj, gcObj.type->beh.release);
items++;
}
return items;
}
int asCGarbageCollector::ReportAndReleaseUndestroyedObjects()
{
int items = 0;
for( asUINT n = 0; n < gcOldObjects.GetLength(); n++ )
{
asSObjTypePair gcObj = GetOldObjectAtIdx(n);
int refCount = 0;
if( gcObj.type->beh.gcGetRefCount && engine->scriptFunctions[gcObj.type->beh.gcGetRefCount] )
refCount = engine->CallObjectMethodRetInt(gcObj.obj, gcObj.type->beh.gcGetRefCount);
// Report the object as not being properly destroyed
asCString msg;
msg.Format(TXT_GC_CANNOT_FREE_OBJ_OF_TYPE_s_REF_COUNT_d, gcObj.type->name.AddressOf(), refCount - 1);
engine->WriteMessage("", 0, 0, asMSGTYPE_ERROR, msg.AddressOf());
// Add additional info for builtin types
if( gcObj.type->name == "_builtin_function_" )
{
msg.Format(TXT_PREV_TYPE_IS_NAMED_s, reinterpret_cast<asCScriptFunction*>(gcObj.obj)->GetName());
engine->WriteMessage("", 0, 0, asMSGTYPE_INFORMATION, msg.AddressOf());
}
else if( gcObj.type->name == "_builtin_objecttype_" )
{
msg.Format(TXT_PREV_TYPE_IS_NAMED_s, reinterpret_cast<asCObjectType*>(gcObj.obj)->GetName());
engine->WriteMessage("", 0, 0, asMSGTYPE_INFORMATION, msg.AddressOf());
}
else if( gcObj.type->name == "_builtin_globalprop_" )
{
msg.Format(TXT_PREV_TYPE_IS_NAMED_s, reinterpret_cast<asCGlobalProperty*>(gcObj.obj)->name.AddressOf());
engine->WriteMessage("", 0, 0, asMSGTYPE_INFORMATION, msg.AddressOf());
}
// Release the reference that the GC holds if the release functions is still available
if( gcObj.type->beh.release && engine->scriptFunctions[gcObj.type->beh.release] )
engine->CallObjectMethod(gcObj.obj, gcObj.type->beh.release);
items++;
}
return items;
}
int asCGarbageCollector::IdentifyGarbageWithCyclicRefs()
{
for(;;)
{
switch( detectState )
{
case clearCounters_init:
detectState = clearCounters_loop;
break;
case clearCounters_loop:
{
// Decrease reference counter for all objects removed from the map
asSMapNode<void*, asSIntTypePair> *cursor = 0;
gcMap.MoveFirst(&cursor);
if( cursor )
{
void *obj = gcMap.GetKey(cursor);
asSIntTypePair it = gcMap.GetValue(cursor);
engine->CallObjectMethod(obj, it.type->beh.release);
ReturnNode(gcMap.Remove(cursor));
return 1;
}
detectState = buildMap_init;
}
break;
case buildMap_init:
detectIdx = 0;
detectState = buildMap_loop;
break;
case buildMap_loop:
{
// Build a map of objects that will be checked, the map will
// hold the object pointer as key, and the gcCount and the
// object's type as value. As objects are added to the map the
// gcFlag must be set in the objects, so we can be verify if
// the object is accessed during the GC cycle.
// If an object is removed from the gcObjects list during the
// iteration of this step, it is possible that an object won't
// be used during the analyzing for cyclic references. This
// isn't a problem, as the next time the GC cycle starts the
// object will be verified.
if( detectIdx < gcOldObjects.GetLength() )
{
// Add the gc count for this object
asSObjTypePair gcObj = GetOldObjectAtIdx(detectIdx);
int refCount = 0;
if( gcObj.type->beh.gcGetRefCount )
refCount = engine->CallObjectMethodRetInt(gcObj.obj, gcObj.type->beh.gcGetRefCount);
if( refCount > 1 )
{
asSIntTypePair it = {refCount-1, gcObj.type};
gcMap.Insert(GetNode(gcObj.obj, it));
// Increment the object's reference counter when putting it in the map
engine->CallObjectMethod(gcObj.obj, gcObj.type->beh.addref);
// Mark the object so that we can
// see if it has changed since read
engine->CallObjectMethod(gcObj.obj, gcObj.type->beh.gcSetFlag);
}
detectIdx++;
// Let the application work a little
return 1;
}
else
detectState = countReferences_init;
}
break;
case countReferences_init:
{
gcMap.MoveFirst(&gcMapCursor);
detectState = countReferences_loop;
}
break;
case countReferences_loop:
{
// Call EnumReferences on all objects in the map to count the number
// of references reachable from between objects in the map. If all
// references for an object in the map is reachable from other objects
// in the map, then we know that no outside references are held for
// this object, thus it is a potential dead object in a circular reference.
// If the gcFlag is cleared for an object we consider the object alive
// and referenced from outside the GC, thus we don't enumerate its references.
// Any new objects created after this step in the GC cycle won't be
// in the map, and is thus automatically considered alive.
if( gcMapCursor )
{
void *obj = gcMap.GetKey(gcMapCursor);
asCObjectType *type = gcMap.GetValue(gcMapCursor).type;
gcMap.MoveNext(&gcMapCursor, gcMapCursor);
if( engine->CallObjectMethodRetBool(obj, type->beh.gcGetFlag) )
{
engine->CallObjectMethod(obj, engine, type->beh.gcEnumReferences);
}
// Allow the application to work a little
return 1;
}
else
detectState = detectGarbage_init;
}
break;
case detectGarbage_init:
{
gcMap.MoveFirst(&gcMapCursor);
liveObjects.SetLength(0);
detectState = detectGarbage_loop1;
}
break;
case detectGarbage_loop1:
{
// All objects that are known not to be dead must be removed from the map,
// along with all objects they reference. What remains in the map after
// this pass is sure to be dead objects in circular references.
// An object is considered alive if its gcFlag is cleared, or all the
// references were not found in the map.
// Add all alive objects from the map to the liveObjects array
if( gcMapCursor )
{
asSMapNode<void*, asSIntTypePair> *cursor = gcMapCursor;
gcMap.MoveNext(&gcMapCursor, gcMapCursor);
void *obj = gcMap.GetKey(cursor);
asSIntTypePair it = gcMap.GetValue(cursor);
bool gcFlag = engine->CallObjectMethodRetBool(obj, it.type->beh.gcGetFlag);
if( !gcFlag || it.i > 0 )
{
liveObjects.PushLast(obj);
}
// Allow the application to work a little
return 1;
}
else
detectState = detectGarbage_loop2;
}
break;
case detectGarbage_loop2:
{
// In this step we are actually removing the alive objects from the map.
// As the object is removed, all the objects it references are added to the
// liveObjects list, by calling EnumReferences. Only objects still in the map
// will be added to the liveObjects list.
if( liveObjects.GetLength() )
{
void *gcObj = liveObjects.PopLast();
asCObjectType *type = 0;
// Remove the object from the map to mark it as alive
asSMapNode<void*, asSIntTypePair> *cursor = 0;
if( gcMap.MoveTo(&cursor, gcObj) )
{
type = gcMap.GetValue(cursor).type;
ReturnNode(gcMap.Remove(cursor));
// We need to decrease the reference count again as we remove the object from the map
engine->CallObjectMethod(gcObj, type->beh.release);
// Enumerate all the object's references so that they too can be marked as alive
engine->CallObjectMethod(gcObj, engine, type->beh.gcEnumReferences);
}
// Allow the application to work a little
return 1;
}
else
detectState = verifyUnmarked_init;
}
break;
case verifyUnmarked_init:
gcMap.MoveFirst(&gcMapCursor);
detectState = verifyUnmarked_loop;
break;
case verifyUnmarked_loop:
{
// In this step we must make sure that none of the objects still in the map
// has been touched by the application. If they have then we must run the
// detectGarbage loop once more.
if( gcMapCursor )
{
void *gcObj = gcMap.GetKey(gcMapCursor);
asCObjectType *type = gcMap.GetValue(gcMapCursor).type;
bool gcFlag = engine->CallObjectMethodRetBool(gcObj, type->beh.gcGetFlag);
if( !gcFlag )
{
// The unmarked object was touched, rerun the detectGarbage loop
detectState = detectGarbage_init;
}
else
gcMap.MoveNext(&gcMapCursor, gcMapCursor);
// Allow the application to work a little
return 1;
}
else
{
// No unmarked object was touched, we can now be sure
// that objects that have gcCount == 0 really is garbage
detectState = breakCircles_init;
}
}
break;
case breakCircles_init:
{
gcMap.MoveFirst(&gcMapCursor);
detectState = breakCircles_loop;
}
break;
case breakCircles_loop:
case breakCircles_haveGarbage:
{
// All objects in the map are now known to be dead objects
// kept alive through circular references. To be able to free
// these objects we need to force the breaking of the circle
// by having the objects release their references.
if( gcMapCursor )
{
numDetected++;
void *gcObj = gcMap.GetKey(gcMapCursor);
asCObjectType *type = gcMap.GetValue(gcMapCursor).type;
engine->CallObjectMethod(gcObj, engine, type->beh.gcReleaseAllReferences);
gcMap.MoveNext(&gcMapCursor, gcMapCursor);
detectState = breakCircles_haveGarbage;
// Allow the application to work a little
return 1;
}
else
{
// If no garbage was detected we can finish now
if( detectState != breakCircles_haveGarbage )
{
// Restart the GC
detectState = clearCounters_init;
return 0;
}
else
{
// Restart the GC
detectState = clearCounters_init;
return 1;
}
}
}
} // switch
}
// Shouldn't reach this point
UNREACHABLE_RETURN;
}
int asCGarbageCollector::DestroyOldGarbage()
{
for(;;)
{
switch( destroyOldState )
{
case destroyGarbage_init:
{
// If there are no objects to be freed then don't start
if( gcOldObjects.GetLength() == 0 )
return 0;
destroyOldIdx = (asUINT)-1;
destroyOldState = destroyGarbage_loop;
}
break;
case destroyGarbage_loop:
case destroyGarbage_haveMore:
{
// If the refCount has reached 1, then only the GC still holds a
// reference to the object, thus we don't need to worry about the
// application touching the objects during collection.
// Destroy all objects that have refCount == 1. If any objects are
// destroyed, go over the list again, because it may have made more
// objects reach refCount == 1.
if( ++destroyOldIdx < gcOldObjects.GetLength() )
{
asSObjTypePair gcObj = GetOldObjectAtIdx(destroyOldIdx);
if( gcObj.type->beh.gcGetRefCount == 0 )
{
// If circular references are formed with registered types that hasn't
// registered the GC behaviours, then the engine may be forced to free
// the object type before the actual object instance. In this case we
// will be forced to skip the destruction of the objects, so as not to
// crash the application.
asCString msg;
msg.Format(TXT_GC_CANNOT_FREE_OBJ_OF_TYPE_s, gcObj.type->name.AddressOf());
engine->WriteMessage("", 0, 0, asMSGTYPE_ERROR, msg.AddressOf());
// Just remove the object, as we will not bother to destroy it
numDestroyed++;
RemoveOldObjectAtIdx(destroyOldIdx);
destroyOldIdx--;
}
else if( engine->CallObjectMethodRetInt(gcObj.obj, gcObj.type->beh.gcGetRefCount) == 1 )
{
// Release the object immediately
// Make sure the refCount is really 0, because the
// destructor may have increased the refCount again.
bool addRef = false;
if( gcObj.type->flags & asOBJ_SCRIPT_OBJECT )
{
// Script objects may actually be resurrected in the destructor
int refCount = ((asCScriptObject*)gcObj.obj)->Release();
if( refCount > 0 ) addRef = true;
}
else
engine->CallObjectMethod(gcObj.obj, gcObj.type->beh.release);
// Was the object really destroyed?
if( !addRef )
{
numDestroyed++;
RemoveOldObjectAtIdx(destroyOldIdx);
destroyOldIdx--;
}
else
{
// Since the object was resurrected in the
// destructor, we must add our reference again
engine->CallObjectMethod(gcObj.obj, gcObj.type->beh.addref);
}
destroyOldState = destroyGarbage_haveMore;
}
// Allow the application to work a little
return 1;
}
else
{
if( destroyOldState == destroyGarbage_haveMore )
{
// Restart the cycle
destroyOldState = destroyGarbage_init;
}
else
{
// Restart the cycle
destroyOldState = destroyGarbage_init;
// Return 0 to tell the application that there
// is no more garbage to destroy at the moment
return 0;
}
}
}
break;
}
}
// Shouldn't reach this point
UNREACHABLE_RETURN;
}
