std::function<void(ExternalObject*)> ObjectDeleter(std::shared_ptr<Simulation> simulation) {
return [=](ExternalObject* obj) {
//We have to make sure to call the callback outside the lock.
//To that end, we gather information as follows, and then queue it.
bool isExternal;
int handle;
LOCK(*simulation);
isExternal = obj->is_external_object;
handle = obj->external_object_handle;
//WARNING: this line can call this deleter recursively, if obj contains the final shared pointer to another ExternalObject.
delete obj;
//Because of the recursion, shell out to the simulation's task thread.
if(isExternal && handle_destroyed_callback) simulation->enqueueTask([handle] () {handle_destroyed_callback(handle);});
};
}
std::function<void(ExternalObject*)> ObjectDeleter(std::shared_ptr<Server> server) {
return [=](ExternalObject* obj) mutable {
//We have to make sure to call the callback outside the lock.
//To that end, we gather information as follows, and then queue it.
bool isExternal;
int handle;
LOCK(*server);
isExternal = obj->is_external_object;
handle = obj->external_object_handle;
//WARNING: this line can call this deleter recursively, if obj contains the final shared pointer to another ExternalObject.
delete obj;
//Because of the recursion, shell out to the server's task thread.
if(isExternal && handle_destroyed_callback) server->enqueueTask([handle] () {handle_destroyed_callback(handle);});
//The server holds weak_ptrs to nodes.
//weak_ptrs hold references to this deleter.
//Therefore there is a cycle.
server = nullptr;
};
}
