import org.ldk.enums.*;
import org.ldk.util.*;
import java.util.Arrays;
+import javax.annotation.Nullable;
/**
- * BackgroundProcessor takes care of tasks that (1) need to happen periodically to keep
+ * `BackgroundProcessor` takes care of tasks that (1) need to happen periodically to keep
* Rust-Lightning running properly, and (2) either can or should be run in the background. Its
* responsibilities are:
- * Monitoring whether the ChannelManager needs to be re-persisted to disk, and if so,
+ * Processing [`Event`]s with a user-provided [`EventHandler`].
+ * Monitoring whether the [`ChannelManager`] needs to be re-persisted to disk, and if so,
* writing it to disk/backups by invoking the callback given to it at startup.
- * ChannelManager persistence should be done in the background.
- * Calling `ChannelManager::timer_tick_occurred()` and
- * `PeerManager::timer_tick_occurred()` every minute (can be done in the
- * background).
+ * [`ChannelManager`] persistence should be done in the background.
+ * Calling [`ChannelManager::timer_tick_occurred`] and [`PeerManager::timer_tick_occurred`]
+ * at the appropriate intervals.
*
- * Note that if ChannelManager persistence fails and the persisted manager becomes out-of-date,
- * then there is a risk of channels force-closing on startup when the manager realizes it's
- * outdated. However, as long as `ChannelMonitor` backups are sound, no funds besides those used
- * for unilateral chain closure fees are at risk.
+ * It will also call [`PeerManager::process_events`] periodically though this shouldn't be relied
+ * upon as doing so may result in high latency.
+ *
+ * # Note
+ *
+ * If [`ChannelManager`] persistence fails and the persisted manager becomes out-of-date, then
+ * there is a risk of channels force-closing on startup when the manager realizes it's outdated.
+ * However, as long as [`ChannelMonitor`] backups are sound, no funds besides those used for
+ * unilateral chain closure fees are at risk.
+ *
+ * [`ChannelMonitor`]: lightning::chain::channelmonitor::ChannelMonitor
+ * [`Event`]: lightning::util::events::Event
+ * BackgroundProcessor will immediately stop on drop. It should be stored until shutdown.
*/
@SuppressWarnings("unchecked") // We correctly assign various generic arrays
public class BackgroundProcessor extends CommonBase {
}
/**
- * Start a background thread that takes care of responsibilities enumerated in the top-level
- * documentation.
+ * Start a background thread that takes care of responsibilities enumerated in the [top-level
+ * documentation].
+ *
+ * The thread runs indefinitely unless the object is dropped, [`stop`] is called, or
+ * `persist_manager` returns an error. In case of an error, the error is retrieved by calling
+ * either [`join`] or [`stop`].
*
- * If `persist_manager` returns an error, then this thread will return said error (and
- * `start()` will need to be called again to restart the `BackgroundProcessor`). Users should
- * wait on [`thread_handle`]'s `join()` method to be able to tell if and when an error is
- * returned, or implement `persist_manager` such that an error is never returned to the
- * `BackgroundProcessor`
+ * # Data Persistence
*
* `persist_manager` is responsible for writing out the [`ChannelManager`] to disk, and/or
* uploading to one or more backup services. See [`ChannelManager::write`] for writing out a
* [`ChannelManager`]. See [`FilesystemPersister::persist_manager`] for Rust-Lightning's
* provided implementation.
*
- * [`thread_handle`]: BackgroundProcessor::thread_handle
+ * Typically, users should either implement [`ChannelManagerPersister`] to never return an
+ * error or call [`join`] and handle any error that may arise. For the latter case,
+ * `BackgroundProcessor` must be restarted by calling `start` again after handling the error.
+ *
+ * # Event Handling
+ *
+ * `event_handler` is responsible for handling events that users should be notified of (e.g.,
+ * payment failed). [`BackgroundProcessor`] may decorate the given [`EventHandler`] with common
+ * functionality implemented by other handlers.
+ * [`NetGraphMsgHandler`] if given will update the [`NetworkGraph`] based on payment failures.
+ *
+ * [top-level documentation]: Self
+ * [`join`]: Self::join
+ * [`stop`]: Self::stop
* [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
* [`ChannelManager::write`]: lightning::ln::channelmanager::ChannelManager#impl-Writeable
* [`FilesystemPersister::persist_manager`]: lightning_persister::FilesystemPersister::persist_manager
+ * [`NetworkGraph`]: lightning::routing::network_graph::NetworkGraph
+ *
+ * Note that net_graph_msg_handler (or a relevant inner pointer) may be NULL or all-0s to represent None
*/
- public static BackgroundProcessor start(ChannelManagerPersister persister, EventHandler event_handler, ChainMonitor chain_monitor, ChannelManager channel_manager, PeerManager peer_manager, Logger logger) {
- long ret = bindings.BackgroundProcessor_start(persister == null ? 0 : persister.ptr, event_handler == null ? 0 : event_handler.ptr, chain_monitor == null ? 0 : chain_monitor.ptr & ~1, channel_manager == null ? 0 : channel_manager.ptr & ~1, peer_manager == null ? 0 : peer_manager.ptr & ~1, logger == null ? 0 : logger.ptr);
+ public static BackgroundProcessor start(ChannelManagerPersister persister, EventHandler event_handler, ChainMonitor chain_monitor, ChannelManager channel_manager, NetGraphMsgHandler net_graph_msg_handler, PeerManager peer_manager, Logger logger) {
+ long ret = bindings.BackgroundProcessor_start(persister == null ? 0 : persister.ptr, event_handler == null ? 0 : event_handler.ptr, chain_monitor == null ? 0 : chain_monitor.ptr & ~1, channel_manager == null ? 0 : channel_manager.ptr & ~1, net_graph_msg_handler == null ? 0 : net_graph_msg_handler.ptr & ~1, peer_manager == null ? 0 : peer_manager.ptr & ~1, logger == null ? 0 : logger.ptr);
+ if (ret >= 0 && ret < 1024) { return null; }
BackgroundProcessor ret_hu_conv = new BackgroundProcessor(null, ret);
ret_hu_conv.ptrs_to.add(ret_hu_conv);
ret_hu_conv.ptrs_to.add(persister);
ret_hu_conv.ptrs_to.add(event_handler);
ret_hu_conv.ptrs_to.add(chain_monitor);
ret_hu_conv.ptrs_to.add(channel_manager);
+ ret_hu_conv.ptrs_to.add(net_graph_msg_handler);
ret_hu_conv.ptrs_to.add(peer_manager);
ret_hu_conv.ptrs_to.add(logger);
return ret_hu_conv;
}
/**
- * Stop `BackgroundProcessor`'s thread.
+ * Join `BackgroundProcessor`'s thread, returning any error that occurred while persisting
+ * [`ChannelManager`].
+ *
+ * # Panics
+ *
+ * This function panics if the background thread has panicked such as while persisting or
+ * handling events.
+ *
+ * [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
+ */
+ public Result_NoneErrorZ join() {
+ long ret = bindings.BackgroundProcessor_join(this.ptr);
+ if (ret >= 0 && ret < 1024) { return null; }
+ Result_NoneErrorZ ret_hu_conv = Result_NoneErrorZ.constr_from_ptr(ret);
+ this.ptrs_to.add(this);
+ // Due to rust's strict-ownership memory model, in some cases we need to "move"
+ // an object to pass exclusive ownership to the function being called.
+ // In most cases, we avoid this being visible in GC'd languages by cloning the object
+ // at the FFI layer, creating a new object which Rust can claim ownership of
+ // However, in some cases (eg here), there is no way to clone an object, and thus
+ // we actually have to pass full ownership to Rust.
+ // Thus, after this call, this is reset to null and is now a dummy object.
+ this.ptr = 0;
+ return ret_hu_conv;
+ }
+
+ /**
+ * Stop `BackgroundProcessor`'s thread, returning any error that occurred while persisting
+ * [`ChannelManager`].
+ *
+ * # Panics
+ *
+ * This function panics if the background thread has panicked such as while persisting or
+ * handling events.
+ *
+ * [`ChannelManager`]: lightning::ln::channelmanager::ChannelManager
*/
public Result_NoneErrorZ stop() {
long ret = bindings.BackgroundProcessor_stop(this.ptr);
+ if (ret >= 0 && ret < 1024) { return null; }
Result_NoneErrorZ ret_hu_conv = Result_NoneErrorZ.constr_from_ptr(ret);
this.ptrs_to.add(this);
// Due to rust's strict-ownership memory model, in some cases we need to "move"