core-lightning/lightningd/io_loop_with_timers.c

#include "config.h"
#include <ccan/io/io.h>
#include <common/timeout.h>
#include <db/exec.h>
#include <lightningd/io_loop_with_timers.h>
#include <lightningd/lightningd.h>

void *io_loop_with_timers(struct lightningd *ld)
{
	void *retval = NULL;
	struct timer *expired;

	while (!retval) {
		/* ~ccan/io's io_loop() continuously calls
		 * io_poll_lightningd() for all file descriptors registered
		 * with it, then calls their callbacks or closes them if they
		 * fail, as appropriate.
		 *
		 * It will only exit if there's an expired timer, *or* someone
		 * calls io_break, or if there are no more file descriptors
		 * (which never happens in our code). */
		retval = io_loop(ld->timers, &expired);

		/*~ Notice that timers are called here in the event loop like
		 * anything else, so there are no weird concurrency issues. */
		if (expired) {
			/* This routine is legal in early startup, too. */
			if (ld->wallet)
				db_begin_transaction(ld->wallet->db);
			timer_expired(expired);
			if (ld->wallet)
				db_commit_transaction(ld->wallet->db);
		}
	}

	return retval;
}