Rewrite default_eventloop to use hash tables instead of arrays

src/extension/default_eventloop.c

@@ -27,12 +27,41 @@
 
 #include "config.h"
 
+#ifdef USE_WINSOCK
+
+#else
 #include <poll.h>
+#endif
 #include <sys/resource.h>
 #include "extension/default_eventloop.h"
 #include "debug.h"
 #include "types-internal.h"
 
+_getdns_eventloop_info *find_event(_getdns_eventloop_info** events, int id)
+{
+	_getdns_eventloop_info* ev;
+
+	DEBUG_SCHED("finding event in events ptr %p with id %d", *events, id);
+	
+	HASH_FIND_INT(*events, &id, ev);
+
+	DEBUG_SCHED("found event in events ptr %p with id %d and ptr %p", *events, id, ev);
+
+	return ev;
+}
+
+void add_event(_getdns_eventloop_info** events, int id, _getdns_eventloop_info* ev)
+{
+	DEBUG_SCHED("adding event in events ptr %p with id %d and ptr %p", *events, id, ev);
+	HASH_ADD_INT(*events, id, ev);
+}
+
+void delete_event(_getdns_eventloop_info** events, _getdns_eventloop_info* ev)
+{
+	DEBUG_SCHED("deleting event in events ptr %p and ptr %p", *events, ev);
+	HASH_DEL(*events, ev);
+}
+
 static uint64_t get_now_plus(uint64_t amount)
 {
 	struct timeval tv;
@@ -72,22 +101,33 @@ default_eventloop_schedule(getdns_eventloop *loop,
 		fd = -1;
 	}
 	if (fd >= 0) {
+		DEBUG_SCHED("default_eventloop_schedule: find_event(default_loop->fd_events)");
+		_getdns_eventloop_info* fd_event = find_event(&default_loop->fd_events, fd);
 #if defined(SCHED_DEBUG) && SCHED_DEBUG
-		if (default_loop->fd_events[fd]) {
+		if (fd_event) {
-			if (default_loop->fd_events[fd] == event) {
+			if (fd_event->event == event) {
 				DEBUG_SCHED("WARNING: Event %p not cleared "
 				            "before being rescheduled!\n"
-				           , default_loop->fd_events[fd]);
+				           , fd_event->event);
 			} else {
 				DEBUG_SCHED("ERROR: A different event is "
 				            "already present at fd slot: %p!\n"
-				           , default_loop->fd_events[fd]);
+				           , fd_event->event);
 			}
 		}
 #endif
-		default_loop->fd_events[fd] = event;
+		/* cleanup the old event if it exists */
-		default_loop->fd_timeout_times[fd] = get_now_plus(timeout);
+		if (fd_event) {
-		event->ev = (void *)(intptr_t)(fd + 1);
+			delete_event(&default_loop->fd_events, fd_event);
+			free(fd_event);
+		}
+		fd_event = calloc(1, sizeof(_getdns_eventloop_info));
+		fd_event->id = fd;
+		fd_event->event = event;
+		fd_event->timeout_time = get_now_plus(timeout);
+		add_event(&default_loop->fd_events, fd, fd_event);
+		event->ev = (void *) (intptr_t) fd + 1;
+
 		DEBUG_SCHED( "scheduled read/write at %d\n", fd);
 		return GETDNS_RETURN_GOOD;
 	}
@@ -104,10 +144,16 @@ default_eventloop_schedule(getdns_eventloop *loop,
 		event->write_cb = NULL;
 	}
 	for (i = 0; i < default_loop->max_timeouts; i++) {
-		if (default_loop->timeout_events[i] == NULL) {
+		_getdns_eventloop_info* timeout_event = NULL;
-			default_loop->timeout_events[i] = event;
+		DEBUG_SCHED("default_eventloop_schedule: find_event(default_loop->timeout_events)");
-			default_loop->timeout_times[i] = get_now_plus(timeout);		
+		if ((timeout_event = find_event(&default_loop->timeout_events, i)) == NULL) {
-			event->ev = (void *)(intptr_t)(i + 1);
+			timeout_event = calloc(1, sizeof(_getdns_eventloop_info));
+			timeout_event->id = i;
+			timeout_event->event = event;
+			timeout_event->timeout_time = get_now_plus(timeout);
+			add_event(&default_loop->timeout_events, i, timeout_event);
+			event->ev = (void *) (intptr_t) i + 1;
+
 			DEBUG_SCHED( "scheduled timeout at %d\n", (int)i);
 			return GETDNS_RETURN_GOOD;
 		}
@@ -132,21 +178,31 @@ default_eventloop_clear(getdns_eventloop *loop, getdns_eventloop_event *event)
 		return GETDNS_RETURN_GENERIC_ERROR;
 	}
 	if (event->timeout_cb && !event->read_cb && !event->write_cb) {
+		DEBUG_SCHED("default_eventloop_clear: find_event(default_loop->timeout_events)");
+		_getdns_eventloop_info* timeout_event = find_event(&default_loop->timeout_events, i);
 #if defined(SCHED_DEBUG) && SCHED_DEBUG
-		if (default_loop->timeout_events[i] != event)
+		if (timeout_event && timeout_event->event != event)
 			DEBUG_SCHED( "ERROR: Different/wrong event present at "
 			             "timeout slot: %p!\n"
-			           , default_loop->timeout_events[i]);
+				     , timeout_event);
 #endif
-		default_loop->timeout_events[i] = NULL;
+		if (timeout_event) {
+			delete_event(&default_loop->timeout_events, timeout_event);
+			free(timeout_event);
+		}
 	} else {
+		DEBUG_SCHED("default_eventloop_clear: find_event(default_loop->fd_events)");
+		_getdns_eventloop_info* fd_event = find_event(&default_loop->fd_events, i);
 #if defined(SCHED_DEBUG) && SCHED_DEBUG
-		if (default_loop->fd_events[i] != event)
+		if (fd_event && fd_event->event != event)
 			DEBUG_SCHED( "ERROR: Different/wrong event present at "
 			             "fd slot: %p!\n"
-			           , default_loop->fd_events[i]);
+			           , fd_event);
 #endif
-		default_loop->fd_events[i] = NULL;
+		if (fd_event) {
+			delete_event(&default_loop->fd_events, fd_event);
+			free(fd_event);
+		}
 	}
 	event->ev = NULL;
 	return GETDNS_RETURN_GOOD;
@@ -156,14 +212,8 @@ static void
 default_eventloop_cleanup(getdns_eventloop *loop)
 {
 	_getdns_default_eventloop *default_loop  = (_getdns_default_eventloop *)loop;
-	if (default_loop->fd_events)
+	HASH_CLEAR(hh, default_loop->fd_events);
-		free(default_loop->fd_events);
+	HASH_CLEAR(hh, default_loop->timeout_events);
-	if (default_loop->fd_timeout_times)
-		free(default_loop->fd_timeout_times);
-	if (default_loop->timeout_events)
-		free(default_loop->timeout_events);
-	if (default_loop->timeout_times)
-		free(default_loop->timeout_times);
 }
 
 static void
@@ -200,10 +250,9 @@ static void
 default_eventloop_run_once(getdns_eventloop *loop, int blocking)
 {
 	_getdns_default_eventloop *default_loop  = (_getdns_default_eventloop *)loop;
-
+	_getdns_eventloop_info *s, *tmp;
-	int      fd, max_fd = -1;
 	uint64_t now, timeout = TIMEOUT_FOREVER;
-	size_t   i;
+	size_t   i=0;
 	int poll_timeout = 0;
 	struct pollfd* pfds = NULL;
 	int num_pfds = 0;
@@ -213,78 +262,81 @@ default_eventloop_run_once(getdns_eventloop *loop, int blocking)
 	
 	now = get_now_plus(0);
 
-	for (i = 0; i < default_loop->max_timeouts; i++) {
+	HASH_ITER(hh, default_loop->timeout_events, s, tmp) {
-		if (!default_loop->timeout_events[i])
+		if (now > s->timeout_time)
-			continue;
+			default_timeout_cb(-1, s->event);
-		if (now > default_loop->timeout_times[i])
+		else if (s->timeout_time < timeout)
-			default_timeout_cb(-1, default_loop->timeout_events[i]);
+			timeout = s->timeout_time;
-		else if (default_loop->timeout_times[i] < timeout)
-			timeout = default_loop->timeout_times[i];
 	}
 	// first we count the number of fds that will be active
-	for (fd = 0; fd < default_loop->max_fds; fd++) {
+	HASH_ITER(hh, default_loop->fd_events, s, tmp) {
-		if (!default_loop->fd_events[fd])
+		if (s->event->read_cb ||
-			continue;
+		    s->event->write_cb)
-		if (default_loop->fd_events[fd]->read_cb ||
-		    default_loop->fd_events[fd]->write_cb)
 			num_pfds++;
-		if (fd > max_fd)
+		if (s->timeout_time < timeout)
-			max_fd = fd;
+			timeout = s->timeout_time;
-		if (default_loop->fd_timeout_times[fd] < timeout)
-			timeout = default_loop->fd_timeout_times[fd];
 	}
 
-	if ((max_fd == -1 && timeout == (uint64_t)-1) || (num_pfds == 0))
+	if ((timeout == (uint64_t)-1) && (num_pfds == 0))
 		return;
 
 	pfds = calloc(num_pfds, sizeof(struct pollfd));
-	for (fd = 0, i=0; fd < default_loop->max_fds; fd++) {
+	i = 0;
-		if (!default_loop->fd_events[fd])
+	HASH_ITER(hh, default_loop->fd_events, s, tmp) {
-			continue;
+		if (s->event->read_cb) {
-		if (default_loop->fd_events[fd]->read_cb) {
+			pfds[i].fd = s->id;
-			pfds[i].fd = fd;
 			pfds[i].events |= POLLIN;
 		}	
-		if (default_loop->fd_events[fd]->write_cb) {
+		if (s->event->write_cb) {
-			pfds[i].fd = fd;
+			pfds[i].fd = s->id;
 			pfds[i].events |= POLLOUT;
 		}
+		i++;
 	}
 
 	if (! blocking || now > timeout) {
 		poll_timeout = 0;
 	} else {
-		poll_timeout = (timeout - now) * 1000; /* turn seconds in millseconds */
+		poll_timeout = (timeout - now) * 1000; /* turn seconds into millseconds */
 	}
+#ifdef USE_WINSOCK
+	if (WSAPoll(pfds, num_pfds, poll_timeout) < 0) {
+#else	
 	if (poll(pfds, num_pfds, poll_timeout) < 0) {
+#endif
 		perror("poll() failed");
 		exit(EXIT_FAILURE);
 	}
 	now = get_now_plus(0);
-	for (int i = 0; i < num_pfds; i++) {
+	for (i = 0; i < num_pfds; i++) {
 		int fd = pfds[i].fd;
-		if (default_loop->fd_events[fd] &&
+		DEBUG_SCHED("default_eventloop_runonce: find_event(default_loop->fd_events)");
-		    default_loop->fd_events[fd]->read_cb &&
+		_getdns_eventloop_info* fd_event = find_event(&default_loop->fd_events, fd);
+		if (fd_event &&
+		    fd_event->event &&
+		    fd_event->event->read_cb &&
 		    (pfds[i].revents & POLLIN))
-			default_read_cb(fd, default_loop->fd_events[fd]);
+			default_read_cb(fd, fd_event->event);
 
-		if (default_loop->fd_events[fd] &&
+		if (fd_event &&
-		    default_loop->fd_events[fd]->write_cb &&
+		    fd_event->event &&
+		    fd_event->event->write_cb &&
 		    (pfds[i].revents & POLLOUT))
-			default_write_cb(fd, default_loop->fd_events[fd]);
+			default_write_cb(fd, fd_event->event);
 	}
 	if (pfds)
 		free(pfds);
-	for (int fd=0; fd < default_loop->max_fds; fd++) {
+	HASH_ITER(hh, default_loop->fd_events, s, tmp) {
-		if (default_loop->fd_events[fd] &&
+		if (s->event &&
-		    default_loop->fd_events[fd]->timeout_cb &&
+		    s->event->timeout_cb &&
-		    now > default_loop->fd_timeout_times[fd])
+		    now > s->timeout_time)
-			default_timeout_cb(fd, default_loop->fd_events[fd]);
+			default_timeout_cb(s->id, s->event);
-		i = fd;
+	}
-		if (default_loop->timeout_events[i] &&
+	HASH_ITER(hh, default_loop->timeout_events, s, tmp) {
-		    default_loop->timeout_events[i]->timeout_cb &&
+		if (s->event &&
-		    now > default_loop->timeout_times[i])
+		    s->event->timeout_cb &&
-			default_timeout_cb(-1, default_loop->timeout_events[i]);
+		    now > s->timeout_time)
+			default_timeout_cb(s->id, s->event);
 	}
 }
 
@@ -292,19 +344,13 @@ static void
 default_eventloop_run(getdns_eventloop *loop)
 {
 	_getdns_default_eventloop *default_loop  = (_getdns_default_eventloop *)loop;
-	size_t        i;
 
 	if (!loop)
 		return;
 
-	i = 0;
+	/* keep going until all the events are cleared */
-	while (i < default_loop->max_timeouts) {
+	while (default_loop->fd_events && default_loop->timeout_events) {
-		if (default_loop->fd_events[i] || default_loop->timeout_events[i]) {
+		default_eventloop_run_once(loop, 1);
-			default_eventloop_run_once(loop, 1);
-			i = 0;
-		} else {
-			i++;
-		}
 	}
 }
 
@@ -325,18 +371,10 @@ _getdns_default_eventloop_init(_getdns_default_eventloop *loop)
 	struct rlimit rl;
 	if (getrlimit(RLIMIT_NOFILE, &rl) == 0) {
 		loop->max_fds = rl.rlim_cur;
-		loop->max_timeouts = loop->max_fds;
+		loop->max_timeouts = loop->max_fds; /* this is somewhat arbitrary */
 	} else {
 		DEBUG_SCHED("ERROR: could not obtain RLIMIT_NOFILE from getrlimit()\n");
 		loop->max_fds = 0;
 		loop->max_timeouts = loop->max_fds;
 	}
-	if (loop->max_fds) {
-		loop->fd_events = calloc(loop->max_fds, sizeof(getdns_eventloop_event *));
-		loop->fd_timeout_times = calloc(loop->max_fds, sizeof(uint64_t));
-	}
-	if (loop->max_timeouts) {
-		loop->timeout_events = calloc(loop->max_timeouts, sizeof(getdns_eventloop_event *));
-		loop->timeout_times = calloc(loop->max_timeouts, sizeof(uint64_t));
-	}
 }

src/extension/default_eventloop.h

@@ -34,19 +34,25 @@
 #include "config.h"
 #include "getdns/getdns.h"
 #include "getdns/getdns_extra.h"
+#include "util/uthash.h"
 
 /* Eventloop based on poll */
+
+typedef struct _getdns_eventloop_info {
+	int			id;
+	getdns_eventloop_event *event;
+	uint64_t                timeout_time;
+	UT_hash_handle		hh;
+} _getdns_eventloop_info;
+
 typedef struct _getdns_default_eventloop {
 	getdns_eventloop        loop;
 	int			max_fds;
 	int			max_timeouts;
-	getdns_eventloop_event **fd_events;
+	_getdns_eventloop_info  *fd_events;
-	uint64_t                *fd_timeout_times;
+	_getdns_eventloop_info  *timeout_events;
-	getdns_eventloop_event **timeout_events;
-	uint64_t                *timeout_times;
 } _getdns_default_eventloop;
 
-
 void
 _getdns_default_eventloop_init(_getdns_default_eventloop *loop);