Add newtypes for absolute and relative time

events.c

@@ -37,20 +37,15 @@ event_create(const EventData * content)
 		event->data = *content;
 		event->data.modifiers = modifier_set_copy(content->modifiers);
 	} else {
-		clock_gettime(CLOCK_MONOTONIC, &event->data.time);
+		event->data.time = get_current_time();
 	}
-	struct timespec self_time = event->data.time;
+	AbsoluteTime self_time = event->data.time;
 	EventNode ** list_pos = &LAST_EVENT;
 	FOREACH_EVENT_DESC(other) {
-		struct timespec other_time = other->data.time;
+		AbsoluteTime other_time = other->data.time;
-		if (self_time.tv_sec > other_time.tv_sec) {
+		if (absolute_time_cmp(self_time, other_time) >= 0) {
 			break;
 		}
-		if (self_time.tv_sec == other_time.tv_sec) {
-			if (self_time.tv_nsec >= other_time.tv_nsec) {
-				break;
-			}
-		}
 		list_pos = &other->next->prev;
 	}
 	EventNode * prev = *list_pos;

events.h

@@ -1,9 +1,9 @@
 #ifndef EVENTS_H_
 #define EVENTS_H_
 
-#include <time.h>
 #include "defs.h"
 #include "modifiers.h"
+#include "time.h"
 
 typedef uint32_t EventNamespace;
 
@@ -18,7 +18,7 @@ typedef struct {
 	int32_t priority;
 	int64_t payload;
 	ModifierSet modifiers;
-	struct timespec time;
+	AbsoluteTime time;
 } EventData;
 
 typedef struct event_position_base EventPositionBase;

main.c

@@ -10,8 +10,8 @@ main(int argc, char ** argv)
 
 	ProcessingState state = (ProcessingState) {
 		.wait_delay = NULL,
+		.reached_time = get_current_time(),
 	};
-	clock_gettime(CLOCK_MONOTONIC, &state.reached_time);
 	io_subscription_list_init(&state.wait_input, 5);
 	io_subscription_list_init(&state.wait_output, 5);
 

nodes/getchar.c

@@ -28,8 +28,8 @@ handle_io(EventPositionBase * self, int fd, bool is_output)
 		.priority = 10,
 		.payload = buf[0],
 		.modifiers = EMPTY_MODIFIER_SET,
+		.time = get_current_time(),
 	};
-	clock_gettime(CLOCK_MONOTONIC, &data.time);
 	if (status == 0) {
 		node->subscription.enabled = false;
 		data.code.value = 2;

nodes/print.c

@@ -18,7 +18,7 @@ handle_event(EventPositionBase * self, EventNode * event)
 		printf("%02x", data.modifiers.bits[i]);
 	}
 	printf("\n");
-	printf("time = %ld.%09ld\n", data.time.tv_sec, data.time.tv_nsec);
+	printf("time.absolute = %ld.%09ld\n", data.time.absolute.tv_sec, data.time.absolute.tv_nsec);
 	printf("---\n\n");
 	event_destroy(event);
 	return true;

processing.c

@@ -117,7 +117,7 @@ run_io_handlers(fd_set * fds, IOSubscriptionList * subs, bool arg)
 }
 
 bool
-process_io(ProcessingState * state, const struct timespec * timeout)
+process_io(ProcessingState * state, const RelativeTime * timeout)
 {
 	int max_fd = 0;
 	fd_set readfds, writefds;
@@ -126,7 +126,7 @@ process_io(ProcessingState * state, const struct timespec * timeout)
 	max_fd = populate_fd_set(&writefds, &state->wait_output, max_fd);
 
 	++max_fd;
-	int ready = pselect(max_fd, &readfds, &writefds, NULL, timeout, NULL);
+	int ready = pselect(max_fd, &readfds, &writefds, NULL, &timeout->relative, NULL);
 
 	if (ready < 0) {
 		FD_ZERO(&readfds);
@@ -143,19 +143,14 @@ process_io(ProcessingState * state, const struct timespec * timeout)
 }
 
 bool
-schedule_delay(ProcessingState * state, EventPositionBase * target, void (*callback) (EventPositionBase*, void*, const struct timespec*), const struct timespec * time)
+schedule_delay(ProcessingState * state, EventPositionBase * target, void (*callback) (EventPositionBase*, void*, const AbsoluteTime*), const AbsoluteTime * time)
 {
 	DelayList **next = &state->wait_delay;
 	while (*next) {
-		struct timespec next_time = (*next)->time;
+		AbsoluteTime next_time = (*next)->time;
-		if (next_time.tv_sec > time->tv_sec) {
+		if (absolute_time_cmp(next_time, *time) > 0) {
 			break;
 		}
-		if (next_time.tv_sec == time->tv_sec) {
-			if (next_time.tv_nsec > time->tv_nsec) {
-				break;
-			}
-		}
 		next = &((*next)->next);
 	}
 
@@ -174,33 +169,22 @@ schedule_delay(ProcessingState * state, EventPositionBase * target, void (*callb
 	return true;
 }
 
-static const struct timespec ZERO_TS = {
+static const RelativeTime ZERO_TO = {
+	.relative ={
 		.tv_sec = 0,
 		.tv_nsec = 0,
+	}
 };
 
-inline static void
-fix_nsec(struct timespec * ts)
-{
-	if (ts->tv_nsec < 0) {
-		ts->tv_nsec += 1000000000;
-		ts->tv_sec -= 1;
-	}
-}
-
 static bool
-process_single_scheduled(ProcessingState * state, const struct timespec extern_time)
+process_single_scheduled(ProcessingState * state, const AbsoluteTime extern_time)
 {
 	if (!state->wait_delay) {
 		return false;
 	}
-	struct timespec next_scheduled_time = state->wait_delay->time;  // abs
+	AbsoluteTime next_scheduled_time = state->wait_delay->time;
-	if (next_scheduled_time.tv_sec > extern_time.tv_sec) {
+	if (absolute_time_cmp(next_scheduled_time, extern_time) > 0) {
 		return false;
-	} else if (next_scheduled_time.tv_sec == extern_time.tv_sec) {
-		if (next_scheduled_time.tv_nsec > extern_time.tv_nsec) {
-			return false;
-		}
 	}
 	DelayList next_scheduled = *state->wait_delay;
 	free(state->wait_delay);
@@ -217,7 +201,7 @@ process_single_scheduled(ProcessingState * state, const struct timespec extern_t
 }
 
 static bool
-process_events_until(ProcessingState * state, const struct timespec * max_time)
+process_events_until(ProcessingState * state, const AbsoluteTime * max_time)
 {
 	bool stable = true;
 	int32_t next_priority = INT32_MIN;
@@ -225,17 +209,11 @@ process_events_until(ProcessingState * state, const struct timespec * max_time)
 
 	FOREACH_EVENT(ev) {
 		if (max_time) {
-			struct timespec ev_time = ev->data.time;
+			AbsoluteTime ev_time = ev->data.time;
-			if (ev_time.tv_sec > max_time->tv_sec) {
+			if (absolute_time_cmp(ev_time, *max_time) > 0) {
 				// stable = false;
 				state->has_future_events = true;
 				break;
-			} else if (ev_time.tv_sec == max_time->tv_sec) {
-				if (ev_time.tv_nsec > max_time->tv_nsec) {
-					// stable = false;
-					state->has_future_events = true;
-					break;
-				}
 			}
 		}
 
@@ -270,15 +248,10 @@ process_events_until(ProcessingState * state, const struct timespec * max_time)
 			}
 
 			if (max_time) {
-				struct timespec ev_time = ev->data.time;
+				AbsoluteTime ev_time = ev->data.time;
-				if (ev_time.tv_sec > max_time->tv_sec) {
+				if (absolute_time_cmp(ev_time, *max_time) > 0) {
 					state->has_future_events = true;
 					break;
-				} else if (ev_time.tv_sec == max_time->tv_sec) {
-					if (ev_time.tv_nsec > max_time->tv_nsec) {
-						state->has_future_events = true;
-						break;
-					}
 				}
 			}
 
@@ -304,28 +277,21 @@ process_events_until(ProcessingState * state, const struct timespec * max_time)
 void
 process_iteration(ProcessingState * state)
 {
-	struct timespec extern_time;
+	AbsoluteTime extern_time = get_current_time();
-	if (clock_gettime(CLOCK_MONOTONIC, &extern_time) < 0) {
-		perror("Failed to get time");
-		exit(1);
-	}
 
 	// late_by.tv_sec = extern_time.tv_sec - state->reached_time.tv_sec;
 	// late_by.tv_nsec = extern_time.tv_nsec - state->reached_time.tv_nsec;
 	// fix_nsec(&late_by);
 
-	struct timespec next_scheduled_delay;
+	RelativeTime next_scheduled_delay;
-	const struct timespec *max_io_timeout = NULL;
+	const RelativeTime *max_io_timeout = NULL;
 	if (state->has_future_events) {
-		max_io_timeout = &ZERO_TS;
+		max_io_timeout = &ZERO_TO;
 	} else {
 		if (state->wait_delay) {
-			next_scheduled_delay = state->wait_delay->time;  // abs
+			next_scheduled_delay = absolute_time_sub_absolute(state->wait_delay->time, extern_time);
-			next_scheduled_delay.tv_sec -= extern_time.tv_sec;
+			if (relative_time_cmp(next_scheduled_delay, ZERO_TO) < 0) {
-			next_scheduled_delay.tv_nsec -= extern_time.tv_nsec;
+				max_io_timeout = &ZERO_TO;
-			fix_nsec(&next_scheduled_delay);
-			if (next_scheduled_delay.tv_sec < 0) {
-				max_io_timeout = &ZERO_TS;
 			} else {
 				max_io_timeout = &next_scheduled_delay;
 			}
@@ -334,19 +300,16 @@ process_iteration(ProcessingState * state)
 
 	// FIXME reason about timeouts
 	process_io(state, max_io_timeout);
-	// process_io(state, &ZERO_TS);
+	// process_io(state, &ZERO_TO);
 
 	while (true) {
 		bool had_scheduled = process_single_scheduled(state, extern_time);
-		const struct timespec *max_event_time = &extern_time;
+		const AbsoluteTime *max_event_time = &extern_time;
 		if (state->wait_delay) {
-			struct timespec next_scheduled_time = state->wait_delay->time;
+			AbsoluteTime next_scheduled_time = state->wait_delay->time;
 			bool use_scheduled = false;
 			if (!use_scheduled) {
-				use_scheduled = next_scheduled_time.tv_sec > extern_time.tv_sec;
+				use_scheduled = absolute_time_cmp(next_scheduled_time, extern_time) > 0;
-			}
-			if (!use_scheduled) {
-				use_scheduled = next_scheduled_time.tv_nsec > extern_time.tv_nsec;
 			}
 			if (use_scheduled) {
 				max_event_time = &state->wait_delay->time;
@@ -356,6 +319,6 @@ process_iteration(ProcessingState * state)
 		if (!had_scheduled && !had_events) {
 			break;
 		}
-		process_io(state, &ZERO_TS);
+		process_io(state, &ZERO_TO);
 	}
 }

processing.h

@@ -23,17 +23,17 @@ typedef struct {
 typedef struct delay_list DelayList;
 
 struct delay_list {
-	void (*callback) (EventPositionBase * target, void * closure, const struct timespec * time);
+	void (*callback) (EventPositionBase * target, void * closure, const AbsoluteTime * time);
 	EventPositionBase *target;
 	void *closure;
 	DelayList *next;
-	struct timespec time;
+	AbsoluteTime time;
 };
 
 typedef struct {
 	IOSubscriptionList wait_input, wait_output;
 	DelayList *wait_delay;
-	struct timespec reached_time;
+	AbsoluteTime reached_time;
 	int32_t pass_priority;
 	bool has_future_events;
 } ProcessingState;
@@ -42,8 +42,8 @@ void io_subscription_list_init(IOSubscriptionList * lst, size_t capacity);
 void io_subscription_list_deinit(IOSubscriptionList * lst);
 void io_subscription_list_add(IOSubscriptionList * lst, int fd, IOHandling *subscriber);
 
-bool schedule_delay(ProcessingState * state, EventPositionBase * target, void (*callback) (EventPositionBase*, void*, const struct timespec*), const struct timespec * time);
+bool schedule_delay(ProcessingState * state, EventPositionBase * target, void (*callback) (EventPositionBase*, void*, const AbsoluteTime*), const AbsoluteTime * time);
-bool process_io(ProcessingState * state, const struct timespec * timeout);
+bool process_io(ProcessingState * state, const RelativeTime * timeout);
 void process_iteration(ProcessingState * state);
 
 #endif /* end of include guard: PROCESSING_H_ */

time.h

@@ -0,0 +1,116 @@
+#ifndef TIME_H_
+#define TIME_H_
+
+#include <time.h>
+#define NANOSECONDS_IN_SECOND 1000000000
+
+typedef struct {
+	struct timespec absolute;
+} AbsoluteTime;
+
+typedef struct {
+	struct timespec relative;
+} RelativeTime;
+
+__attribute__((unused)) inline static void
+timespec_add(struct timespec *accum, const struct timespec *item)
+{
+	accum->tv_sec += item->tv_sec;
+	accum->tv_nsec += item->tv_nsec;
+	while (accum->tv_nsec >= NANOSECONDS_IN_SECOND) {
+		++(accum->tv_sec);
+		accum->tv_nsec -= NANOSECONDS_IN_SECOND;
+	}
+}
+
+__attribute__((unused)) inline static void
+timespec_sub(struct timespec *accum, const struct timespec *item)
+{
+	accum->tv_sec -= item->tv_sec;
+	accum->tv_nsec -= item->tv_nsec;
+	while (accum->tv_nsec < 0) {
+		--(accum->tv_sec);
+		accum->tv_nsec += NANOSECONDS_IN_SECOND;
+	}
+}
+
+__attribute__((unused)) inline static int
+timespec_cmp(const struct timespec *lhs, const struct timespec *rhs)
+{
+	if (lhs->tv_sec > rhs->tv_sec) {
+		return 1;
+	}
+	if (lhs->tv_sec < rhs->tv_sec) {
+		return -1;
+	}
+	if (lhs->tv_nsec > rhs->tv_nsec) {
+		return 1;
+	}
+	if (lhs->tv_nsec < rhs->tv_nsec) {
+		return -1;
+	}
+	return 0;
+}
+
+__attribute__((unused)) inline static AbsoluteTime
+get_current_time()
+{
+	AbsoluteTime time;
+	if (clock_gettime(CLOCK_MONOTONIC, &time.absolute) < 0) {
+		time.absolute.tv_sec = 0;
+		time.absolute.tv_nsec = 0;
+	}
+	return time;
+}
+
+__attribute__((unused)) inline static AbsoluteTime
+absolute_time_add_relative(AbsoluteTime lhs, RelativeTime rhs)
+{
+	timespec_add(&lhs.absolute, &rhs.relative);
+	return lhs;
+}
+
+__attribute__((unused)) inline static AbsoluteTime
+absolute_time_sub_relative(AbsoluteTime lhs, RelativeTime rhs)
+{
+	timespec_sub(&lhs.absolute, &rhs.relative);
+	return lhs;
+}
+
+__attribute__((unused)) inline static RelativeTime
+absolute_time_sub_absolute(AbsoluteTime lhs, AbsoluteTime rhs)
+{
+	RelativeTime result = {
+		.relative = lhs.absolute,
+	};
+	timespec_sub(&result.relative, &rhs.absolute);
+	return result;
+}
+
+__attribute__((unused)) inline static RelativeTime
+relative_time_add(RelativeTime lhs, RelativeTime rhs)
+{
+	timespec_add(&lhs.relative, &rhs.relative);
+	return lhs;
+}
+
+__attribute__((unused)) inline static RelativeTime
+relative_time_sub(RelativeTime lhs, RelativeTime rhs)
+{
+	timespec_sub(&lhs.relative, &rhs.relative);
+	return lhs;
+}
+
+__attribute__((unused)) inline static int
+absolute_time_cmp(AbsoluteTime lhs, AbsoluteTime rhs)
+{
+	return timespec_cmp(&lhs.absolute, &rhs.absolute);
+}
+
+__attribute__((unused)) inline static int
+relative_time_cmp(RelativeTime lhs, RelativeTime rhs)
+{
+	return timespec_cmp(&lhs.relative, &rhs.relative);
+}
+
+#endif /* end of include guard: TIME_H_ */