Wakeup actually working (probably), add delay calculator.

adsbus/adsbus.c

@@ -102,6 +102,7 @@ int main(int argc, char *argv[]) {
 	hex_init();
 
 	peer_init();
+	retry_init();
 	wakeup_init();
 
 	send_init();
@@ -116,6 +117,7 @@ int main(int argc, char *argv[]) {
 
 	peer_loop();
 
+	retry_cleanup();
 	wakeup_cleanup();
 	send_cleanup();
 

adsbus/common.c

@@ -216,3 +216,34 @@ void uuid_gen(char *out) {
 	uuid_generate(uuid);
 	uuid_unparse(uuid, out);
 }
+
+
+static int retry_rand_fd;
+
+void retry_init() {
+	retry_rand_fd = open("/dev/urandom", O_RDONLY);
+	assert(retry_rand_fd >= 0);
+}
+
+void retry_cleanup() {
+	assert(!close(retry_rand_fd));
+}
+
+#define RETRY_MIN_MS 2000
+#define RETRY_MAX_MS 64000
+#define RETRY_MULT 2
+#define RETRY_MAX_JITTER_DIV 2
+uint32_t retry_get_delay_ms(uint32_t prev_delay) {
+	uint32_t delay = prev_delay * RETRY_MULT;
+	delay = delay < RETRY_MIN_MS ? RETRY_MIN_MS : delay;
+	delay = delay > RETRY_MAX_MS ? RETRY_MAX_MS : delay;
+
+	uint32_t max_jitter = delay / RETRY_MAX_JITTER_DIV;
+	uint32_t jitter;
+	assert(read(retry_rand_fd, &jitter, sizeof(jitter)) == sizeof(jitter));
+	delay += jitter % max_jitter;
+
+	delay = delay > RETRY_MAX_MS ? RETRY_MAX_MS : delay;
+
+	return delay;
+}

adsbus/common.h

@@ -91,3 +91,10 @@ void hex_from_int(char *, uint64_t, size_t);
 
 #define UUID_LEN 37
 void uuid_gen(char *);
+
+
+///////// retry timing
+
+void retry_init();
+void retry_cleanup();
+uint32_t retry_get_delay_ms(uint32_t);

adsbus/incoming.c

@@ -13,7 +13,6 @@
 #include "common.h"
 #include "incoming.h"
 
-struct incoming;
 struct incoming {
 	struct peer peer;
 	char id[UUID_LEN];

adsbus/outgoing.c

@@ -11,7 +11,6 @@
 #include "common.h"
 #include "outgoing.h"
 
-struct outgoing;
 struct outgoing {
 	struct peer peer;
 	char id[UUID_LEN];

adsbus/wakeup.c

@@ -1,7 +1,13 @@
+#define _GNU_SOURCE
+
+#include <stdlib.h>
 #include <stdio.h>
 #include <assert.h>
+#include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
+#include <time.h>
+#include <string.h>
 #include <sys/epoll.h>
 #include <pthread.h>
 
@@ -9,9 +15,53 @@
 
 #include "wakeup.h"
 
+struct wakeup_peer {
+	struct peer peer;
+	struct peer *inner_peer;
+};
+
+struct wakeup_request {
+	int fd;
+	uint64_t absolute_time_ms;
+};
+
+struct wakeup_entry {
+	struct wakeup_request request;
+	struct wakeup_entry *next;
+};
+
 static pthread_t wakeup_thread;
 static int wakeup_write_fd;
 
+static uint64_t wakeup_get_time_ms() {
+	struct timespec tp;
+	assert(!clock_gettime(CLOCK_MONOTONIC_COARSE, &tp));
+#define NS_PER_MS 1000000
+	return tp.tv_sec + (tp.tv_nsec / NS_PER_MS);
+}
+
+static void wakeup_request_add(struct wakeup_entry **head, struct wakeup_request *request) {
+	struct wakeup_entry *entry = malloc(sizeof(*entry));
+	memcpy(&entry->request, request, sizeof(entry->request));
+
+	struct wakeup_entry *prev = NULL, *iter = *head;
+	while (iter) {
+		if (iter->request.absolute_time_ms > entry->request.absolute_time_ms) {
+			break;
+		}
+		prev = iter;
+		iter = iter->next;
+	}
+
+	if (prev) {
+		entry->next = prev->next;
+		prev->next = entry;
+	} else {
+		entry->next = *head;
+		*head = entry;
+	}
+}
+
 static void *wakeup_main(void *arg) {
 	int read_fd = (intptr_t) arg;
 
@@ -20,18 +70,50 @@ static void *wakeup_main(void *arg) {
 
 	struct epoll_event ev = {
 		.events = EPOLLIN,
+		.data = {
+			.fd = read_fd,
+		},
 	};
 	assert(!epoll_ctl(epoll_fd, EPOLL_CTL_ADD, read_fd, &ev));
 
+	struct wakeup_entry *head = NULL;
+
 	while (1) {
-#define MAX_EVENTS 10
+#define MAX_EVENTS 1
 		struct epoll_event events[MAX_EVENTS];
 		int nfds = epoll_wait(epoll_fd, events, MAX_EVENTS, -1);
 		if (nfds == -1 && errno == EINTR) {
 			continue;
 		}
-		assert(nfds >= 0);
-		break; // XXX
+
+		if (nfds == 1) {
+			assert(events[0].data.fd == read_fd);
+			struct wakeup_request request;
+			ssize_t result = read(read_fd, &request, sizeof(request));
+			if (result == 0) {
+				// Peer closed connection, shutdown thread
+				break;
+			}
+			assert(result == sizeof(request));
+			wakeup_request_add(&head, &request);
+		} else {
+			assert(nfds == 0);
+		}
+
+		uint64_t now = wakeup_get_time_ms();
+		while (head && head->request.absolute_time_ms < now) {
+			close(head->request.fd);
+			struct wakeup_entry *next = head->next;
+			free(head);
+			head = next;
+		}
+	}
+
+	while (head) {
+		close(head->request.fd);
+		struct wakeup_entry *next = head->next;
+		free(head);
+		head = next;
 	}
 
 	assert(!close(read_fd));
@@ -39,9 +121,18 @@ static void *wakeup_main(void *arg) {
 	return NULL;
 }
 
+static void wakeup_handler(struct peer *peer) {
+	struct wakeup_peer *outer_peer = (struct wakeup_peer *) peer;
+	assert(!close(outer_peer->peer.fd));
+
+	struct peer *inner_peer = outer_peer->inner_peer;
+	free(outer_peer);
+	inner_peer->event_handler(inner_peer);
+}
+
 void wakeup_init() {
 	int pipefd[2];
-	assert(!pipe(pipefd));
+	assert(!pipe2(pipefd, O_NONBLOCK));
 	assert(!pthread_create(&wakeup_thread, NULL, wakeup_main, (void *) (intptr_t) pipefd[0]));
 	wakeup_write_fd = pipefd[1];
 }
@@ -51,5 +142,21 @@ void wakeup_cleanup() {
 	assert(!pthread_join(wakeup_thread, NULL));
 }
 
-void wakeup_add(struct peer *peer, int delay_ms) {
+void wakeup_add(struct peer *peer, uint32_t delay_ms) {
+	int pipefd[2];
+	assert(!pipe2(pipefd, O_NONBLOCK));
+
+	struct wakeup_request request = {
+		.fd = pipefd[1],
+		.absolute_time_ms = wakeup_get_time_ms() + delay_ms,
+	};
+	assert(write(wakeup_write_fd, &request, sizeof(request)) == sizeof(request));
+
+	struct wakeup_peer *outer_peer = malloc(sizeof(*outer_peer));
+	assert(outer_peer);
+	outer_peer->peer.fd = pipefd[0];
+	outer_peer->peer.event_handler = wakeup_handler;
+	outer_peer->inner_peer = peer;
+
+	peer_epoll_add((struct peer *) outer_peer, EPOLLRDHUP);
 }

adsbus/wakeup.h

@@ -4,4 +4,4 @@ struct peer;
 
 void wakeup_init();
 void wakeup_cleanup();
-void wakeup_add(struct peer *, int);
+void wakeup_add(struct peer *, uint32_t);