From e86bedd95a049007f77d03cdf9e027f54b389c4c Mon Sep 17 00:00:00 2001
From: Kamil Trzcinski <ayufan@ayufan.eu>
Date: Thu, 7 Apr 2022 12:57:02 +0200
Subject: [PATCH] Improve tracking

---
 hw/buffer_list.h  |  1 +
 hw/buffer_queue.c |  2 +-
 hw/links.c        | 27 +++++++++++----------------
 hw/links.h        |  2 +-
 4 files changed, 14 insertions(+), 18 deletions(-)

diff --git a/hw/buffer_list.h b/hw/buffer_list.h
index 40d1510..5d62746 100644
--- a/hw/buffer_list.h
+++ b/hw/buffer_list.h
@@ -18,6 +18,7 @@ typedef struct buffer_list_s {
   unsigned fmt_width, fmt_height, fmt_format, fmt_bytesperline, fmt_interval_us;
   bool do_timestamps;
 
+  uint64_t last_enqueued_us;
   uint64_t last_dequeued_us;
 
   bool streaming;
diff --git a/hw/buffer_queue.c b/hw/buffer_queue.c
index dea45a2..d74da43 100644
--- a/hw/buffer_queue.c
+++ b/hw/buffer_queue.c
@@ -58,7 +58,7 @@ bool buffer_consumed(buffer_t *buf, const char *who)
 
     E_XIOCTL(buf, buf->buf_list->device->fd, VIDIOC_QBUF, &buf->v4l2_buffer, "Can't queue buffer.");
     buf->enqueued = true;
-    buf->enqueue_time_us = get_monotonic_time_us(NULL, NULL);
+    buf->enqueue_time_us = buf->buf_list->last_enqueued_us = get_monotonic_time_us(NULL, NULL);
   }
 
   pthread_mutex_unlock(&buffer_lock);
diff --git a/hw/links.c b/hw/links.c
index 631eca4..575408c 100644
--- a/hw/links.c
+++ b/hw/links.c
@@ -68,20 +68,9 @@ int _build_fds(link_t *all_links, struct pollfd *fds, link_t **links, buffer_lis
   
     int count_enqueued = buffer_list_count_enqueued(source);
 
-    bool can_dequeue = count_enqueued > 0;
-    int64_t since_last_us = now_us - source->last_dequeued_us;
-    if (since_last_us < source->fmt_interval_us) {
-      can_dequeue = false;
-
-      int64_t since_last_ms = since_last_us / 1000;
-      if (since_last_ms < *max_timeout_ms) {
-        *max_timeout_ms = since_last_ms;
-      }
-    }
-
     fds[n].fd = source->device->fd;
     fds[n].events = POLLHUP;
-    if (can_dequeue)
+    if (count_enqueued > 0)
       fds[n].events |= POLLIN;
     fds[n].revents = 0;
     buf_lists[n] = source;
@@ -144,18 +133,20 @@ void print_pollfds(struct pollfd *fds, int n)
   printf("pollfds = %d\n", n);
 }
 
-int links_step(link_t *all_links, int timeout_ms)
+int links_step(link_t *all_links, int *timeout_ms)
 {
   struct pollfd fds[N_FDS] = {0};
   link_t *links[N_FDS];
   buffer_list_t *buf_lists[N_FDS];
   buffer_t *buf;
 
-  int n = _build_fds(all_links, fds, links, buf_lists, N_FDS, &timeout_ms);
+  int n = _build_fds(all_links, fds, links, buf_lists, N_FDS, timeout_ms);
   print_pollfds(fds, n);
-  int ret = poll(fds, n, timeout_ms);
+  int ret = poll(fds, n, *timeout_ms);
   print_pollfds(fds, n);
 
+  uint64_t now_us = get_monotonic_time_us(NULL, NULL);
+
   if (ret < 0 && errno != EINTR) {
     return errno;
   }
@@ -241,11 +232,15 @@ int links_loop(link_t *all_links, bool *running)
     return -1;
   }
 
+  int timeout_ms = LINKS_LOOP_INTERVAL;
+
   while(*running) {
-    if (links_step(all_links, LINKS_LOOP_INTERVAL) < 0) {
+    if (links_step(all_links, &timeout_ms) < 0) {
       links_stream(all_links, false);
       return -1;
     }
+
+    timeout_ms = LINKS_LOOP_INTERVAL;
   }
 
   links_stream(all_links, false);
diff --git a/hw/links.h b/hw/links.h
index a064311..7248f6d 100644
--- a/hw/links.h
+++ b/hw/links.h
@@ -20,5 +20,5 @@ typedef struct link_s {
 } link_t;
 
 int links_init(link_t *all_links);
-int links_step(link_t *all_links, int timeout);
+int links_step(link_t *all_links, int *timeout_ms);
 int links_loop(link_t *all_links, bool *running);