Use new fdstate subsystem to store per fd cookie and timeout

1 files changed, 26 insertions, 2 deletions

diff --git a/ot_fdstate.c b/ot_fdstate.c
index 6ddbea3..7f73d3d 100644
--- a/ot_fdstate.c
+++ b/ot_fdstate.c
@@ -34,8 +34,11 @@ typedef struct {
    range descriptor is rejected */
 #define FD_SLOTS_MAX (1u << 20)
 
-static ot_fdslot *g_slots;
-static size_t     g_slot_count;
+static ot_fdslot      *g_slots;
+static size_t          g_slot_count;
+/* Descriptors are handed out lowest first, so a sweep only has to walk as
+   far as the highest one ever seen rather than the whole table. */
+static _Atomic size_t  g_slot_highest;
 
 int fdstate_init(void) {
   struct rlimit limit;
@@ -51,6 +54,7 @@ int fdstate_init(void) {
   }
 
   g_slot_count = count;
+  atomic_store(&g_slot_highest, 0);
   return 0;
 }
 
@@ -59,6 +63,7 @@ void fdstate_deinit(void) {
     munmap(g_slots, g_slot_count * sizeof(ot_fdslot));
   g_slots      = NULL;
   g_slot_count = 0;
+  atomic_store(&g_slot_highest, 0);
 }
 
 size_t fdstate_slots(void) { return g_slot_count; }
@@ -76,6 +81,15 @@ uint32_t fdstate_open(int fd, void *cookie, ot_time expiry) {
   if (!slot)
     return 0;
 
+  {
+    size_t highest = atomic_load_explicit(&g_slot_highest, memory_order_relaxed);
+
+    while ((size_t)fd > highest &&
+           !atomic_compare_exchange_weak_explicit(&g_slot_highest, &highest, (size_t)fd, memory_order_relaxed,
+                                                  memory_order_relaxed))
+      ;
+  }
+
   word = atomic_load_explicit(&slot->state, memory_order_relaxed);
   atomic_store_explicit(&slot->cookie, cookie, memory_order_relaxed);
   atomic_store_explicit(&slot->expiry, expiry, memory_order_relaxed);
@@ -150,6 +164,16 @@ void fdstate_close(int fd) {
   atomic_store_explicit(&slot->state, FD_WORD(FD_GEN(word) + 1, FD_FREE), memory_order_release);
 }
 
+int fdstate_next_expired(ot_time now, int *cursor) {
+  size_t highest = atomic_load_explicit(&g_slot_highest, memory_order_relaxed);
+
+  for (; (size_t)*cursor <= highest; ++*cursor)
+    if (fdstate_claim_expired(*cursor, now))
+      return (*cursor)++;
+
+  return -1;
+}
+
 void *fdstate_cookie(int fd) {
   ot_fdslot *slot = fdstate_slot(fd);