Fix two race conditions where an ASIO wakeup notifications can be lost

src/libponyc/options/options.c

@@ -194,7 +194,8 @@ static void usage(void)
     "  --ponythreads    Use N scheduler threads. Defaults to the number of\n"
     "                   cores (not hyperthreads) available.\n"
     "  --ponyminthreads Minimum number of active scheduler threads allowed.\n"
-    "                   Defaults to 0.\n"
+    "                   Defaults to 1.  Use of 0 is considered experimental\n"
+    "                   and may cause improper scheduler behavior.\n"
     "  --ponycdmin      Defer cycle detection until 2^N actors have blocked.\n"
     "                   Defaults to 2^4.\n"
     "  --ponycdmax      Always cycle detect when 2^N actors have blocked.\n"

src/libponyrt/asio/epoll.c

@@ -401,7 +401,13 @@ PONY_API void pony_asio_event_unsubscribe(asio_event_t* ev)
     // tell scheduler threads that asio has no noisy actors
     // if the old_count was 1
     if (old_count == 1)
+    {
       ponyint_sched_unnoisy_asio(SPECIAL_THREADID_EPOLL);
+
+      // maybe wake up a scheduler thread if they've all fallen asleep
+      ponyint_sched_maybe_wakeup_if_all_asleep(-1);
+    }
+
     ev->noisy = false;
   }
 

src/libponyrt/asio/iocp.c

@@ -329,7 +329,13 @@ PONY_API void pony_asio_event_unsubscribe(asio_event_t* ev)
     // tell scheduler threads that asio has no noisy actors
     // if the old_count was 1
     if (old_count == 1)
+    {
       ponyint_sched_unnoisy_asio(SPECIAL_THREADID_IOCP);
+
+      // maybe wake up a scheduler thread if they've all fallen asleep
+      ponyint_sched_maybe_wakeup_if_all_asleep(-1);
+    }
+
     ev->noisy = false;
   }
 

src/libponyrt/asio/kqueue.c

@@ -387,7 +387,13 @@ PONY_API void pony_asio_event_unsubscribe(asio_event_t* ev)
     // tell scheduler threads that asio has no noisy actors
     // if the old_count was 1
     if (old_count == 1)
+    {
       ponyint_sched_unnoisy_asio(SPECIAL_THREADID_KQUEUE);
+
+      // maybe wake up a scheduler thread if they've all fallen asleep
+      ponyint_sched_maybe_wakeup_if_all_asleep(-1);
+    }
+
     ev->noisy = false;
   }