core: simplify background IO API

- removes unused "completed" IO callback handler
- moves primary post-IO callback handlers from the queue definition to
  the actual IO objects.
- allows IO object callbacks to be handled generically instead of based
  on the queue they were submitted from.

1 files changed, 4 insertions, 0 deletions

diff --git a/proxy_await.c b/proxy_await.c
index 33e4cd3..582c3d5 100644
--- a/proxy_await.c
+++ b/proxy_await.c
@@ -147,6 +147,8 @@ static void mcp_queue_await_io(conn *c, lua_State *Lc, mcp_request_t *rq, int aw
     p->client_resp = r;
     p->flushed = false;
     p->ascii_multiget = rq->ascii_multiget;
+    p->return_cb = proxy_return_cb;
+    p->finalize_cb = proxy_finalize_cb;
 
     // io_p needs to hold onto its own response reference, because we may or
     // may not include it in the final await() result.
@@ -201,6 +203,8 @@ static void mcp_queue_await_dummy_io(conn *c, lua_State *Lc, int await_ref) {
     p->is_await = true;
     p->await_ref = await_ref;
     p->await_background = true;
+    p->return_cb = proxy_return_cb;
+    p->finalize_cb = proxy_finalize_cb;
 
     // Dummy IO has no backend, and no request attached.