Merge pull request #6337 from andzdroid/patch-2

nbio: fix op re-use

core/nbio/impl_posix.odin

@@ -336,6 +336,12 @@ __tick :: proc(l: ^Event_Loop, timeout: time.Duration) -> General_Error {
 				if .Error in event.flags { curr._impl.flags += {.Error} }
 				if .EOF   in event.flags { curr._impl.flags += {.EOF} }
 				curr._impl.result = event.data
+
+				// Remove refs to the list in case the operation would still block and `add_pending`
+				// is executed on it again.
+				curr._impl.prev = nil
+				curr._impl.next = nil
+
 				handle_completed(curr)
 			}
 		}
@@ -1154,6 +1160,8 @@ stat_exec :: proc(op: ^Operation) {
 
 add_pending :: proc(op: ^Operation, filter: kq.Filter, ident: uintptr) {
 	debug("adding pending", op.type)
+	assert(op._impl.next == nil)
+	assert(op._impl.prev == nil)
 	op._impl.flags += {.For_Kernel}
 
 	_, val, just_inserted, err := map_entry(&op.l.submitted, Queue_Identifier{ ident = ident, filter = filter })

tests/core/nbio/nbio.odin

@@ -256,3 +256,50 @@ wake_up :: proc(t: ^testing.T) {
 		}
 	}
 }
+
+// Tests that if multiple accepts are queued, and a dial comes in which completes one of them,
+// the rest are queued again properly.
+@(test)
+still_pending :: proc(t: ^testing.T) {
+	if event_loop_guard(t) {
+		testing.set_fail_timeout(t, time.Minute)
+
+		sock, ep := open_next_available_local_port(t)
+		defer nbio.close(sock)
+
+		N :: 3
+
+		State :: struct {
+			accepted: int,
+		}
+		state: State
+
+		on_accept :: proc(op: ^nbio.Operation, t: ^testing.T, state: ^State) {
+			ev(t, op.accept.err, nil)
+			state.accepted += 1
+			nbio.close(op.accept.client)
+		}
+
+		on_dial :: proc(op: ^nbio.Operation, t: ^testing.T) {
+			ev(t, op.dial.err, nil)
+			nbio.close(op.dial.socket)
+		}
+
+		for _ in 0..<N {
+			nbio.accept_poly2(sock, t, &state, on_accept)
+		}
+
+		nbio.dial_poly(ep, t, on_dial)
+
+		for state.accepted < 1 {
+			ev(t, nbio.tick(), nil)
+		}
+
+		for _ in 0..<N-1 {
+			nbio.dial_poly(ep, t, on_dial)
+		}
+
+		ev(t, nbio.run(), nil)
+		ev(t, state.accepted, N)
+ 	}
+ }