Commit a44a9472 authored by Scott Vokes's avatar Scott Vokes
Browse files

Ensure status in message box is sent before listener receives EXPECT message. 

This closes a very narrow race condition where the status was still
BUS_SEND_UNDEFINED when the listener processed the EXPECT notification,
causing an assert failure.
parent ec5b24da

src/lib/bus/bus_types.h

+1 −1
Original line number Diff line number Diff line
@@ -197,7 +197,7 @@ typedef enum { 
typedef enum {

    BUS_SEND_UNDEFINED = 0,

    BUS_SEND_REQUEST_COMPLETE = 1,

    BUS_SEND_SUCCESS = 2,

    BUS_SEND_SUCCESS = 3,

    BUS_SEND_TX_TIMEOUT = -51,

    BUS_SEND_TX_FAILURE = -52,  // -> socket error

    BUS_SEND_RX_TIMEOUT = -53,

src/lib/bus/listener.c

+1 −0
Original line number Diff line number Diff line
@@ -161,6 +161,7 @@ bool listener_expect_response(struct listener *l, boxed_msg *box, 
    msg->type = MSG_EXPECT_RESPONSE;

    msg->u.expect.box = box;

    *backpressure = ListenerTask_GetBackpressure(l);

    BUS_ASSERT(b, b->udata, box->result.status != BUS_SEND_UNDEFINED);



    bool pm = listener_helper_push_message(l, msg, NULL);

    if (!pm) {

src/lib/bus/listener_cmd.c

+3 −0
Original line number Diff line number Diff line
@@ -250,6 +250,9 @@ static void expect_response(listener *l, struct boxed_msg *box) { 
            info->u.expect.box = box;

            info->u.expect.has_result = true;

            info->u.expect.result = result;

            BUS_ASSERT(b, b->udata,

                box->result.status != BUS_SEND_UNDEFINED);



            ListenerTask_AttemptDelivery(l, info);

        } else {

            BUS_LOG_SNPRINTF(b, 3, LOG_LISTENER, b->udata, 256,

src/lib/bus/listener_task.c

+1 −0
Original line number Diff line number Diff line
@@ -319,6 +319,7 @@ void ListenerTask_NotifyMessageFailure(listener *l, 
    BUS_ASSERT(b, b->udata, info->state == RIS_EXPECT);

    BUS_ASSERT(b, b->udata, info->u.expect.box);

    

    BUS_ASSERT(b, b->udata, status != BUS_SEND_UNDEFINED);

    info->u.expect.box->result.status = status;

    

    boxed_msg *box = info->u.expect.box;

src/lib/bus/send.c

+4 −6
Original line number Diff line number Diff line
@@ -45,7 +45,7 @@ int poll_errno = 0; 
int write_errno = 0;

#endif



static bool attempt_to_enqueue_hold_message_to_listener(struct bus *b,

static bool attempt_to_enqueue_HOLD_message_to_listener(struct bus *b,

    int fd, int64_t seq_id, int16_t timeout_sec);

/* Do a blocking send.

 *
@@ -96,7 +96,7 @@ bool send_do_blocking_send(bus *b, boxed_msg *box) { 
     * EXPECT hasn't, leading to ambiguity about what to do with

     * the response (which may or may not have arrived).

     * */

    if (!attempt_to_enqueue_hold_message_to_listener(b,

    if (!attempt_to_enqueue_HOLD_message_to_listener(b,

            box->fd, box->out_seq_id, box->timeout_sec + 5)) {

        return false;

    }
@@ -159,9 +159,6 @@ bool send_do_blocking_send(bus *b, boxed_msg *box) { 
                case SHHW_OK:

                    continue;

                case SHHW_DONE:

                    box->result = (bus_msg_result_t){

                        .status = BUS_SEND_REQUEST_COMPLETE,

                    };

                    return true;

                case SHHW_ERROR:

                    return true;
@@ -182,7 +179,7 @@ bool send_do_blocking_send(bus *b, boxed_msg *box) { 
    return true;

}



static bool attempt_to_enqueue_hold_message_to_listener(struct bus *b,

static bool attempt_to_enqueue_HOLD_message_to_listener(struct bus *b,

    int fd, int64_t seq_id, int16_t timeout_sec) {

    BUS_LOG_SNPRINTF(b, 5, LOG_SENDER, b->udata, 128,

      "telling listener to expect response, with <fd%d, seq_id:%lld>",
@@ -207,6 +204,7 @@ void send_handle_failure(struct bus *b, boxed_msg *box, bus_send_status_t status 
    BUS_LOG_SNPRINTF(b, 5, LOG_SENDER, b->udata, 64,

        "send_handle_failure: box %p, <fd:%d, seq_id:%lld>, status %d",

        (void*)box, box->fd, (long long)box->out_seq_id, status);

    BUS_ASSERT(b, b->udata, status != BUS_SEND_UNDEFINED);



    box->result = (bus_msg_result_t){

        .status = status,