ibv_ack_async_event(3)

1IBV_GET_ASYNC_EVENT(3)  Libibverbs Programmer's Manual  IBV_GET_ASYNC_EVENT(3)
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NAME

6       ibv_get_async_event, ibv_ack_async_event - get or acknowledge asynchro‐
7       nous events
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SYNOPSIS

10       #include <infiniband/verbs.h>
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12       int ibv_get_async_event(struct ibv_context *context,
13                               struct ibv_async_event *event);
14       void ibv_ack_async_event(struct ibv_async_event *event);
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DESCRIPTION

17       ibv_get_async_event() waits for the next async event of the  InfiniBand
18       device  context context and returns it through the pointer event, which
19       is an ibv_async_event struct, as defined in <infiniband/verbs.h>.
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21       struct ibv_async_event {
22               union {
23                       struct ibv_cq  *cq;             /* CQ that got the event */
24                       struct ibv_qp  *qp;             /* QP that got the event */
25                       struct ibv_srq *srq;            /* SRQ that got the event */
26                       int             port_num;       /* port number that got the event */
27               } element;
28               enum ibv_event_type     event_type;     /* type of the event */
29       };
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31       One member of the  element  union  will  be  valid,  depending  on  the
32       event_type member of the structure.  event_type will be one of the fol‐
33       lowing events:
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35       QP events:
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37       IBV_EVENT_QP_FATAL  Error occurred on a QP and it transitioned to error
38       state
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40       IBV_EVENT_QP_REQ_ERR  Invalid Request Local Work Queue Error
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42       IBV_EVENT_QP_ACCESS_ERR  Local access violation error
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44       IBV_EVENT_COMM_EST  Communication was established on a QP
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46       IBV_EVENT_SQ_DRAINED  Send Queue was drained of outstanding messages in
47       progress
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49       IBV_EVENT_PATH_MIG  A connection has migrated to the alternate path
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51       IBV_EVENT_PATH_MIG_ERR  A connection failed to migrate to the alternate
52       path
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54       IBV_EVENT_QP_LAST_WQE_REACHED  Last WQE Reached on a QP associated with
55       an SRQ
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57       CQ events:
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59       IBV_EVENT_CQ_ERR  CQ is in error (CQ overrun)
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61       SRQ events:
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63       IBV_EVENT_SRQ_ERR  Error occurred on an SRQ
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65       IBV_EVENT_SRQ_LIMIT_REACHED  SRQ limit was reached
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67       Port events:
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69       IBV_EVENT_PORT_ACTIVE  Link became active on a port
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71       IBV_EVENT_PORT_ERR  Link became unavailable on a port
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73       IBV_EVENT_LID_CHANGE  LID was changed on a port
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75       IBV_EVENT_PKEY_CHANGE  P_Key table was changed on a port
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77       IBV_EVENT_SM_CHANGE  SM was changed on a port
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79       IBV_EVENT_CLIENT_REREGISTER  SM sent a CLIENT_REREGISTER request  to  a
80       port
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82       CA events:
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84       IBV_EVENT_DEVICE_FATAL  CA is in FATAL state
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86       ibv_ack_async_event() acknowledge the async event event.
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RETURN VALUE

89       ibv_get_async_event() returns 0 on success, and -1 on error.
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91       ibv_ack_async_event() returns no value.
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NOTES

94       All  async  events  that ibv_get_async_event() returns must be acknowl‐
95       edged using  ibv_ack_async_event().   To  avoid  races,  destroying  an
96       object  (CQ,  SRQ  or  QP)  will wait for all affiliated events for the
97       object to be acknowledged; this avoids  an  application  retrieving  an
98       affiliated  event  after  the  corresponding  object  has  already been
99       destroyed.
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101       ibv_get_async_event() is a blocking function.  If multiple threads call
102       this function simultaneously, then when an async event occurs, only one
103       thread will receive it, and it is not possible to predict which  thread
104       will receive it.
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EXAMPLES

107       The  following  code example demonstrates one possible way to work with
108       async events in non-blocking mode.  It performs the following steps:
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110       1. Set the async events queue work mode to be non-blocked
111       2. Poll the queue until it has an async event
112       3. Get the async event and ack it
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114       /* change the blocking mode of the async event queue */
115       flags = fcntl(ctx->async_fd, F_GETFL);
116       rc = fcntl(ctx->async_fd, F_SETFL, flags | O_NONBLOCK);
117       if (rc < 0) {
118               fprintf(stderr, "Failed to change file descriptor of async event queue\n");
119               return 1;
120       }
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122       /*
123        * poll the queue until it has an event and sleep ms_timeout
124        * milliseconds between any iteration
125        */
126       my_pollfd.fd      = ctx->async_fd;
127       my_pollfd.events  = POLLIN;
128       my_pollfd.revents = 0;
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130       do {
131               rc = poll(&my_pollfd, 1, ms_timeout);
132       } while (rc == 0);
133       if (rc < 0) {
134               fprintf(stderr, "poll failed\n");
135               return 1;
136       }
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138       /* Get the async event */
139       if (ibv_get_async_event(ctx, &async_event)) {
140               fprintf(stderr, "Failed to get async_event\n");
141               return 1;
142       }
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144       /* Ack the event */
145       ibv_ack_async_event(&async_event);
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AUTHORS

152       Dotan Barak <dotanb@mellanox.co.il>
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156libibverbs                        2006-10-31            IBV_GET_ASYNC_EVENT(3)