dat_ep_disconnect

- terminate a connection or a connection establishment

Synopsis

cc [ flag… ] file… -ldat [ library… ] 
#include <dat/udat.h>

DAT_RETURN
    dat_ep_disconnect (
    IN    DAT_EP_HANDLE      ep_handle,
    IN    DAT_CLOSE_FLAGS    disconnect_flags
    )

Parameters

ep_handle

Handle for an instance of Endpoint.

disconnect_flags

Flags for disconnect. Flag values are as follows:

DAT_CLOSE_ABRUPT_FLAG

Abrupt close. This is the default value.

DAT_CLOSE_GRACEFUL_FLAG

Graceful close.

Description

The dat_ep_disconnect() function requests a termination of a connection or connection establishment. This operation is used by the active/client or a passive/server side Consumer of the connection model.

The disconnect_flags parameter allows Consumers to specify whether they want graceful or abrupt disconnect. Upon disconnect, all outstanding and in-progress DTOs and RMR Binds must be completed.

For abrupt disconnect, all outstanding DTOs and RMR Binds are completed unsuccessfully, and in-progress DTOs and RMR Binds can be completed successfully or unsuccessfully. If an in-progress DTO is completed unsuccessfully, all follow on in-progress DTOs in the same direction also must be completed unsuccessfully. This order is presented to the Consumer through a DTO completion Event Stream of the recv_evd_handle and and request_evd_handle of the Endpoint.

For graceful disconnect, all outstanding and in-progress request DTOs and RMR Binds must try to be completed successfully first, before disconnect proceeds. During that time, the local Endpoint is in a DAT_EP_DISCONNECT_PENDING state.

The Consumer can call abrupt dat_ep_disconnect() when the local Endpoint is in the DAT_EP_DISCONNECT_PENDING state. This causes the Endpoint to transition into DAT_EP_STATE_DISCONNECTED without waiting for outstanding and in-progress request DTOs and RMR Binds to successfully complete. The graceful dat_ep_disconnect() call when the local Endpoint is in the DAT_EP_DISCONNECT_PENDING state has no effect.

If the Endpoint is not in DAT_EP_STATE_CONNECTED, the semantic of the operation is the same for graceful or abrupt disconnect_flags value.

No new Send, RDMA Read, and RDMA Write DTOs, or RMR Binds can be posted to the Endpoint when the local Endpoint is in the DAT_EP_DISCONNECT_PENDING state.

The successful completion of the disconnect is reported to the Consumer through a DAT_CONNECTION_EVENT_DISCONNECTED event on connect_evd_handle of the Endpoint. The Endpoint is automatically transitioned into a DAT_EP_STATE_DISCONNECTED state upon successful asynchronous completion. If the same EVD is used for connect_evd_handle and any recv_evd_handle and request_evd_handle, all successful Completion events of in-progress DTOs precede the Disconnect Completion event.

Disconnecting an unconnected Disconnected Endpoint is no-op. Disconnecting an Endpoint in DAT_EP_STATE_UNCONNECTED, DAT_EP_STATE_RESERVED, DAT_EP_STATE_PASSIVE_CONNECTION_PENDING, and DAT_EP_STATE_TENTATIVE_CONNECTION_PENDING is disallowed.

Both abrupt and graceful disconnect of the Endpoint during connection establishment, DAT_EP_STATE_ACTIVE_CONNECTION_PENDING and DAT_EP_STATE_COMPLETION_PENDING, "aborts" the connection establishment and transitions the local Endpoint into DAT_EP_STATE_DISCONNECTED. That causes preposted Recv DTOs to be flushed to recv_evd_handle.

Return Values

DAT_SUCCESS

The operation was successful.

DAT_INVALID_HANDLE

The ep_handle parameter is invalid.

DAT_INSUFFICIENT_RESOURCES

The operation failed due to resource limitations.

DAT_INVALID_PARAMETER

The disconnect_flags parameter is invalid.

DAT_INVALID_STATE

A parameter is in an invalid state. Endpoint is not in the valid state for disconnect.

Attributes

See attributes(5) for descriptions of the following attributes:

See Also

libdat(3LIB), attributes(5)