MC_SEND_ERROR

The MC_SEND_ERROR verb notifies the partner TP that the local TP has encountered an application-level error.

For the Microsoft® Windows® version 3.x system, it is recommended that you use WinAsyncAPPC rather than the blocking version of this call.

The following structure describes the verb control block used by the MC_SEND_ERROR verb.

struct mc_send_error {
    unsigned short      opcode;
    unsigned char       opext;
    unsigned char       reserv2;
    unsigned short      primary_rc;
    unsigned long       secondary_rc;
    unsigned char       tp_id[8];
    unsigned long       conv_id;
    unsigned char       rts_rcvd;
    unsigned char       err_type;
    unsigned char       err_dir;
    unsigned char       reserv4;
    unsigned char       reserv5[2];
    unsigned char       reserv6[4];
};

Members

opcode
Supplied parameter. Specifies the verb operation code, AP_M_SEND_ERROR.
opext
Supplied parameter. Specifies the verb operation extension, AP_MAPPED_CONVERSATION.
primary_rc
Returned parameter. Specifies the primary return code set by APPC at the completion of the verb. The valid return codes vary depending on the APPC verb issued. See Return Codes for valid error codes for this verb.
secondary_rc
Returned parameter. Specifies the secondary return code set by APPC at the completion of the verb. The valid return codes vary depending on the APPC verb issued. See Return Codes for valid error codes for this verb.
tp_id
Supplied parameter. Identifies the local TP.

The value of this parameter is returned by TP_STARTED in the invoking TP or by RECEIVE_ALLOCATE in the invoked TP.

conv_id
Supplied parameter. Provides the conversation identifier. The value of this parameter is returned by MC_ALLOCATE in the invoking TP or by RECEIVE_ALLOCATE in the invoked TP.
rts_rcvd
Returned parameter. Indicates whether the partner TP issued MC_REQUEST_TO_SEND. Possible values include:
err_type
For a mapped conversation, this parameter is supplied if Sync Point is supported. Valid values are:

AP_PROG

AP_BACKOUT_NO_RESYNC

AP_BACKOUT_RESYNC

err_dir
Supplied parameter. Indicates whether the error is with data just received or with data that is about to be sent. Use this parameter only when the conversation is in SEND_PENDING state. The parameter is ignored otherwise. The following are allowed values:

Return Codes

ap_ok
Primary return code; the verb executed successfully.
ap_parameter_check
Primary return code; the verb did not execute because of a parameter error.
ap_bad_conv_id
Secondary return code; the value of conv_id did not match a conversation identifier assigned by APPC.
ap_bad_tp_id
Secondary return code; the value of tp_id did not match a TP identifier assigned by APPC.
ap_bad_error_direction
Secondary return code; the specified err_dir was not recognized by APPC.
ap_send_error_bad_type
Secondary return code; the value of err_type was invalid.
ap_send_error_log_ll_wrong
Secondary return code; the LL field of the error log GDS variable did not match the actual length of the data.

The following return codes can be generated when MC_SEND_ERROR is issued in any allowed state:

ap_comm_subsystem_abended
Primary return code; indicates one of the following conditions:

The system administrator should examine the error log to determine the reason for the ABEND.

ap_comm_subsystem_not_loaded
Primary return code; a required component could not be loaded or has terminated while processing the verb. Thus, communication could not take place. Contact the system administrator for corrective action.

When this return code is used with MC_ALLOCATE, it may indicate that no communications subsystem could be found to support the local LU. (For example, the local LU alias specified with TP_STARTED is incorrect or has not been configured.) Note that if lu_alias or mode_name is fewer than eight characters, you must ensure that these fields are filled with spaces to the right. This error is returned if these parameters are not filled with spaces, since there is no node available that can satisfy the MC_ALLOCATE request.

When MC_ALLOCATE produces this return code for an SNA Server Client system configured with multiple nodes, there are two secondary return codes as follows:

0xf0000001
Secondary return code; no nodes have been started.
0xf0000002
Secondary return code; at least one node has been started, but the local LU (when TP_STARTED is issued) is not configured on any active nodes. The problem could be either of the following:
·    The node with the local LU is not started.
·    The local LU is not configured.

ap_conv_failure_no_retry
Primary return code; the conversation was terminated because of a permanent condition, such as a session protocol error. The system administrator should examine the system error log to determine the cause of the error. Do not retry the conversation until the error has been corrected.
ap_conv_failure_retry
Primary return code; the conversation was terminated because of a temporary error. Restart the TP to see if the problem occurs again. If it does, the system administrator should examine the error log to determine the cause of the error.
ap_conversation_type_mixed
Primary return code; the TP has issued both basic and mapped conversation verbs. Only one type can be issued in a single conversation.
ap_invalid_verb_segment
Primary return code; the VCB extended beyond the end of the data segment.
ap_stack_too_small
Primary return code; the stack size of the application is too small to execute the verb. Increase the stack size of your application.
ap_conv_busy
Primary return code; there can only be one outstanding conversation verb at a time on any conversation. This may occur if the local TP has multiple threads, and more than one thread is issuing APPC calls using the same conv_id.
ap_thread_blocking
Primary return code; the calling thread is already in a blocking call.
ap_unexpected_dos_error
Primary return code; the operating system has returned an error to APPC while processing an APPC call from the local TP. The operating system return code is returned through the secondary_rc. It appears in Intel byte-swapped order. If the problem persists, consult the system administrator.

The following return codes can be generated only if MC_SEND_ERROR is issued in SEND state:

ap_allocation_error
Primary return code; APPC has failed to allocate a conversation. The conversation state is set to RESET.

This code may be returned through a verb issued after MC_ALLOCATE.

ap_allocation_failure_no_retry
Secondary return code; the conversation cannot be allocated because of a permanent condition, such as a configuration error or session protocol error. To determine the error, the system administrator should examine the error log file. Do not retry the allocation until the error has been corrected.
ap_allocation_failure_retry
Secondary return code; the conversation could not be allocated because of a temporary condition, such as a link failure. The reason for the failure is logged in the system error log. Retry the allocation.
ap_conversation_type_mismatch
Secondary return code; the partner LU or TP does not support the conversation type (basic or mapped) specified in the allocation request.
ap_pip_not_allowed
Secondary return code; the allocation request specified PIP data, but either the partner TP does not require this data, or the partner LU does not support it.
ap_pip_not_specified_correctly
Secondary return code; the partner TP requires PIP data, but the allocation request specified either no PIP data or an incorrect number of parameters.
ap_security_not_valid
Secondary return code; the user identifier or password specified in the allocation request was not accepted by the partner LU.
ap_sync_level_not_supported
Secondary return code; the partner TP does not support the sync_level (AP_NONE or AP_CONFIRM_SYNC_LEVEL) specified in the allocation request, or the sync_level was not recognized.
ap_tp_name_not_recognized
Secondary return code; the partner LU does not recognize the TP name specified in the allocation request.
ap_trans_pgm_not_avail_no_retry
Secondary return code; the remote LU rejected the allocation request because it was unable to start the requested partner TP. The condition is permanent. The reason for the error may be logged on the remote node. Do not retry the allocation until the error has been corrected.
ap_trans_pgm_not_avail_retry
Secondary return code; the remote LU rejected the allocation request because it was unable to start the requested partner TP. The condition may be temporary, such as a time-out. The reason for the error may be logged on the remote node. Retry the allocation.
ap_prog_error_purging
Primary return code; while in RECEIVE, PENDING, PENDING_POST (Windows NT, Windows 95, and OS/2 only), CONFIRM, CONFIRM_SEND, or CONFIRM_DEALLOCATE state, the partner TP issued MC_SEND_ERROR. Data sent but not yet received is purged.
ap_dealloc_abend
Primary return code; the conversation has been deallocated for one of the following reasons:

The following return code can be generated only if MC_SEND_ERROR is issued in RECEIVE state:

ap_dealloc_normal
Primary return code; this return code does not indicate an error.

The partner TP issued MC_DEALLOCATE with dealloc_type set to one of the following:

Remarks

The conversation can be in any state except RESET when the TP issues this verb. The conversation state must be SEND_PENDING if err_dir is used.

The local TP sends the error notification immediately to the partner TP; it does not hold the information in the local LU's send buffer.

Upon successful execution of this verb, the conversation is in SEND state for the local TP and in RECEIVE state for the partner TP.

The new state is determined by primary_rc. Possible state changes are summarized in the following table.

primary_rc New state
ap_ok SEND
ap_allocation_error RESET
ap_conv_failure_retry RESET
ap_conv_failure_no_retry RESET
ap_dealloc_abend RESET
ap_dealloc_abend_prog RESET
ap_dealloc_abend_svc RESET
ap_dealloc_abend_timer RESET
ap_dealloc_normal RESET
ap_prog_error_purging RECEIVE
ap_svc_error_purging RECEIVE

If the conversation is in RECEIVE state when the TP issues MC_SEND_ERROR, incoming data is purged by APPC. This data includes:

APPC does not purge an incoming request-to-send indicator. APPC replaces purged incoming return code indicators with other return codes. The primary return code ap_ok replaces the following purged return code indicators:

AP_PROG_ERROR_NO_TRUNC

AP_PROG_ERROR_PURGING

AP_PROG_ERROR_TRUNC

AP_SVC_ERROR_NO_TRUNC

AP_SVC_ERROR_PURGING

AP_SVC_ERROR_TRUNC

The primary return code ap_dealloc_normal replaces the following purged return code indicators:

AP_ALLOCATION_ERROR

AP_ALLOCATION_FAILURE_NO_RETRY

AP_ALLOCATION_FAILURE_RETRY

AP_CONVERSATION_TYPE_MISMATCH

AP_DEALLOC_ABEND

AP_DEALLOC_ABEND_PROG

AP_DEALLOC_ABEND_SVC

AP_DEALLOC_ABEND_TIMER

AP_PIP_NOT_ALLOWED

AP_PIP_NOT_SPECIFIED_CORRECTLY

AP_SECURITY_NOT_VALID

AP_SYNC_LEVEL_NOT_SUPPORTED

AP_TP_NAME_NOT_RECOGNIZED

AP_TRANS_PGM_NOT_AVAIL_NO_RETRY

AP_TRANS_PGM_NOT_AVAIL_RETRY

When the conversation is in SEND_PENDING state, APPC reports the following return codes to the partner TP based on the value in err_dir:

ap_prog_error_purging
The local TP issued MC_SEND_ERROR with RECEIVE as the err_dir.
ap_prog_error_no_trunc
The local TP issued MC_SEND_ERROR with SEND as the err_dir.