Structure of the message-flags field

This information describes the structure of the message-flags field.

• Message flags that are rejected if the local queue manager does not recognize them
• Message flags that are always accepted, even if the local queue manager does not recognize them
• Message flags that are accepted only if certain other conditions are satisfied

Note: All subfields in MsgFlags are reserved for use by the queue manager. Each subfield is identified by a bit mask that has 1-bits in the positions corresponding to the subfield, and 0-bits elsewhere. The bits are numbered such that bit 0 is the most significant bit, and bit 31 the least significant bit. The following masks are defined to identify the subfields:

MQMF_REJECT_UNSUP_MASK

This mask identifies the bit positions within the MsgFlags field where message flags that are not supported by the local queue manager cause the MQPUT or MQPUT1 call to fail with completion code MQCC_FAILED and reason code MQRC_MSG_FLAGS_ERROR.

This subfield occupies bit positions 20 through 31.

The following message flags are included in this subfield:

• MQMF_LAST_MSG_IN_GROUP
• MQMF_LAST_SEGMENT
• MQMF_MSG_IN_GROUP
• MQMF_SEGMENT
• MQMF_SEGMENTATION_ALLOWED
• MQMF_SEGMENTATION_INHIBITED

MQMF_ACCEPT_UNSUP_MASK

This mask identifies the bit positions within the MsgFlags field where message flags that are not supported by the local queue manager are nevertheless accepted on the MQPUT or MQPUT1 calls. The completion code is MQCC_OK.

This subfield occupies bit positions 0 through 11.

MQMF_ACCEPT_UNSUP_IF_XMIT_MASK

This mask identifies the bit positions within the MsgFlags field where message flags that are not supported by the local queue manager are nevertheless accepted on the MQPUT or MQPUT1 calls provided that both of the following conditions are satisfied:

• The message is destined for a remote queue manager.
• The application is not putting the message directly on a local transmission queue (that is, the queue identified by the ObjectQMgrName and ObjectName fields in the object descriptor specified on the MQOPEN or MQPUT1 call is not a local transmission queue).

Completion code MQCC_OK is returned if these conditions are satisfied, and MQCC_FAILED with reason code MQRC_MSG_FLAGS_ERROR if not.

This subfield occupies bit positions 12 through 19.

If there are flags specified in the MsgFlags field that the queue manager does not recognize, the queue manager checks each subfield in turn by using the bitwise AND operation to combine the MsgFlags field with the mask for that subfield. If the result of that operation is not zero, the completion code and reason codes described previously are returned.