prcv_mbx

iprcv_mbx

Outline

Receive from mailbox (polling).

C format

 ER      prcv_mbx (ID mbxid, T_MSG **ppk_msg);

 ER      iprcv_mbx (ID mbxid, T_MSG **ppk_msg);

Parameter(s)

I/O	Parameter	Description
I	ID mbxid;	ID number of the mailbox from which a message is received.
O	T_MSG **ppk_msg;	Start address of the message packet received from the mailbox.

[Message packet: T_MSG]

typedef struct t_msg { struct t_msg *msgnext; /*Reserved for future use*/ } T_MSG;

[Message packet: T_MSG_PRI]

typedef struct t_msg_pri { struct t_msg msgque; /*Reserved for future use*/ PRI msgpri; /*Message priority*/ } T_MSG_PRI;

Explanation

This service call receives a message from the mailbox specified by parameter mbxid, and stores its start address in the area specified by parameter ppk_msg.

If the message could not be received from the target mailbox (no messages were queued in the wait queue) when this service call is issued, message reception processing is not executed but "E_TMOUT" is returned.

Note 1 If no message could be received from the target mailbox (no messages were queued to the wait queue) when this service call is issued, the contents in the area specified by parameter ppk_msg become undefined.

Note 2 For details about the message packet, refer to "15.2.6 Message packet".

Return value

Macro	Value	Description
E_OK	0	Normal completion.
E_ID	-18	Invalid ID number. - mbxid < 0x0 - mbxid > Maximum ID number
E_CTX	-25	Context error. - This service call was issued in the CPU locked state.
E_NOEXS	-42	Non-existent object. - Specified mailbox is not registered.
E_TMOUT	-50	Polling failure. - No message exists in the target mailbox.