get_mpf

Outline

Acquire fixed-sized memory block (waiting forever).

C format

 ER      get_mpf (ID mpfid, VP *p_blk);

Parameter(s)

I/O	Parameter	Description
I	ID mpfid;	ID number of the fixed-sized memory pool from which a memory block is acquired.
O	VP *p_blk;	Start address of the acquired memory block.

Explanation

This service call acquires the fixed-sized memory block from the fixed-sized memory pool specified by parameter mpfid and stores the start address in the area specified by parameter p_blk.

If no fixed-size memory blocks could be acquired from the target fixed-size memory pool (no available fixed-size memory blocks exist) when this service call is issued, this service call does not acquire the fixed-size memory block but queues the invoking task to the target fixed-size memory pool wait queue and moves it from the RUNNING state to the WAITING state (fixed-size memory block acquisition wait state).

The WAITING state for a fixed-sized memory block is cancelled in the following cases, and then moved to the READY state.

WAITING State for a Fixed-sized Memory Block Cancel Operation	Return Value
A fixed-sized memory block was returned to the target fixed-sized memory pool as a result of issuing rel_mpf.	E_OK
A fixed-sized memory block was returned to the target fixed-sized memory pool as a result of issuing irel_mpf.	E_OK
Forced release from waiting (accept rel_wai while waiting).	E_RLWAI
Forced release from waiting (accept irel_wai while waiting).	E_RLWAI

Note 1 The RI850V4 does not perform memory clear processing when acquiring a fixed-sized memory block. The contents of the acquired fixed-sized memory block are therefore undefined.

Note 2 Invoking tasks are queued to the target fixed-size memory pool wait queue in the order defined during configuration (FIFO order or priority order).

Note 3 If the fixed-size memory block acquisition wait state is cancelled because rel_wai or irel_wai was issued, the contents in the area specified by parameter p_blk become undefined.

Return value

Macro	Value	Description
E_OK	0	Normal completion.
E_ID	-18	Invalid ID number. - mpfid < 0x0 - mpfid > Maximum ID number
E_CTX	-25	Context error. - This service call was issued from a task. - This service call was issued in the CPU locked state. - This service call was issued in the dispatching disabled state.
E_NOEXS	-42	Non-existent object. - Specified fixed-sized memory pool is not registered.
E_RLWAI	-49	Forced release from the WAITING state. - Accept rel_wai/irel_wai while waiting.