waitrsv

Wait for Reservation Loss

waitrsv

Waits until a reservation is lost (Multithreading sync).

Details

The waitrsv instruction is used to wait for a reservation loss on a storage location. It checks if the reservation associated with the effective address (EA) has been lost due to another processor's store operation.

Pseudocode Operation

if RESERVE_ADDR = real_addr(EA) then
    result ← false
else
    result ← true

Programming Note

Use waitrsv when you need to ensure that a storage location has not been modified by another processor since it was reserved. This instruction is useful in multi-processor environments where data consistency is critical. Ensure that the address is correctly aligned and that the reservation is properly set before using this instruction. If the reservation is lost, the instruction will return true; otherwise, it returns false.

Example

waitrsv

Encoding

Binary Layout
31
0
0
6
0
11
0
16
62
21
/
31
 
Format X-form
Opcode 0x7C00007C
Extension Base

Operands