unix socket與共享記憶體的差別

It's more a question of design, than speed (Shared Memory is faster), domain sockets are definitively more UNIX-style, and do a lot less problems. In terms of choice know beforehand:

Domain Sockets advantages

• blocking and non-blocking mode and switching between them
• you don't have to free them when tasks are completed

Domain sockets disadvantages

• must read and write in a linear fashion

Shared Memory advantages

• non-linear storage
• will never block
• multiple programs can access it

Shared Memory disadvantages

• need locking implementation