Examples of IPC Systems

• Shared Memory : POSIX Shared Memory
  • POSIX : Portable Operating System Interface (for UNIX)
• Message Passing : Pipes
  • One of the earliest IPC mechanisms on UNIX systems.

Posix shared memory

• using memory-mapped files(hdd, ssd가 아닌 memory에 파일 저장)

  → which associate the region of shared memory with a file

• Producer

Producer process illustrating POSIX shared-memory API

• Consumer

Producer와 차이

1. ftruncate(shm_fd, SIZE) → 공유 메모리의 크기를 결정하는 코드가 없다.
2. sprintf → 메모리에 쓰지 않고 / printf → 메모리에서 읽어들인다.
3. shm_unlink → 공유메모리를 제거한다.

Consumer process illustrating POSIX shared-memory API

Pipes Message Passing

• A pipe acts as a conduit allowing two processes to communicate