IPC

1. What Is Inter-Process Communication?

It is the exchange of information between processes.

2. Why Inter-Process Communication Is Needed

Because each process has an independent address space, for security reasons the operating system does not allow one process to directly access the address space of another process.

3. Inter-Process Communication Methods

3.1. Semaphore

• A counter used to provide multiple processes with access to shared data objects.

3.2. Shared Memory

• Multiple processes communicate by sharing the same address space. Because data does not need to be copied between processes, this is the fastest form of IPC.
• Semaphores are needed to synchronize access to shared memory.

3.3. Pipe

• Can only implement one-way transmission.
• Can only be used between parent and child processes.

3.4. FIFO

• Also called a named pipe; removes the restriction that pipes can only be used between parent and child processes.

3.5. Message Queue

• A message queue can exist independently of the reading and writing processes.
• Processes do not need to synchronize by themselves.

3.6. socket

• Can be used for inter-process communication between different machines.

4. References

• Master Operating System Interviews with This Article (1) - Juejin