IPC stands for inter-process-communication. There are 6 ways of communication and processes can talk to each other.
Types of IPC in Linux:
- Message Queue
- Shared Memory
- Easy way to pass data between processes.
- This is the advance version of pipes and here we don’t need to worry about opening and closing of pipes.
- Message Queue exists independently (if processes they were using it and terminated now but MQ still exists in system).
- Disadvantage: Size restriction, they can be full at some point (same like pipes).
- Highly efficient way of data sharing between processes.
- When we need to share huge data then we can go shared memory.
- It is a special range of address that appear in process that created.
- Other process can attached the above address.
- If any change happens in that share address then this modification will be visible to attached process.
- It does n’t provide any synchronisation (its developer responsibility to take care of synchronisation).
- For managing access to resources.
- when we have critical section of code where you need to ensure that a single process has exclusive access to resource.
- Here, we are NOT passing any data between process.
- Here, two process are communicating (talking to each other)BUT not sharing any data.
- There are 2 type of pipe (unnamed and named pipes)
- Unnamed pipes are used for only related processes.
- Named pipes can be used with unrelated processes also.
- Its developer responsibility to take care of open/close of pipes.
- Disadvantage: Size restriction, they can be full at some point.
- Their names are self explanatory (like SIGINT etc).
- Their are 30 signal in Linux kernel (like CTRL+C, segmentation fault etc).
- They don’t carry any argument.
- They are like notification or alert.
- They are one way asynchronous notification.
- They may send from kernel to process or process to another process or process to itself.