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# OS

## Thread

A **thread** of execution is the smallest sequence of programmed instructions that can be managed independently by a scheduler

### advantage

1. processes are typically independent, while threads exist as subsets of a process
2. processes carry considerably more state information than threads, whereas multiple threads within a process share process state as well as memory and other resources
3. processes have separate address spaces, whereas threads share their address space
4. processes interact only through system-provided inter-process communication mechanisms
5. context switching between threads in the same process is typically faster than context switching between processes

### drawbacks

1. Synchronization: Careless use of such primitives can lead to deadlocks, livelocks or races over a resources.
2. Thread crashes a process: an illegal operation performed by a thread crashes the entire process