Definition

Threads are like lightweight process

• They execute concurrently like process
  • multiple threads can run simultaneously on multiple CPUs/cores
• Unlike processes, threads cohabitate the same address space
  • Threads within a process see the same heap and globals and can communicate with each other through variables and memory
  • But, they can interfere with each other, need synchronization for shared resources
  • Each thread has its own stack

Why We Want to Use Threads

• Code Responsiveness
  • While doing an expensive computation, you don’t what your interface to freeze
• Processor Utilization
  • If one thread is waiting on a deep-hierarchy memory access you can still use that processor time
• Failure Isolation
  • If one portion of your code fails, it will only crash that one portion