Process

is a instance of a running program
- logical control flow: process execution interleaved
- private address space: managed by virtual memory machine
- for security

Concurrent process

their time flow are overlapped

A Process with multithreaded

Similar

Each has its own logical control flow Each can run concurrently Each is context switched

different

Threads share code and data, Threads are less expensive than processes in some degree

Thread is blocked when preforming IO operations, the thread gives the cup to other threads

Java threads: java.lang.Thread implements run()

Thread Synchronization

safety

• if it behaves correctly when accessed from multiple threads
• don’t depend on OS scheduling
• no additional Synchronization needed from the calling code

liveness