进程就是一个运行中的程序。
进程的组成：machine state: what a program can read or update when running
- memory： that the process can address (called its address space) is part of the process
- registers：
- program counter (PC) | instruction pointer (IP):tells which instruction of the program is currently being executed
- stack pointer and associated frame pointer:manage the stack for function parameters, local variables, and return addresses
- I/O
进程创建
- load its code and any static data into memory, into the address space of the process
- allocate memory for the program’s run-time stack (or just stack), C programs use the stack for local variables, function parameters, and return addresses
- allocate memory for the program’s heap,heap is used for explicitly requested dynamically-allocated data (malloc,free)
- other initialization some as I/O
- start the program running at the entry point, namely main()
进程状态
- Running
- Ready
- Blocked
数据结构
- fork
- wait
- exec
近期评论