操作系统课上机实验：进程管理。实现使用先来先服务调度以及：1. 固定优先级的优先数法 2. 可变优先级的优先数法的进程调度算法。进程调度的基本时间单位为：时间片。
推荐使用Linux + (C++17标准的编译器编译)：已经配置好了CMakeLists.txt，可以使用cmake进行编译。没有附加依赖库。理论上，C++11至C++20都支持：
git clone https://github.com/Enigmatisms/ProcMan.git
cd ProcMan/
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=RELEASE .. && make -j
./pctrl 程序支持非编译配置参数：在根目录下的config.yaml文件中，有如下配置内容：
arrive_ddl: 10 # 由于程序是完全随机的，需要设置进程最晚到达的时间，才能更好观察到并发
min_life_period: 2 # 进程执行最少需要的时间片数
max_life_period: 7 # 进程执行最多需要的时间片数
max_level: 3 # 最大优先等级（从1开始，到max_level）
process_number: 5 # 并发的进程数
use_fifo: 0 # 是否使用先来先服务调度
fixed_seed: 1
# 随机数种子是否是固定的（如果为0（false），随机数种子为0，每次运行程序生成的进程都一致，否则随机数种子使用std::chrono获得当前时间作为种子，每次生成的进程都会不一样） 标准输出如下（本程序是优先级可变的优先数调度算法）：
| Name | PRT | AVT | RQT | CST | Status |
|---|---|---|---|---|---|
| 进程名字 | Priority（优先级：越小越高） | Arrival time | Required time | Consumed time | 状态：共四种 |
默认刚创建的进程是NEW状态。程序将会显示在初始化时“On initialization”的进程状态以及每次 发生调度 时的情况（并不是每一个时间片结束都会输出一次）。
======================== On intialization ========================
Current CPU time: -1, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 1 3 3 0 NEW
Process--1 2 5 5 0 NEW
Process--2 1 6 4 0 NEW
Process--3 2 1 4 0 NEW
Process--4 3 0 6 0 NEW
======================== First process ========================
Current CPU time: 0, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 1 3 3 0 NEW
Process--1 2 5 5 0 NEW
Process--2 1 6 4 0 NEW
Process--3 2 1 4 0 NEW
Process--4 3 0 6 0 RUN
======================== Preemption ========================
Current CPU time: 1, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 1 3 3 0 NEW
Process--1 2 5 5 0 NEW
Process--2 1 6 4 0 NEW
Process--3 2 1 4 0 RUN
Process--4 4 0 6 1 WAIT
======================== Preemption ========================
Current CPU time: 3, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 1 3 3 0 RUN
Process--1 2 5 5 0 NEW
Process--2 1 6 4 0 NEW
Process--3 4 1 4 2 WAIT
Process--4 4 0 6 1 WAIT
======================== Preemption ========================
Current CPU time: 5, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 3 3 3 2 WAIT
Process--1 2 5 5 0 RUN
Process--2 1 6 4 0 NEW
Process--3 4 1 4 2 WAIT
Process--4 4 0 6 1 WAIT
======================== Preemption ========================
Current CPU time: 6, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 3 3 3 2 WAIT
Process--1 3 5 5 1 WAIT
Process--2 1 6 4 0 RUN
Process--3 4 1 4 2 WAIT
Process--4 4 0 6 1 WAIT
======================== Preemption ========================
Current CPU time: 9, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 3 3 3 2 RUN
Process--1 3 5 5 1 WAIT
Process--2 4 6 4 3 WAIT
Process--3 4 1 4 2 WAIT
Process--4 4 0 6 1 WAIT
======================== Slice expired ========================
Current CPU time: 10, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 3 3 3 3 FINISH
Process--1 3 5 5 1 RUN
Process--2 4 6 4 3 WAIT
Process--3 4 1 4 2 WAIT
Process--4 4 0 6 1 WAIT
======================== Preemption ========================
Current CPU time: 12, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 3 3 3 3 FINISH
Process--1 5 5 5 3 WAIT
Process--2 4 6 4 3 WAIT
Process--3 4 1 4 2 WAIT
Process--4 4 0 6 1 RUN
======================== Preemption ========================
Current CPU time: 13, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 3 3 3 3 FINISH
Process--1 5 5 5 3 WAIT
Process--2 4 6 4 3 WAIT
Process--3 4 1 4 2 RUN
Process--4 5 0 6 2 WAIT
======================== Preemption ========================
Current CPU time: 14, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 3 3 3 3 FINISH
Process--1 5 5 5 3 WAIT
Process--2 4 6 4 3 RUN
Process--3 5 1 4 3 WAIT
Process--4 5 0 6 2 WAIT
======================== Slice expired ========================
Current CPU time: 15, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 3 3 3 3 FINISH
Process--1 5 5 5 3 WAIT
Process--2 4 6 4 4 FINISH
Process--3 5 1 4 3 WAIT
Process--4 5 0 6 2 RUN
======================== Preemption ========================
Current CPU time: 16, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 3 3 3 3 FINISH
Process--1 5 5 5 3 WAIT
Process--2 4 6 4 4 FINISH
Process--3 5 1 4 3 RUN
Process--4 6 0 6 3 WAIT
======================== Slice expired ========================
Current CPU time: 17, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 3 3 3 3 FINISH
Process--1 5 5 5 3 RUN
Process--2 4 6 4 4 FINISH
Process--3 5 1 4 4 FINISH
Process--4 6 0 6 3 WAIT
======================== Slice expired ========================
Current CPU time: 19, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 3 3 3 3 FINISH
Process--1 6 5 5 5 FINISH
Process--2 4 6 4 4 FINISH
Process--3 5 1 4 4 FINISH
Process--4 6 0 6 3 RUN
======================== Slice expired ========================
Current CPU time: 22, scheduling occurs
Process name PRT AVT RQT CST Status
Process--0 3 3 3 3 FINISH
Process--1 6 5 5 5 FINISH
Process--2 4 6 4 4 FINISH
Process--3 5 1 4 4 FINISH
Process--4 8 0 6 6 FINISH
All processes are completed.