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2 章 实时系统概念 ...........................................................................................................
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2.0 前后台系统 （ F OREGROUND /B ACKGROUND S YSTEM ） ............................................. 1
2.1 代码的临界段 ............................................................................................................... 2
2.2 资源 ............................................................................................................................... 2
2.3 共享资源 ....................................................................................................................... 2
2.4 多任务 ........................................................................................................................... 2
2.5 任务 ............................................................................................................................... 2
2.6 任务切换
(C ONTEXT S WITCH OR T ASK S WITCH )
.................................................................. 3
2.7 内核（ K ERNEL ） ............................................................................................................. 3
2.8 调度（
S CHEDULER ）
.................................................................................................... 4
2.9 不可剥夺型内核 （ N ON -P REEMPTIVE K ERNEL ） ...................................................... 4
2.10 可 剥夺型内核 ............................................................................................................... 5
2.11 可重入性（
R EENTRANCY ）
........................................................................................... 5
2.12 时间片轮番调度法 ....................................................................................................... 7
2.13 任务优先级 ................................................................................................................... 7
2.14 2.14 静态优先级 .......................................................................................................... 7
2.15 动态优先级 ................................................................................................................... 7
2.16 优先级反转 ................................................................................................................... 7
2.17 任务优先级分配 ........................................................................................................... 8
2.18 互斥条件 ..................................................................................................................... 10
2.18.1 关中断和开中断 ................................................................................................. 10
2.18.2 测试并置位 .........................................................................................................
11
2.18.3 禁止 , 然后允许任务切换 ...................................................................................
11
2.18.4 信号量 (Semaphores) ......................................................................................... 12
2.19 死锁 ( 或抱死 ) （ D EADLOCK ( OR D EADLY E MBRACE ) ） ..................................................... 16
2.20 同步 ............................................................................................................................. 16
2.21 事件标志 (E VENT F LAGS ) .............................................................................................. 18
2.22 任务间的通讯 (I NTERTASK C OMMUNICATION ) ................................................................... 18
2.23 消息邮箱 (M ESSAGE M AIL BOXES ) ................................................................................... 18
2.24 消息队列 (M ESSAGE Q UEUE ) ........................................................................................... 19
2.25 中断 ............................................................................................................................. 20
2.26 中断延迟 ..................................................................................................................... 20
2.27 中断响应 ..................................................................................................................... 21
2.28 中断恢复时间 (I NTERRUPT R ECOVERY ) ........................................................................... 21
2.29 中断延迟、响应和恢复 ............................................................................................. 22
2.30 中断处理时间 ............................................................................................................. 22
2.31 非屏蔽中断 (NMI) ....................................................................................................... 23
2.32 时钟节拍 (C LOCK T ICK ) ................................................................................................ 24
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