CS-Notes/notes/计算机操作系统.md

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* [<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>](#<23><>һ<EFBFBD><D2BB>-<2D><><EFBFBD><EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD>ϵͳ<CFB5><CDB3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
        * [1. <20><><EFBFBD><EFBFBD>](#1-<2D><><EFBFBD><EFBFBD>)
        * [2. <20><><EFBFBD><EFBFBD>](#2-<2D><><EFBFBD><EFBFBD>)
        * [3. <20><><EFBFBD><EFBFBD>](#3-<2D><><EFBFBD><EFBFBD>)
        * [4. <20>첽](#4-<2D>첽)
    * [ϵͳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#ϵͳ<CFB5><CDB3><EFBFBD><EFBFBD>)
    * [<EFBFBD>жϷ<EFBFBD><EFBFBD><EFBFBD>](#<23>жϷ<D0B6><CFB7><EFBFBD>)
        * [1. <20><><EFBFBD>ж<EFBFBD>](#1-<2D><><EFBFBD>ж<EFBFBD>)
        * [2. <20>쳣](#2-<2D>쳣)
        * [3. <20><><EFBFBD><EFBFBD>](#3-<2D><><EFBFBD><EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD>ں˺<EFBFBD>΢<EFBFBD>ں<EFBFBD>](#<23><><EFBFBD>ں˺<DABA>΢<EFBFBD>ں<EFBFBD>)
        * [1. <20><><EFBFBD>ں<EFBFBD>](#1-<2D><><EFBFBD>ں<EFBFBD>)
        * [2. ΢<>ں<EFBFBD>](#2-΢<>ں<EFBFBD>)
* [<EFBFBD>ڶ<EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD>̹<EFBFBD><CCB9><EFBFBD>](#<23>ڶ<EFBFBD><DAB6><EFBFBD>-<2D><><EFBFBD>̹<EFBFBD><CCB9><EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>߳<EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>߳<EFBFBD>)
        * [1. <20><><EFBFBD><EFBFBD>](#1-<2D><><EFBFBD><EFBFBD>)
        * [2. <20>߳<EFBFBD>](#2-<2D>߳<EFBFBD>)
        * [3. <20><><EFBFBD><EFBFBD>](#3-<2D><><EFBFBD><EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD>״̬<EFBFBD><EFBFBD><EFBFBD>л<EFBFBD>](#<23><><EFBFBD><EFBFBD>״̬<D7B4><CCAC><EFBFBD>л<EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㷨](#<23><><EFBFBD><EFBFBD><EFBFBD>㷨)
        * [1. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ<CFB5>еĵ<D0B5><C4B5><EFBFBD>](#1-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ<CFB5>еĵ<D0B5><C4B5><EFBFBD>)
            * [1.1 <20><><EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD><C8B7><EFBFBD>](#11-<2D><><EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD><C8B7><EFBFBD>)
            * [1.2 <20><><EFBFBD><EFBFBD>ҵ<EFBFBD><D2B5><EFBFBD><EFBFBD>](#12-<2D><><EFBFBD><EFBFBD>ҵ<EFBFBD><D2B5><EFBFBD><EFBFBD>)
            * [1.3 <20><><EFBFBD><EFBFBD>ʣ<EFBFBD><CAA3>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#13-<2D><><EFBFBD><EFBFBD>ʣ<EFBFBD><CAA3>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
        * [2. <20><><EFBFBD><EFBFBD>ʽϵͳ<CFB5>еĵ<D0B5><C4B5><EFBFBD>](#2-<2D><><EFBFBD><EFBFBD>ʽϵͳ<CFB5>еĵ<D0B5><C4B5><EFBFBD>)
            * [2.1 <20><><EFBFBD><EFBFBD>Ȩ<EFBFBD><C8A8><EFBFBD><EFBFBD>](#21-<2D><><EFBFBD><EFBFBD>Ȩ<EFBFBD><C8A8><EFBFBD><EFBFBD>)
            * [2.2 ʱ<><CAB1>Ƭ<EFBFBD><C6AC>ת](#22-ʱ<><CAB1>Ƭ<EFBFBD><C6AC>ת)
            * [2.3 <20>༶<EFBFBD><E0BCB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#23-<2D>༶<EFBFBD><E0BCB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
            * [2.4 <20>̽<EFBFBD><CCBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#24-<2D>̽<EFBFBD><CCBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
        * [3. ʵʱϵͳ<CFB5>еĵ<D0B5><C4B5><EFBFBD>](#3-ʵʱϵͳ<CFB5>еĵ<D0B5><C4B5><EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬ<EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD>ͬ<EFBFBD><CDAC>)
        * [1. <20>ٽ<EFBFBD><D9BD><EFBFBD>](#1-<2D>ٽ<EFBFBD><D9BD><EFBFBD>)
        * [2. ͬ<><CDAC><EFBFBD>뻥<EFBFBD><EBBBA5>](#2-ͬ<><CDAC><EFBFBD>뻥<EFBFBD><EBBBA5>)
        * [3. <20>ź<EFBFBD><C5BA><EFBFBD>](#3-<2D>ź<EFBFBD><C5BA><EFBFBD>)
        * [4. <20>ܳ<EFBFBD>](#4-<2D>ܳ<EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD>ͨ<EFBFBD><CDA8>)
        * [1. <20>ܵ<EFBFBD>](#1-<2D>ܵ<EFBFBD>)
        * [2. <20>ź<EFBFBD><C5BA><EFBFBD>](#2-<2D>ź<EFBFBD><C5BA><EFBFBD>)
        * [3. <20><>Ϣ<EFBFBD><CFA2><EFBFBD><EFBFBD>](#3-<2D><>Ϣ<EFBFBD><CFA2><EFBFBD><EFBFBD>)
        * [4. <20>ź<EFBFBD>](#4-<2D>ź<EFBFBD>)
        * [5. <20><><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD>](#5-<2D><><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD>)
        * [6. <20>׽<EFBFBD><D7BD><EFBFBD>](#6-<2D>׽<EFBFBD><D7BD><EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD>ͬ<EFBFBD><CDAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
        * [1. <20><><EFBFBD><EFBFBD>-д<><D0B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#1-<2D><><EFBFBD><EFBFBD>-д<><D0B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
        * [2. <20><>ѧ<EFBFBD>ҽ<EFBFBD><D2BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#2-<2D><>ѧ<EFBFBD>ҽ<EFBFBD><D2BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
* [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ĵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD>Ĵ<EFBFBD><C4B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
        * [1. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#1-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
        * [2. <20><><EFBFBD><EFBFBD>Ԥ<EFBFBD><D4A4>](#2-<2D><><EFBFBD><EFBFBD>Ԥ<EFBFBD><D4A4>)
            * [2.1 <20>ƻ<EFBFBD><C6BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#21-<2D>ƻ<EFBFBD><C6BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
            * [2.2 <20>ƻ<EFBFBD><C6BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>뱣<EFBFBD><EBB1A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#22-<2D>ƻ<EFBFBD><C6BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>뱣<EFBFBD><EBB1A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
            * [2.3 <20>ƻ<EFBFBD><C6BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ռ<EFBFBD><D5BC><EFBFBD><EFBFBD>](#23-<2D>ƻ<EFBFBD><C6BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ռ<EFBFBD><D5BC><EFBFBD><EFBFBD>)
            * [2.4 <20>ƻ<EFBFBD><C6BB><EFBFBD>·<EFBFBD>ȴ<EFBFBD>](#24-<2D>ƻ<EFBFBD><C6BB><EFBFBD>·<EFBFBD>ȴ<EFBFBD>)
        * [3. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#3-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
            * [3.1 <20><>ȫ״̬](#31-<2D><>ȫ״̬)
            * [3.2 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD><EFBFBD>м<EFBFBD><D0BC>㷨](#32-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD><EFBFBD>м<EFBFBD><D0BC>㷨)
            * [3.3 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD><EFBFBD>м<EFBFBD><D0BC>㷨](#33-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD><EFBFBD>м<EFBFBD><D0BC>㷨)
        * [4. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD>](#4-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD>)
            * [4.1 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㷨](#41-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㷨)
            * [4.2 <20><><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD>](#42-<2D><><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD>)
* [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>洢<EFBFBD><E6B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D>洢<EFBFBD><E6B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD>)
    * [<EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD>ֶ<EFBFBD>](#<23><>ҳ<EFBFBD><D2B3><EFBFBD>ֶ<EFBFBD>)
        * [1. <20><>ҳ](#1-<2D><>ҳ)
        * [2. <20>ֶ<EFBFBD>](#2-<2D>ֶ<EFBFBD>)
        * [3. <20><>ҳʽ](#3-<2D><>ҳʽ)
        * [4. <20><>ҳ<EFBFBD><D2B3><EFBFBD>ֶ<EFBFBD><D6B6><EFBFBD><EFBFBD><EFBFBD>](#4-<2D><>ҳ<EFBFBD><D2B3><EFBFBD>ֶ<EFBFBD><D6B6><EFBFBD><EFBFBD><EFBFBD>)
    * [ҳ<EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><EFBFBD>㷨](#ҳ<><D2B3><EFBFBD>û<EFBFBD><C3BB>㷨)
        * [1. <20><><EFBFBD>ѣ<EFBFBD>Optimal<61><6C>](#1-<2D><><EFBFBD><EFBFBD>optimal)
        * [2. <20>Ƚ<EFBFBD><C8BD>ȳ<EFBFBD><C8B3><EFBFBD>FIFO<46><4F>](#2-<2D>Ƚ<EFBFBD><C8BD>ȳ<EFBFBD>fifo)
        * [3. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>δʹ<CEB4>ã<EFBFBD>LRU, Least Recently Used<65><64>](#3-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>δʹ<CEB4><CAB9>lru,-least-recently-used)
        * [4. ʱ<>ӣ<EFBFBD>Clock<63><6B>](#4-ʱ<><CAB1>clock)
* [<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>豸<EFBFBD><E8B1B8><EFBFBD><EFBFBD>](#<23><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D>豸<EFBFBD><E8B1B8><EFBFBD><EFBFBD>)
    * [<EFBFBD><EFBFBD><EFBFBD>̵<EFBFBD><EFBFBD><EFBFBD><EFBFBD>㷨](#<23><><EFBFBD>̵<EFBFBD><CCB5><EFBFBD><EFBFBD>㷨)
        * [1. <20><><EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD><C8B7><EFBFBD><EFBFBD><EFBFBD>FCFS, First Come First Serverd<72><64>](#1-<2D><><EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD><C8B7><EFBFBD>fcfs,-first-come-first-serverd)
        * [2. <20><><EFBFBD><EFBFBD>Ѱ<EFBFBD><D1B0>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD>ȣ<EFBFBD>SSTF, Shortest Seek Time First<73><74>](#2-<2D><><EFBFBD><EFBFBD>Ѱ<EFBFBD><D1B0>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>sstf,-shortest-seek-time-first)
        * [3. ɨ<><C9A8><EFBFBD>㷨<EFBFBD><E3B7A8>SCAN<41><4E>](#3-ɨ<><C9A8><EFBFBD>㷨scan)
        * [4. ѭ<><D1AD>ɨ<EFBFBD><C9A8><EFBFBD>㷨<EFBFBD><E3B7A8>CSCAN<41><4E>](#4-ѭ<><D1AD>ɨ<EFBFBD><C9A8><EFBFBD>㷨cscan)
* [<EFBFBD>ο<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>](#<23>ο<EFBFBD><CEBF><EFBFBD><EFBFBD><EFBFBD>)
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# <20><>һ<EFBFBD><D2BB> <20><><EFBFBD><EFBFBD>

## <20><><EFBFBD><EFBFBD>ϵͳ<CFB5><CDB3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

### 1. <20><><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬʱ<EFBFBD><EFBFBD><EFBFBD>ж<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>򣬶<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָͬһʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ж<EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҪӲ<EFBFBD><EFBFBD>֧<EFBFBD>֣<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ˮ<EFBFBD>߻<EFBFBD><EFBFBD>߶ദ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̺<EFBFBD><EFBFBD>̣߳<EFBFBD>ʹ<EFBFBD>ó<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>С<EFBFBD>

### 2. <20><><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָϵͳ<EFBFBD>е<EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD>Թ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̹<EFBFBD>ͬʹ<EFBFBD>á<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>⹲<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>⹲<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD>Ϊ<EFBFBD>ٽ<EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӡ<EFBFBD><EFBFBD><EFBFBD>ȣ<EFBFBD><EFBFBD><EFBFBD>ͬһʱ<EFBFBD><EFBFBD>ֻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̷<EFBFBD><EFBFBD>ʣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD>ֶ<EFBFBD><EFBFBD>ٽ<EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD>ķ<EFBFBD><EFBFBD>ʡ<EFBFBD>

### 3. <20><><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>⼼<EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD><EFBFBD>ת<EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>߼<EFBFBD>ʵ<EFBFBD>塣<EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>⼼<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD>ָ<EFBFBD><EFBFBD>ü<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϳշָ<EFBFBD><EFBFBD>ü<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϲ<EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD><EFBFBD>ʹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD>ָ<EFBFBD><EFBFBD>ü<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ÿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ռ<EFBFBD>д<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ÿ<EFBFBD><EFBFBD>ִֻ<EFBFBD><EFBFBD>һС<EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD>Ƭ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><EFBFBD><EFBFBD>

### 4. <20>첽

<EFBFBD>첽<EFBFBD><EFBFBD>ָ<EFBFBD><EFBFBD><EFBFBD>̲<EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͣͣ<EFBFBD><EFBFBD><EFBFBD>Բ<EFBFBD><EFBFBD><EFBFBD>֪<EFBFBD><EFBFBD><EFBFBD>ٶ<EFBFBD><EFBFBD><EFBFBD>ǰ<EFBFBD>ƽ<EFBFBD><EFBFBD><EFBFBD>

## ϵͳ<CFB5><CDB3><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD>̬<EFBFBD><EFBFBD>Ҫ<EFBFBD>õ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ<EFBFBD><EFBFBD>һЩ<EFBFBD><EFBFBD><EFBFBD>ܣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫʹ<EFBFBD><EFBFBD>ϵͳ<EFBFBD><EFBFBD><EFBFBD>ôӶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ںˣ<EFBFBD><EFBFBD>ɲ<EFBFBD><EFBFBD><EFBFBD>ϵͳ<EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD>ɡ<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ĺ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>豸<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̹<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>š<EFBFBD><EFBFBD>洢<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȡ<EFBFBD>

## <20>жϷ<D0B6><CFB7><EFBFBD>

### 1. <20><><EFBFBD>ж<EFBFBD>

<EFBFBD><EFBFBD> CPU ִ<><D6B4>ָ<EFBFBD><D6B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD><C2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> I/O <20><><EFBFBD><EFBFBD><EFBFBD>жϣ<D0B6><CFA3><EFBFBD>ʾ<EFBFBD>豸<EFBFBD><E8B1B8><EFBFBD><EFBFBD>/<2F><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ѿ<EFBFBD><D1BE><EFBFBD><EFBFBD>ɣ<EFBFBD><C9A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܹ<EFBFBD><DCB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>/<2F><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>󡣴<EFBFBD><F3A1A3B4>⻹<EFBFBD><E2BBB9>ʱ<EFBFBD><CAB1><EFBFBD>жϡ<D0B6><CFA1><EFBFBD><EFBFBD><EFBFBD>̨<EFBFBD>жϵȡ<CFB5>

### 2. <20>쳣

<EFBFBD><EFBFBD> CPU ִ<><D6B4>ָ<EFBFBD><D6B8><EFBFBD><EFBFBD><EFBFBD>ڲ<EFBFBD><DAB2>¼<EFBFBD><C2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƿ<EFBFBD><C7B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>롢<EFBFBD><EBA1A2>ַԽ<D6B7>硢<EFBFBD><E7A1A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȡ<EFBFBD>

### 3. <20><><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD><EFBFBD>ϵͳ<EFBFBD><EFBFBD><EFBFBD>á<EFBFBD>

## <20><><EFBFBD>ں˺<DABA>΢<EFBFBD>ں<EFBFBD>

### 1. <20><><EFBFBD>ں<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>ں<EFBFBD><EFBFBD>ǽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܽ<EFBFBD><EFBFBD>ϵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ŵ<EFBFBD><EFBFBD>ںˣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڸ<EFBFBD>ģ<EFBFBD>鹲<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>кܸߵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܡ<EFBFBD>

### 2. ΢<>ں<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>ڲ<EFBFBD><EFBFBD><EFBFBD>ϵͳ<EFBFBD><EFBFBD><EFBFBD>ϸ<EFBFBD><EFBFBD>ӣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>˽<EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>ֲ<EFBFBD><EFBFBD><EFBFBD>ϵͳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƴ<EFBFBD><EFBFBD>ںˣ<EFBFBD><EFBFBD>Ӷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ں˵ĸ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ԡ<EFBFBD><EFBFBD>Ƴ<EFBFBD><EFBFBD>IJ<EFBFBD><EFBFBD>ָ<EFBFBD><EFBFBD>ݷֲ<EFBFBD><EFBFBD><EFBFBD>ԭ<EFBFBD>򻮷ֳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>໥<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҪƵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD>̬<EFBFBD>ͺ<EFBFBD><EFBFBD><EFBFBD>̬֮<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʧ<EFBFBD><EFBFBD>

# <20>ڶ<EFBFBD><DAB6><EFBFBD> <20><><EFBFBD>̹<EFBFBD><CCB9><EFBFBD>

## <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>߳<EFBFBD>

### 1. <20><><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Dz<EFBFBD><EFBFBD><EFBFBD>ϵͳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ļ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>̿<EFBFBD><EFBFBD>ƿ<EFBFBD> (Process Control Block, PCB) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̵Ļ<CCB5><C4BB><EFBFBD><EFBFBD><EFBFBD>Ϣ<EFBFBD><CFA2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>״̬<D7B4><CCAC><EFBFBD><EFBFBD>ν<EFBFBD>Ĵ<EFBFBD><C4B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̺ͳ<CCBA><CDB3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̣<EFBFBD><CCA3><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><D6B8> PCB <20>IJ<EFBFBD><C4B2><EFBFBD><EFBFBD><EFBFBD>

### 2. <20>߳<EFBFBD>

һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>п<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ж<EFBFBD><EFBFBD><EFBFBD><EFBFBD>̣߳<EFBFBD><EFBFBD>߳<EFBFBD><EFBFBD>Ƕ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȵĻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><EFBFBD>ͬһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>еĶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>߳<EFBFBD>֮<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Բ<EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD>У<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD>

### 3. <20><><EFBFBD><EFBFBD>

- ӵ<><D3B5><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD><EFBFBD>Ļ<EFBFBD><C4BB><EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><CEBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̲߳<DFB3>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD>߳̿<DFB3><CCBF>Է<EFBFBD><D4B7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̵<EFBFBD><CCB5><EFBFBD>Դ<EFBFBD><D4B4>

- <20><><EFBFBD>ȣ<EFBFBD><C8A3>߳<EFBFBD><DFB3>Ƕ<EFBFBD><C7B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȵĻ<C8B5><C4BB><EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><CEBB><EFBFBD><EFBFBD>ͬһ<CDAC><D2BB><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><D0A3>̵߳<DFB3><CCB5>л<EFBFBD><D0BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><D0BB><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڵ<EFBFBD><DAB5>߳<EFBFBD><DFB3>л<EFBFBD><D0BB><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD><D0B5>߳<EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><D0BB><EFBFBD>

- ϵͳ<CFB5><CDB3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><DAB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>ϵͳ<CFB5><CDB3>ҪΪ֮<CEAA><D6AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><DAB4>ռ䡢I/O <20>豸<EFBFBD>ȣ<EFBFBD><C8A3><EFBFBD><EFBFBD>˲<EFBFBD><CBB2><EFBFBD>ϵͳ<CFB5><CDB3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ŀ<EFBFBD><C4BF><EFBFBD>Զ<EFBFBD><D4B6><EFBFBD>ڴ<EFBFBD><DAB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>߳<EFBFBD>ʱ<EFBFBD>Ŀ<EFBFBD><C4BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƶأ<C6B5><D8A3>ڽ<EFBFBD><DABD>н<EFBFBD><D0BD><EFBFBD><EFBFBD>л<EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD>漰<EFBFBD><E6BCB0>ǰִ<C7B0>н<EFBFBD><D0BD><EFBFBD> CPU <20><><EFBFBD><EFBFBD><EFBFBD>ı<EFBFBD><C4B1>漰<EFBFBD>µ<EFBFBD><C2B5>Ƚ<EFBFBD><C8BD><EFBFBD> CPU <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>á<EFBFBD><C3A1><EFBFBD><EFBFBD>߳<EFBFBD><DFB3>л<EFBFBD>ʱֻ<CAB1>豣<EFBFBD><E8B1A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ĵ<EFBFBD><C4B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݣ<EFBFBD><DDA3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>С<EFBFBD><D0A1>

- ͨ<>ŷ<EFBFBD><C5B7>棺<EFBFBD><E6A3BA><EFBFBD>̼<EFBFBD>ͨ<EFBFBD><CDA8> (IPC) <20><>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD>ͬ<EFBFBD><CDAC><EFBFBD>ͻ<EFBFBD><CDBB><EFBFBD><EFBFBD>ֶεĸ<CEB5><C4B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ա<EFBFBD>֤<EFBFBD><D6A4><EFBFBD>ݵ<EFBFBD>һ<EFBFBD><D2BB><EFBFBD>ԣ<EFBFBD><D4A3><EFBFBD><EFBFBD>̼߳<DFB3><CCBC><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><CDA8>ֱ<EFBFBD>Ӷ<EFBFBD>/дͬһ<CDAC><D2BB><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD><D0B5><EFBFBD><EFBFBD>ݶΣ<DDB6><CEA3><EFBFBD>ȫ<EFBFBD>ֱ<EFBFBD><D6B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>š<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>QQ <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̣<EFBFBD><CCA3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>кܶ<D0BA><DCB6>̣߳<DFB3><CCA3><EFBFBD><EFBFBD><EFBFBD> HTTP <20><><EFBFBD><EFBFBD><EFBFBD>̡߳<DFB3><CCA1>¼<EFBFBD><C2BC><EFBFBD>Ӧ<EFBFBD>̡߳<DFB3><CCA1><EFBFBD>Ⱦ<EFBFBD>̵߳ȵȣ<C8B5><C8A3>̵߳IJ<CCB5><C4B2><EFBFBD>ִ<EFBFBD><D6B4>ʹ<EFBFBD><CAB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD><D0B5><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӴӶ<D3B4><D3B6><EFBFBD><EFBFBD><EFBFBD> HTTP <20><><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD>û<EFBFBD><C3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD><C2BC><EFBFBD>

## <20><><EFBFBD><EFBFBD>״̬<D7B4><CCAC><EFBFBD>л<EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/1706ce58-a081-4fed-9b36-c3c0d7e22b3a.jpg)

<EFBFBD><EFBFBD><EFBFBD><EFBFBD>״̬<EFBFBD><EFBFBD>ȱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD>Ӷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>״̬ת<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ǹ<EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> CPU<50><55>ȱ<EFBFBD><C8B1> CPU <20><><EFBFBD>ý<EFBFBD><C3BD>̴<EFBFBD><CCB4><EFBFBD><EFBFBD><EFBFBD>̬ת<CCAC><D7AA>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD>̬<EFBFBD><CCAC>

ֻ<EFBFBD>о<EFBFBD><EFBFBD><EFBFBD>̬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>໥ת<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ķ<EFBFBD><EFBFBD>ǵ<EFBFBD><EFBFBD><EFBFBD>ת<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>״̬<EFBFBD>Ľ<EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㷨<EFBFBD>Ӷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> CPU ʱ<>䣬תΪ<D7AA><CEAA><EFBFBD><EFBFBD>״̬<D7B4><CCAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>״̬<D7B4>Ľ<EFBFBD><C4BD>̣<EFBFBD><CCA3>ڷ<EFBFBD><DAB7><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> CPU ʱ<><CAB1>Ƭ<EFBFBD><C6AC><EFBFBD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD>ͻ<EFBFBD>תΪ<D7AA><CEAA><EFBFBD><EFBFBD>״̬<D7B4><CCAC><EFBFBD>ȴ<EFBFBD><C8B4><EFBFBD>һ<EFBFBD>ε<EFBFBD><CEB5>ȡ<EFBFBD>

## <20><><EFBFBD><EFBFBD><EFBFBD>㷨

<EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD>Բ<EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>۵<EFBFBD><EFBFBD><EFBFBD><EFBFBD>㷨<EFBFBD><EFBFBD>

### 1. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ<CFB5>еĵ<D0B5><C4B5><EFBFBD>

#### 1.1 <20><><EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD><C8B7><EFBFBD>

first-come first-serverd<72><64>FCFS<46><53><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƚ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڳ<EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڶ<EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>һֱ<EFBFBD>ȴ<EFBFBD>ǰ<EFBFBD><EFBFBD><EFBFBD>ij<EFBFBD><EFBFBD><EFBFBD>ҵִ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϲ<EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD>У<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫִ<EFBFBD>кܳ<EFBFBD>ʱ<EFBFBD>䣬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>˶<EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD>ȴ<EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

#### 1.2 <20><><EFBFBD><EFBFBD>ҵ<EFBFBD><D2B5><EFBFBD><EFBFBD>

shortest job first<73><74>SJF<4A><46><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>ȹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̵<EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD>п<EFBFBD><EFBFBD>ܻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һֱ<EFBFBD>ȴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҵִ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD>״̬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һֱ<EFBFBD>ж<EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ô<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD><EFBFBD>Զ<EFBFBD>ò<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȡ<EFBFBD>

#### 1.3 <20><><EFBFBD><EFBFBD>ʣ<EFBFBD><CAA3>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

shortest remaining time next<78><74>SRTN<54><4E><EFBFBD><EFBFBD>

### 2. <20><><EFBFBD><EFBFBD>ʽϵͳ<CFB5>еĵ<D0B5><C4B5><EFBFBD>

#### 2.1 <20><><EFBFBD><EFBFBD>Ȩ<EFBFBD><C8A8><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>˿<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ȩ֮<EFBFBD>⣬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>԰<EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ȩ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֵ<EFBFBD><EFBFBD>ȷ<EFBFBD>ʽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>㷨<EFBFBD><EFBFBD>

<EFBFBD><EFBFBD>Ӧ<EFBFBD><EFBFBD> = (<28>ȴ<EFBFBD>ʱ<EFBFBD><CAB1> + Ҫ<><D2AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>) / Ҫ<><D2AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1> = <20><>Ӧʱ<D3A6><CAB1> / Ҫ<><D2AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>

<EFBFBD><EFBFBD><EFBFBD>ֵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>㷨<EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD>Ϊ<EFBFBD>˽<EFBFBD><EFBFBD><EFBFBD> SJF <20>г<EFBFBD><D0B3><EFBFBD>ҵ<EFBFBD><D2B5><EFBFBD>ܻ<EFBFBD><DCBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>⣬<EFBFBD><E2A3AC>Ϊ<EFBFBD><CEAA><EFBFBD>ŵȴ<C5B5>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD><D3A6>Ҳ<EFBFBD><D2B2>Խ<EFBFBD><D4BD>Խ<EFBFBD>ߡ<EFBFBD>

#### 2.2 ʱ<><CAB1>Ƭ<EFBFBD><C6AC>ת

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>о<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̰<EFBFBD> FCFS <20><>ԭ<EFBFBD><D4AD><EFBFBD>ų<EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD>ÿ<EFBFBD>ε<EFBFBD><CEB5><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD> CPU <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>׽<EFBFBD><D7BD>̣<EFBFBD><CCA3>ý<EFBFBD><C3BD>̿<EFBFBD><CCBF><EFBFBD>ִ<EFBFBD><D6B4>һ<EFBFBD><D2BB>ʱ<EFBFBD><CAB1>Ƭ<EFBFBD><C6AC><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>Ƭ<EFBFBD><C6AC><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD>ɼ<EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD>жϣ<D0B6><CFA3><EFBFBD><EFBFBD>ȳ<EFBFBD><C8B3><EFBFBD><EFBFBD><EFBFBD>ֹͣ<CDA3>ý<EFBFBD><C3BD>̵<EFBFBD>ִ<EFBFBD>У<EFBFBD><D0A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD>ĩβ<C4A9><CEB2>ͬʱ<CDAC><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD> CPU <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>׵Ľ<D7B5><C4BD>̡<EFBFBD>

ʱ<EFBFBD><EFBFBD>Ƭ<EFBFBD><EFBFBD>ת<EFBFBD>㷨<EFBFBD><EFBFBD>Ч<EFBFBD>ʺ<EFBFBD>ʱ<EFBFBD><EFBFBD>Ƭ<EFBFBD>Ĵ<EFBFBD>С<EFBFBD>кܴ<EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊÿ<EFBFBD>ν<EFBFBD><EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̵<EFBFBD><EFBFBD><EFBFBD>Ϣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>½<EFBFBD><EFBFBD>̵<EFBFBD><EFBFBD><EFBFBD>Ϣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD>Ƭ̫С<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>л<EFBFBD>̫Ƶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>л<EFBFBD><EFBFBD>ϾͻỨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD>䡣

#### 2.3 <20>༶<EFBFBD><E0BCB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/042cf928-3c8e-4815-ae9c-f2780202c68f.png)

1. <20><><EFBFBD>ö<EFBFBD><C3B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><D0A3><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>и<EFBFBD><D0B8>費ͬ<E8B2BB><CDAC><EFBFBD><EFBFBD><EFBFBD>ȼ<EFBFBD><C8BC><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD><D0B5><EFBFBD><EFBFBD>ȼ<EFBFBD><C8BC><EFBFBD><EFBFBD>ߣ<EFBFBD><DFA3>ڶ<EFBFBD><DAB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>д<EFBFBD>֮<EFBFBD><D6AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD><D0B5><EFBFBD><EFBFBD><EFBFBD>Ȩ<EFBFBD><C8A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>͡<EFBFBD><CDA1><EFBFBD><EFBFBD>㷨<EFBFBD><E3B7A8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>н<EFBFBD><D0BD><EFBFBD>ִ<EFBFBD><D6B4>ʱ<EFBFBD><CAB1>Ƭ<EFBFBD>Ĵ<EFBFBD>СҲ<D0A1><D2B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬ<EFBFBD><CDAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȨԽ<C8A8>ߵĶ<DFB5><C4B6><EFBFBD><EFBFBD>У<EFBFBD>Ϊÿ<CEAA><C3BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>涨<EFBFBD><E6B6A8>ִ<EFBFBD><D6B4>ʱ<EFBFBD><CAB1>Ƭ<EFBFBD><C6AC>ԽС<D4BD><D0A1>

2. <20><>һ<EFBFBD><D2BB><EFBFBD>½<EFBFBD><C2BD>̽<EFBFBD><CCBD><EFBFBD><EFBFBD>ڴ<EFBFBD><DAB4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƚ<EFBFBD><C8BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD>е<EFBFBD>ĩβ<C4A9><CEB2><EFBFBD><EFBFBD> FCFS ԭ<><D4AD><EFBFBD>Ŷӵȴ<D3B5><C8B4><EFBFBD><EFBFBD>ȡ<EFBFBD><C8A1><EFBFBD><EFBFBD>ֵ<EFBFBD><D6B5>ý<EFBFBD><C3BD><EFBFBD>ִ<EFBFBD><D6B4>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڸ<EFBFBD>ʱ<EFBFBD><CAB1>Ƭ<EFBFBD><C6AC><EFBFBD><EFBFBD><EFBFBD>ɣ<EFBFBD><C9A3><EFBFBD><EFBFBD><EFBFBD>׼<EFBFBD><D7BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ<CFB5><CDB3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB>ʱ<EFBFBD><CAB1>Ƭ<EFBFBD><C6AC><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1>δ<EFBFBD><CEB4><EFBFBD>ɣ<EFBFBD><C9A3><EFBFBD><EFBFBD>ȳ<EFBFBD><C8B3><EFBFBD><EFBFBD>㽫<EFBFBD>ý<EFBFBD><C3BD><EFBFBD>ת<EFBFBD><D7AA><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>еĶ<D0B5>β<EFBFBD><CEB2>

3. <20><><EFBFBD><EFBFBD>ǰ i -1 <20><><EFBFBD><EFBFBD><EFBFBD>о<EFBFBD><D0BE><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD>Ż<EFBFBD><C5BB><EFBFBD><EFBFBD>ȵ<EFBFBD> i <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>еĽ<D0B5><C4BD>̡<EFBFBD>

<EFBFBD>ŵ㣺ʵʱ<EFBFBD>Ժã<EFBFBD>ͬʱ<EFBFBD>ʺ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ж<EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD>ͳ<EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD><EFBFBD>

#### 2.4 <20>̽<EFBFBD><CCBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

### 3. ʵʱϵͳ<CFB5>еĵ<D0B5><C4B5><EFBFBD>

ʵʱϵͳҪһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>ȷ<EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD>ڵõ<EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD><EFBFBD>

<EFBFBD><EFBFBD>ΪӲʵʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵʱ<EFBFBD><EFBFBD>ǰ<EFBFBD>߱<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ԵĽ<EFBFBD>ֹʱ<EFBFBD>䣬<EFBFBD><EFBFBD><EFBFBD>߿<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>ij<EFBFBD>ʱ<EFBFBD><EFBFBD>

## <20><><EFBFBD><EFBFBD>ͬ<EFBFBD><CDAC>

### 1. <20>ٽ<EFBFBD><D9BD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>ٽ<EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD>з<EFBFBD><EFBFBD>ʵ<EFBFBD><EFBFBD>Ƕδ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD>ٽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

Ϊ<EFBFBD>˻<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ٽ<EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD>ÿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ٽ<EFBFBD><EFBFBD><EFBFBD>֮ǰ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD>Ƚ<EFBFBD><EFBFBD>м<EFBFBD><EFBFBD>顣

```html
// entry section
// critical section;
// exit section
```

### 2. ͬ<><CDAC><EFBFBD>뻥<EFBFBD><EBBBA5>

ͬ<EFBFBD><EFBFBD>ָ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̰<EFBFBD>һ<EFBFBD><EFBFBD>˳<EFBFBD><EFBFBD>ִ<EFBFBD>У<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬһʱ<EFBFBD><EFBFBD>ֻ<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ٽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڶ<EFBFBD><EFBFBD>ٽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵĻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϣ<EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵġ<EFBFBD>

### 3. <20>ź<EFBFBD><C5BA><EFBFBD>

**<2A>ź<EFBFBD><C5BA><EFBFBD><EFBFBD><EFBFBD>Samaphore<72><65>** <20><>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>ͱ<EFBFBD><CDB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Զ<EFBFBD><D4B6><EFBFBD>ִ<EFBFBD><D6B4> down <20><> up <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҳ<EFBFBD><D2B2><EFBFBD>dz<EFBFBD><C7B3><EFBFBD><EFBFBD><EFBFBD> P <20><> V <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

- **down** : <20><><EFBFBD><EFBFBD><EFBFBD>ź<EFBFBD><C5BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 0 <20><>ִ<EFBFBD><D6B4> -1 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ź<EFBFBD><C5BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 0<><30><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>˯<EFBFBD>ߣ<EFBFBD><DFA3>ȴ<EFBFBD><C8B4>ź<EFBFBD><C5BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 0<><30>
- **up**<2A><><EFBFBD><EFBFBD><EFBFBD>ź<EFBFBD><C5BA><EFBFBD>ִ<EFBFBD><D6B4> +1 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD>˯<EFBFBD>ߵĽ<DFB5><C4BD>̣<EFBFBD><CCA3>ý<EFBFBD><C3BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> down <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

down <20><> up <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD><EFBFBD>Ƴ<EFBFBD>ԭ<EFBFBD><EFBFBD><EFA3AC><EFBFBD>ɷָͨ<EEA3AC><CDA8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD><D6B4><EFBFBD><EFBFBD>Щ<EFBFBD><D0A9><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>жϡ<D0B6>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ź<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȡֵֻ<EFBFBD><EFBFBD>Ϊ 0 <20><><EFBFBD><EFBFBD> 1<><31><EFBFBD><EFBFBD>ô<EFBFBD>ͳ<EFBFBD>Ϊ<EFBFBD><CEAA>**<2A><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Mutex<65><78>**<2A><>0 <20><>ʾ<EFBFBD>ٽ<EFBFBD><D9BD><EFBFBD><EFBFBD>Ѿ<EFBFBD><D1BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>1 <20><>ʾ<EFBFBD>ٽ<EFBFBD><D9BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

```c
typedef int samaphore;
samaphore mutex = 1;
void P1() {
    down(mutex);
    // <20>ٽ<EFBFBD><D9BD><EFBFBD>
    up(mutex);
}

void P2() {
    down(mutex);
    // <20>ٽ<EFBFBD><D9BD><EFBFBD>
    up(mutex);
}
```

**ʹ<><CAB9><EFBFBD>ź<EFBFBD><C5BA><EFBFBD>ʵ<EFBFBD><CAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>**

ʹ<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> mutex <20><><EFBFBD><EFBFBD><EFBFBD>ٽ<EFBFBD><D9BD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD>з<EFBFBD><D0B7>ʣ<EFBFBD>empty <20><>¼<EFBFBD>ջ<EFBFBD><D5BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>full <20><>¼<EFBFBD><C2BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

ע<EFBFBD>⣬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD><EFBFBD> down <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><C3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ٽ<EFBFBD><D9BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȶ<EFBFBD><C8B6>ٽ<EFBFBD><D9BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ȼ<EFBFBD><C8BB><EFBFBD><EFBFBD>ִ<EFBFBD><D6B4> down <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ô<EFBFBD><C3B4><EFBFBD>ܻ<EFBFBD><DCBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>߶<EFBFBD><DFB6>ٽ<EFBFBD><D9BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD><D6B4> down(empty) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> empty = 0<><30><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>˯<EFBFBD>ߡ<EFBFBD><DFA1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ߴ<EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD>ܽ<EFBFBD><DCBD><EFBFBD><EFBFBD>ٽ<EFBFBD><D9BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD><EFBFBD>߶<EFBFBD><DFB6>ٽ<EFBFBD><D9BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ˣ<EFBFBD>Ҳ<EFBFBD><D2B2><EFBFBD>޷<EFBFBD>ִ<EFBFBD><D6B4> up(empty) <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ô<EFBFBD><C3B4><EFBFBD><EFBFBD><EFBFBD>ߺ<EFBFBD><DFBA><EFBFBD><EFBFBD><EFBFBD><EFBFBD>߾ͻ<DFBE>һֱ<D2BB>ȴ<EFBFBD><C8B4><EFBFBD>ȥ<EFBFBD><C8A5>

```c
#define N 100
typedef int samaphore;
samaphore mutex = 1;
samaphore empty = N;
samaphore full = 0;

void producer() {
    while(TRUE){
        int item = produce_item;
        down(empty);
        down(mutex);
        insert_item(item);
        up(mutex);
        up(full);
    }
}

void consumer() {
    while(TRUE){
        down(full);
        down(mutex);
        int item = remove_item(item);
        up(mutex);
        up(empty);
        consume_item(item);
    }
}
```

### 4. <20>ܳ<EFBFBD>

ʹ<EFBFBD><EFBFBD><EFBFBD>ź<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD>ֵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD>ͻ<EFBFBD><EFBFBD>˴<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>̰ܳѿ<EFBFBD><EFBFBD>ƵĴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>׳<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҳʹ<EFBFBD>ÿͻ<EFBFBD><EFBFBD>˴<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ø<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ס<EFBFBD>

c <20><><EFBFBD>Բ<EFBFBD>֧<EFBFBD>ֹ̣ܳ<DCB3><CCA3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD><CAB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD> Pascal <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̡ܳ<DCB3>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>еĹܳ<C4B9><DCB3>ṩ<EFBFBD><E1B9A9> insert() <20><> remove() <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͻ<EFBFBD><CDBB>˴<EFBFBD><CBB4><EFBFBD>ͨ<EFBFBD><CDA8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>⡣

```pascal
monitor ProducerConsumer
    integer i;
    condition c;
    
    procedure insert();
    begin
    
    end;
    
    procedure remove();
    begin
    
    end;
end monitor;
```

<EFBFBD>ܳ<EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD>ԣ<EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD>ֻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>ù̡ܳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>޷<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD>е<EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һֱռ<EFBFBD>ụ̀ܳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Զ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>ù̡ܳ<EFBFBD>

<EFBFBD>ܳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> **<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>** <20>Լ<EFBFBD><D4BC><EFBFBD><EFBFBD>صIJ<D8B5><C4B2><EFBFBD><EFBFBD><EFBFBD>**wait()** <20><> **signal()** <20><>ʵ<EFBFBD><CAB5>ͬ<EFBFBD><CDAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD><D6B4> wait() <20><><EFBFBD><EFBFBD><EFBFBD>ᵼ<EFBFBD>µ<EFBFBD><C2B5>ý<EFBFBD><C3BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѹܳ<D1B9><DCB3>ó<EFBFBD><C3B3><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>̳<EFBFBD><CCB3>С<EFBFBD>signal() <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڻ<EFBFBD><DABB>ѱ<EFBFBD><D1B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ľ<EFBFBD><C4BD>̡<EFBFBD>

**ʹ<>ùܳ<C3B9>ʵ<EFBFBD><CAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>-<2D><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>**

```pascal
monitor ProducerConsumer
    condition full, empty;
    integer count := 0;
    condition c;

    procedure insert(item: integer);
    begin
        if count = N then wait(full);
        insert_item(item);
        count := count + 1;
        if count = 1 ten signal(empty);
    end;

    function remove: integer;
    begin
        if count = 0 then wait(empty);
        remove = remove_item;
        count := count - 1;
        if count = N -1 then signal(full);
    end;
end monitor;

procedure producer
begin
    while true do
    begin
        item = produce_item;
        ProducerConsumer.insert(item);
    end
end;

procedure consumer
begin
    while true do
    begin
        item = ProducerConsumer.remove;
        consume_item(item);
    end
end;
```

## <20><><EFBFBD><EFBFBD>ͨ<EFBFBD><CDA8>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>ſ<EFBFBD><EFBFBD>Կ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Dz<EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD>̼<EFBFBD><EFBFBD><EFBFBD><EFBFBD>߳<EFBFBD>ͨ<EFBFBD>ţ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̵߳<EFBFBD>ͨ<EFBFBD>ŷ<EFBFBD>ʽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫʹ<EFBFBD><EFBFBD><EFBFBD>ź<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ơ<EFBFBD>

### 1. <20>ܵ<EFBFBD>

<EFBFBD>ܵ<EFBFBD><EFBFBD>ǵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ġ<EFBFBD><EFBFBD>Ƚ<EFBFBD><EFBFBD>ȳ<EFBFBD><EFBFBD>ġ<EFBFBD><EFBFBD>޽ṹ<EFBFBD>ġ<EFBFBD><EFBFBD>̶<EFBFBD><EFBFBD><EFBFBD>С<EFBFBD><EFBFBD><EFBFBD>ֽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̵ı<EFBFBD>׼<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̵ı<EFBFBD>׼<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>д<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڹܵ<EFBFBD><EFBFBD><EFBFBD>β<EFBFBD><EFBFBD>д<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڹܵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>׶˶<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>󽫴ӹܵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ߣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̶<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ٶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Щ<EFBFBD><EFBFBD><EFBFBD>ݡ<EFBFBD>

<EFBFBD>ܵ<EFBFBD><EFBFBD>ṩ<EFBFBD>˼򵥵<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƻ<EFBFBD><EFBFBD>ƣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͼ<EFBFBD><EFBFBD><EFBFBD>չܵ<EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>д<EFBFBD><EFBFBD><EFBFBD>ܵ<EFBFBD>ǰ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̽<EFBFBD>һֱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD>أ<EFBFBD><EFBFBD>ܵ<EFBFBD><EFBFBD>Ѿ<EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͼд<EFBFBD>ܵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̴ӹܵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮ǰ<EFBFBD><EFBFBD>д<EFBFBD><EFBFBD><EFBFBD>̽<EFBFBD>һֱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

Linux <20>йܵ<D0B9><DCB5><EFBFBD>ͨ<EFBFBD><CDA8><EFBFBD><EFBFBD><EFBFBD>ļ<EFBFBD><C4BC><EFBFBD>ʵ<EFBFBD>֡<EFBFBD>

<EFBFBD>ܵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֣<EFBFBD>

1. <20><>ͨ<EFBFBD>ܵ<EFBFBD><DCB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƣ<EFBFBD>һ<EFBFBD><D2BB>ֻ֧<D6BB>ְ<EFBFBD>˫<EFBFBD><CBAB>ͨ<EFBFBD>ŷ<EFBFBD>ʽ<EFBFBD><CABD><EFBFBD><EFBFBD>ֻ<EFBFBD>ܵ<EFBFBD><DCB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD>䣻<EFBFBD><E4A3BB><EFBFBD><EFBFBD>ֻ<EFBFBD><D6BB><EFBFBD>ڸ<EFBFBD><DAB8>ӽ<EFBFBD><D3BD><EFBFBD>֮<EFBFBD><D6AE>ʹ<EFBFBD>ã<EFBFBD>
2. <20><><EFBFBD>ܵ<EFBFBD><DCB5><EFBFBD>ȥ<EFBFBD><C8A5><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>ƣ<EFBFBD>֧<EFBFBD><D6A7>˫<EFBFBD><CBAB><EFBFBD><EFBFBD><EFBFBD>䣻
3. <20><><EFBFBD><EFBFBD><EFBFBD>ܵ<EFBFBD><DCB5><EFBFBD>ȥ<EFBFBD><C8A5><EFBFBD>ڶ<EFBFBD><DAB6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƣ<EFBFBD><C6A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڲ<EFBFBD><DAB2><EFBFBD><EFBFBD>ؽ<EFBFBD><D8BD><EFBFBD>֮<EFBFBD><D6AE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>š<EFBFBD>

### 2. <20>ź<EFBFBD><C5BA><EFBFBD>

<EFBFBD>ź<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̶Թ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD>ķ<EFBFBD><EFBFBD>ʡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƣ<EFBFBD><EFBFBD><EFBFBD>ֹij<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڷ<EFBFBD><EFBFBD>ʹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҳ<EFBFBD><EFBFBD><EFBFBD>ʸ<EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ˣ<EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD>̼<EFBFBD><EFBFBD>Լ<EFBFBD>ͬһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڲ<EFBFBD>ͬ<EFBFBD>߳<EFBFBD>֮<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD>ֶΡ<EFBFBD>

### 3. <20><>Ϣ<EFBFBD><CFA2><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD>Ϣ<EFBFBD><EFBFBD><EFBFBD>п˷<EFBFBD><EFBFBD><EFBFBD><EFBFBD>źŴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϣ<EFBFBD>١<EFBFBD><EFBFBD>ܵ<EFBFBD>ֻ<EFBFBD>ܳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>޸<EFBFBD>ʽ<EFBFBD>ֽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Լ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>С<EFBFBD><EFBFBD><EFBFBD>޵<EFBFBD>ȱ<EFBFBD>㡣

### 4. <20>ź<EFBFBD>

<EFBFBD>ź<EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD>ֱȽϸ<EFBFBD><EFBFBD>ӵ<EFBFBD>ͨ<EFBFBD>ŷ<EFBFBD>ʽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֪ͨ<EFBFBD><EFBFBD><EFBFBD>ս<EFBFBD><EFBFBD><EFBFBD>ij<EFBFBD><EFBFBD><EFBFBD>¼<EFBFBD><EFBFBD>Ѿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

### 5. <20><><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӳ<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>ܱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD><EFBFBD>ڴ棬<EFBFBD><EFBFBD><EFBFBD>ι<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̴<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̶<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Է<EFBFBD><EFBFBD>ʡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> IPC <20><>ʽ<EFBFBD><CABD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> IPC <20><><EFBFBD><EFBFBD>Ч<EFBFBD>ʵͶ<CAB5>ר<EFBFBD><D7A8><EFBFBD><EFBFBD><EFBFBD>Ƶġ<C6B5><C4A1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>Ż<EFBFBD><C5BB>ƣ<EFBFBD><C6A3><EFBFBD><EFBFBD>ź<EFBFBD><C5BA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>ã<EFBFBD><C3A3><EFBFBD>ʵ<EFBFBD>ֽ<EFBFBD><D6BD>̼<EFBFBD><CCBC><EFBFBD>ͬ<EFBFBD><CDAC><EFBFBD><EFBFBD>ͨ<EFBFBD>š<EFBFBD>

### 6. <20>׽<EFBFBD><D7BD><EFBFBD>

<EFBFBD>׽<EFBFBD><EFBFBD><EFBFBD>Ҳ<EFBFBD><EFBFBD>һ<EFBFBD>ֽ<EFBFBD><EFBFBD>̼<EFBFBD>ͨ<EFBFBD>Ż<EFBFBD><EFBFBD>ƣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>Ż<EFBFBD><EFBFBD>Ʋ<EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD>ǣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڲ<EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ľ<EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>š<EFBFBD>

## <20><><EFBFBD><EFBFBD>ͬ<EFBFBD><CDAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ߺ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ<EFBFBD><EFBFBD><EFBFBD>Ѿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>۹<EFBFBD><EFBFBD><EFBFBD>

### 1. <20><><EFBFBD><EFBFBD>-д<><D0B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݽ<EFBFBD><EFBFBD>ж<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Dz<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>д<EFBFBD>Լ<EFBFBD>д<EFBFBD><EFBFBD>д<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͱ<EFBFBD><EFBFBD><EFBFBD> count <20><>¼<EFBFBD>ڶ<EFBFBD><DAB6><EFBFBD><EFBFBD>ݽ<EFBFBD><DDBD>ж<EFBFBD><D0B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ľ<EFBFBD><C4BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> count_mutex <20><><EFBFBD>ڶ<EFBFBD> count <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> data_mutex <20><><EFBFBD>ڶԶ<DAB6>д<EFBFBD><D0B4><EFBFBD><EFBFBD><EFBFBD>ݼ<EFBFBD><DDBC><EFBFBD><EFBFBD><EFBFBD>

```c
typedef int semaphore;
semaphore count_mutex = 1;
semaphore data_mutex = 1;
int count = 0;

void reader() {
    while(TRUE) {
        down(count_mutex);
        count++;
        if(count == 1) down(data_mutex); // <20><>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD><EFBFBD>ݽ<EFBFBD><DDBD>м<EFBFBD><D0BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֹд<D6B9><D0B4><EFBFBD>̷<EFBFBD><CCB7><EFBFBD>
        up(count_mutex);
        read();
        down(count_mutex);
        count--;
        if(count == 0) up(data_mutex);
        up(count_mutex);
    }
}

void writer() {
    while(TRUE) {
        down(data_mutex);
        write();
        up(data_mutex);
    }
}
```

### 2. <20><>ѧ<EFBFBD>ҽ<EFBFBD><D2BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/a9077f06-7584-4f2b-8c20-3a8e46928820.jpg)

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѧ<EFBFBD><EFBFBD>Χ<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>Բ<EFBFBD>ܣ<EFBFBD>ÿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѧ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ<EFBFBD><EFBFBD><EFBFBD>ŷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѧ<EFBFBD>ҵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Է<EFBFBD><EFBFBD>Լ<EFBFBD>˼<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѧ<EFBFBD>ҳԷ<EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ߵĿ<EFBFBD><EFBFBD>ӡ<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD>ִ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ľⷨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ÿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѧ<EFBFBD><EFBFBD>ͬʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֱߵĿ<EFBFBD><EFBFBD>ӣ<EFBFBD><EFBFBD><EFBFBD>ô<EFBFBD><EFBFBD><EFBFBD>޷<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֱߵĿ<EFBFBD><EFBFBD>ӣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

```c
#define N 5
#define LEFT (i + N - 1) % N
#define RIGHT (i + N) % N
typedef int semaphore;
semaphore chopstick[N];

void philosopher(int i) {
    while(TURE){
        think();
        down(chopstick[LEFT[i]]);
        down(chopstick[RIGHT[i]]);
        eat();
        up(chopstick[RIGHT[i]]);
        up(chopstick[LEFT[i]]);
    }
}
```

Ϊ<EFBFBD>˷<EFBFBD>ֹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ķ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Լ<EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƣ<EFBFBD>ֻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ߵĿ<EFBFBD><EFBFBD>ӣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD><EFBFBD>Ƕδ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

```c
semaphore mutex = 1;

void philosopher(int i) {
    while(TURE){
        think();
        down(mutex);
        down(chopstick[LEFT[i]]);
        down(chopstick[RIGHT[i]]);
        up(mutex);
        eat();
        down(mutex);
        up(chopstick[RIGHT[i]]);
        up(chopstick[LEFT[i]]);
        up(mutex);
    }
}
```

# <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>

## <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/c037c901-7eae-4e31-a1e4-9d41329e5c3e.png)

1. <20><><EFBFBD><EFBFBD>
2. <20><><EFBFBD><EFBFBD><EFBFBD>뱣<EFBFBD><EBB1A3>
3. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ռ
4. <20><>·<EFBFBD>ȴ<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>뱣<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѻ<EFBFBD><EFBFBD>õ<EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD>ֲ<EFBFBD><EFBFBD>š<EFBFBD>

## <20><><EFBFBD><EFBFBD><EFBFBD>Ĵ<EFBFBD><C4B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

### 1. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>װ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>⡣

<EFBFBD><EFBFBD><EFBFBD>ֲ<EFBFBD><EFBFBD>Բ<EFBFBD><EFBFBD><EFBFBD>ȡ<EFBFBD><EFBFBD>

### 2. <20><><EFBFBD><EFBFBD>Ԥ<EFBFBD><D4A4>

<EFBFBD>ڳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮ǰԤ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

#### 2.1 <20>ƻ<EFBFBD><C6BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѻ<EFBFBD><EFBFBD><EFBFBD>ӡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɸ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ψһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӡ<EFBFBD><EFBFBD><EFBFBD>Ľ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ǵ<EFBFBD>ӡ<EFBFBD><EFBFBD><EFBFBD>ػ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>̡<EFBFBD>

#### 2.2 <20>ƻ<EFBFBD><C6BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>뱣<EFBFBD><EBB1A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

һ<EFBFBD><EFBFBD>ʵ<EFBFBD>ַ<EFBFBD>ʽ<EFBFBD>ǹ涨<EFBFBD><EFBFBD><EFBFBD>н<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڿ<EFBFBD>ʼִ<EFBFBD><EFBFBD>ǰ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD>ȫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD>

#### 2.3 <20>ƻ<EFBFBD><C6BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ռ<EFBFBD><D5BC><EFBFBD><EFBFBD>

#### 2.4 <20>ƻ<EFBFBD><C6BB><EFBFBD>·<EFBFBD>ȴ<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դͳһ<EFBFBD><EFBFBD><EFBFBD>ţ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֻ<EFBFBD>ܰ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>˳<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD>

### 3. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD>ڳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD>ⷢ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

#### 3.1 <20><>ȫ״̬

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/ed523051-608f-4c3f-b343-383e2d194470.png)

ͼ a <20>ĵڶ<C4B5><DAB6><EFBFBD> has <20><>ʾ<EFBFBD><CABE>ӵ<EFBFBD>е<EFBFBD><D0B5><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> max <20><>ʾ<EFBFBD>ܹ<EFBFBD><DCB9><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD>free <20><>ʾ<EFBFBD><CABE><EFBFBD>п<EFBFBD><D0BF><EFBFBD>ʹ<EFBFBD>õ<EFBFBD><C3B5><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͼ a <20><>ʼ<EFBFBD><CABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> B ӵ<><D3B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD><EFBFBD>н<EFBFBD><D0BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD> B<><42><EFBFBD><EFBFBD>ʱ free <20><>Ϊ 4<><34><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬ<EFBFBD><CDAC><EFBFBD>ķ<EFBFBD>ʽ<EFBFBD><CABD><EFBFBD><EFBFBD> C <20><> A<><41>ʹ<EFBFBD><CAB9><EFBFBD><EFBFBD><EFBFBD>н<EFBFBD><D0BD>̶<EFBFBD><CCB6>ܳɹ<DCB3><C9B9><EFBFBD><EFBFBD>У<EFBFBD><D0A3><EFBFBD><EFBFBD>˿<EFBFBD><CBBF>Գ<EFBFBD>ͼ a <20><>ʾ<EFBFBD><CABE>״̬ʱ<CCAC><CAB1>ȫ<EFBFBD>ġ<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD>壺<EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҽ<EFBFBD>ʹ<EFBFBD><EFBFBD><EFBFBD>н<EFBFBD><EFBFBD><EFBFBD>ͻȻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҳ<EFBFBD><EFBFBD>Ȼ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ij<EFBFBD>ֵ<EFBFBD><EFBFBD>ȴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܹ<EFBFBD>ʹ<EFBFBD><EFBFBD>ÿһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƹ<EFBFBD>״̬<EFBFBD>ǰ<EFBFBD>ȫ<EFBFBD>ġ<EFBFBD>

#### 3.2 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD><EFBFBD>м<EFBFBD><D0BC>㷨

һ<EFBFBD><EFBFBD>С<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>мң<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һȺ<EFBFBD>ͻ<EFBFBD><EFBFBD>ֱ<EFBFBD><EFBFBD><EFBFBD>ŵ<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>Ĵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȣ<EFBFBD><EFBFBD>㷨Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ж϶<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>벻<EFBFBD><EFBFBD>ȫ״̬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǣ<EFBFBD><EFBFBD>;ܾ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>󣻷<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Է<EFBFBD><EFBFBD>䡣

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/d160ec2e-cfe2-4640-bda7-62f53e58b8c0.png)

<EFBFBD><EFBFBD>ͼ c Ϊ<><CEAA><EFBFBD><EFBFBD>ȫ״̬<D7B4><CCAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㷨<EFBFBD><E3B7A8><EFBFBD>ܾ<EFBFBD>֮ǰ<D6AE><C7B0><EFBFBD><EFBFBD><EFBFBD>󣬴Ӷ<F3A3ACB4><D3B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͼ c <20>е<EFBFBD>״̬<D7B4><CCAC>

#### 3.3 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD><EFBFBD>м<EFBFBD><D0BC>㷨

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/62e0dd4f-44c3-43ee-bb6e-fedb9e068519.png)

<EFBFBD><EFBFBD>ͼ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̣<EFBFBD><EFBFBD>ĸ<EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ߵ<EFBFBD>ͼ<EFBFBD><EFBFBD>ʾ<EFBFBD>Ѿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD>ұߵ<EFBFBD>ͼ<EFBFBD><EFBFBD>ʾ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ұߵ<EFBFBD> E<><45>P <20>Լ<EFBFBD> A <20>ֱ<EFBFBD><D6B1><EFBFBD>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD>ѷ<EFBFBD><D1B7><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD>Լ<EFBFBD><D4BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4>ע<EFBFBD><D7A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ǿ<EFBFBD><C7BE><EFBFBD><EFBFBD><EFBFBD>ֵ<EFBFBD><D6B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD> A=(1020)<29><><EFBFBD><EFBFBD>ʾ 4 <20><><EFBFBD><EFBFBD>Դ<EFBFBD>ֱ<EFBFBD><D6B1><EFBFBD>ʣ<EFBFBD><CAA3> 1/0/2/0<><30>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>״̬<EFBFBD>Ƿ<EFBFBD><EFBFBD><EFBFBD>ȫ<EFBFBD><EFBFBD><EFBFBD>㷨<EFBFBD><EFBFBD><EFBFBD>£<EFBFBD>

- <20><><EFBFBD><EFBFBD><EFBFBD>ұߵľ<DFB5><C4BE><EFBFBD><EFBFBD>Ƿ<EFBFBD><C7B7><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB>С<EFBFBD>ڵ<EFBFBD><DAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> A<><41><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><D0A3><EFBFBD>ôϵͳ<CFB5><CDB3><EFBFBD>ᷢ<EFBFBD><E1B7A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>״̬<D7B4>Dz<EFBFBD><C7B2><EFBFBD>ȫ<EFBFBD>ġ<EFBFBD>
- <20><><EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD><D2B5><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD>У<EFBFBD><D0A3><EFBFBD><EFBFBD>ý<EFBFBD><C3BD>̱<EFBFBD><CCB1><EFBFBD>Ϊ<EFBFBD><CEAA>ֹ<EFBFBD><D6B9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѷ<EFBFBD><D1B7><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD>ӵ<EFBFBD> A <20>С<EFBFBD>
- <20>ظ<EFBFBD><D8B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֱ<EFBFBD><D6B1><EFBFBD><EFBFBD><EFBFBD>н<EFBFBD><D0BD>̶<EFBFBD><CCB6><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA>ֹ<EFBFBD><D6B9><EFBFBD><EFBFBD>״̬ʱ<CCAC><CAB1>ȫ<EFBFBD>ġ<EFBFBD>

### 4. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͼ<EFBFBD><EFBFBD>ֹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>⵽<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȡ<EFBFBD><EFBFBD>ʩ<EFBFBD><EFBFBD><EFBFBD>лָ<EFBFBD><EFBFBD><EFBFBD>

#### 4.1 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㷨

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ļ<EFBFBD><EFBFBD><EFBFBD>˼<EFBFBD><EFBFBD><EFBFBD>ǣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD>ܹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㣬<EFBFBD><EFBFBD>ô<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD>У<EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD>е<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD>Ȼ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ľ<EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD>С<EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/e1eda3d5-5ec8-4708-8e25-1a04c5e11f48.png)

<EFBFBD><EFBFBD>ͼ<EFBFBD>У<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĸ<EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><EFBFBD>ÿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĺ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>£<EFBFBD>

- E <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD>
- A <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դʣ<D4B4><CAA3><EFBFBD><EFBFBD>
- C <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ÿ<EFBFBD><C3BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD>е<EFBFBD><D0B5><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ÿһ<C3BF>ж<EFBFBD><D0B6><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD><D3B5><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
- R <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ÿ<EFBFBD><C3BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD> P<sub>1</sub> <20><> P<sub>2</sub> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD>ò<EFBFBD><C3B2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㣬ֻ<E3A3AC>н<EFBFBD><D0BD><EFBFBD> P<sub>3</sub> <20><><EFBFBD>ԣ<EFBFBD><D4A3><EFBFBD> P<sub>3</sub> ִ<>У<EFBFBD>֮<EFBFBD><D6AE><EFBFBD>ͷ<EFBFBD> P<sub>3</sub> ӵ<>е<EFBFBD><D0B5><EFBFBD>Դ<EFBFBD><D4B4><EFBFBD><EFBFBD>ʱ A = (2 2 2 0)<29><>P<sub>1</sub> <20><><EFBFBD><EFBFBD>ִ<EFBFBD>У<EFBFBD>ִ<EFBFBD>к<EFBFBD><D0BA>ͷ<EFBFBD> P<sub>1</sub> ӵ<>е<EFBFBD><D0B5><EFBFBD>Դ<EFBFBD><D4B4>A = (4 2 2 2) <20><>P<sub>2</sub> Ҳ<><D2B2><EFBFBD><EFBFBD>ִ<EFBFBD>С<EFBFBD><D0A1><EFBFBD><EFBFBD>н<EFBFBD><D0BD>̶<EFBFBD><CCB6><EFBFBD><EFBFBD><EFBFBD>˳<EFBFBD><CBB3>ִ<EFBFBD>У<EFBFBD>û<EFBFBD><C3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

<EFBFBD>㷨<EFBFBD>ܽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>£<EFBFBD>

ÿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʼʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǣ<EFBFBD>ִ<EFBFBD>й<EFBFBD><EFBFBD><EFBFBD><EFBFBD>п<EFBFBD><EFBFBD>ܱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>㷨<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD>κ<EFBFBD>û<EFBFBD>б<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǵĽ<EFBFBD><EFBFBD>̶<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̡<EFBFBD>

1. Ѱ<><D1B0>һ<EFBFBD><D2BB>û<EFBFBD>б<EFBFBD><D0B1>ǵĽ<C7B5><C4BD><EFBFBD> P<sub>i</sub><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ԴС<EFBFBD>ڵ<EFBFBD><EFBFBD><EFBFBD> A<><41>
2. <20><><EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD><D2B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>̣<EFBFBD><CCA3><EFBFBD>ô<EFBFBD><C3B4> C <20><><EFBFBD><EFBFBD><EFBFBD>ĵ<EFBFBD> i <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD> A <20>У<EFBFBD><D0A3><EFBFBD><EFBFBD>Ǹý<C7B8><C3BD>̣<EFBFBD><CCA3><EFBFBD>ת<EFBFBD><D7AA> 1<><31>
3. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><C3BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>̣<EFBFBD><CCA3>㷨<EFBFBD><E3B7A8>ֹ<EFBFBD><D6B9>

#### 4.2 <20><><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD>

- <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ռ<EFBFBD>ָ<EFBFBD>
- ɱ<><C9B1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

# <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>洢<EFBFBD><E6B4A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

## <20><><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD>

ÿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӵ<EFBFBD><EFBFBD><EFBFBD>Լ<EFBFBD><EFBFBD>ĵ<EFBFBD>ַ<EFBFBD>ռ䣬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ַ<EFBFBD>ռ䱻<EFBFBD>ָ<EFBFBD><EFBFBD>ɶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>飬ÿһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊһҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Щҳ<EFBFBD><EFBFBD>ӳ<EFBFBD>䵽<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ棬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫӳ<EFBFBD>䵽<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ棬Ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><EFBFBD>С<EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>õ<EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><EFBFBD>еĵ<EFBFBD>ַ<EFBFBD>ռ<EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӳ<EFBFBD><EFBFBD>ִ<EFBFBD>б<EFBFBD>Ҫ<EFBFBD><EFBFBD>ӳ<EFBFBD>䣬<EFBFBD><EFBFBD>ȱʧ<EFBFBD>IJ<EFBFBD><EFBFBD><EFBFBD>װ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ沢<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ִ<EFBFBD><EFBFBD>ʧ<EFBFBD>ܵ<EFBFBD>ָ<EFBFBD>

## <20><>ҳ<EFBFBD><D2B3><EFBFBD>ֶ<EFBFBD>

### 1. <20><>ҳ

<EFBFBD>û<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĵ<EFBFBD>ַ<EFBFBD>ռ䱻<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD>ɹ̶<EFBFBD><EFBFBD><EFBFBD>С<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>򣬳<EFBFBD>Ϊ<EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӧ<EFBFBD>أ<EFBFBD><EFBFBD>ڴ<EFBFBD><EFBFBD>ռ<EFBFBD><EFBFBD>ֳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɸ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>飬ҳ<EFBFBD>Ϳ<EFBFBD><EFBFBD>Ĵ<EFBFBD>С<EFBFBD><EFBFBD><EFBFBD>ȡ<EFBFBD><EFBFBD>ɽ<EFBFBD><EFBFBD>û<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>У<EFBFBD>ʵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ɢ<EFBFBD><EFBFBD><EFBFBD>䣬<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ά<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֮<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD><EFBFBD>

### 2. <20>ֶ<EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/22de0538-7c6e-4365-bd3b-8ce3c5900216.png)

<EFBFBD><EFBFBD>ͼΪһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>н<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ķ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> 4 <20><><EFBFBD><EFBFBD><EFBFBD>Ƕ<EFBFBD>̬<EFBFBD><CCAC><EFBFBD><EFBFBD><EFBFBD>ģ<EFBFBD><C4A3><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD>÷<EFBFBD>ҳϵͳ<CFB5><CDB3>һά<D2BB><CEAC>ַ<EFBFBD>ռ䣬<D5BC><E4A3AC>̬<EFBFBD><CCAC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ص<EFBFBD><D8B5>ᵼ<EFBFBD>¸<EFBFBD><C2B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ij<EFBFBD><C4B3>֡<EFBFBD>

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/e0900bb2-220a-43b7-9aa9-1d5cd55ff56e.png)

<EFBFBD>ֶε<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ<EFBFBD>ÿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֳɶΣ<EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD>ι<EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĵ<EFBFBD>ַ<EFBFBD>ռ䡣ÿ<EFBFBD><EFBFBD><EFBFBD>εij<EFBFBD><EFBFBD>ȿ<EFBFBD><EFBFBD>Բ<EFBFBD>ͬ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҿ<EFBFBD><EFBFBD>Զ<EFBFBD>̬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

ÿ<EFBFBD><EFBFBD><EFBFBD>ζ<EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ա<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>֡<EFBFBD>

### 3. <20><>ҳʽ

<EFBFBD>÷ֶη<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>͹<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>洢<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĵ<EFBFBD>ַ<EFBFBD>ռ䰴<EFBFBD>߼<EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD>ֳɻ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ĶΣ<EFBFBD><EFBFBD><EFBFBD>ÿһ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Լ<EFBFBD><EFBFBD>Ķ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ٰ<EFBFBD>ÿ<EFBFBD>ηֳɹ̶<EFBFBD><EFBFBD><EFBFBD>С<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD>

<EFBFBD>÷<EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>͹<EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD>档<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD>С<EFBFBD><EFBFBD><EFBFBD>ȵĴ洢<EFBFBD>飬<EFBFBD><EFBFBD>װ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҵ<EFBFBD><EFBFBD><EFBFBD>κ<EFBFBD>һҳ<EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><EFBFBD>ĵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǰ<EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD>еģ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֿɰ<EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD>ֹ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>

### 4. <20><>ҳ<EFBFBD><D2B3><EFBFBD>ֶ<EFBFBD><D6B6><EFBFBD><EFBFBD><EFBFBD>

- <20>Գ<EFBFBD><D4B3><EFBFBD>Ա<EFBFBD><D4B1>͸<EFBFBD><CDB8><EFBFBD>ԣ<EFBFBD><D4A3><EFBFBD>ҳ͸<D2B3><CDB8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƿֶ<C7B7><D6B6><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD>Ա<EFBFBD><D4B1>ʾ<EFBFBD><CABE><EFBFBD><EFBFBD>ÿ<EFBFBD><C3BF><EFBFBD>Ρ<EFBFBD>

- <20><>ַ<EFBFBD>ռ<EFBFBD><D5BC><EFBFBD>ά<EFBFBD>ȣ<EFBFBD><C8A3><EFBFBD>ҳ<EFBFBD><D2B3>һά<D2BB><CEAC>ַ<EFBFBD>ռ䣬<D5BC>ֶ<EFBFBD><D6B6>Ƕ<EFBFBD>ά<EFBFBD>ġ<EFBFBD>

- <20><>С<EFBFBD>Ƿ<EFBFBD><C7B7><EFBFBD><EFBFBD>Ըı䣺ҳ<E4A3BA>Ĵ<EFBFBD>С<EFBFBD><D0A1><EFBFBD>ɱ䣬<C9B1>εĴ<CEB5>С<EFBFBD><D0A1><EFBFBD>Զ<EFBFBD>̬<EFBFBD>ı䡣

- <20><><EFBFBD>ֵ<EFBFBD>ԭ<EFBFBD>򣺷<EFBFBD>ҳ<EFBFBD><D2B3>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD>ʵ<EFBFBD><CAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ棬<DAB4>Ӷ<EFBFBD><D3B6><EFBFBD><EFBFBD>ø<EFBFBD><C3B8><EFBFBD><EFBFBD>ĵ<EFBFBD>ַ<EFBFBD>ռ䣻<D5BC>ֶ<EFBFBD><D6B6><EFBFBD>Ҫ<EFBFBD><D2AA>Ϊ<EFBFBD><CEAA>ʹ<EFBFBD><CAB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ݿ<EFBFBD><DDBF>Ա<EFBFBD><D4B1><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD>߼<EFBFBD><DFBC>϶<EFBFBD><CFB6><EFBFBD><EFBFBD>ĵ<EFBFBD>ַ<EFBFBD>ռ䲢<D5BC><E4B2A2><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڹ<EFBFBD><DAB9><EFBFBD><EFBFBD>ͱ<EFBFBD><CDB1><EFBFBD><EFBFBD><EFBFBD>

## ҳ<><D2B3><EFBFBD>û<EFBFBD><C3BB>㷨

<EFBFBD>ڳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>й<EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD>ҳ<EFBFBD>治<EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ棬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>޿<EFBFBD><EFBFBD>пռ<EFBFBD>ʱ<EFBFBD><EFBFBD>ϵͳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><EFBFBD>е<EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>ҳ<EFBFBD>浽<EFBFBD><EFBFBD><EFBFBD>̶Ի<EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><EFBFBD>С<EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD>û<EFBFBD><EFBFBD>㷨<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҪĿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹҳ<EFBFBD><EFBFBD><EFBFBD>û<EFBFBD>Ƶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͣ<EFBFBD>Ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>˵ȱҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͣ<EFBFBD><EFBFBD><EFBFBD>

### 1. <20><><EFBFBD>ѣ<EFBFBD>Optimal<61><6C>

<EFBFBD><EFBFBD>ѡ<EFBFBD><EFBFBD><EFBFBD>ı<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҳ<EFBFBD>潫<EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD>ڲ<EFBFBD><EFBFBD>ٱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʣ<EFBFBD>ͨ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ա<EFBFBD>֤<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>͵<EFBFBD>ȱҳ<EFBFBD>ʡ<EFBFBD>

<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵ<EFBFBD><EFBFBD>㷨<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD>޷<EFBFBD>֪<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD>೤ʱ<EFBFBD><EFBFBD><EFBFBD>ᱻ<EFBFBD>ٷ<EFBFBD><EFBFBD>ʵ<EFBFBD><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>ϵͳΪij<EFBFBD><EFBFBD><EFBFBD>̷<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>飬<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD>

7<EFBFBD><EFBFBD>0<EFBFBD><EFBFBD>1<EFBFBD><EFBFBD>2<EFBFBD><EFBFBD>0<EFBFBD><EFBFBD>3<EFBFBD><EFBFBD>0<EFBFBD><EFBFBD>4<EFBFBD><EFBFBD>2<EFBFBD><EFBFBD>3<EFBFBD><EFBFBD>0<EFBFBD><EFBFBD>3<EFBFBD><EFBFBD>2<EFBFBD><EFBFBD>1<EFBFBD><EFBFBD>2<EFBFBD><EFBFBD>0<EFBFBD><EFBFBD>1<EFBFBD><EFBFBD>7<EFBFBD><EFBFBD>0<EFBFBD><EFBFBD>1

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD>Ƚ<EFBFBD> 7,0,1 <20><><EFBFBD><EFBFBD>ҳ<EFBFBD><D2B3>װ<EFBFBD><D7B0><EFBFBD>ڴ档<DAB4><E6A1A3><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD>ҳ<EFBFBD><D2B3> 2 ʱ<><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȱҳ<C8B1>жϣ<D0B6><CFA3>Ὣҳ<E1BDAB><D2B3> 7 <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊҳ<CEAA><D2B3> 7 <20>ٴα<D9B4><CEB1><EFBFBD><EFBFBD>ʵ<EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EEB3A4>

### 2. <20>Ƚ<EFBFBD><C8BD>ȳ<EFBFBD><C8B3><EFBFBD>FIFO<46><4F>

<EFBFBD><EFBFBD>ѡ<EFBFBD>񻻳<EFBFBD><EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƚ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҳ<EFBFBD>档

<EFBFBD><EFBFBD><EFBFBD>㷨<EFBFBD>Ὣ<EFBFBD><EFBFBD>Щ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD>ҳ<EFBFBD><EFBFBD>Ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӷ<EFBFBD>ʹȱҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ߡ<EFBFBD>

### 3. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>δʹ<CEB4>ã<EFBFBD>LRU, Least Recently Used<65><64>

<EFBFBD><EFBFBD>Ȼ<EFBFBD>޷<EFBFBD>֪<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫʹ<EFBFBD>õ<EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǿ<EFBFBD><EFBFBD><EFBFBD>֪<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȥʹ<EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>LRU <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>δʹ<CEB4>õ<EFBFBD>ҳ<EFBFBD>滻<EFBFBD><E6BBBB><EFBFBD><EFBFBD>

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ջ<EFBFBD><EFBFBD>ʵ<EFBFBD>ָ<EFBFBD><EFBFBD>㷨<EFBFBD><EFBFBD>ջ<EFBFBD>д洢ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD>š<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̷<EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD>Ŵ<EFBFBD>ջ<EFBFBD>Ƴ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ѹ<EFBFBD><EFBFBD>ջ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵ<EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ջ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>δʹ<EFBFBD>õ<EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ջ<EFBFBD>ס<EFBFBD>

4<EFBFBD><EFBFBD>7<EFBFBD><EFBFBD>0<EFBFBD><EFBFBD>7<EFBFBD><EFBFBD>1<EFBFBD><EFBFBD>0<EFBFBD><EFBFBD>1<EFBFBD><EFBFBD>2<EFBFBD><EFBFBD>1<EFBFBD><EFBFBD>2<EFBFBD><EFBFBD>6

![](https://github.com/CyC2018/InterviewNotes/blob/master/pics/eb859228-c0f2-4bce-910d-d9f76929352b.png)

### 4. ʱ<>ӣ<EFBFBD>Clock<63><6B>

Clock ҳ<><D2B3><EFBFBD>û<EFBFBD><C3BB>㷨<EFBFBD><E3B7A8>Ҫ<EFBFBD>õ<EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><CEBB><EFBFBD><EFBFBD>һ<EFBFBD><D2BB>ҳ<EFBFBD>汻<EFBFBD><E6B1BB><EFBFBD><EFBFBD>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><CEAA>Ϊ 1<><31>

<EFBFBD><EFBFBD><EFBFBD>ȣ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڴ<EFBFBD><EFBFBD>е<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӳ<EFBFBD>һ<EFBFBD><EFBFBD>ѭ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><EFBFBD><EFBFBD>ȱҳ<EFBFBD>жϷ<EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>鵱ǰָ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ָ<EFBFBD><EFBFBD>ҳ<EFBFBD><EFBFBD><EFBFBD>ķ<EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>λΪ 0<><30><EFBFBD>ͽ<EFBFBD><CDBD><EFBFBD>ҳ<EFBFBD>滻<EFBFBD><E6BBBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>򽫸<EFBFBD>ҳ<EFBFBD>ķ<EFBFBD><C4B7><EFBFBD>λ<EFBFBD><CEBB><EFBFBD><EFBFBD>Ϊ 0<><30><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ҳ<EFBFBD><D2B3><EFBFBD>ڶ<EFBFBD><DAB6>εĻ<CEB5><C4BB>ᣬ<EFBFBD>ƶ<EFBFBD>ָ<EFBFBD><D6B8><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>顣

# <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20>豸<EFBFBD><E8B1B8><EFBFBD><EFBFBD>

## <20><><EFBFBD>̵<EFBFBD><CCB5><EFBFBD><EFBFBD>㷨

<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͬʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʴ<EFBFBD><EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><EFBFBD><EFBFBD>д<EFBFBD><EFBFBD>̵<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƶԴ<EFBFBD><EFBFBD>̵ķ<EFBFBD><EFBFBD>ʡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>̵<EFBFBD><EFBFBD>ȵ<EFBFBD><EFBFBD><EFBFBD>ҪĿ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʹ<EFBFBD><EFBFBD><EFBFBD>̵<EFBFBD>ƽ<EFBFBD><EFBFBD>Ѱ<EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>١<EFBFBD>

### 1. <20><><EFBFBD><EFBFBD><EFBFBD>ȷ<EFBFBD><C8B7><EFBFBD><EFBFBD><EFBFBD>FCFS, First Come First Serverd<72><64>

<EFBFBD><EFBFBD><EFBFBD>ݽ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʴ<EFBFBD><EFBFBD>̵<EFBFBD><EFBFBD>Ⱥ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD><EFBFBD>ȡ<EFBFBD><EFBFBD>ŵ<EFBFBD><EFBFBD>ǹ<EFBFBD>ƽ<EFBFBD>ͼ򵥣<EFBFBD>ȱ<EFBFBD><EFBFBD>Ҳ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ԣ<EFBFBD><EFBFBD><EFBFBD>Ϊδ<EFBFBD><EFBFBD>Ѱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>κ<EFBFBD><EFBFBD>Ż<EFBFBD><EFBFBD><EFBFBD>ʹƽ<EFBFBD><EFBFBD>Ѱ<EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܽϳ<EFBFBD><EFBFBD><EFBFBD>

### 2. <20><><EFBFBD><EFBFBD>Ѱ<EFBFBD><D1B0>ʱ<EFBFBD><CAB1><EFBFBD><EFBFBD><EFBFBD>ȣ<EFBFBD>SSTF, Shortest Seek Time First<73><74>

Ҫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵĴŵ<EFBFBD><EFBFBD>뵱ǰ<EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD><EFBFBD>ڴŵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ƚ<EFBFBD><EFBFBD>е<EFBFBD><EFBFBD>ȡ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>㷨<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ܱ<EFBFBD>֤ƽ<EFBFBD><EFBFBD>Ѱ<EFBFBD><EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>̣<EFBFBD><EFBFBD><EFBFBD><EFBFBD>DZ<EFBFBD> FCFS <20>úܶࡣ

### 3. ɨ<><C9A8><EFBFBD>㷨<EFBFBD><E3B7A8>SCAN<41><4E>

SSTF <20><><EFBFBD><EFBFBD><EFBFBD>ֽ<EFBFBD><D6BD>м<EFBFBD><D0BC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>󡣿<EFBFBD><F3A1A3BF><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>½<EFBFBD><C2BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵĴŵ<C4B4><C5B5><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><CDB7><EFBFBD>ڴŵ<DAB4><C5B5>ľ<EFBFBD><C4BE><EFBFBD><EFBFBD><EFBFBD><EFBFBD>DZ<EFBFBD>һ<EFBFBD><D2BB><EFBFBD>ڵȴ<DAB5><C8B4>Ľ<EFBFBD><C4BD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ľ<EFBFBD><C4BD><EFBFBD><EFBFBD><EFBFBD>ô<EFBFBD>ȴ<EFBFBD><C8B4>Ľ<EFBFBD><C4BD>̻<EFBFBD>һֱ<D2BB>ȴ<EFBFBD><C8B4><EFBFBD>ȥ<EFBFBD><C8A5>

SCAN <20>㷨<EFBFBD><E3B7A8> SSTF <20>㷨֮<E3B7A8>Ͽ<EFBFBD><CFBF><EFBFBD><EFBFBD>˴<EFBFBD>ͷ<EFBFBD><CDB7><EFBFBD>ƶ<EFBFBD><C6B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵĴŵ<C4B4><C5B5>ڴ<EFBFBD>ͷ<EFBFBD><CDB7>ǰ<EFBFBD>ƶ<EFBFBD><C6B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϲ<EFBFBD><CFB2>ܹ<EFBFBD><DCB9>õ<EFBFBD><C3B5><EFBFBD><EFBFBD>ȡ<EFBFBD><C8A1><EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƶ<EFBFBD><C6B6><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ôһ<C3B4><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʵĴŵ<C4B4>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD>õ<EFBFBD><C3B5><EFBFBD><EFBFBD>ȡ<EFBFBD>

<EFBFBD><EFBFBD>һ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>ͷ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƶ<EFBFBD>ʱ<EFBFBD><EFBFBD><EFBFBD>Ƶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ı<EFBFBD><EFBFBD>ƶ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƶ<EFBFBD><EFBFBD>Ĺ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ڵ<EFBFBD><EFBFBD>ݵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>У<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ֳ<EFBFBD><EFBFBD><EFBFBD> SCAN <20>㷨Ϊ<E3B7A8><CEAA><EFBFBD>ݵ<EFBFBD><DDB5><EFBFBD><EFBFBD>㷨<EFBFBD><E3B7A8>

### 4. ѭ<><D1AD>ɨ<EFBFBD><C9A8><EFBFBD>㷨<EFBFBD><E3B7A8>CSCAN<41><4E>

CSCAN <20><> SCAN <20><><EFBFBD><EFBFBD><EFBFBD>˸Ķ<CBB8><C4B6><EFBFBD>Ҫ<EFBFBD><D2AA><EFBFBD><EFBFBD>ͷʼ<CDB7><CABC><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ƶ<EFBFBD><C6B6><EFBFBD>

# <20>ο<EFBFBD><CEBF><EFBFBD><EFBFBD><EFBFBD>

- Tanenbaum A S, Bos H. Modern operating systems[M]. Prentice Hall Press, 2014.
- <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>, <20>ܷ<EFBFBD><DCB7><EFBFBD>, <20><>С<EFBFBD><D0A1>. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ[M]. <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ӿƼ<D3BF><C6BC><EFBFBD>ѧ<EFBFBD><D1A7><EFBFBD><EFBFBD><EFBFBD><EFBFBD>, 2001.
- Bryant, R. E., & O<><4F>Hallaron, D. R. (2004). <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϵͳ.
- [<EFBFBD><EFBFBD><EFBFBD>̼<EFBFBD><EFBFBD>ļ<EFBFBD><EFBFBD><EFBFBD>ͨ<EFBFBD>ŷ<EFBFBD>ʽ](http://blog.csdn.net/yufaw/article/details/7409596)