第 3 章 分布式系统的同步
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第 3 章 分布式系统的同步. 中国科技大学软件学院 丁箐. 主要内容. 3.1 时钟同步 3.2 互斥 3.3 选举算法 3.4 原子性事务 3.5 分布式系统中的死锁. 主要内容. 3.1 时 钟 同步 3.2 互斥 3.3 选举算法 3.4 原子性事务 3.5 分布式系统中的死锁. 3.1 时钟同步. 分布式算法的特点 相关 信息散布 在多个场地上 每个进程只能基于 本地信息 做决定 应避免因 单点故障 造成整个系统的失败 不存在公共时钟或精确的 全局时间. 时钟同步问题. output.o ： - PowerPoint PPT Presentation
Transcript of 第 3 章 分布式系统的同步
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3
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3.1 3.2 3.3 3.4 3.5
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3.1 3.2 3.3 3.4 3.5
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3.1
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makefile
output.o cc C output.c
Connect
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+clock skew: ababambmabab, bc,acconcurrent
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3.2 Critical Section
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CCC
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Win Thread CreateMutex()WaitForSingleObject()ReleaseMutex()
InitializeCriticalSection()EnterCriticalSection()LeaveCriticalSection()
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Ricart-Agrawala1. PR 2. PPRRPOKPRPPRPPOK;P3. POKR4. PROK
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3.1 3.2 3.3 3.4 3.5
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PEPQ,PQ456564656
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3.1 3.2 3.3 3.4 3.5
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3.4 Atomic 1
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Stable Storage
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1BEGIN_TRA NSACTION2END_TRANSACTION3ABORT_TRANSACTION4READ5WRITE
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BEGIN TRANSACTION reserve WPJFK reserve JFKNairobi reserve NairobiMalindi END TRANSACTION BEGIN TRANSACTION
reserve WPJFK reserve JFKNairobi NairobiMalindi full
ABORT TRASACTION JFKNairobi
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BEGIN_TRANSACTIONx = 0; x = x+1;END_TRANSACTION
BEGIN_TRANSACTIONx = 0; x = x+2;END_TRANSACTION
BEGIN_TRANSACTIONx = 0; x = x+3;END_TRANSACTION
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x=0; x=0; x=x+1; x=0; x=x+2; x=x+3;
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two-phase commit protocol
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- -(wait-die)0t0, 1t1t0
- -wound-wait)0t0,1t1t0
