W4D2 & W8D2 &W12D2 : Guo Yijin

GuoYijin/GuoYijin-W12.md

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+# Distributed Shared Memory
+
+-Q: addressing (寻址问题)
+
+-Case: DHT (哈希查找)
+
+### Addressing
+
+#### Message
+
+- Packet
+
+- Document
+
+  Linda (Tuple)
+
+  JINI (Java Space) - 基于内容的寻址
+
+- “file”(page)
+
+#### SHM
+
+- “file”(page)
+- Directory (Translation)
+
+<img src="DHT.png" />

GuoYijin/GuoYijin-W4.md

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+3/9
+
+# Memory Management
+
+**Contents**
+
+- swap
+- Overlay replacement
+
+**Implementation**
+
+- Phy Mem Mgnt
+
+  - Buddy System (Unix)
+  - address_space (Linux)
+
+- Virtual Mem Mgnt
+
+  - vm_area_struct (Process)
+
+  - vm_struct
+
+
+
+过一遍ppt
+
+<img src="no_memory_abstraction" style="zoom:50%;" />
+
+
+
+#### Swap
+
+物理内存无法同时容纳多个程序的运行
+
+swap in, swap out
+
+#### Overlay
+
+程序员自发进行的事
+
+<img src="overlay.png" style="zoom:33%;" />
+
+#### Replacement
+
+**page replacement algorithm**
+
+Optimal algorithm（最优算法；知道未来；只是理想概念）
+
+Not recently used algorithm （两个无序集合）
+
+First-in, first-out (FIFO) algorithn
+
+Second-chance algorithm
+
+Clock algorithm （Corbato@MIT）
+
+Least recently used (LRU) algorithm (有序队列)
+
+Working set algorithm
+
+WSClock algorithm
+
+
+
+<img src="NRU" style="zoom:50%;" >
+
+<img src="second_chance" style="zoom:50%;" >
+
+<img src="clock" style="zoom: 33%;" >
+
+<img src="LRU" style="zoom: 33%;" >

GuoYijin/GuoYijin-W8.md

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+4/6
+
+# Security
+
+<img src="BOA" style="zoom: 33%;" >
+
+canary-
+
+return to libc
+
+<img src="stack_canaries" style="zoom: 50%;" >
+
+<img src="code_reuse_attacks" style="zoom: 25%;" >
+
+<img src="format_string_attacks" style="zoom: 25%;" >
+
+<img src="cmd_injec_attacks" style="zoom: 25%;" >