add Progress Notes class-9

Progress/class-9/CS61-class-9.tex

@@ -0,0 +1,175 @@
+\documentclass[a4paper, 11pt]{article}
+
+%%%%%% use packages %%%%%%
+\usepackage{CJKutf8}
+\usepackage{graphicx}
+\usepackage[unicode]{hyperref}
+\usepackage{indentfirst}
+\usepackage{latexsym}
+\usepackage{amsmath}
+\usepackage{flafter}
+\usepackage{enumerate}
+\usepackage{leftidx}
+
+%%%%%% indent settings %%%%%%
+\setlength{\parindent}{20pt}
+\setlength{\parskip}{1ex plus 0.5ex minus 0.25ex}
+\setlength{\baselineskip}{1.0ex}
+\renewcommand{\baselinestretch}{1.5}
+
+\begin{CJK}{UTF8}{gbsn}
+
+
+\title{CS61第九次课程记录}
+\author{傅海平\\
+\textsc{Institute Of Computing Technology,}\\
+\textsc{Chinese Academy Of Sciences}\\
+[email protected]\\
+}
+\date{\today}
+\begin{document}
+\maketitle
+\newpage
+\tableofcontents
+\newpage
+\section{Topics}
+\begin{center}
+  \Large{线程}
+\end{center}
+
+\section{progress}
+晚上7:30点开始，7:30 - 10:00 学习 lec17-threads.pdf 课程讲义，然后10:00开始讨论学习过程中遇到的问题。
+\section{learning details}
+\subsection{course sketch}
+\subsubsection{Threads: Allowing a single program to do
+multiple things concurrently.}
+\begin{itemize}
+  \item{并行编程}
+	\begin{itemize}
+	  \item{许多程序都需要并行执行：}
+	  \item{浏览器}
+	  \item{服务器}
+	  \item{科学计算}
+	  \end{itemize}
+	\item{利用进程可以达到程序的并行执行}
+	\item{但是，进程不太高效}
+	  \begin{itemize}
+		\item{每个进程有自己的也表，文件表，sockets\dots}
+		\item{所以进程切换时代价较大，1.7KB的 $task\_struct$.}
+		\item{进程的创建代价大。}
+		\end{itemize}
+	  \item{进程并不直接共享内存}
+		\begin{itemize}
+		  \item{并行程序需要对相同的内存区域进行操作。}
+		  \item{许多 OS 提供了进程间通信的手段，如共享内存，$shmget(),
+			shmat()$}
+		  \end{itemize}
+		\item{更好的办法}
+		  \begin{itemize}
+			\item{任务间共享了什么？}
+			  \begin{itemize}
+				\item{相同的代码}
+				\item{相同的数据}
+				\item{优先级}
+				\item{某些系统资源：文件，sockets\dots}
+				\end{itemize}
+			\item{每个任务间哪些东西是私有的？}
+			  \begin{itemize}
+				\item{执行状态：CPU 寄存器，栈，和程序计数器PC}
+				\end{itemize}
+			  \item{线程}
+			\end{itemize}
+		  \item{线程和进程}
+			\begin{itemize}
+			  \item{线程与进程的相同点和区别}
+			  \item{每个线程有自己的栈，栈指针，PC，和一些 CPU 寄存器,但共享相同
+				的地址空间和系统资源，由于线程共享内存，所以方便线程间通信}
+			  \end{itemize}
+\end{itemize}
+\begin{figure}[htbp]
+  \centering
+  \includegraphics[width=10cm, keepaspectratio]{thread-va.png}
+  \par\vspace{0pt}
+  \rule{10cm}{0.1ex}
+  \par{图1: 引入线程后，程序的进程空间}
+\end{figure}
+\subsubsection{Implementing}
+\begin{itemize}
+  \item{线程控制块TCB vs. 进程控制块PCB}
+  \item{每个线程控制块内部都有指针指向相关的进程控制块。}
+  \item{TCB包含了与线程相关的信息，处理器状态和指向PCB的指针}
+  \item{PCB 包含了进程的相关信息，如地址空间，系统资源，但是没有处理器状态}
+  \item{Linux：TCB(thread\_struct), PCB(task\_struct)}
+  \item{用户空间的线程实现}
+	\begin{itemize}
+	  \item{setcontext, getcontext, makecontext, swapcontext}
+	  \item{int setcontext(const ucontext\_t *ucp) }
+		\begin{itemize}
+		  \item{This function transfers control to the context in ucp. Execution
+			continues from the point at which the context was stored in ucp.
+			setcontext does not return.}
+		  \end{itemize}
+
+		\item{int getcontext(ucontext\_t *ucp) }
+		\begin{itemize}
+		  \item{Saves current context into ucp. This function returns in two
+			possible cases: after the initial call, or when a thread switches to
+			the context in ucp via setcontext or swapcontext. The getcontext
+			function does not provide a return value to distinguish the cases
+			(its return value is used solely to signal error), so the programmer
+			must use an explicit flag variable, which must not be a register
+			variable and must be declared volatile to avoid constant propagation
+			or other compiler optimisations.}	
+		  \end{itemize}
+
+		\item{void makecontext(ucontext\_t *ucp, void *func(), int argc, \dots)}
+		\begin{itemize}
+		  \item{The makecontext function sets up an alternate thread of control
+			in ucp, which has previously been initialised using getcontext. The
+			ucp.uc\_stack member should be pointed to an appropriately sized
+			stack; the constant SIGSTKSZ is commonly used. When ucp is jumped to
+			using setcontext or swapcontext, execution will begin at the entry
+			point to the function pointed to by func, with argc arguments as
+			specified. When func terminates, control is returned to ucp.uc\_link.}
+		  \end{itemize}
+
+		\item{int swapcontext(ucontext\_t *oucp, ucontext\_t *ucp) }
+		\begin{itemize}
+		  \item{Transfers control to ucp and saves the current execution state
+			into oucp. }
+		  \end{itemize}
+
+	  \end{itemize}
+  \end{itemize}
+\subsubsection{Scheduling}
+\begin{itemize}
+  \item{线程是CPU调度的基本单位。}
+  \item{上下文切换}
+  \item{抢占调度}
+  \item{协同调度}
+  \end{itemize}
+\subsubsection{Programming with threads (pthreads library)}
+\begin{itemize}
+  \item{Pthread}
+	\begin{itemize}
+	  \item{线程的创建，终结}
+	  \item{同步}
+	  \item{通信}
+	  \end{itemize}
+  \item{Pth}
+  \item{Pthread: API}
+	\begin{itemize}
+	  \item{pthread\_create}
+	  \item{pthread\_self}
+	  \item{pthread\_exit}
+	  \item{pthread\_cancel}
+	  \item{pthread\_join}
+	  \end{itemize}
+  \end{itemize}
+\subsubsection{Shared vs. private resources}
+
+\subsubsection{The need for synchronization}
+\subsection{Problems}
+\subsection{Solutions}
+\end{CJK}
+\end{document}

Progress/class-9/Makefile

@@ -0,0 +1,10 @@
+all:CS61-class-9.pdf 
+
+CS61-class-9.pdf:CS61-class-9.tex 
+	pdflatex $^
+	pdflatex $(shell pwd)/*.tex  $(shell pwd)/*.toc $(shell pwd)/*.aux 
+	evince $@
+
+.PHONY:clean
+clean:
+	rm *.log *.aux *.out *.toc *.pdf