github-mirror/lkmpg
2
0
Fork 0
mirror of https://github.com/sysprog21/lkmpg.git synced 2024-11-23 01:43:24 +08:00
Code Issues Actions Packages Projects Releases Wiki Activity

Merge pull request #2 from 25077667/master

Browse Source 
Redraw figure: seq_file
This commit is contained in:
Jim Huang 2021-07-23 14:33:30 +08:00 committed by GitHub
commit 40ae17c1f8
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 27 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

BIN
img/seq_file.png
View File

Binary file not shown.
Side by Side

Before

Width:  |  Height:  |  Size: 26 KiB

28
lkmpg.tex
View File

@ -5,6 +5,16 @@
\usepackage{graphicx}
\usepackage{fancyhdr}
% tikz settings
\usepackage{tikz}
\usetikzlibrary{shapes.geometric, arrows, shadows, decorations.text}
\tikzstyle{startstop} = [rectangle, rounded corners, minimum width=3cm, minimum height=1cm,text centered, draw=black, fill=red!30, drop shadow]
\tikzstyle{io} = [trapezium, trapezium left angle=70, trapezium right angle=110, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=blue!30]
\tikzstyle{process} = [rectangle, minimum width=3cm, minimum height=1cm, text centered, text width=3cm, draw=black, fill=orange!30]
\tikzstyle{decision} = [diamond, minimum width=1cm, minimum height=1cm, text centered, draw=black, fill=green!30]
\tikzstyle{arrow} = [thick,->,>=stealth]
\tikzstyle{line} = [draw, -latex']
% packages for code
\usepackage{verbatim}
\usepackage{minted}
@ -786,7 +796,23 @@ non NULL value, the function next() is called. This function is an iterator, the
BE CAREFUL: when a sequence is finished, another one starts. That means that at the end of function stop(), the function start() is called again. This loop finishes when the function start() returns NULL. You can see a scheme of this in the figure "How seq\_file works".
\begin{center}
\includegraphics[width=.9\linewidth]{img/seq_file.png}
\begin{tikzpicture}[node distance=2cm, thick]
\node (start) [startstop] {start() treatment};
\node (branch1) [decision, below of=start, yshift=-1cm] {return is NULL?};
\node (emptynode) [right of=branch1, xshift=2cm] {Yes};
\node (next) [process, below of=branch1, yshift=-1cm] {next() treatment};
\node (branch2) [decision, below of=next, yshift=-1cm] {return is NULL?};
\node (stop) [startstop, below of=branch2, yshift=-1cm] {stop() treatment};
\draw [->] (start) -- (branch1);
\draw [->] (branch1) -- node[anchor=east] {} (emptynode);
\draw [->] (branch1) -- node[left=2em, anchor=south] {No} (next);
\draw [->] (next) -- (branch2);
\draw [->] (branch2.west) to [out=135, in=-135, bend left=45] node [left] {No} (next.west);
\draw [->] (branch2) -- node[left=2em, anchor=south] {Yes} (stop);
\draw [->] (stop.west) to [out=135, in=-135] node [left] {} (start.west);
\end{tikzpicture}
\end{center}
Seq\_file provides basic functions for proc\_ops, as seq\_read, seq\_lseek, and some others. But nothing to write in the /proc file. Of course, you can still use the same way as in the previous example.