📄 pipe.c
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<!doctype html public "-//W3C//DTD HTML 3.2//EN"><html><head><title>Linux/fs/pipe.c</title><meta http-equiv=Content-Type content="text/html; charset=gb2312"><base href="http://oldlinux.org/lxr/http/"></head><body bgcolor=white><div align=center> [<b><i>源代码浏览</i></b>] [<a href="diff/fs/pipe.c">区别标定</a>] [<a href="ident">标识符搜索</a>] [<a href="search">文本搜索</a>] [<a href="find">文件搜索</a>]</div><h1 align=center> <a href="http:/"> OldLinux</a> <a href="http:blurb.html"> 交叉引用</a><br> <a href="source/">Linux</a>/<a href="source/fs/">fs</a>/<a href="source/fs/pipe.c">pipe.c</a></h1><div align=center> <b>版本:</b> [<a href="source/fs/pipe.c?v=1.0">1.0</a>] [<a href="source/fs/pipe.c?v=0.99.11">0.99.11</a>] [<a href="source/fs/pipe.c?v=0.99">0.99</a>] [<a href="source/fs/pipe.c?v=0.97">0.97</a>] [<a href="source/fs/pipe.c?v=0.96a">0.96a</a>] [<a href="source/fs/pipe.c?v=0.95">0.95</a>] [<a href="source/fs/pipe.c?v=0.12">0.12</a>] [<b><i>0.11</i></b>] [<a href="source/fs/pipe.c?v=0.01">0.01</a>] <br> <b>体系结构:</b> [<b><i>i386</i></b>] <br></div><hr><pre> <a name=L1 href="source/fs/pipe.c#L1">1</a> <b><i>/*</i></b> <a name=L2 href="source/fs/pipe.c#L2">2</a> <b><i> * linux/fs/pipe.c</i></b> <a name=L3 href="source/fs/pipe.c#L3">3</a> <b><i> *</i></b> <a name=L4 href="source/fs/pipe.c#L4">4</a> <b><i> * (C) 1991 Linus Torvalds</i></b> <a name=L5 href="source/fs/pipe.c#L5">5</a> <b><i> */</i></b> <a name=L6 href="source/fs/pipe.c#L6">6</a> <a name=L7 href="source/fs/pipe.c#L7">7</a> #include <signal.h> <a name=L8 href="source/fs/pipe.c#L8">8</a> <a name=L9 href="source/fs/pipe.c#L9">9</a> #include <linux/sched.h> <a name=L10 href="source/fs/pipe.c#L10">10</a> #include <linux/mm.h> /* for get_free_page */ <a name=L11 href="source/fs/pipe.c#L11">11</a> #include <asm/segment.h> <a name=L12 href="source/fs/pipe.c#L12">12</a> <a name=L13 href="source/fs/pipe.c#L13">13</a> int <a href="ident?i=read_pipe">read_pipe</a>(struct <a href="ident?i=m_inode">m_inode</a> * inode, char * <a href="ident?i=buf">buf</a>, int <a href="ident?i=count">count</a>) <a name=L14 href="source/fs/pipe.c#L14">14</a> { <a name=L15 href="source/fs/pipe.c#L15">15</a> int chars, size, <a href="ident?i=read">read</a> = 0; <a name=L16 href="source/fs/pipe.c#L16">16</a> <a name=L17 href="source/fs/pipe.c#L17">17</a> while (<a href="ident?i=count">count</a>>0) { <a name=L18 href="source/fs/pipe.c#L18">18</a> while (!(size=<a href="ident?i=PIPE_SIZE">PIPE_SIZE</a>(*inode))) { <a name=L19 href="source/fs/pipe.c#L19">19</a> <a href="ident?i=wake_up">wake_up</a>(&inode->i_wait); <a name=L20 href="source/fs/pipe.c#L20">20</a> if (inode->i_count != 2) <b><i>/* are there any writers? */</i></b> <a name=L21 href="source/fs/pipe.c#L21">21</a> return <a href="ident?i=read">read</a>; <a name=L22 href="source/fs/pipe.c#L22">22</a> <a href="ident?i=sleep_on">sleep_on</a>(&inode->i_wait); <a name=L23 href="source/fs/pipe.c#L23">23</a> } <a name=L24 href="source/fs/pipe.c#L24">24</a> chars = <a href="ident?i=PAGE_SIZE">PAGE_SIZE</a>-<a href="ident?i=PIPE_TAIL">PIPE_TAIL</a>(*inode); <a name=L25 href="source/fs/pipe.c#L25">25</a> if (chars > <a href="ident?i=count">count</a>) <a name=L26 href="source/fs/pipe.c#L26">26</a> chars = <a href="ident?i=count">count</a>; <a name=L27 href="source/fs/pipe.c#L27">27</a> if (chars > size) <a name=L28 href="source/fs/pipe.c#L28">28</a> chars = size; <a name=L29 href="source/fs/pipe.c#L29">29</a> <a href="ident?i=count">count</a> -= chars; <a name=L30 href="source/fs/pipe.c#L30">30</a> <a href="ident?i=read">read</a> += chars; <a name=L31 href="source/fs/pipe.c#L31">31</a> size = <a href="ident?i=PIPE_TAIL">PIPE_TAIL</a>(*inode); <a name=L32 href="source/fs/pipe.c#L32">32</a> <a href="ident?i=PIPE_TAIL">PIPE_TAIL</a>(*inode) += chars; <a name=L33 href="source/fs/pipe.c#L33">33</a> <a href="ident?i=PIPE_TAIL">PIPE_TAIL</a>(*inode) &= (<a href="ident?i=PAGE_SIZE">PAGE_SIZE</a>-1); <a name=L34 href="source/fs/pipe.c#L34">34</a> while (chars-->0) <a name=L35 href="source/fs/pipe.c#L35">35</a> <a href="ident?i=put_fs_byte">put_fs_byte</a>(((char *)inode->i_size)[size++],<a href="ident?i=buf">buf</a>++); <a name=L36 href="source/fs/pipe.c#L36">36</a> } <a name=L37 href="source/fs/pipe.c#L37">37</a> <a href="ident?i=wake_up">wake_up</a>(&inode->i_wait); <a name=L38 href="source/fs/pipe.c#L38">38</a> return <a href="ident?i=read">read</a>; <a name=L39 href="source/fs/pipe.c#L39">39</a> } <a name=L40 href="source/fs/pipe.c#L40">40</a> <a name=L41 href="source/fs/pipe.c#L41">41</a> int <a href="ident?i=write_pipe">write_pipe</a>(struct <a href="ident?i=m_inode">m_inode</a> * inode, char * <a href="ident?i=buf">buf</a>, int <a href="ident?i=count">count</a>) <a name=L42 href="source/fs/pipe.c#L42">42</a> { <a name=L43 href="source/fs/pipe.c#L43">43</a> int chars, size, written = 0; <a name=L44 href="source/fs/pipe.c#L44">44</a> <a name=L45 href="source/fs/pipe.c#L45">45</a> while (<a href="ident?i=count">count</a>>0) { <a name=L46 href="source/fs/pipe.c#L46">46</a> while (!(size=(<a href="ident?i=PAGE_SIZE">PAGE_SIZE</a>-1)-<a href="ident?i=PIPE_SIZE">PIPE_SIZE</a>(*inode))) { <a name=L47 href="source/fs/pipe.c#L47">47</a> <a href="ident?i=wake_up">wake_up</a>(&inode->i_wait); <a name=L48 href="source/fs/pipe.c#L48">48</a> if (inode->i_count != 2) { <b><i>/* no readers */</i></b> <a name=L49 href="source/fs/pipe.c#L49">49</a> <a href="ident?i=current">current</a>->signal |= (1<<(<a href="ident?i=SIGPIPE">SIGPIPE</a>-1)); <a name=L50 href="source/fs/pipe.c#L50">50</a> return written?written:-1; <a name=L51 href="source/fs/pipe.c#L51">51</a> } <a name=L52 href="source/fs/pipe.c#L52">52</a> <a href="ident?i=sleep_on">sleep_on</a>(&inode->i_wait); <a name=L53 href="source/fs/pipe.c#L53">53</a> } <a name=L54 href="source/fs/pipe.c#L54">54</a> chars = <a href="ident?i=PAGE_SIZE">PAGE_SIZE</a>-<a href="ident?i=PIPE_HEAD">PIPE_HEAD</a>(*inode); <a name=L55 href="source/fs/pipe.c#L55">55</a> if (chars > <a href="ident?i=count">count</a>) <a name=L56 href="source/fs/pipe.c#L56">56</a> chars = <a href="ident?i=count">count</a>; <a name=L57 href="source/fs/pipe.c#L57">57</a> if (chars > size) <a name=L58 href="source/fs/pipe.c#L58">58</a> chars = size; <a name=L59 href="source/fs/pipe.c#L59">59</a> <a href="ident?i=count">count</a> -= chars; <a name=L60 href="source/fs/pipe.c#L60">60</a> written += chars; <a name=L61 href="source/fs/pipe.c#L61">61</a> size = <a href="ident?i=PIPE_HEAD">PIPE_HEAD</a>(*inode); <a name=L62 href="source/fs/pipe.c#L62">62</a> <a href="ident?i=PIPE_HEAD">PIPE_HEAD</a>(*inode) += chars; <a name=L63 href="source/fs/pipe.c#L63">63</a> <a href="ident?i=PIPE_HEAD">PIPE_HEAD</a>(*inode) &= (<a href="ident?i=PAGE_SIZE">PAGE_SIZE</a>-1); <a name=L64 href="source/fs/pipe.c#L64">64</a> while (chars-->0) <a name=L65 href="source/fs/pipe.c#L65">65</a> ((char *)inode->i_size)[size++]=<a href="ident?i=get_fs_byte">get_fs_byte</a>(<a href="ident?i=buf">buf</a>++); <a name=L66 href="source/fs/pipe.c#L66">66</a> } <a name=L67 href="source/fs/pipe.c#L67">67</a> <a href="ident?i=wake_up">wake_up</a>(&inode->i_wait); <a name=L68 href="source/fs/pipe.c#L68">68</a> return written; <a name=L69 href="source/fs/pipe.c#L69">69</a> } <a name=L70 href="source/fs/pipe.c#L70">70</a> <a name=L71 href="source/fs/pipe.c#L71">71</a> int <a href="ident?i=sys_pipe">sys_pipe</a>(unsigned long * fildes) <a name=L72 href="source/fs/pipe.c#L72">72</a> { <a name=L73 href="source/fs/pipe.c#L73">73</a> struct <a href="ident?i=m_inode">m_inode</a> * inode; <a name=L74 href="source/fs/pipe.c#L74">74</a> struct <a href="ident?i=file">file</a> * f[2]; <a name=L75 href="source/fs/pipe.c#L75">75</a> int fd[2]; <a name=L76 href="source/fs/pipe.c#L76">76</a> int i,j; <a name=L77 href="source/fs/pipe.c#L77">77</a> <a name=L78 href="source/fs/pipe.c#L78">78</a> j=0; <a name=L79 href="source/fs/pipe.c#L79">79</a> for(i=0;j<2 && i<<a href="ident?i=NR_FILE">NR_FILE</a>;i++) <a name=L80 href="source/fs/pipe.c#L80">80</a> if (!<a href="ident?i=file_table">file_table</a>[i].f_count) <a name=L81 href="source/fs/pipe.c#L81">81</a> (f[j++]=i+<a href="ident?i=file_table">file_table</a>)->f_count++; <a name=L82 href="source/fs/pipe.c#L82">82</a> if (j==1) <a name=L83 href="source/fs/pipe.c#L83">83</a> f[0]->f_count=0; <a name=L84 href="source/fs/pipe.c#L84">84</a> if (j<2) <a name=L85 href="source/fs/pipe.c#L85">85</a> return -1; <a name=L86 href="source/fs/pipe.c#L86">86</a> j=0; <a name=L87 href="source/fs/pipe.c#L87">87</a> for(i=0;j<2 && i<<a href="ident?i=NR_OPEN">NR_OPEN</a>;i++) <a name=L88 href="source/fs/pipe.c#L88">88</a> if (!<a href="ident?i=current">current</a>->filp[i]) { <a name=L89 href="source/fs/pipe.c#L89">89</a> <a href="ident?i=current">current</a>->filp[ fd[j]=i ] = f[j]; <a name=L90 href="source/fs/pipe.c#L90">90</a> j++; <a name=L91 href="source/fs/pipe.c#L91">91</a> } <a name=L92 href="source/fs/pipe.c#L92">92</a> if (j==1) <a name=L93 href="source/fs/pipe.c#L93">93</a> <a href="ident?i=current">current</a>->filp[fd[0]]=<a href="ident?i=NULL">NULL</a>; <a name=L94 href="source/fs/pipe.c#L94">94</a> if (j<2) { <a name=L95 href="source/fs/pipe.c#L95">95</a> f[0]->f_count=f[1]->f_count=0; <a name=L96 href="source/fs/pipe.c#L96">96</a> return -1; <a name=L97 href="source/fs/pipe.c#L97">97</a> } <a name=L98 href="source/fs/pipe.c#L98">98</a> if (!(inode=<a href="ident?i=get_pipe_inode">get_pipe_inode</a>())) { <a name=L99 href="source/fs/pipe.c#L99">99</a> <a href="ident?i=current">current</a>->filp[fd[0]] =<a name=L100 href="source/fs/pipe.c#L100">100</a> <a href="ident?i=current">current</a>->filp[fd[1]] = <a href="ident?i=NULL">NULL</a>;<a name=L101 href="source/fs/pipe.c#L101">101</a> f[0]->f_count = f[1]->f_count = 0;<a name=L102 href="source/fs/pipe.c#L102">102</a> return -1;<a name=L103 href="source/fs/pipe.c#L103">103</a> }<a name=L104 href="source/fs/pipe.c#L104">104</a> f[0]->f_inode = f[1]->f_inode = inode;<a name=L105 href="source/fs/pipe.c#L105">105</a> f[0]->f_pos = f[1]->f_pos = 0;<a name=L106 href="source/fs/pipe.c#L106">106</a> f[0]->f_mode = 1; <b><i>/* read */</i></b><a name=L107 href="source/fs/pipe.c#L107">107</a> f[1]->f_mode = 2; <b><i>/* write */</i></b><a name=L108 href="source/fs/pipe.c#L108">108</a> <a href="ident?i=put_fs_long">put_fs_long</a>(fd[0],0+fildes);<a name=L109 href="source/fs/pipe.c#L109">109</a> <a href="ident?i=put_fs_long">put_fs_long</a>(fd[1],1+fildes);<a name=L110 href="source/fs/pipe.c#L110">110</a> return 0;<a name=L111 href="source/fs/pipe.c#L111">111</a> }<a name=L112 href="source/fs/pipe.c#L112">112</a> </pre><hr><div align=center> [<b><i>源代码浏览</i></b>] [<a href="diff/fs/pipe.c">区别标定</a>] [<a href="ident">标识符搜索</a>] [<a href="search">文本搜索</a>] [<a href="find">文件搜索</a>] </div><hr>本网页由 <a href="http:blurb.html">LXR引擎</a> 自动生成.<br></html>⌨️ 快捷键说明
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