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<div id="pf1" class="pf w0 h0" data-page-no="1"><div class="pc pc1 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/626f447240256a40cea4c5ae/bg1.jpg"><div class="t m0 x1 h2 y1 ff1 fs0 fc0 sc0 ls0 ws0">操作系统存储桶实验</div><div class="t m0 x2 h3 y2 ff1 fs1 fc1 sc1 ls1 ws0">模拟内存页的分配与回收</div><div class="t m0 x2 h3 y3 ff1 fs1 fc1 sc1 ls1 ws0">内存块的分配与释放函数</div><div class="t m0 x2 h3 y4 ff1 fs1 fc1 sc1 ls2 ws0">存储桶数据结构</div><div class="t m0 x2 h3 y5 ff1 fs1 fc1 sc1 ls3 ws0">存储桶原理分配管理内存结构示意图</div><div class="t m0 x2 h4 y6 ff2 fs1 fc1 sc2 ls4 ws1">void *my_malloc(int<span class="_"> </span>size)</div><div class="t m0 x2 h4 y7 ff2 fs1 fc1 sc2 ls5 ws2">void my_free_s(void<span class="_"> </span>*obj, int<span class="_"> </span>size)</div><div class="t m0 x3 h5 y8 ff1 fs2 fc2 sc3 ls0 ws0">杨云强</div><div class="t m0 x4 h6 y9 ff2 fs2 fc2 sc2 ls6 ws0">2010<span class="ff1 sc3 ls0">年</span>06<span class="ff1 sc3 ls0">月</span>19<span class="ff1 sc3 ls0">日</span></div></div><div class="pi" data-data='{"ctm":[0.000000,-1.337047,1.337047,0.000000,-82.896936,758.105850]}'></div></div>
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<div id="pf2" class="pf w0 h0" data-page-no="2"><div class="pc pc2 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/626f447240256a40cea4c5ae/bg2.jpg"><div class="t m0 x5 h7 ya ff3 fs3 fc3 sc2 ls7 ws0">yunqiangyoung@163.com</div><div class="t m0 x6 h8 yb ff1 fs4 fc4 sc4 ls0 ws0">模拟内存页的分配与回收</div><div class="t m0 x7 h9 yc ff4 fs5 fc4 sc2 ls0 ws0"><span class="_ _0"> </span><span class="ff5 fs2 fc3 ls8 ws3">#define PAGE_SIZE<span class="_ _1"> </span>4096<span class="_ _2"> </span>//the size of a page</span></div><div class="t m0 x7 h9 yd ff4 fs5 fc4 sc2 ls0 ws0"><span class="_ _0"> </span><span class="ff5 fs2 fc3 ls9 ws4">#define MEM_PAGES<span class="_ _3"> </span>1000</span></div><div class="t m0 x7 h6 ye ff4 fs5 fc4 sc2 ls0 ws0"><span class="_ _4"> </span><span class="ff2 fs2 fc3 lsa">struct</span></div><div class="t m0 x8 ha yf ff4 fs3 fc5 sc2 ls0 ws0">)<span class="_ _5"> </span><span class="ff2 fs5 fc3">{</span></div><div class="t m0 x8 ha y10 ff4 fs3 fc5 sc2 ls0 ws0">)<span class="_ _6"> </span><span class="ff2 fs5 fc3 lsb">char<span class="_"> </span>mem[PAGE_SIZE];</span></div><div class="t m0 x8 ha y11 ff4 fs3 fc5 sc2 ls0 ws0">)<span class="_ _5"> </span><span class="ff2 fs5 fc3">}</span></div><div class="t m0 x8 ha y12 ff4 fs3 fc5 sc2 ls0 ws0">)<span class="_ _2"> </span><span class="ff2 fs5 fc3 lsc">memblock[MEM_P<span class="_ _7"></span>AGES];<span class="_ _8"> </span><span class="ff5 lsd">//1000<span class="ff1 lse">页的空闲内存供模拟分配</span></span></span></div><div class="t m0 x8 hb y13 ff4 fs3 fc5 sc2 ls0 ws0">)<span class="_ _5"> </span><span class="ff5 fs5 fc3 lsf">//<span class="ff1 ls0">内存映射表</span></span></div><div class="t m0 x8 hb y14 ff4 fs3 fc5 sc2 ls0 ws0">)<span class="_ _5"> </span><span class="ff5 fs5 fc3 ls10 ws5">// 0-<span class="ff1 ls11 ws0">(未分配)空闲,<span class="ff5 ls12">1-</span>(已分配)有数据</span></span></div><div class="t m0 x7 hc y15 ff4 fs5 fc4 sc2 ls0 ws0"></div><div class="t m0 x9 h6 y16 ff2 fs2 fc3 sc2 ls0 ws6">char memmap[MEM_PAG<span class="_ _7"></span>ES];</div><div class="t m0 x7 h6 y17 ff4 fs5 fc4 sc2 ls0 ws0"><span class="_ _0"> </span><span class="ff1 fs2 fc3 sc5">内存初始化:<span class="ff2 sc2 ls13 ws7">memory_init( );<span class="_ _9"> </span><span class="ff5 ls8 ws0">//memmap[i]</span></span><span class="sc2">全置<span class="ff5">0</span></span></span></div><div class="t m0 x7 h6 y18 ff4 fs5 fc4 sc2 ls0 ws0"><span class="_ _0"> </span><span class="ff1 fs2 fc3 sc5">获得空闲页:<span class="ff2 sc2 ls8 ws3">get_empty_page( ); <span class="ff5 ls14 ws0">//</span></span><span class="sc2">若<span class="ff5 ls13">memmap[i]==0</span>,分配并置<span class="ff5">1</span></span></span></div><div class="t m0 x7 h6 y19 ff4 fs5 fc4 sc2 ls0 ws0"><span class="_ _0"> </span><span class="ff1 fs2 fc3 sc5">释放分配页:<span class="ff2 sc2 ls15 ws8">free_page( );<span class="_ _a"> </span><span class="ff5 ls14 ws0">//<span class="ff1 ls16">找到</span><span class="ls17">memmap[i]</span></span></span><span class="sc2">,置<span class="ff5">0</span></span></span></div></div><div class="pi" data-data='{"ctm":[0.000000,-1.337047,1.337047,0.000000,-82.896936,758.105850]}'></div></div>