{"id":965,"date":"2021-12-19T12:13:03","date_gmt":"2021-12-19T04:13:03","guid":{"rendered":"https:\/\/blog.cauchyschwarz.com\/?p=965"},"modified":"2021-12-19T12:13:07","modified_gmt":"2021-12-19T04:13:07","slug":"apiue%e8%af%bb%e4%b9%a6%e7%ac%94%e8%ae%b0chapter7","status":"publish","type":"post","link":"https:\/\/blog.cauchyschwarz.com\/?p=965","title":{"rendered":"APIUE\u8bfb\u4e66\u7b14\u8bb0chapter7"},"content":{"rendered":"\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_82_2 ez-toc-wrap-right counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<label for=\"ez-toc-cssicon-toggle-item-69fc679055a91\" class=\"ez-toc-cssicon-toggle-label\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" 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href=\"https:\/\/blog.cauchyschwarz.com\/?p=965\/#%E8%BF%9B%E7%A8%8B%E7%BB%88%E6%AD%A2\" >\u8fdb\u7a0b\u7ec8\u6b62<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=965\/#%E8%BF%9B%E7%A8%8B%E7%BB%88%E6%AD%A2%E7%9A%848%E7%A7%8D%E6%96%B9%E5%BC%8F\" >\u8fdb\u7a0b\u7ec8\u6b62\u76848\u79cd\u65b9\u5f0f<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=965\/#atexit%E5%87%BD%E6%95%B0\" >atexit\u51fd\u6570<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=965\/#%E5%91%BD%E4%BB%A4%E8%A1%8C%E5%8F%82%E6%95%B0\" >\u547d\u4ee4\u884c\u53c2\u6570<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=965\/#%E7%8E%AF%E5%A2%83%E5%8F%98%E9%87%8F%E5%88%97%E8%A1%A8\" >\u73af\u5883\u53d8\u91cf\u5217\u8868<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=965\/#C%E7%A8%8B%E5%BA%8F%E7%9A%84%E5%86%85%E5%AD%98%E5%B8%83%E5%B1%80\" >C\u7a0b\u5e8f\u7684\u5185\u5b58\u5e03\u5c40<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=965\/#%E5%85%B1%E4%BA%AB%E5%BA%93\" >\u5171\u4eab\u5e93<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=965\/#%E5%8A%A8%E6%80%81%E5%86%85%E5%AD%98%E5%88%86%E9%85%8D\" >\u52a8\u6001\u5185\u5b58\u5206\u914d<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=965\/#alloca%E5%87%BD%E6%95%B0\" >alloca\u51fd\u6570<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=965\/#%E7%8E%AF%E5%A2%83%E5%8F%98%E9%87%8F\" >\u73af\u5883\u53d8\u91cf<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=965\/#setjmp%E4%B8%8Elongjmp\" >setjmp\u4e0elongjmp<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/blog.cauchyschwarz.com\/?p=965\/#getrlimit%E5%92%8Csetrlimit%E5%87%BD%E6%95%B0\" >getrlimit\u548csetrlimit\u51fd\u6570<\/a><\/li><\/ul><\/nav><\/div>\n<h1 class=\"wp-block-heading\" id=\"%E8%BF%9B%E7%A8%8B%E7%BB%88%E6%AD%A2\"><span class=\"ez-toc-section\" id=\"%E8%BF%9B%E7%A8%8B%E7%BB%88%E6%AD%A2\"><\/span>\u8fdb\u7a0b\u7ec8\u6b62<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"%E8%BF%9B%E7%A8%8B%E7%BB%88%E6%AD%A2%E7%9A%848%E7%A7%8D%E6%96%B9%E5%BC%8F\"><span class=\"ez-toc-section\" id=\"%E8%BF%9B%E7%A8%8B%E7%BB%88%E6%AD%A2%E7%9A%848%E7%A7%8D%E6%96%B9%E5%BC%8F\"><\/span>\u8fdb\u7a0b\u7ec8\u6b62\u76848\u79cd\u65b9\u5f0f<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<ol class=\"wp-block-list\"><li>\u4ecemain\u4e2d(\u81ea\u7136)\u8fd4\u56de<\/li><li>\u8c03\u7528exit<\/li><li>\u8c03\u7528_exit\u6216_Exit<\/li><li>\u6700\u540e\u4e00\u4e2a\u7ebf\u7a0b\u81ea\u7136\u9000\u51fa<\/li><li>\u6700\u540e\u4e00\u4e2a\u7ebf\u7a0b\u8c03\u7528pthread_exit<\/li><\/ol>\n\n\n\n<p>\u5f02\u5e38\u7ec8\u6b62\u76843\u79cd\u65b9\u5f0f<\/p>\n\n\n\n<ol class=\"wp-block-list\" start=\"6\"><li>\u8c03\u7528abort<\/li><li>\u6536\u5230\u4e00\u4e2a\u4fe1\u53f7(signal)<\/li><li>\u6700\u540e\u4e00\u4e2a\u7ebf\u7a0b\u54cd\u5e94\u64a4\u9500\u8bf7\u6c42<\/li><\/ol>\n\n\n\n<pre class=\"wp-block-code\"><code class=\"\">#include &lt;stdlib.h&gt;\n\nvoid exit(int status);\n\nvoiod _Exit(int status);\n\n#include &lt;unistd.h&gt;\n\nvoid _exit(int status);\n<\/code><\/pre>\n\n\n\n<p>main\u51fd\u6570\u4e2d\u7684<code>return status<\/code>\u8bed\u53e5\uff0c\u7b49\u4ef7\u4e8e<code>exit(status)<\/code>\u8bed\u53e5\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"atexit%E5%87%BD%E6%95%B0\"><span class=\"ez-toc-section\" id=\"atexit%E5%87%BD%E6%95%B0\"><\/span>atexit\u51fd\u6570<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>\u5bf9\u4e8eISO C\uff0c\u81f3\u5c11\u53ef\u4ee5\u6ce8\u518c32\u4e2aexit handlers\u88abexit\u8c03\u7528\u3002\u8c03\u7528\u7684\u987a\u5e8f\u4e0e\u6ce8\u518c\u7684\u987a\u5e8f\u76f8\u53cd\uff0c\u4e14\u4e00\u4e2a\u51fd\u6570\u6ce8\u518c\u4e86\u591a\u5c11\u6b21\u5c31\u4f1a\u540c\u6837\u7684\u8c03\u7528\u591a\u5c11\u6b21\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code class=\"\">#include &lt;stdlib.h&gt;\n\nint atexit(void (*func)(void));\n<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"874\" height=\"717\" src=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/apiue_main-exit.png\" alt=\"\" class=\"wp-image-966\" srcset=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/apiue_main-exit.png 874w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/apiue_main-exit-300x246.png 300w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/apiue_main-exit-768x630.png 768w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/apiue_main-exit-670x550.png 670w\" sizes=\"auto, (max-width: 874px) 100vw, 874px\" \/><\/figure>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"%E5%91%BD%E4%BB%A4%E8%A1%8C%E5%8F%82%E6%95%B0\"><span class=\"ez-toc-section\" id=\"%E5%91%BD%E4%BB%A4%E8%A1%8C%E5%8F%82%E6%95%B0\"><\/span>\u547d\u4ee4\u884c\u53c2\u6570<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"%E7%8E%AF%E5%A2%83%E5%8F%98%E9%87%8F%E5%88%97%E8%A1%A8\"><span class=\"ez-toc-section\" id=\"%E7%8E%AF%E5%A2%83%E5%8F%98%E9%87%8F%E5%88%97%E8%A1%A8\"><\/span>\u73af\u5883\u53d8\u91cf\u5217\u8868<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<p>\u901a\u8fc7<code>extern char **environ<\/code>\u8fd9\u4e2a\u5168\u5c40\u53d8\u91cf\u5f15\u7528\u73af\u5883\u53d8\u91cf\u3002<br>\u7531\u4e8e\u5386\u53f2\u539f\u56e0\uff0c\u591a\u6570UNIX\u7cfb\u7edf\u4e3amain\u51fd\u6570\u63d0\u4f9b\u4e86\u7b2c\u4e09\u4e2a\u53c2\u6570\u4ee3\u8868\u73af\u5883\u53d8\u91cf\uff1a<br><code>int main(int argc, char *argv[], char *envp[]);<\/code><br>\u7531\u4e8eISO C\u89c4\u5b9amain\u51fd\u6570\u6709\u4e24\u4e2a\u53c2\u6570\uff0c\u800c\u4e0a\u9762\u8fd9\u79cd\u6709\u4e09\u4e2a\u53c2\u6570\u7684\u5f62\u5f0f\u4e5f\u4e0d\u6bd4\u901a\u8fc7\u5168\u5c40\u53d8\u91cf\u6765\u5f15\u7528\u73af\u5883\u53d8\u91cf\u7684\u65b9\u5f0f\u597d\u5230\u54ea\u53bb\uff0c\u6240\u4ee5POSIX.1\u89c4\u5b9a\u5e94\u8be5\u4f7f\u7528<code>environ<\/code>\u5168\u5c40\u53d8\u91cf\u800c\u4e0d\u662f\u4e3amain\u4f20\u5165\u7b2c\u4e09\u4e2a\u53c2\u6570\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"c%E7%A8%8B%E5%BA%8F%E7%9A%84%E5%86%85%E5%AD%98%E5%B8%83%E5%B1%80\"><span class=\"ez-toc-section\" id=\"C%E7%A8%8B%E5%BA%8F%E7%9A%84%E5%86%85%E5%AD%98%E5%B8%83%E5%B1%80\"><\/span>C\u7a0b\u5e8f\u7684\u5185\u5b58\u5e03\u5c40<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<ul class=\"wp-block-list\"><li>\u4ee3\u7801\u6bb5(Text segment)<\/li><li>\u6570\u636e\u6bb5(Initialized data segment\uff0c\u7b80\u79f0data segment)\uff0c\u5305\u542b\u4e86\u7a0b\u5e8f\u4e2d\u521d\u59cb\u5316\u4e86\u7684(\u5168\u5c40)\u53d8\u91cf\u3002<\/li><li>bss\u6bb5(block started by symbol)\uff0cuninitialized data segment\u3002\u5728\u7a0b\u5e8f\u88ab\u6267\u884c\u524d\uff0c\u6b64\u6bb5\u4e2d\u7684\u6570\u636e\u88ab\u521d\u59cb\u5316\u4e3a0\u6216null\u6307\u9488\u3002\u5305\u542b\u7a0b\u5e8f\u4e2d\u672a\u521d\u59cb\u5316\u7684\u5168\u5c40\u53d8\u91cf\u3002<\/li><li>stack<\/li><li>heap\uff0c\u4e00\u822c\u4f4d\u4e8ebss\u4e0e\u6808\u4e4b\u95f4<\/li><\/ul>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"606\" height=\"568\" src=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/apiue_process-memory-layout.png\" alt=\"\" class=\"wp-image-967\" srcset=\"https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/apiue_process-memory-layout.png 606w, https:\/\/blog.cauchyschwarz.com\/wp-content\/uploads\/2021\/12\/apiue_process-memory-layout-300x281.png 300w\" sizes=\"auto, (max-width: 606px) 100vw, 606px\" \/><\/figure>\n\n\n\n<p>\u572832\u4f4dIntel x86\u5904\u7406\u5668\u4e0a\uff0cLinux\u7684text\u6bb5\u4ece0x08048000\u5f00\u59cb(\u5f80\u4e0a),stack\u5219\u4ece0xC0000000(\u5f80\u4e0b\u4e14\u4e0d\u542b)\u5f00\u59cb\u3002<br>\u53ef\u4ee5\u7528size\u5de5\u5177\u67e5\u770b\u7a0b\u5e8f\u7684\u5404\u4e2a\u6bb5\u5927\u5c0f\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"%E5%85%B1%E4%BA%AB%E5%BA%93\"><span class=\"ez-toc-section\" id=\"%E5%85%B1%E4%BA%AB%E5%BA%93\"><\/span>\u5171\u4eab\u5e93<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<p>\u4f18\u70b9\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u540c\u6837\u7684\u4ee3\u7801\u4e0d\u7528\u5728\u6bcf\u4e2a\u7a0b\u5e8f\u4e2d\u90fd\u4fdd\u5b58\u4e00\u4efd\uff1b\u51cf\u5c11\u4e86\u5355\u4e2a\u7a0b\u5e8f\u7684\u5927\u5c0f\uff1b<\/li><li>\u53ef\u4ee5\u5355\u72ec\u66f4\u65b0\u5171\u4eab\u5e93\uff0c\u800c\u4e0d\u9700\u8981\u91cd\u65b0\u94fe\u63a5\u53ef\u6267\u884c\u7a0b\u5e8f\uff1b<\/li><\/ul>\n\n\n\n<p>\u7f3a\u70b9\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u4f1a\u5e26\u6765\u8fd0\u884c\u65f6\u7684\u4e00\u70b9\u70b9overhead(\u7b2c\u4e00\u6b21\u8fd0\u884c\u8be5\u7a0b\u5e8f\u6216\u8005\u5171\u4eab\u5e93\u91cc\u7684\u51fd\u6570\u88ab\u7b2c\u4e00\u6b21\u8c03\u7528\u65f6)<\/li><\/ul>\n\n\n\n<p>\u7528gcc\u7f16\u8bd1hello world\u4f8b\u7a0b\u65f6\uff0c\u52a0\u4e0a<code>-static<\/code>\u9009\u9879\u5c31\u53ef\u4ee5\u611f\u53d7\u5230\u7528\u5171\u4eab\u5e93\u4e0e\u4e0d\u7528\u5171\u4eab\u5e93\u65f6\u53ef\u6267\u884c\u7a0b\u5e8f\u5927\u5c0f\u7684\u5929\u58e4\u4e4b\u522b\u4e86\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"%E5%8A%A8%E6%80%81%E5%86%85%E5%AD%98%E5%88%86%E9%85%8D\"><span class=\"ez-toc-section\" id=\"%E5%8A%A8%E6%80%81%E5%86%85%E5%AD%98%E5%88%86%E9%85%8D\"><\/span>\u52a8\u6001\u5185\u5b58\u5206\u914d<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<p>\u6807\u51c6malloc\u5b9e\u73b0\u4e4b\u5916\u7684\u51e0\u79cd\u52a8\u6001\u5185\u5b58\u5206\u914d\u5b9e\u73b0\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>libmalloc<br>\u63d0\u4f9b\u4e86mallopt\uff0cmallinfo\u7b49\u51fd\u6570<\/li><li>vmalloc<br>\u53ef\u4ee5\u4e3a\u4e0d\u540c\u7c7b\u578b\u7684\u5185\u5b58\u63d0\u4f9b\u4f7f\u7528\u4e0d\u540c\u6280\u672f\u7684alloctor\u3002<\/li><li>quick-fit<br>\u8c8c\u4f3c\u662f\u6700\u65e9\u4f7f\u7528\u5206\u79bb\u94fe\u8868\u6280\u672f\u7684\u52a8\u6001\u5185\u5b58\u5206\u914d\u5668?<\/li><li>jemalloc<br>\u9002\u7528\u4e8e\u591a\u5904\u7406\u5668\u591a\u7ebf\u7a0b\u573a\u666f\u4e0b\u7684\u52a8\u6001\u5185\u5b58\u5206\u914d\u5668\uff0c\u8c8c\u4f3c\u5728\u548cAndroid\u6709\u5173\u7684\u4ec0\u4e48\u5730\u65b9\u770b\u5230\u8fc7<\/li><li>TCMalloc<br>Google\u641e\u7684\u8c8c\u4f3c\u5f88\u5389\u5bb3\u7684\u5e93\uff1f<\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"alloca%E5%87%BD%E6%95%B0\"><span class=\"ez-toc-section\" id=\"alloca%E5%87%BD%E6%95%B0\"><\/span>alloca\u51fd\u6570<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>\u4ece\u6808\u4e0a\u5f00\u8f9f\u5185\u5b58\uff0c\u5f53\u8c03\u7528alloca\u7684\u51fd\u6570\u8fd4\u56de\u65f6alloca\u5f00\u8f9f\u7684\u5185\u5b58\u88ab\u81ea\u52a8\u91ca\u653e\u3002\u6709\u4e9b\u7cfb\u7edf\u4e0d\u63d0\u4f9balloca\u51fd\u6570\uff0c\u4e0d\u8fc7\u4e00\u822c\u7684Unix\/Linux\u7cfb\u7edf\u90fd\u652f\u6301\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"%E7%8E%AF%E5%A2%83%E5%8F%98%E9%87%8F\"><span class=\"ez-toc-section\" id=\"%E7%8E%AF%E5%A2%83%E5%8F%98%E9%87%8F\"><\/span>\u73af\u5883\u53d8\u91cf<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<p>\u6700\u597d\u4f7f\u7528getenv\u3001putenv\u3001setenv\u7b49\u51fd\u6570\u83b7\u53d6\u3001\u4fee\u6539\u73af\u5883\u53d8\u91cf\uff0c\u800c\u4e0d\u662f\u624b\u52a8\u901a\u8fc7environ\u53d8\u91cf\u6765\u76f4\u63a5\u64cd\u4f5c\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code class=\"\">#include &lt;stdlib.h&gt;\n\nchar *getenv(const char *name);\n\nint putenv(char *str);\n\nint setenv(const char *name, const char *value, int rewrite);\n\nint unsetenv(const char *name);\n<\/code><\/pre>\n\n\n\n<p>\u5176\u4e2d\u6ce8\u610fputenv\u548csetenv\u7684\u533a\u522b\uff1asetenv\u7684\u5b9e\u73b0\u603b\u4f1a\u989d\u5916\u5f00\u8f9f\u7a7a\u95f4\u6765\u5b58\u653e\u7531\u53c2\u6570\u7ec4\u6210\u7684name=value\u5f62\u5f0f\u7684\u5b57\u7b26\u4e32\uff0c\u800cputenv\u53ef\u80fd\u76f4\u63a5\u5c06\u4f20\u5165\u7684\u5b57\u7b26\u4e32\u6307\u9488\u52a0\u5165\u5230\u73af\u5883\u53d8\u91cf\u5217\u8868\u91cc\u4e86\u3002\u6240\u4ee5\u4f20\u5165putenv\u7684\u5b57\u7b26\u4e32\u4e0d\u80fd\u662f\u5728\u6808\u4e0a\u5f00\u8f9f\u7684(\u4e00\u65e6\u76f8\u5e94\u7684\u51fd\u6570\u8fd4\u56de\u8fd9\u4e2a\u51fd\u6570frame\u7684\u7a7a\u95f4\u5c31\u56de\u6536\u4e86)\uff0c\u9700\u8981\u662f\u5728\u5806\u4e2d\u5f00\u8f9f\u7684\u3002<br>\u800c\u5bf9\u4e8e\u73af\u5883\u53d8\u91cf\u5217\u8868\u7684\u5b9e\u73b0\uff0c\u5728\u9700\u8981\u7684\u65f6\u5019\u8be5\u73af\u5883\u53d8\u91cf\u5217\u8868\u4f1a\u8f6c\u79fb\u5230\u5806\u4e2d(\u53c2\u770b\u539f\u4e66213\u9875\uff0c\u61d2\u5f97\u8d58\u8ff0)\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"setjmp%E4%B8%8Elongjmp\"><span class=\"ez-toc-section\" id=\"setjmp%E4%B8%8Elongjmp\"><\/span>setjmp\u4e0elongjmp<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<p>goto\u53ea\u80fd\u5728\u4e00\u4e2a\u51fd\u6570\u7684\u5185\u90e8\u8fdb\u884c\u8df3\u8f6c\uff0c\u800c\u4f7f\u7528setjmp\u3001longjmp\u6211\u4eec\u53ef\u4ee5\u8fdb\u884c\u8de8stack frames\u7684\u8df3\u8f6c(\u51c6\u786e\u5730\u8bf4\uff0c\u662f\u8df3\u8f6c\u5230\u8c03\u7528\u4e86setjmp\u7684\u5730\u65b9)\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code class=\"\">#include &lt;setjmp.h&gt;\n\nint setjmp(jmp_buf env);\n\nvoid longjmp(jmp_buf env, int val);\n<\/code><\/pre>\n\n\n\n<p>\u5728\u8c03\u7528longjmp\u540e\uff0cautomatic\u3001register\u548cvolatile\u7b49\u7c7b\u578b\u53d8\u91cf\u7684\u503c\uff1a<br>\u5927\u591a\u6570\u5b9e\u73b0\u4e0d\u4f1a\u56de\u6edaautomatic\u548cregister\u7c7b\u578b\u53d8\u91cf\u7684\u503c\uff0c\u800c\u6807\u51c6\u4e5f\u53ea\u8bf4\u4ed6\u4eec\u7684\u503c\u662f\u4e0d\u786e\u5b9a\u7684\u3002\u5982\u679c\u6709\u786e\u5b9a\u4e0d\u60f3\u8981\u56de\u6eda\u7684automatic\u53d8\u91cf\uff0c\u53ef\u4ee5\u7528volatile\u5c5e\u6027\u4fee\u9970\u3002<br>\u5728\u6267\u884clongjmp\u65f6,\u5168\u5c40\u6216\u8005static\u53d8\u91cf\u4e0d\u4f1a\u88ab\u56de\u6eda\u3002<br>\u5982\u679c\u60f3\u8981\u5199robust\u3001portable\u7684\u4f7f\u7528\u4e86non-local jump\u7684\u7a0b\u5e8f\uff0c\u90a3\u4e48\u9700\u8981\u8bb0\u4f4flongjmp\u65f6\uff0c\u53ea\u6709\u5168\u5c40\u53d8\u91cf\u3001static\u53d8\u91cf\u548cvolatile\u53d8\u91cf\u7684\u503c\u4e0d\u4f1a\u56de\u6eda\uff0cautomatic\u53d8\u91cf\u548cregister\u53d8\u91cf\u5219\u4f1a\u89c6\u60c5\u51b5\u56de\u6eda\u6216\u4e0d\u56de\u6eda\u3002<\/p>\n\n\n\n<h1 class=\"wp-block-heading\" id=\"getrlimit%E5%92%8Csetrlimit%E5%87%BD%E6%95%B0\"><span class=\"ez-toc-section\" id=\"getrlimit%E5%92%8Csetrlimit%E5%87%BD%E6%95%B0\"><\/span>getrlimit\u548csetrlimit\u51fd\u6570<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<pre class=\"wp-block-code\"><code class=\"\">#include &lt;sys\/resource.h&gt;\n\nint getrlimit(int resource, struct rlimit *rlptr);\n\nint setrlimit(int resource, const struct rlimit *rlptr);\n\nstruct rlimit {\n\trlimit_t rlim_cur;\t<em>\/* soft limit: current limit *\/<\/em>\n\trlimit_t rlim_max;\t<em>\/* hard limit: maximum value for rlim_cur *\/<\/em>\n};\n<\/code><\/pre>\n\n\n\n<p>\u5173\u4e8erlimit\u76843\u4e2a\u89c4\u5219\uff1a<\/p>\n\n\n\n<ol class=\"wp-block-list\"><li>\u8fdb\u7a0b\u53ef\u4ee5\u66f4\u6539soft limit\uff0c\u4f46\u662f\u4e0d\u80fd\u8d85\u8fc7\u76f8\u5e94\u7684hard limit;<\/li><li>\u8fdb\u7a0b\u53ef\u4ee5\u4fee\u6539hard limit\u4e3a\u4e0d\u5c0f\u4e8esoft limit\u7684\u503c\uff0c\u800c\u4e14\u5bf9\u666e\u901a\u7528\u6237\u800c\u8a00\uff0c\u8fd9\u79cd\u66f4\u6539\u662f\u4e0d\u53ef\u9006\u7684\uff1b<\/li><li>\u53ea\u6709\u8d85\u7ea7\u7528\u6237\u53ef\u4ee5\u63d0\u5347hard limit\u7684\u503c\u3002<\/li><\/ol>\n\n\n\n<p>\u5404rlimit\u7684\u503c\u7531process 0\u5efa\u7acb\uff0c\u5e76\u4e14\u7531\u5b50\u8fdb\u7a0b\u7ee7\u627f\u3002<br>\u5e38\u7528rlimit\uff1aRLIMIT_AS,RLIMIT_CORE,RLIMIT_CPU,RLIMIT_DATA,RLIMIT_FSIZE,RLIMIT_MEMLOCK,RLIMIT_MSGQUEUE,RLIMIT_NICE,RLIMIT_NOFILE,RLIMIT_NPROC,RLIMIT_NPTS,RLIMIT_RSS,RLIMIT_SBSIZE,RLIMIT_SIGPENDING,RLIMIT_STACK,RLIMIT_SWAP,RLIMIT_VMEM\u3002<\/p>\n\n\n\n<p>\u5173\u4e8e\u5b8f\u7684\u4e00\u4e2a\u5c0f\u70b9\uff1a<code>#name<\/code>\u8868\u793a\u751f\u6210\u4e00\u4e2a<code>\"name\"<\/code>\u5b57\u7b26\u4e32\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u8fdb\u7a0b\u7ec8\u6b62 \u8fdb\u7a0b\u7ec8\u6b62\u76848\u79cd\u65b9\u5f0f \u4ecemain\u4e2d(\u81ea\u7136)\u8fd4\u56de \u8c03\u7528exit \u8c03\u7528_exit\u6216_Exit \u6700\u540e\u4e00\u4e2a\u7ebf\u7a0b\u81ea\u7136\u9000\u51fa \u6700\u540e\u4e00\u4e2a\u7ebf\u7a0b\u8c03\u7528pthread_exit \u5f02\u5e38\u7ec8\u6b62\u76843\u79cd\u65b9\u5f0f \u8c03\u7528abort \u6536&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10,6],"tags":[109],"class_list":["post-965","post","type-post","status-publish","format-standard","hentry","category-10","category-6","tag-apiue"],"_links":{"self":[{"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/posts\/965","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=965"}],"version-history":[{"count":1,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/posts\/965\/revisions"}],"predecessor-version":[{"id":968,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=\/wp\/v2\/posts\/965\/revisions\/968"}],"wp:attachment":[{"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=965"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=965"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.cauchyschwarz.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=965"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}