{"id":1825,"date":"2019-01-19T11:22:25","date_gmt":"2019-01-19T03:22:25","guid":{"rendered":"https:\/\/www.yusian.com\/blog\/?p=1825"},"modified":"2020-12-02T11:25:15","modified_gmt":"2020-12-02T03:25:15","slug":"linux%e7%bc%96%e7%a8%8b-%e4%bf%a1%e5%8f%b7%e9%87%8f","status":"publish","type":"post","link":"https:\/\/www.yusian.com\/blog\/cpp\/2019\/01\/19\/1122251825.html","title":{"rendered":"Linux\u7f16\u7a0b&#8211;\u4fe1\u53f7\u91cf"},"content":{"rendered":"<h3>1\u3001\u76f8\u5173\u51fd\u6570<\/h3>\n<pre><code class=\"language-c line-numbers\">#include &lt;semaphore.h&gt;\n\/\/ \u521d\u59cb\u5316\nint sem_init(sem_t *sem, int pshared, unsigned int value);\n\/\/ \u52a0\u9501\u4fe1\u53f7\u91cf\nint sem_wait(sem_t *sem);\n\nint sem_trywait(sem_t *sem);\n\nint sem_timedwait(sem_t *sem, const struct timespec *abs_timeout);\n\/\/ \u89e3\u9664\u4fe1\u53f7\u91cf\nint sem_post(sem_t *sem);\n<\/code><\/pre>\n<p><!--more--><\/p>\n<h3>2\u3001\u4fe1\u53f7\u91cf\u793a\u4f8b\u5b9e\u73b0\u751f\u4ea7\u8005&amp;\u6d88\u8d39\u8005\u6a21\u578b<\/h3>\n<pre><code class=\"language-c line-numbers\">#include &lt;stdio.h&gt;\n#include &lt;stdlib.h&gt;\n#include &lt;pthread.h&gt;\n#include &lt;semaphore.h&gt;\n#include &lt;unistd.h&gt;\n\n#define NUM 5    \/\/ \u5b9a\u4e49\u6700\u5927\u4fe1\u53f7\u91cf\n\/\/ \u5b9a\u4e49\u6570\u636e\u6a21\u578b\nstruct object{\n    int num;\n};\n\/\/ \u751f\u4ea7\u6d88\u606f\u6570\u636e\u7ed3\u6784\nstruct object* queue[NUM];\n\/\/ 1\u3001\u5b9a\u4e492\u4e2a\u4fe1\u53f7\u91cf(\u751f\u4ea7&amp;\u6d88\u8d39)\nsem_t consumer, producer;\n\/\/ \u6d88\u606f\u8005\u51fd\u6570\u4e3b\u4f53\nvoid *consume(void *arg){\n    int i = 0;\n    while(1){\n        \/\/ \u6d88\u8d39\u8005\u5e94\u8be5\u7b49\u5f85\u751f\u4ea7\u8005\u7684\u4fe1\u53f7\u91cf\u91ca\u653e\uff0c\u6ca1\u6709\u751f\u4ea7\u5c31\u6ca1\u6709\u6d88\u8d39\n        sem_wait(&amp;producer);\n        \/\/ \u6d88\u8d39\u6389\u4e00\u4e2a\u91cf\n        struct object *obj = queue[i];\n        printf(\"consumer ----- %d |\", obj-&gt;num);\n        queue[i] = NULL;\n        \/\/ \u6253\u5370\u5f53\u524d\u8fd8\u5269\u4e0b\u7684\u5f85\u6d88\u8d39\u91cf\n        int j = i+1;\n        struct object *p = queue[j%NUM];\n        while(p){\n            printf(\" %d\", p-&gt;num);\n            p = queue[++j%NUM];\n        }\n        putchar('\\n');\n        \/\/ \u589e\u52a0\u4e00\u4e2a\u6d88\u8d39\u91cf\n        sem_post(&amp;consumer);\n        usleep(rand()%500000);\n        free(obj);\n        i = ++i % NUM;\n    }\n}\n\/\/ \u751f\u4ea7\u8005\u51fd\u6570\u4e3b\u4f53\nvoid *production(void *arg){\n    int i = 0;\n    while(1){\n        \/\/ \u7b49\u5f85\u6d88\u8d39\u4fe1\u53f7\u91cf(\u6d88\u8d39\u4fe1\u53f7\u91cf\u521d\u59cb\u4e3a5)\n        sem_wait(&amp;consumer);\n        \/\/ \u6709\u9700\u6c42\u624d\u751f\u4ea7\n        struct object *obj = malloc(sizeof(struct object));\n        obj-&gt;num = rand() &amp; 99;\n        \/\/ \u751f\u4ea7\u51fa\u6765\u7684\u4ea7\u54c1\u5faa\u73af\u6302\u5230\u961f\u5217\u4e2d\n        queue[i] = obj;\n        printf(\"producer ----- %d\\n\", obj-&gt;num);\n        \/\/ \u589e\u52a0\u4e00\u4e2a\u751f\u4ea7\u91cf\n        sem_post(&amp;producer);\n        usleep(rand()%500000);\n        i = ++i % NUM;\n    }\n}\nint main(){\n    \/\/ \u4ea7\u751f\u4e00\u4e2a\u968f\u673a\u6570\u79cd\u5b50\n    srand(time(NULL));\n    \/\/ \u521d\u59cb\u5316\u4e24\u4e2a\u4fe1\u53f7\u91cf\n    sem_init(&amp;consumer, 0, NUM);\n    sem_init(&amp;producer, 0, 0);\n\n    \/\/ \u521d\u59cb\u53162\u4e2a\u7ebf\u7a0b\uff0c\u5206\u522b\u6a21\u62df\u751f\u4ea7\u4e0e\u6d88\u8d39\n    pthread_t tid_c, tid_p;\n    pthread_create(&amp;tid_c, NULL, consume, NULL);\n    pthread_create(&amp;tid_p, NULL, production, NULL);\n\n    \/\/ \u4e3b\u7ebf\u7a0b\u5408\u5e76(\u56de\u6536)\u4e24\u4e2a\u5b50\u7ebf\u7a0b\n    pthread_join(tid_c, NULL);\n    pthread_join(tid_p, NULL);\n\n    \/\/ \u4fe1\u53f7\u91cf\u4f7f\u7528\u540e\u53ca\u65f6\u91ca\u653e\u9500\u6bc1\n    sem_destroy(&amp;consumer);\n    sem_destroy(&amp;producer);\n\n    return 0;\n}\n<\/code><\/pre>\n<p>\u6267\u884c\u7ed3\u679c\uff1a<\/p>\n<pre><code class=\"language-cmd line-numbers\">parallels@ubuntu:~\/Linux\/sem$ .\/sem.out\nproducer ----- 98\nconsumer ----- 98 |\nproducer ----- 34\nproducer ----- 1\nconsumer ----- 34 | 1\nconsumer ----- 1 |\nproducer ----- 98\nproducer ----- 2\nconsumer ----- 98 | 2\nconsumer ----- 2 |\nproducer ----- 35\nconsumer ----- 35 |\nproducer ----- 0\nproducer ----- 96\nconsumer ----- 0 | 96\nproducer ----- 98\nconsumer ----- 96 | 98\nproducer ----- 35\nproducer ----- 1\nconsumer ----- 98 | 35 1\nproducer ----- 99\nproducer ----- 1\nproducer ----- 3\nconsumer ----- 35 | 1 99 1 3\nconsumer ----- 1 | 99 1 3\nconsumer ----- 99 | 1 3\nproducer ----- 32\nconsumer ----- 1 | 3 32\nproducer ----- 65\nconsumer ----- 3 | 32 65\nproducer ----- 0\nproducer ----- 3\nconsumer ----- 32 | 65 0 3\nproducer ----- 96\nconsumer ----- 65 | 0 3 96\nproducer ----- 98\nproducer ----- 96\nconsumer ----- 0 | 3 96 98 96\nconsumer ----- 3 | 96 98 96\nproducer ----- 97\nconsumer ----- 96 | 98 96 97\nconsumer ----- 98 | 96 97\nconsumer ----- 96 | 97\nconsumer ----- 97 |\nproducer ----- 0\nconsumer ----- 0 |\nproducer ----- 66\nconsumer ----- 66 |\nproducer ----- 35\nproducer ----- 65\nproducer ----- 97\nconsumer ----- 35 | 65 97\n^C\nparallels@ubuntu:~\/Linux\/sem$\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>1\u3001\u76f8\u5173\u51fd\u6570 #include &lt;semaphore.h&gt; \/\/ \u521d\u59cb\u5316 int sem_init(sem_t *sem, int pshared, unsigned int value); \/\/ \u52a0\u9501\u4fe1\u53f7\u91cf int sem_wait(sem_t *sem); int sem_trywait(sem_t *sem); int sem_timedwait(sem_t *sem, const struct timespec *abs_timeout); \/\/ \u89e3\u9664\u4fe1\u53f7\u91cf int sem_post(sem_t *sem);<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[88],"tags":[310,317],"class_list":["post-1825","post","type-post","status-publish","format-standard","hentry","category-cpp","tag-linux","tag-317"],"_links":{"self":[{"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/posts\/1825","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/comments?post=1825"}],"version-history":[{"count":0,"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/posts\/1825\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/media?parent=1825"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/categories?post=1825"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.yusian.com\/blog\/wp-json\/wp\/v2\/tags?post=1825"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}