c++ - Mongoose 正在阻塞其他请求并一一处理

Question

我试图在“示例”下运行“restful_server”示例。 ev_handler 函数一个接一个地处理所有请求，因此一个请求必须等到前一个请求完成。

/*
 * Copyright (c) 2014 Cesanta Software Limited
 * All rights reserved
 */

#include "mongoose.h"
#include <unistd.h>

static const char *s_http_port = "8004";
static struct mg_serve_http_opts s_http_server_opts;

static void handle_sum_call(struct mg_connection *nc, struct http_message *hm) {
  char n1[100], n2[100];
  double result;

  /* Get form variables */
  mg_get_http_var(&hm->body, "n1", n1, sizeof(n1));
  mg_get_http_var(&hm->body, "n2", n2, sizeof(n2));

    int n2s = (int) strtod(n2, NULL);
    if(n2s == 100){
        while(n2s == 100){
            n2s = 100;  
        }
    }

  /* Send headers */
  mg_printf(nc, "%s", "HTTP/1.1 200 OK\r\nTransfer-Encoding: chunked\r\n\r\n");

  /* Compute the result and send it back as a JSON object */
  result = strtod(n1, NULL) + strtod(n2, NULL);
  mg_printf_http_chunk(nc, "{ \"result\": %lf }", result);
  mg_send_http_chunk(nc, "", 0); /* Send empty chunk, the end of response */
}

static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
  struct http_message *hm = (struct http_message *) ev_data;

  switch (ev) {
    case MG_EV_HTTP_REQUEST:
      if (mg_vcmp(&hm->uri, "/api/v1/sum") == 0) {
        handle_sum_call(nc, hm); /* Handle RESTful call */
      } else if (mg_vcmp(&hm->uri, "/printcontent") == 0) {
        char buf[100] = {0};
        memcpy(buf, hm->body.p,
               sizeof(buf) - 1 < hm->body.len ? sizeof(buf) - 1 : hm->body.len);
        printf("%s\n", buf);
      } else {
        mg_serve_http(nc, hm, s_http_server_opts); /* Serve static content */
      }
      break;
    default:
      break;
  }
}

int main(int argc, char *argv[]) {
  struct mg_mgr mgr;
  struct mg_connection *nc;
  struct mg_bind_opts bind_opts;
  int i;
  char *cp;
  const char *err_str;
#if MG_ENABLE_SSL
  const char *ssl_cert = NULL;
#endif

  mg_mgr_init(&mgr, NULL);

  /* Use current binary directory as document root */
  if (argc > 0 && ((cp = strrchr(argv[0], DIRSEP)) != NULL)) {
    *cp = '\0';
    s_http_server_opts.document_root = argv[0];
  }

  /* Process command line options to customize HTTP server */
  for (i = 1; i < argc; i++) {
    if (strcmp(argv[i], "-D") == 0 && i + 1 < argc) {
      mgr.hexdump_file = argv[++i];
    } else if (strcmp(argv[i], "-d") == 0 && i + 1 < argc) {
      s_http_server_opts.document_root = argv[++i];
    } else if (strcmp(argv[i], "-p") == 0 && i + 1 < argc) {
      s_http_port = argv[++i];
    } else if (strcmp(argv[i], "-a") == 0 && i + 1 < argc) {
      s_http_server_opts.auth_domain = argv[++i];
#if MG_ENABLE_JAVASCRIPT
    } else if (strcmp(argv[i], "-j") == 0 && i + 1 < argc) {
      const char *init_file = argv[++i];
      mg_enable_javascript(&mgr, v7_create(), init_file);
#endif
    } else if (strcmp(argv[i], "-P") == 0 && i + 1 < argc) {
      s_http_server_opts.global_auth_file = argv[++i];
    } else if (strcmp(argv[i], "-A") == 0 && i + 1 < argc) {
      s_http_server_opts.per_directory_auth_file = argv[++i];
    } else if (strcmp(argv[i], "-r") == 0 && i + 1 < argc) {
      s_http_server_opts.url_rewrites = argv[++i];
#if MG_ENABLE_HTTP_CGI
    } else if (strcmp(argv[i], "-i") == 0 && i + 1 < argc) {
      s_http_server_opts.cgi_interpreter = argv[++i];
#endif
#if MG_ENABLE_SSL
    } else if (strcmp(argv[i], "-s") == 0 && i + 1 < argc) {
      ssl_cert = argv[++i];
#endif
    } else {
      fprintf(stderr, "Unknown option: [%s]\n", argv[i]);
      exit(1);
    }
  }

  /* Set HTTP server options */
  memset(&bind_opts, 0, sizeof(bind_opts));
  bind_opts.error_string = &err_str;
#if MG_ENABLE_SSL
  if (ssl_cert != NULL) {
    bind_opts.ssl_cert = ssl_cert;
  }
#endif
  nc = mg_bind_opt(&mgr, s_http_port, ev_handler, bind_opts);
  if (nc == NULL) {
    fprintf(stderr, "Error starting server on port %s: %s\n", s_http_port,
            *bind_opts.error_string);
    exit(1);
  }

  mg_set_protocol_http_websocket(nc);
  s_http_server_opts.enable_directory_listing = "yes";

  printf("Starting RESTful server on port %s, serving %s\n", s_http_port,
         s_http_server_opts.document_root);
  for (;;) {
    mg_mgr_poll(&mgr, 1000);
  }
  mg_mgr_free(&mgr);

  return 0;
}

我也尝试过在 handle_sum_call 中添加 sleep 函数。

static void handle_sum_call(struct mg_connection *nc, struct http_message *hm) {
  char n1[100], n2[100];
  double result;

  /* Get form variables */
  mg_get_http_var(&hm->body, "n1", n1, sizeof(n1));
  mg_get_http_var(&hm->body, "n2", n2, sizeof(n2));

    int n2s = (int) strtod(n2, NULL);
    if(n2s == 100){
        sleep(6000);
    }

  /* Send headers */
  mg_printf(nc, "%s", "HTTP/1.1 200 OK\r\nTransfer-Encoding: chunked\r\n\r\n");

  /* Compute the result and send it back as a JSON object */
  result = strtod(n1, NULL) + strtod(n2, NULL);
  mg_printf_http_chunk(nc, "{ \"result\": %lf }", result);
  mg_send_http_chunk(nc, "", 0); /* Send empty chunk, the end of response */
}

我计划使用 mongoose 创建一个简单的 Web 应用程序，供 10-20 个用户使用(不要太多)。它说它是异步非阻塞的？我做错了什么吗？

Answer 1

请查看https://github.com/cesanta/fossa用于基于多线程的网络服务器

我们需要在初始化模块后调用下面的语句(标记为粗体)

{ ...

ns_mgr_init(&mgr, NULL);

nc = ns_bind(&mgr, s_http_port, ev_handler);

ns_set_protocol_http_websocket(nc);

ns_enable_multithreading(nc);

...

不要忘记在编译标志中启用定义的 NS_ENABLE_THREADS