multi-legacy.c

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * SPDX-License-Identifier: curl
 *
 ***************************************************************************/
/* <DESC>
 * A basic application source code using the multi interface doing two
 * transfers in parallel without curl_multi_wait/poll.
 * </DESC>
 */
 
#include <stdio.h>
#include <string.h>
 
/* somewhat Unix-specific */
#ifndef _WIN32
#include <sys/time.h>
#include <unistd.h>
#endif
 
/* curl stuff */
#include <curl/curl.h>
 
/*
 * Download an HTTP file and upload an FTP file simultaneously.
 */
 
#define HTTP_HANDLE 0   /* Index for the HTTP transfer */
#define FTP_HANDLE 1    /* Index for the FTP transfer */
#define HANDLECOUNT 2   /* Number of simultaneous transfers */
 
int main(void)
{
  CURL *handles[HANDLECOUNT];
  CURLM *multi_handle;
 
  int i;
 
  CURLcode res = curl_global_init(CURL_GLOBAL_ALL);
  if(res)
    return (int)res;
 
  /* Allocate one curl handle per transfer */
  for(i = 0; i < HANDLECOUNT; i++)
    handles[i] = curl_easy_init();
 
  /* set the options (I left out a few, you get the point anyway) */
  curl_easy_setopt(handles[HTTP_HANDLE], CURLOPT_URL, "https://example.com");
 
  curl_easy_setopt(handles[FTP_HANDLE], CURLOPT_URL, "ftp://example.com");
  curl_easy_setopt(handles[FTP_HANDLE], CURLOPT_UPLOAD, 1L);
 
  /* init a multi stack */
  multi_handle = curl_multi_init();
  if(multi_handle) {
 
    int still_running = 0; /* keep number of running handles */
 
    CURLMsg *msg; /* for picking up messages with the transfer status */
    int msgs_left; /* how many messages are left */
 
    /* add the individual transfers */
    for(i = 0; i < HANDLECOUNT; i++)
      curl_multi_add_handle(multi_handle, handles[i]);
 
    /* we start some action by calling perform right away */
    curl_multi_perform(multi_handle, &still_running);
 
    while(still_running) {
 
      struct timeval timeout;
      int rc; /* select() return code */
      CURLMcode mc; /* curl_multi_fdset() return code */
 
      fd_set fdread;
      fd_set fdwrite;
      fd_set fdexcep;
      int maxfd = -1;
 
      long curl_timeo = -1;
 
      FD_ZERO(&fdread);
      FD_ZERO(&fdwrite);
      FD_ZERO(&fdexcep);
 
      /* set a suitable timeout to play around with */
      timeout.tv_sec = 1;
      timeout.tv_usec = 0;
 
      curl_multi_timeout(multi_handle, &curl_timeo);
      if(curl_timeo >= 0) {
#if defined(MSDOS) || defined(__AMIGA__)
        timeout.tv_sec = (time_t)(curl_timeo / 1000);
#else
        timeout.tv_sec = curl_timeo / 1000;
#endif
        if(timeout.tv_sec > 1)
          timeout.tv_sec = 1;
        else
#if defined(MSDOS) || defined(__AMIGA__)
          timeout.tv_usec = (time_t)(curl_timeo % 1000) * 1000;
#else
          timeout.tv_usec = (int)(curl_timeo % 1000) * 1000;
#endif
      }
 
      /* get file descriptors from the transfers */
      mc = curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
 
      if(mc != CURLM_OK) {
        fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc);
        break;
      }
 
      /* On success the value of maxfd is guaranteed to be >= -1. We call
         select(maxfd + 1, ...); specially in case of (maxfd == -1) there are
         no fds ready yet so we call select(0, ...) --or Sleep() on Windows--
         to sleep 100ms, which is the minimum suggested value in the
         curl_multi_fdset() doc. */
 
      if(maxfd == -1) {
#ifdef _WIN32
        Sleep(100);
        rc = 0;
#else
        /* Portable sleep for platforms other than Windows. */
        struct timeval wait = {0};
        wait.tv_usec = 100 * 1000; /* 100ms */
        rc = select(0, NULL, NULL, NULL, &wait);
#endif
      }
      else {
        /* Note that on some platforms 'timeout' may be modified by select().
           If you need access to the original value save a copy beforehand. */
        rc = select(maxfd + 1, &fdread, &fdwrite, &fdexcep, &timeout);
      }
 
      switch(rc) {
      case -1:
        /* select error */
        break;
      case 0: /* timeout */
      default: /* action */
        curl_multi_perform(multi_handle, &still_running);
        break;
      }
    }
 
    /* See how the transfers went */
    /* !checksrc! disable EQUALSNULL 1 */
    while((msg = curl_multi_info_read(multi_handle, &msgs_left)) != NULL) {
      if(msg->msg == CURLMSG_DONE) {
        int idx;
 
        /* Find out which handle this message is about */
        for(idx = 0; idx < HANDLECOUNT; idx++) {
          int found = (msg->easy_handle == handles[idx]);
          if(found)
            break;
        }
 
        switch(idx) {
        case HTTP_HANDLE:
          printf("HTTP transfer completed with status %d\n", msg->data.result);
          break;
        case FTP_HANDLE:
          printf("FTP transfer completed with status %d\n", msg->data.result);
          break;
        }
      }
    }
 
    curl_multi_cleanup(multi_handle);
  }
 
  /* Free the curl handles */
  for(i = 0; i < HANDLECOUNT; i++)
    curl_easy_cleanup(handles[i]);
 
  curl_global_cleanup();
 
  return 0;
}

Notice