bool	CMultiHttp::Perform()
	{
		struct timeval timeout;
		int still_running=0;
		int rc=0;			/* 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 = 5;
		timeout.tv_usec = 0;
		curl_multi_timeout(m_murl, &curl_timeo);
		if( curl_timeo==0 )
			curl_timeo=50;
		if(curl_timeo >= 0)
		{
			timeout.tv_sec = curl_timeo/1000;
			if(timeout.tv_sec > 1)
				timeout.tv_sec = 1;
			else
				timeout.tv_usec = (curl_timeo % 1000) * 1000;
		}
		/* get file descriptors from the transfers */ 
		mc = curl_multi_fdset(m_murl, &fdread, &fdwrite, &fdexcep, &maxfd);
		if(mc != CURLM_OK)
		{
			LOG_FUNC_P1(_T("curl_multi_fdset() failed, code %d"),mc);
			return false;
		}
		/* 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)
		{
			Sleep(100);
			rc = 0;
		}
		else
		{
			FD_SET(m_fds[1],&fdread);
			FD_SET(m_fds[1],&fdwrite);
			FD_SET(m_fds[1],&fdexcep);
			rc = ::select(maxfd+2, &fdread,&fdwrite, &fdexcep, &timeout);
			if(FD_ISSET(m_fds[1],&fdread))
			{
				std::string cmd;
				if( !recvcmd(m_fds[1],cmd) )
				{
					m_state = CMultiHttp::Terminate;
					return false;
				}
				if( cmd==CMD_CANCEL )
				{
					LOG_FUNC_P0(_T("url 后台线程 收到退出指令"));
					m_state = CMultiHttp::Terminate;
					return false;
				}
			}
		}
		switch(rc)
		{
		case -1:
			/* select error */ 
			break;
		case 0:
		default:
			while( CURLM_CALL_MULTI_PERFORM==curl_multi_perform(m_murl,&still_running) )
				;
			{
				struct CURLMsg *m;
				int msgQ=0;
				m = curl_multi_info_read(m_murl,&msgQ);
				if(m && (m->msg == CURLMSG_DONE))
				{
					CURL *e = m->easy_handle;
					if( !OneComplete(e,m->data.result) )
						still_running=0;
				}
			}
			break;
		}
		if( still_running )
			return true;
		m_state = CMultiHttp::Terminate;
		return false;
	}

URL_FILE *
CoolUrlFopen(const char *url,const char *operation)
{
    /* this code could check for URLs or types in the 'url' and
       basicly use the real fopen() for standard files */

    URL_FILE *file;
	int ret;
    (void)operation;
	char head_buffer[BUFFER_SIZE];
	
    file = (URL_FILE *)malloc(sizeof(URL_FILE));
    if(!file)
        return NULL;

    memset(file, 0, sizeof(URL_FILE));
	if(url)
		file->url=strdup(url);
	else
		file->url=NULL;

        curl_global_init(CURL_GLOBAL_ALL);
	//get http head
	file->curl = curl_easy_init();

	curl_easy_setopt(file->curl, CURLOPT_URL, file->url);
	curl_easy_setopt(file->curl, CURLOPT_WRITEDATA, head_buffer);
	curl_easy_setopt(file->curl, CURLOPT_NOBODY, 1);
	curl_easy_setopt(file->curl, CURLOPT_HEADER, 1);
	curl_easy_setopt(file->curl, CURLOPT_VERBOSE, 0);
	curl_easy_setopt(file->curl, CURLOPT_WRITEFUNCTION, write_head_callback);
	ret = curl_easy_perform(file->curl);
	curl_easy_cleanup(file->curl);
	if(ret != CURLE_OK)
	{
		printf("get file size error url=%s",file->url);
		return NULL;
	}
	file->size = get_file_size_from_head(head_buffer);
	if(!file->size)
		return NULL;

	file->curl = curl_easy_init();
	curl_easy_setopt(file->curl, CURLOPT_URL, file->url);
	curl_easy_setopt(file->curl, CURLOPT_WRITEDATA, file);
	curl_easy_setopt(file->curl, CURLOPT_VERBOSE, 0);
	curl_easy_setopt(file->curl, CURLOPT_WRITEFUNCTION, write_callback);

	multi_handle = curl_multi_init();

	curl_multi_add_handle(multi_handle, file->curl);

    // lets start the fetch 
	while(curl_multi_perform(multi_handle, &file->still_running) ==
			CURLM_CALL_MULTI_PERFORM );

	if((file->buffer_pos == 0) && (!file->still_running))
	{
		// if still_running is 0 now, we should return NULL 

		// make sure the easy handle is not in the multi handle anymore 
		curl_multi_remove_handle(multi_handle, file->curl);

		// cleanup 
		curl_easy_cleanup(file->curl);

		free(file);

		file = NULL;
	}
    return file;
}

static void
curl_main ()
{
  fd_set rs;
  fd_set ws;
  fd_set es;
  int max;
  struct GNUNET_NETWORK_FDSet nrs;
  struct GNUNET_NETWORK_FDSet nws;
  struct GNUNET_TIME_Relative delay;
  long timeout;
  int running;
  struct CURLMsg *msg;

  max = 0;
  FD_ZERO (&rs);
  FD_ZERO (&ws);
  FD_ZERO (&es);
  curl_multi_perform (multi, &running);
  if (running == 0)
  {
    GNUNET_assert (NULL != (msg = curl_multi_info_read (multi, &running)));
    if (msg->msg == CURLMSG_DONE)
    {
      if (msg->data.result != CURLE_OK)
      {
	fprintf (stderr,
		 "%s failed at %s:%d: `%s'\n",
		 "curl_multi_perform",
		__FILE__,
		__LINE__, curl_easy_strerror (msg->data.result));
	global_ret = 1;
      }
    }
    curl_multi_remove_handle (multi, curl);
    curl_multi_cleanup (multi);
    curl_easy_cleanup (curl);
    curl = NULL;
    multi = NULL;
    if (cbc.pos != strlen ("/hello_world"))
    {
      GNUNET_break (0);
      global_ret = 2;
    }
    if (0 != strncmp ("/hello_world", cbc.buf, strlen ("/hello_world")))
    {
      GNUNET_break (0);
      global_ret = 3;
    }
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Download complete, shutting down!\n");
    do_shutdown ();
    return;
  }
  GNUNET_assert (CURLM_OK == curl_multi_fdset (multi, &rs, &ws, &es, &max));
  if ( (CURLM_OK != curl_multi_timeout (multi, &timeout)) ||
       (-1 == timeout) )
    delay = GNUNET_TIME_UNIT_SECONDS;
  else
    delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, (unsigned int) timeout);
  GNUNET_NETWORK_fdset_copy_native (&nrs,
				    &rs,
				    max + 1);
  GNUNET_NETWORK_fdset_copy_native (&nws,
				    &ws,
				    max + 1);
  curl_task_id = GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_DEFAULT,
					      delay,
					      &nrs,
					      &nws,
					      &curl_task,
					      NULL);
}

void rest_multi_perform(MultiRestState *state) {
    int still_running;
    curl_multi_perform(state->multi_handle, &still_running);
}

CURLcode CURLNetRequest::CURLHolder::perform()
{
    activate();
    
    int const CHUNK = 1;
    
    long noactivity = 0;
    
    CURLcode result;
    for(;;) {
        int running;
        CURLMcode err = curl_multi_perform(m_curlm, &running);
        if (err == CURLM_CALL_MULTI_PERFORM)
            continue;
        if (err != CURLM_OK) {
            RAWLOG_ERROR1("curl_multi_perform error: %d", (int)err);
        }
        else {
            if (running > 0 && noactivity < timeout) {
                RAWTRACE("we still have active transfers but no data ready at this moment; waiting...");
                fd_set rfd, wfd, efd;
                int n = 0;
                FD_ZERO(&rfd);
                FD_ZERO(&wfd);
                FD_ZERO(&efd);
                err = curl_multi_fdset(m_curlm, &rfd, &wfd, &efd, &n);
                if (err == CURLM_OK) {
                    if (n > 0) {
                        timeval tv;
                        tv.tv_sec = CHUNK;
                        tv.tv_usec = 0;
                        int e = select(n + 1, &rfd, &wfd, &efd, &tv);
                        if (e < 0) {
                            RAWLOG_ERROR1("select (on curl handles) error: %d", errno);
                        }
                        else {
                            if (e == 0) {
                                RAWTRACE("No activity on sockets, check them again");
                                noactivity += CHUNK;
                            }
                            else noactivity = 0;
                            continue;
                        }
                    }
                }
                else {
                    RAWLOG_ERROR1("curl_multi_fdset error: %d", (int)err);
                }

            }
        }
        int nmsgs;
        CURLMsg *msg = curl_multi_info_read(m_curlm, &nmsgs);
        result = CURLE_OK;
        if (msg && msg->msg == CURLMSG_DONE)
            result = msg->data.result;
        if (result == CURLE_OK && noactivity >= timeout)
            result = CURLE_OPERATION_TIMEDOUT;
        if (result == CURLE_OK || result == CURLE_PARTIAL_FILE)
            RAWTRACE("Operation completed successfully");
        else
            RAWLOG_ERROR2("Operation finished with error %d: %s", (int)result, curl_easy_strerror(result));
        break;
    }

    deactivate();
    return result;
}

static int
testExternalGet ()
{
  struct MHD_Daemon *d;
  CURL *c;
  char buf[2048];
  struct CBC cbc;
  CURLM *multi;
  CURLMcode mret;
  fd_set rs;
  fd_set ws;
  fd_set es;
  int max;
  int running;
  struct CURLMsg *msg;
  time_t start;
  struct timeval tv;

  multi = NULL;
  cbc.buf = buf;
  cbc.size = 2048;
  cbc.pos = 0;
  d = MHD_start_daemon (MHD_USE_DEBUG | MHD_USE_SSL,
                        1082, NULL, NULL, &ahc_echo, "GET", 
                        MHD_OPTION_HTTPS_MEM_KEY, srv_key_pem,
                        MHD_OPTION_HTTPS_MEM_CERT, srv_self_signed_cert_pem,
			MHD_OPTION_END);
  if (d == NULL)
    return 256;

  char *aes256_sha = "AES256-SHA";
  if (curl_uses_nss_ssl() == 0)
    {
      aes256_sha = "rsa_aes_256_sha";
    }

  c = curl_easy_init ();
  curl_easy_setopt (c, CURLOPT_URL, "https://localhost:1082/hello_world");
  curl_easy_setopt (c, CURLOPT_WRITEFUNCTION, &copyBuffer);
  curl_easy_setopt (c, CURLOPT_WRITEDATA, &cbc);
  /* TLS options */
  curl_easy_setopt (c, CURLOPT_SSLVERSION, CURL_SSLVERSION_SSLv3);
  curl_easy_setopt (c, CURLOPT_SSL_CIPHER_LIST, aes256_sha);
  curl_easy_setopt (c, CURLOPT_SSL_VERIFYPEER, 0);
  curl_easy_setopt (c, CURLOPT_SSL_VERIFYHOST, 0);
  curl_easy_setopt (c, CURLOPT_FAILONERROR, 1);
  if (oneone)
    curl_easy_setopt (c, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
  else
    curl_easy_setopt (c, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_0);
  curl_easy_setopt (c, CURLOPT_TIMEOUT, 150L);
  curl_easy_setopt (c, CURLOPT_CONNECTTIMEOUT, 15L);
  /* NOTE: use of CONNECTTIMEOUT without also
     setting NOSIGNAL results in really weird
     crashes on my system! */
  curl_easy_setopt (c, CURLOPT_NOSIGNAL, 1);


  multi = curl_multi_init ();
  if (multi == NULL)
    {
      curl_easy_cleanup (c);
      MHD_stop_daemon (d);
      return 512;
    }
  mret = curl_multi_add_handle (multi, c);
  if (mret != CURLM_OK)
    {
      curl_multi_cleanup (multi);
      curl_easy_cleanup (c);
      MHD_stop_daemon (d);
      return 1024;
    }
  start = time (NULL);
  while ((time (NULL) - start < 5) && (multi != NULL))
    {
      max = 0;
      FD_ZERO (&rs);
      FD_ZERO (&ws);
      FD_ZERO (&es);
      curl_multi_perform (multi, &running);
      mret = curl_multi_fdset (multi, &rs, &ws, &es, &max);
      if (mret != CURLM_OK)
        {
          curl_multi_remove_handle (multi, c);
          curl_multi_cleanup (multi);
          curl_easy_cleanup (c);
          MHD_stop_daemon (d);
          return 2048;
        }
      if (MHD_YES != MHD_get_fdset (d, &rs, &ws, &es, &max))
        {
          curl_multi_remove_handle (multi, c);
          curl_multi_cleanup (multi);
          curl_easy_cleanup (c);
          MHD_stop_daemon (d);
          return 4096;
        }
      tv.tv_sec = 0;
      tv.tv_usec = 1000;
//.........这里部分代码省略.........

int test(char *URL)
{
  CURL *easy;
  CURLM *multi_handle;
  int still_running; /* keep number of running handles */
  CURLMsg *msg; /* for picking up messages with the transfer status */
  int msgs_left; /* how many messages are left */

  /* Allocate one CURL handle per transfer */
  easy = curl_easy_init();

  /* init a multi stack */
  multi_handle = curl_multi_init();

  /* add the individual transfer */
  curl_multi_add_handle(multi_handle, easy);

  /* set the options (I left out a few, you'll get the point anyway) */
  curl_easy_setopt(easy, CURLOPT_URL, URL);
  curl_easy_setopt(easy, CURLOPT_POSTFIELDSIZE_LARGE,
                   (curl_off_t)testDataSize);
  curl_easy_setopt(easy, CURLOPT_POSTFIELDS, testData);

  /* we start some action by calling perform right away */
  curl_multi_perform(multi_handle, &still_running);

  do {
    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) {
      timeout.tv_sec = curl_timeo / 1000;
      if(timeout.tv_sec > 1)
        timeout.tv_sec = 1;
      else
        timeout.tv_usec = (curl_timeo % 1000) * 1000;
    }

    /* 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, 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;
    }
  } while(still_running);

  /* See how the transfers went */
  while((msg = curl_multi_info_read(multi_handle, &msgs_left))) {
    if(msg->msg == CURLMSG_DONE) {
      printf("HTTP transfer completed with status %d\n", msg->data.result);
//.........这里部分代码省略.........

void CurlDownloadManager::downloadThread(void* data)
{
    CurlDownloadManager* downloadManager = reinterpret_cast<CurlDownloadManager*>(data);

    while (downloadManager->runThread()) {

        downloadManager->updateHandleList();

        // Retry 'select' if it was interrupted by a process signal.
        int rc = 0;
        do {
            fd_set fdread;
            fd_set fdwrite;
            fd_set fdexcep;

            int maxfd = 0;

            const int selectTimeoutMS = 5;

            struct timeval timeout;
            timeout.tv_sec = 0;
            timeout.tv_usec = selectTimeoutMS * 1000; // select waits microseconds

            FD_ZERO(&fdread);
            FD_ZERO(&fdwrite);
            FD_ZERO(&fdexcep);
            curl_multi_fdset(downloadManager->getMultiHandle(), &fdread, &fdwrite, &fdexcep, &maxfd);
            // When the 3 file descriptors are empty, winsock will return -1
            // and bail out, stopping the file download. So make sure we
            // have valid file descriptors before calling select.
            if (maxfd >= 0)
                rc = ::select(maxfd + 1, &fdread, &fdwrite, &fdexcep, &timeout);
        } while (rc == -1 && errno == EINTR);

        int activeDownloadCount = 0;
        while (curl_multi_perform(downloadManager->getMultiHandle(), &activeDownloadCount) == CURLM_CALL_MULTI_PERFORM) { }

        int messagesInQueue = 0;
        CURLMsg* msg = curl_multi_info_read(downloadManager->getMultiHandle(), &messagesInQueue);

        if (!msg)
            continue;

        CurlDownload* download = 0;
        CURLcode err = curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE, &download);

        if (msg->msg == CURLMSG_DONE) {
            if (msg->data.result == CURLE_OK)
                callOnMainThread([download] {
                    if (download)
                        download->didFinish();
                });
            else
                callOnMainThread([download] {
                    if (download)
                        download->didFail();
                });

            downloadManager->removeFromCurl(msg->easy_handle);
        }

        downloadManager->stopThreadIfIdle();
    }
}

int main(void)
{
  signal(SIGINT, sighandler);
  LIBXML_TEST_VERSION;
  curl_global_init(CURL_GLOBAL_DEFAULT);
  CURLM *multi_handle = curl_multi_init();
  curl_multi_setopt(multi_handle, CURLMOPT_MAX_TOTAL_CONNECTIONS, max_con);
  curl_multi_setopt(multi_handle, CURLMOPT_MAX_HOST_CONNECTIONS, 6L);

  /* enables http/2 if available */
#ifdef CURLPIPE_MULTIPLEX
  curl_multi_setopt(multi_handle, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
#endif

  /* sets html start page */
  curl_multi_add_handle(multi_handle, make_handle(start_page));

  int msgs_left;
  int pending = 0;
  int complete = 0;
  int still_running = 1;
  while(still_running && !pending_interrupt) {
    int numfds;
    curl_multi_wait(multi_handle, NULL, 0, 1000, &numfds);
    curl_multi_perform(multi_handle, &still_running);

    /* See how the transfers went */
    CURLMsg *m = NULL;
    while((m = curl_multi_info_read(multi_handle, &msgs_left))) {
      if(m->msg == CURLMSG_DONE) {
        CURL *handle = m->easy_handle;
        char *url;
        memory *mem;
        curl_easy_getinfo(handle, CURLINFO_PRIVATE, &mem);
        curl_easy_getinfo(handle, CURLINFO_EFFECTIVE_URL, &url);
        if(m->data.result == CURLE_OK) {
          long res_status;
          curl_easy_getinfo(handle, CURLINFO_RESPONSE_CODE, &res_status);
          if(res_status == 200) {
            char *ctype;
            curl_easy_getinfo(handle, CURLINFO_CONTENT_TYPE, &ctype);
            printf("[%d] HTTP 200 (%s): %s\n", complete, ctype, url);
            if(is_html(ctype) && mem->size > 100) {
              if(pending < max_requests && (complete + pending) < max_total) {
                pending += follow_links(multi_handle, mem, url);
                still_running = 1;
              }
            }
          }
          else {
            printf("[%d] HTTP %d: %s\n", complete, (int) res_status, url);
          }
        }
        else {
          printf("[%d] Connection failure: %s\n", complete, url);
        }
        curl_multi_remove_handle(multi_handle, handle);
        curl_easy_cleanup(handle);
        free(mem->buf);
        free(mem);
        complete++;
        pending--;
      }
    }
  }
  curl_multi_cleanup(multi_handle);
  curl_global_cleanup();
  return 0;
}

/*
 * Source code in here hugely as reported in bug report 651464 by
 * Christopher R. Palmer.
 *
 * Use multi interface to get document over proxy with bad port number.
 * This caused the interface to "hang" in libcurl 7.10.2.
 */
int test(char *URL)
{
    CURL *c;
    int ret=0;
    CURLM *m;
    fd_set rd, wr, exc;
    CURLMcode res;
    int running;
    int max_fd;
    int rc;

    curl_global_init(CURL_GLOBAL_ALL);
    c = curl_easy_init();

    /* the point here being that there must not run anything on the given
       proxy port */
    curl_easy_setopt(c, CURLOPT_PROXY, arg2);
    curl_easy_setopt(c, CURLOPT_URL, URL);
    curl_easy_setopt(c, CURLOPT_VERBOSE, 1);

    m = curl_multi_init();

    res = curl_multi_add_handle(m, c);
    if(res && (res != CURLM_CALL_MULTI_PERFORM))
        return 1; /* major failure */
    do
    {
        struct timeval interval;

        interval.tv_sec = 1;
        interval.tv_usec = 0;

        fprintf(stderr, "curl_multi_perform()\n");

        do
        {
            res = curl_multi_perform(m, &running);
        }
        while (res == CURLM_CALL_MULTI_PERFORM);
        if(!running)
        {
            /* This is where this code is expected to reach */
            int numleft;
            CURLMsg *msg = curl_multi_info_read(m, &numleft);
            fprintf(stderr, "Expected: not running\n");
            if(msg && !numleft)
                ret = 100; /* this is where we should be */
            else
                ret = 99; /* not correct */
            break;
        }
        fprintf(stderr, "running == %d, res == %d\n", running, res);

        if (res != CURLM_OK)
        {
            ret = 2;
            break;
        }

        FD_ZERO(&rd);
        FD_ZERO(&wr);
        FD_ZERO(&exc);
        max_fd = 0;

        fprintf(stderr, "curl_multi_fdset()\n");
        if (curl_multi_fdset(m, &rd, &wr, &exc, &max_fd) != CURLM_OK)
        {
            fprintf(stderr, "unexpected failured of fdset.\n");
            ret = 3;
            break;
        }
        rc = select(max_fd+1, &rd, &wr, &exc, &interval);
        fprintf(stderr, "select returned %d\n", rc);

    }
    while(rc);

    curl_multi_remove_handle(m, c);
    curl_easy_cleanup(c);
    curl_multi_cleanup(m);

    return ret;
}

/*
 * Upload all files over HTTP/2, using the same physical connection!
 */
int main(int argc, char **argv)
{
  CURL *easy[NUM_HANDLES];
  CURLM *multi_handle;
  int i;
  int still_running; /* keep number of running handles */
  const char *filename = "index.html";

  if(argc > 1)
    /* if given a number, do that many transfers */
    num_transfers = atoi(argv[1]);

  if(argc > 2)
    /* if given a file name, upload this! */
    filename = argv[2];

  if(!num_transfers || (num_transfers > NUM_HANDLES))
    num_transfers = 3; /* a suitable low default */

  /* init a multi stack */
  multi_handle = curl_multi_init();

  for(i=0; i<num_transfers; i++) {
    easy[i] = curl_easy_init();
    /* set options */
    setup(easy[i], i, filename);

    /* add the individual transfer */
    curl_multi_add_handle(multi_handle, easy[i]);
  }

  curl_multi_setopt(multi_handle, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);

  /* We do HTTP/2 so let's stick to one connection per host */
  curl_multi_setopt(multi_handle, CURLMOPT_MAX_HOST_CONNECTIONS, 1L);

  /* we start some action by calling perform right away */
  curl_multi_perform(multi_handle, &still_running);

  do {
    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) {
      timeout.tv_sec = curl_timeo / 1000;
      if(timeout.tv_sec > 1)
        timeout.tv_sec = 1;
      else
        timeout.tv_usec = (curl_timeo % 1000) * 1000;
    }

    /* 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, 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);
//.........这里部分代码省略.........

void IStreamUrlImplCurl::fillBuffer( int wantBytes ) const
{
	// first make sure we've started reading, and do so if not
	if( ! mStartedRead ) {
		while( curl_multi_perform( mMulti, &still_running ) == CURLM_CALL_MULTI_PERFORM );
		if( ( bufferRemaining() == 0 ) && ( ! still_running ) ) {			
			throw StreamExc();
		}
		
		mStartedRead = true;
	}
	

    // only attempt to fill buffer if transactions still running and buffer
    // doesnt exceed required size already
    if( ( ! still_running ) || ( bufferRemaining() >= wantBytes ) )
        return;

	// if we want more bytes than will fit in the rest of the buffer, let's make some room
	if( mBufferSize - mBufferedBytes < wantBytes ) {
		int bytesCulled = mBufferOffset;
		memmove( mBuffer, &mBuffer[mBufferOffset], mBufferedBytes - bytesCulled );
		mBufferedBytes -= bytesCulled;
		mBufferOffset = 0;
		mBufferFileOffset += bytesCulled;
	}

    // attempt to fill buffer
    do {
		fd_set fdread;
		fd_set fdwrite;
		fd_set fdexcep;
		int maxfd;
		struct timeval timeout;

		FD_ZERO( &fdread );
		FD_ZERO( &fdwrite );
		FD_ZERO( &fdexcep );

		// set a suitable timeout to fail on
		timeout.tv_sec = 60; /* 1 minute */
		timeout.tv_usec = 0;

		// get file descriptors from the transfers
		curl_multi_fdset( mMulti, &fdread, &fdwrite, &fdexcep, &maxfd );

		int rc = select( maxfd + 1, &fdread, &fdwrite, &fdexcep, &timeout );

		switch( rc ) {
			case -1:
				throw StreamExc();
			break;
			case 0:
			break;
			default:
				// timeout or readable/writable sockets
				// note we *could* be more efficient and not wait for
				// CURLM_CALL_MULTI_PERFORM to clear here and check it on re-entry
				// but that gets messy
				while( curl_multi_perform( mMulti, &still_running ) == CURLM_CALL_MULTI_PERFORM );
			break;
		}
    } while( still_running && ( bufferRemaining() < wantBytes ) );
}

int main(void)
{
   CURL *curl;
   CURLM *mcurl;
   int still_running = 1;
   struct timeval mp_start;
   char mp_timedout = 0;
   struct WriteThis pooh;
   struct curl_slist* rcpt_list = NULL;

   pooh.counter = 0;

   curl_global_init(CURL_GLOBAL_DEFAULT);

   curl = curl_easy_init();
   if(!curl)
     return 1;

   mcurl = curl_multi_init();
   if(!mcurl)
     return 2;

   rcpt_list = curl_slist_append(rcpt_list, RECEPIENT);
   /* more addresses can be added here
      rcpt_list = curl_slist_append(rcpt_list, "[email protected]");
   */

   curl_easy_setopt(curl, CURLOPT_URL, "smtp://" SMTPSERVER SMTPPORT);
   curl_easy_setopt(curl, CURLOPT_USERNAME, USERNAME);
   curl_easy_setopt(curl, CURLOPT_PASSWORD, PASSWORD);
   curl_easy_setopt(curl, CURLOPT_READFUNCTION, read_callback);
   curl_easy_setopt(curl, CURLOPT_MAIL_FROM, MAILFROM);
   curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, rcpt_list);
   curl_easy_setopt(curl, CURLOPT_USE_SSL, CURLUSESSL_ALL);
   curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER,0);
   curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
   curl_easy_setopt(curl, CURLOPT_READDATA, &pooh);
   curl_easy_setopt(curl, CURLOPT_VERBOSE, 1);
   curl_easy_setopt(curl, CURLOPT_SSLVERSION, 0);
   curl_easy_setopt(curl, CURLOPT_SSL_SESSIONID_CACHE, 0);
   curl_multi_add_handle(mcurl, curl);

   mp_timedout = 0;
   mp_start = tvnow();

  /* we start some action by calling perform right away */
  curl_multi_perform(mcurl, &still_running);

  while(still_running) {
    struct timeval timeout;
    int rc; /* select() 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(mcurl, &curl_timeo);
    if(curl_timeo >= 0) {
      timeout.tv_sec = curl_timeo / 1000;
      if(timeout.tv_sec > 1)
        timeout.tv_sec = 1;
      else
        timeout.tv_usec = (curl_timeo % 1000) * 1000;
    }

    /* get file descriptors from the transfers */
    curl_multi_fdset(mcurl, &fdread, &fdwrite, &fdexcep, &maxfd);

    /* In a real-world program you OF COURSE check the return code of the
       function calls.  On success, the value of maxfd is guaranteed to be
       greater or equal than -1.  We call select(maxfd + 1, ...), specially in
       case of (maxfd == -1), we call select(0, ...), which is basically equal
       to sleep. */

    rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout);

    if (tvdiff(tvnow(), mp_start) > MULTI_PERFORM_HANG_TIMEOUT) {
      fprintf(stderr, "ABORTING TEST, since it seems "
              "that it would have run forever.\n");
      break;
    }

    switch(rc) {
    case -1:
      /* select error */
      break;
    case 0: /* timeout */
    default: /* action */
      curl_multi_perform(mcurl, &still_running);
//.........这里部分代码省略.........

/*
 * Simply download two HTTP files!
 */
int main(int argc, char **argv)
{
  CURL *http_handle;
  CURL *http_handle2;
  CURLM *multi_handle;

  int still_running; /* keep number of running handles */

  http_handle = curl_easy_init();
  http_handle2 = curl_easy_init();

  /* set options */
  curl_easy_setopt(http_handle, CURLOPT_URL, "http://www.haxx.se/");

  /* set options */
  curl_easy_setopt(http_handle2, CURLOPT_URL, "http://localhost/");

  /* init a multi stack */
  multi_handle = curl_multi_init();

  /* add the individual transfers */
  curl_multi_add_handle(multi_handle, http_handle);
  curl_multi_add_handle(multi_handle, http_handle2);

  /* we start some action by calling perform right away */
  while(CURLM_CALL_MULTI_PERFORM ==
        curl_multi_perform(multi_handle, &still_running));

  while(still_running) {
    struct timeval timeout;
    int rc; /* select() 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) {
      timeout.tv_sec = curl_timeo / 1000;
      if(timeout.tv_sec > 1)
        timeout.tv_sec = 1;
      else
        timeout.tv_usec = (curl_timeo % 1000) * 1000;
    }

    /* get file descriptors from the transfers */
    curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);

    /* In a real-world program you OF COURSE check the return code of the
       function calls.  On success, the value of maxfd is guaranteed to be
       greater or equal than -1.  We call select(maxfd + 1, ...), specially in
       case of (maxfd == -1), we call select(0, ...), which is basically equal
       to sleep. */

    rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout);

    switch(rc) {
    case -1:
      /* select error */
      break;
    case 0:
    default:
      /* timeout or readable/writable sockets */
      while(CURLM_CALL_MULTI_PERFORM ==
            curl_multi_perform(multi_handle, &still_running));
      break;
    }
  }

  curl_multi_cleanup(multi_handle);

  curl_easy_cleanup(http_handle);
  curl_easy_cleanup(http_handle2);

  return 0;
}

static int
testExternalPut ()
{
  struct MHD_Daemon *d;
  CURL *c;
  char buf[2048];
  struct CBC cbc;
  CURLM *multi;
  CURLMcode mret;
  fd_set rs;
  fd_set ws;
  fd_set es;
  MHD_socket max;
  int running;
  struct CURLMsg *msg;
  time_t start;
  struct timeval tv;
  unsigned int pos = 0;
  int done_flag = 0;

  multi = NULL;
  cbc.buf = buf;
  cbc.size = 2048;
  cbc.pos = 0;
  d = MHD_start_daemon (MHD_USE_DEBUG,
                        1082,
                        NULL, NULL, &ahc_echo, &done_flag, MHD_OPTION_END);
  if (d == NULL)
    return 256;
  c = curl_easy_init ();
  curl_easy_setopt (c, CURLOPT_URL, "http://127.0.0.1:1082/hello_world");
  curl_easy_setopt (c, CURLOPT_WRITEFUNCTION, &copyBuffer);
  curl_easy_setopt (c, CURLOPT_WRITEDATA, &cbc);
  curl_easy_setopt (c, CURLOPT_READFUNCTION, &putBuffer);
  curl_easy_setopt (c, CURLOPT_READDATA, &pos);
  curl_easy_setopt (c, CURLOPT_UPLOAD, 1L);
  curl_easy_setopt (c, CURLOPT_INFILESIZE_LARGE, (curl_off_t) 8L);
  curl_easy_setopt (c, CURLOPT_FAILONERROR, 1);
  curl_easy_setopt (c, CURLOPT_TIMEOUT, 150L);
  if (oneone)
    curl_easy_setopt (c, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_1);
  else
    curl_easy_setopt (c, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_1_0);
  curl_easy_setopt (c, CURLOPT_CONNECTTIMEOUT, 150L);
  // NOTE: use of CONNECTTIMEOUT without also
  //   setting NOSIGNAL results in really weird
  //   crashes on my system!
  curl_easy_setopt (c, CURLOPT_NOSIGNAL, 1);


  multi = curl_multi_init ();
  if (multi == NULL)
    {
      curl_easy_cleanup (c);
      MHD_stop_daemon (d);
      return 512;
    }
  mret = curl_multi_add_handle (multi, c);
  if (mret != CURLM_OK)
    {
      curl_multi_cleanup (multi);
      curl_easy_cleanup (c);
      MHD_stop_daemon (d);
      return 1024;
    }
  start = time (NULL);
  while ((time (NULL) - start < 5) && (multi != NULL))
    {
      max = 0;
      FD_ZERO (&rs);
      FD_ZERO (&ws);
      FD_ZERO (&es);
      curl_multi_perform (multi, &running);
      mret = curl_multi_fdset (multi, &rs, &ws, &es, &max);
      if (mret != CURLM_OK)
        {
          curl_multi_remove_handle (multi, c);
          curl_multi_cleanup (multi);
          curl_easy_cleanup (c);
          MHD_stop_daemon (d);
          return 2048;
        }
      if (MHD_YES != MHD_get_fdset (d, &rs, &ws, &es, &max))
        {
          curl_multi_remove_handle (multi, c);
          curl_multi_cleanup (multi);
          curl_easy_cleanup (c);
          MHD_stop_daemon (d);
          return 4096;
        }
      tv.tv_sec = 0;
      tv.tv_usec = 1000;
      select (max + 1, &rs, &ws, &es, &tv);
      curl_multi_perform (multi, &running);
      if (running == 0)
        {
          msg = curl_multi_info_read (multi, &running);
          if (msg == NULL)
            break;
          if (msg->msg == CURLMSG_DONE)
//.........这里部分代码省略.........

void HttpMgr::run()
{
	if (m_httpCmdList.empty()) {
		return;
	}

	int runningHandles = 0;
	CURLMcode code = curl_multi_perform( m_currentCurl, &runningHandles);
	if( CURLM_OK != code ) {
		LOG_ERROR << "curl_multi_perform failed!";
		return;
	}

	// 用于缓存当前已执行完成的http请求
	HttpCmdList doneHttpCmds;

	int MsgNumLeft = 0;
	CURLMsg* pMsg = NULL;

	// 获取已返回结果的http请求
	while((pMsg = curl_multi_info_read( m_currentCurl, &MsgNumLeft)) != NULL) {
		if( pMsg->msg != CURLMSG_DONE ) {
			continue;
		}

		HttpCmdList::iterator itr = m_httpCmdList.begin();
		HttpCmdList::iterator end = m_httpCmdList.end();
		for(; itr != end; ++itr) {
			if( (*itr)->m_curl != pMsg->easy_handle) {
				continue;
			}

			break;
		}

		if( itr == m_httpCmdList.end() ) {
			LOG_ERROR << "find easy handle failed!";
			break;
		}

		HttpCmd *cmd = *itr;
		cmd->m_ok = (CURLE_OK == pMsg->data.result) ? true : false;

		doneHttpCmds.push_back(cmd);
		m_httpCmdList.erase(itr);

		//释放
		curl_multi_remove_handle(m_currentCurl, cmd->m_curl);
	}

	// 检查超时
	HttpCmdList::iterator itr = m_httpCmdList.begin();
	HttpCmdList::iterator end = m_httpCmdList.end();

	Timestamp now = timetool::getTimeOfDay();
	for(; itr != end;) {
		HttpCmd *cmd = *itr;

		if(now - cmd->m_lastAddTime > 30 * 1000) {
			cmd->m_ok = false;

			doneHttpCmds.push_back(cmd);
			m_httpCmdList.erase(itr++);

			//释放
			curl_multi_remove_handle(m_currentCurl, cmd->m_curl);
		}
		else {
			itr++;
		}
	}

	// 处理已返回结果的http请求
	for(HttpCmdList::iterator itr = doneHttpCmds.begin(); itr != doneHttpCmds.end(); ++itr) {
		HttpCmd *httpcmd = *itr;

		httpcmd->onExecuted();
		httpcmd->release();
	}
}

        int run() {
                if (NULL == m_handler) {
                        LOGE("m_handler is null.");
                        return -1;
                }

                int  msgs_in_queue = -1;
                int  running = -1;
                int  max_fds = -1;
                fd_set  read_fd;
                fd_set  write_fd;
                fd_set  exec_fd;
                CURLMsg  *msg;

                if (add_multiple_handlers() != 0)
                        return -2;

                while (running) {
                        curl_multi_perform(m_handler, &running);

                        if (running) {
                                FD_ZERO(&read_fd);
                                FD_ZERO(&write_fd);
                                FD_ZERO(&exec_fd);

                                if (curl_multi_fdset(m_handler, &read_fd, &write_fd, &exec_fd, &max_fds)) {
                                        LOGE("curl_multi_fdset");
                                        return -3;
                                }

                                if (set_timeout())
                                        return -4;

                                if (max_fds == -1) {
                                        sleep(MULTI_SELECT_TIMEOUT / 1000);
                                } else {
                                        #if 0
                                        if (0 > select(max_fds + 1, &read_fd, &write_fd, &exec_fd, &m_timeout)) {
                                                LOGE("select(%i,,,,%d)", max_fds + 1, (int)m_timeout.tv_sec);
                                                return -5;
                                        }
                                        #endif
                                        if (0 > select(max_fds + 1, &read_fd, &write_fd, &exec_fd, NULL)) {
                                                LOGE("select(%i)", max_fds + 1);
                                                return -5;
                                        }
                                }
                        }

                        while ((msg = curl_multi_info_read(m_handler, &msgs_in_queue))) {
                                if (CURLMSG_DONE == msg->msg) {
                                        Conn*  conn;
                                        CURL*  eh = msg->easy_handle;
                                        curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE, &conn);

                                        fclose(conn->output);
                                        conn->output = NULL;

                                        m_done_callback(conn);
                                        LOGI("%d - %s", msg->data.result, curl_easy_strerror(msg->data.result));

                                        remove_done_url(conn->url);
                                        free(conn);

                                        curl_multi_remove_handle(m_handler, eh);
                                        curl_easy_cleanup(eh);

                                        m_eh_array.erase(eh);
                                        m_crawling_urls.erase(conn->url);