Commit a691e044 authored by Daniel Stenberg's avatar Daniel Stenberg
Browse files

multi_socket: improved 100-continue timeout handling 

When waiting for a 100-continue response from the server, the
Curl_readwrite() will refuse to run if called until the timeout has been
reached.

We timeout code in multi_socket() allows code to run slightly before the
actual timeout time, so for test 154 it could lead to the function being
executed but refused in Curl_readwrite() and then the application would
just sit idling forever.

This was detected with runtests.pl -e on test 154.
parent 3d1a453d

lib/easy.c

+4 −8
Original line number Diff line number Diff line
@@ -489,7 +489,6 @@ static int events_timer(CURLM *multi, /* multi handle */ 


  ev->ms = timeout_ms;

  ev->msbump = TRUE;

  /* fprintf(stderr, "%s: timeout %ld\n", __func__, timeout_ms); */

  return 0;

}
@@ -647,8 +646,6 @@ static CURLcode wait_or_timeout(struct Curl_multi *multi, struct events *ev) 
    /* get the time stamp to use to figure out how long poll takes */

    before = curlx_tvnow();



    /* fprintf(stderr, "poll(), %d numfds\n", numfds); */



    /* wait for activity or timeout */

    pollrc = Curl_poll(fds, numfds, (int)ev->ms);
@@ -793,15 +790,14 @@ static CURLcode easy_transfer(CURLM *multi) 
 * DEBUG: if 'events' is set TRUE, this function will use a replacement engine

 * instead of curl_multi_perform() and use curl_multi_socket_action().

 */

static CURLcode easy_perform(CURL *easy, bool events)

static CURLcode easy_perform(struct SessionHandle *data, bool events)

{

  CURLM *multi;

  CURLMcode mcode;

  CURLcode code = CURLE_OK;

  struct SessionHandle *data = easy;

  SIGPIPE_VARIABLE(pipe_st);



  if(!easy)

  if(!data)

    return CURLE_BAD_FUNCTION_ARGUMENT;



  if(data->multi) {
@@ -823,7 +819,7 @@ static CURLcode easy_perform(CURL *easy, bool events) 
  /* Copy the MAXCONNECTS option to the multi handle */

  curl_multi_setopt(multi, CURLMOPT_MAXCONNECTS, data->set.maxconnects);



  mcode = curl_multi_add_handle(multi, easy);

  mcode = curl_multi_add_handle(multi, data);

  if(mcode) {

    curl_multi_cleanup(multi);

    if(mcode == CURLM_OUT_OF_MEMORY)
@@ -843,7 +839,7 @@ static CURLcode easy_perform(CURL *easy, bool events) 


  /* ignoring the return code isn't nice, but atm we can't really handle

     a failure here, room for future improvement! */

  (void)curl_multi_remove_handle(multi, easy);

  (void)curl_multi_remove_handle(multi, data);



  sigpipe_restore(&pipe_st);

lib/multi.c

+1 −7
Original line number Diff line number Diff line
@@ -2104,12 +2104,6 @@ static CURLMcode add_next_timeout(struct timeval now, 
  return CURLM_OK;

}



#ifdef WIN32

#define TIMEOUT_INACCURACY 40000

#else

#define TIMEOUT_INACCURACY 3000

#endif



static CURLMcode multi_socket(struct Curl_multi *multi,

                              bool checkall,

                              curl_socket_t s,
@@ -2215,7 +2209,7 @@ static CURLMcode multi_socket(struct Curl_multi *multi, 
     margin.

  */



  now.tv_usec += TIMEOUT_INACCURACY;

  now.tv_usec += MULTI_TIMEOUT_INACCURACY;

  if(now.tv_usec >= 1000000) {

    now.tv_sec++;

    now.tv_usec -= 1000000;

lib/multiif.h

+7 −1
Original line number Diff line number Diff line
@@ -22,7 +22,13 @@ 
 *

 ***************************************************************************/





/* See multi_socket() for the explanation of this constant. Counted in number

   of microseconds. */

#ifdef WIN32

#define MULTI_TIMEOUT_INACCURACY 40000

#else

#define MULTI_TIMEOUT_INACCURACY 3000

#endif



/*

 * Prototypes for library-wide functions provided by multi.c

lib/transfer.c

+4 −2
Original line number Diff line number Diff line
@@ -1952,8 +1952,10 @@ Curl_setup_transfer( 
        k->exp100 = EXP100_AWAITING_CONTINUE;

        k->start100 = Curl_tvnow();



        /* set a timeout for the multi interface */

        Curl_expire(data, CURL_TIMEOUT_EXPECT_100);

        /* Set a timeout for the multi interface. Add the inaccuracy margin so

           that we don't fire slightly too early and get denied to run. */

        Curl_expire(data, CURL_TIMEOUT_EXPECT_100 +

                    MULTI_TIMEOUT_INACCURACY / 1000);

      }

      else {

        if(data->state.expect100header)