Commit 4fb48301 authored by Yang Tse's avatar Yang Tse
Browse files

Add a couple of local macros to improve code readability. 

For completeness sake, wait_ms() might also get interrupted when
experimental CURL_ACKNOWLEDGE_EINTR is defined.
parent f1a8fd84

lib/select.c

+66 −43
Original line number Diff line number Diff line
@@ -72,6 +72,16 @@ 
} while(0)

#endif



/* Convenience local macros */



#define elapsed_ms  (int)curlx_tvdiff(curlx_tvnow(), initial_tv)



#ifdef CURL_ACKNOWLEDGE_EINTR

#define sockerrno_not_EINTR  (SOCKERRNO != EINTR)

#else

#define sockerrno_not_EINTR  (1)

#endif



/*

 * Internal function used for waiting a specific amount of ms

 * in Curl_select() and Curl_poll() when no file descriptor is
@@ -80,27 +90,56 @@ 
 * socket descriptor in a not null file descriptor set to work.

 * Waiting indefinitely with this function is not allowed, a

 * zero or negative timeout value will return immediately.

 * Timeout resolution, accuracy, as well as maximum supported

 * value is system dependant, neither factor is a citical issue

 * for the intended use of this function in the library.

 * On non-DOS and non-Winsock platforms, when compiled with

 * CURL_ACKNOWLEDGE_EINTR defined, EINTR condition is honored

 * and function might exit early without awaiting full timeout,

 * otherwise EINTR will be ignored and full timeout will elapse.

 *

 * Return values:

 *   -1 = system call error, invalid timeout value, or interrupted

 *    0 = specified timeout has elapsed

 */

static void wait_ms(int timeout_ms)

static int wait_ms(int timeout_ms)

{

#if !defined(__MSDOS__)   && \

    !defined(USE_WINSOCK) && \

    !defined(HAVE_POLL_FINE)

  struct timeval timeout;

#if !defined(__MSDOS__) && !defined(USE_WINSOCK)

#ifndef HAVE_POLL_FINE

  struct timeval pending_tv;

#endif

  if (timeout_ms <= 0)

    return;

  struct timeval initial_tv;

  int pending_ms;

#endif

  int r = 0;



  if (!timeout_ms)

    return 0;

  if (timeout_ms < 0) {

    SET_SOCKERRNO(EINVAL);

    return -1;

  }

#if defined(__MSDOS__)

  delay(timeout_ms);

#elif defined(USE_WINSOCK)

  Sleep(timeout_ms);

#elif defined(HAVE_POLL_FINE)

  poll(NULL, 0, timeout_ms);

#else

  timeout.tv_sec = timeout_ms / 1000;

  timeout.tv_usec = (timeout_ms % 1000) * 1000;

  select(0, NULL, NULL, NULL, &timeout);

#endif

  pending_ms = timeout_ms;

  initial_tv = curlx_tvnow();

  do {

#if defined(HAVE_POLL_FINE)

    r = poll(NULL, 0, pending_ms);

#else

    pending_tv.tv_sec = pending_ms / 1000;

    pending_tv.tv_usec = (pending_ms % 1000) * 1000;

    r = select(0, NULL, NULL, NULL, &pending_tv);

#endif /* HAVE_POLL_FINE */

  } while ((r == -1) && (SOCKERRNO != EINVAL) && sockerrno_not_EINTR &&

           ((pending_ms = timeout_ms - elapsed_ms) > 0));

#endif /* USE_WINSOCK */

  if (r)

    r = -1;

  return r;

}



/*
@@ -113,7 +152,7 @@ static void wait_ms(int timeout_ms) 
 * unles no valid file descriptor is given, when this happens the

 * negative timeout is ignored and the function times out immediately.

 * When compiled with CURL_ACKNOWLEDGE_EINTR defined, EINTR condition

 * is honored and function will exit early without awaiting timeout,

 * is honored and function might exit early without awaiting timeout,

 * otherwise EINTR will be ignored.

 *

 * Return values:
@@ -140,8 +179,8 @@ int Curl_select(curl_socket_t readfd, curl_socket_t writefd, int timeout_ms) 
  int ret;



  if((readfd == CURL_SOCKET_BAD) && (writefd == CURL_SOCKET_BAD)) {

    wait_ms(timeout_ms);

    return 0;

    r = wait_ms(timeout_ms);

    return r;

  }



  pending_ms = timeout_ms;
@@ -167,12 +206,8 @@ int Curl_select(curl_socket_t readfd, curl_socket_t writefd, int timeout_ms) 
    if (timeout_ms < 0)

      pending_ms = -1;

    r = poll(pfd, num, pending_ms);

  } while ((r == -1) && (SOCKERRNO != EINVAL) &&

#ifdef CURL_ACKNOWLEDGE_EINTR

    (SOCKERRNO != EINTR) &&

#endif

    ((timeout_ms < 0) ||

    ((pending_ms = timeout_ms - (int)curlx_tvdiff(curlx_tvnow(), initial_tv)) > 0)));

  } while ((r == -1) && (SOCKERRNO != EINVAL) && sockerrno_not_EINTR &&

           ((timeout_ms < 0) || ((pending_ms = timeout_ms - elapsed_ms) > 0)));



  if (r < 0)

    return -1;
@@ -234,12 +269,8 @@ int Curl_select(curl_socket_t readfd, curl_socket_t writefd, int timeout_ms) 
      pending_tv.tv_usec = (pending_ms % 1000) * 1000;

    }

    r = select((int)maxfd + 1, &fds_read, &fds_write, &fds_err, ptimeout);

  } while ((r == -1) && (SOCKERRNO != EINVAL) &&

#ifdef CURL_ACKNOWLEDGE_EINTR

    (SOCKERRNO != EINTR) &&

#endif

    ((timeout_ms < 0) ||

    ((pending_ms = timeout_ms - (int)curlx_tvdiff(curlx_tvnow(), initial_tv)) > 0)));

  } while ((r == -1) && (SOCKERRNO != EINVAL) && sockerrno_not_EINTR &&

           ((timeout_ms < 0) || ((pending_ms = timeout_ms - elapsed_ms) > 0)));



  if (r < 0)

    return -1;
@@ -274,7 +305,7 @@ int Curl_select(curl_socket_t readfd, curl_socket_t writefd, int timeout_ms) 
 * unles no valid file descriptor is given, when this happens the

 * negative timeout is ignored and the function times out immediately.

 * When compiled with CURL_ACKNOWLEDGE_EINTR defined, EINTR condition

 * is honored and function will exit early without awaiting timeout,

 * is honored and function might exit early without awaiting timeout,

 * otherwise EINTR will be ignored.

 *

 * Return values:
@@ -307,8 +338,8 @@ int Curl_poll(struct pollfd ufds[], unsigned int nfds, int timeout_ms) 
    }

  }

  if (fds_none) {

    wait_ms(timeout_ms);

    return 0;

    r = wait_ms(timeout_ms);

    return r;

  }



  pending_ms = timeout_ms;
@@ -320,12 +351,8 @@ int Curl_poll(struct pollfd ufds[], unsigned int nfds, int timeout_ms) 
    if (timeout_ms < 0)

      pending_ms = -1;

    r = poll(ufds, nfds, pending_ms);

  } while ((r == -1) && (SOCKERRNO != EINVAL) &&

#ifdef CURL_ACKNOWLEDGE_EINTR

    (SOCKERRNO != EINTR) &&

#endif

    ((timeout_ms < 0) ||

    ((pending_ms = timeout_ms - (int)curlx_tvdiff(curlx_tvnow(), initial_tv)) > 0)));

  } while ((r == -1) && (SOCKERRNO != EINVAL) && sockerrno_not_EINTR &&

           ((timeout_ms < 0) || ((pending_ms = timeout_ms - elapsed_ms) > 0)));



#else  /* HAVE_POLL_FINE */
@@ -359,12 +386,8 @@ int Curl_poll(struct pollfd ufds[], unsigned int nfds, int timeout_ms) 
      pending_tv.tv_usec = (pending_ms % 1000) * 1000;

    }

    r = select((int)maxfd + 1, &fds_read, &fds_write, &fds_err, ptimeout);

  } while ((r == -1) && (SOCKERRNO != EINVAL) &&

#ifdef CURL_ACKNOWLEDGE_EINTR

    (SOCKERRNO != EINTR) &&

#endif

    ((timeout_ms < 0) ||

    ((pending_ms = timeout_ms - (int)curlx_tvdiff(curlx_tvnow(), initial_tv)) > 0)));

  } while ((r == -1) && (SOCKERRNO != EINVAL) && sockerrno_not_EINTR &&

           ((timeout_ms < 0) || ((pending_ms = timeout_ms - elapsed_ms) > 0)));



  if (r < 0)

    return -1;