The R Project SVN R

	/* increment used value _before_ the select in case select

	   modifies tv (as Linux does) */

	used += tv.tv_sec + 1e-6 * tv.tv_usec;

/**** FIXME: merge with R_SocketWait */

/**** FIXME: add timeout argument instead of using global?? */

int R_SocketWaitMultiple(int nsock, int *insockfd, int *ready, int *write,

			 double mytimeout)

{

    fd_set rfd, wfd;

    struct timeval tv;

    double used = 0.0;

    int nready = 0;

    while(1) {

	int maxfd = 0, howmany, i;

#ifdef Unix

	InputHandler *what;

	if(R_wait_usec > 0) {

	    int delta;

	    if (mytimeout < 0 || R_wait_usec / 1e-6 < mytimeout - used)

		delta = R_wait_usec;

	    else

		delta = 1e6 * (mytimeout - used);

	    R_PolledEvents();

	    tv.tv_sec = 0;

	    tv.tv_usec = delta;

	} else if (mytimeout >= 0) {

	    tv.tv_sec = mytimeout - used;

	    tv.tv_usec = 1e6 * (mytimeout - used - tv.tv_sec);

	} else {  /* always poll occationally--not really necessary */

	    tv.tv_sec = timeout;

	    tv.tv_usec = 0;

	}

#elif defined(Win32)

	tv.tv_sec = 0;

	tv.tv_usec = 2e5;

	R_ProcessEvents();

#else

	if (mytimeout >= 0) {

	    tv.tv_sec = mytimeout - used;

	    tv.tv_usec = 1e6 * (mytimeout - used - tv.tv_sec);

	} else {  /* always poll occationally--not really necessary */

	    tv.tv_sec = timeout;

	    tv.tv_usec = 0;

	}

#endif

#ifdef Unix

	maxfd = setSelectMask(R_InputHandlers, &rfd);

#else

	FD_ZERO(&rfd);

#endif

	FD_ZERO(&wfd);

	for (i = 0; i < nsock; i++) {

	    if(write[i]) FD_SET(insockfd[i], &wfd);

	    else FD_SET(insockfd[i], &rfd);

	    if(maxfd < insockfd[i]) maxfd = insockfd[i];

	}

	/* increment used value _before_ the select in case select

	   modifies tv (as Linux does) */

	used += tv.tv_sec + 1e-6 * tv.tv_usec;

	howmany = R_SelectEx(maxfd+1, &rfd, &wfd, NULL, &tv, NULL);

	if (howmany < 0) {

	    return -1;

	}

	if (howmany == 0) {

	    if(mytimeout >= 0 && used >= mytimeout) {

		for (i = 0; i < nsock; i++)

		    ready[i] = 0; /* FALSE */

		return 0;

	    }

	    continue;

	}

	for (i = 0; i < nsock; i++)

	    if ((!write[i] && FD_ISSET(insockfd[i], &rfd)) ||

		(write[i] && FD_ISSET(insockfd[i], &wfd))) {

		ready[i] = 1; /* TRUE */

		nready++;

	    }

	    else ready[i] = 0; /* FALSE */

#ifdef Unix

	if(howmany > nready) {

	    /* one of the extras is ready */

	    what = getSelectedHandler(R_InputHandlers, &rfd);

	    if(what != NULL) what->handler((void*) NULL);

	    continue;

	}

#endif

	/* some sockets are ready */

	break;

    }

    return nready;

}

int in_Rsockselect(int nsock, int *insockfd, int *ready, int *write,

		   double timeout)

{

    return R_SocketWaitMultiple(nsock, insockfd, ready, write, timeout);

}