SDL_poll.c File Reference

#include "../../SDL_internal.h"
#include "SDL_assert.h"
#include "SDL_poll.h"
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>

Include dependency graph for SDL_poll.c:

Go to the source code of this file.

Functions
int	SDL_IOReady (int fd, SDL_bool forWrite, int timeoutMS)

Function Documentation

int SDL_IOReady	(	int	fd,
		SDL_bool	forWrite,
		int	timeoutMS
	)

Definition at line 38 of file SDL_poll.c.

References NULL, and SDL_assert.

{
    int result;

    /* Note: We don't bother to account for elapsed time if we get EINTR */
    do
    {
#ifdef HAVE_POLL
        struct pollfd info;

        info.fd = fd;
        if (forWrite) {
            info.events = POLLOUT;
        } else {
            info.events = POLLIN | POLLPRI;
        }
        result = poll(&info, 1, timeoutMS);
#else
        fd_set rfdset, *rfdp = NULL;
        fd_set wfdset, *wfdp = NULL;
        struct timeval tv, *tvp = NULL;

        /* If this assert triggers we'll corrupt memory here */
        SDL_assert(fd >= 0 && fd < FD_SETSIZE);

        if (forWrite) {
            FD_ZERO(&wfdset);
            FD_SET(fd, &wfdset);
            wfdp = &wfdset;
        } else {
            FD_ZERO(&rfdset);
            FD_SET(fd, &rfdset);
            rfdp = &rfdset;
        }

        if (timeoutMS >= 0) {
            tv.tv_sec = timeoutMS / 1000;
            tv.tv_usec = (timeoutMS % 1000) * 1000;
            tvp = &tv;
        }

        result = select(fd + 1, rfdp, wfdp, NULL, tvp);
#endif /* HAVE_POLL */

    } while ( result < 0 && errno == EINTR );

    return result;
}