ch3_progress_poll_elem.i

刚才是说明 现在是安装程序在 LINUX环境下进行编程的MPICH安装文件

/* -*- Mode: C; c-basic-offset:4 ; -*- */
/*
 *  (C) 2001 by Argonne National Laboratory.
 *      See COPYRIGHT in top-level directory.
 */

#if !defined(MPIDI_CH3I_POLLFD_INC)
#define MPIDI_CH3I_POLLFD_INC 64
#endif

static int poll_elem_alloc(int fd)
{
    int elem;
    struct pollfd * fds;
    struct pollinfo * infos;

    /* MT - allcation of array element and array resizing not thread safe! */
    
    for (elem = 0; elem < poll_sz; elem++)
    {
	if (poll_fds[elem].fd < 0)
	{
	    poll_fds[elem].fd = fd;
	    poll_fds[elem].events = 0;
	    poll_fds[elem].revents = 0;
	    if (elem + 1 > poll_num)
	    {
		poll_num = elem + 1;
	    }
	    
	    return elem;
	}
    }

    /* No more pollfd and pollinfo elements.  Resize... */
    fds = MPIU_Malloc((poll_sz + MPIDI_CH3I_POLLFD_INC) *
		      sizeof(struct pollfd));
    if (fds == NULL)
    {
	return -1;
    }
    infos = MPIU_Malloc((poll_sz + MPIDI_CH3I_POLLFD_INC) *
		      sizeof(struct pollinfo));
    if (infos == NULL)
    {
	MPIU_Free(fds);
	return -1;
    }
    
    /* Copy information from old arrays */
    if (poll_sz > 0)
    {
	memcpy(fds, poll_fds, poll_sz * sizeof(struct pollfd));
	memcpy(infos, poll_infos, poll_sz * sizeof(struct pollinfo));
    }

    /* Register new file descriptor */
    fds[poll_sz].fd = fd;
    fds[poll_sz].events = 0;
    fds[elem].revents = 0;
    
    /* Initialize new unallocated elements */
    for (elem = poll_sz + 1; elem < poll_sz + MPIDI_CH3I_POLLFD_INC; elem++)
    {
	fds[elem].fd = -1;
	fds[elem].events = 0;
	fds[elem].revents = 0;
    }

    /* Free old arrays and set pointers to new arrays */
    MPIU_Free(poll_fds);
    MPIU_Free(poll_infos);
    poll_fds = fds;
    poll_infos = infos;
    elem = poll_sz;
    poll_num = poll_sz + 1;
    poll_sz += MPIDI_CH3I_POLLFD_INC;

    return elem;
}

static void poll_elem_free(int elem)
{
    poll_fds[elem].fd = -1;
    poll_fds[elem].events = 0;
    poll_fds[elem].revents = 0;
}