uxpoll.c

Netscape NSPR库源码

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/MPL/
 * 
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 * 
 * The Original Code is the Netscape Portable Runtime (NSPR).
 * 
 * The Initial Developer of the Original Code is Netscape
 * Communications Corporation.  Portions created by Netscape are 
 * Copyright (C) 1998-2000 Netscape Communications Corporation.  All
 * Rights Reserved.
 * 
 * Contributor(s):
 * 
 * Alternatively, the contents of this file may be used under the
 * terms of the GNU General Public License Version 2 or later (the
 * "GPL"), in which case the provisions of the GPL are applicable 
 * instead of those above.  If you wish to allow use of your 
 * version of this file only under the terms of the GPL and not to
 * allow others to use your version of this file under the MPL,
 * indicate your decision by deleting the provisions above and
 * replace them with the notice and other provisions required by
 * the GPL.  If you do not delete the provisions above, a recipient
 * may use your version of this file under either the MPL or the
 * GPL.
 */

#if defined(_PR_PTHREADS)

#error "This file should not be compiled"

#else  /* defined(_PR_PTHREADS) */

#include "primpl.h"

#include <sys/time.h>

#include <fcntl.h>
#ifdef _PR_USE_POLL
#include <poll.h>
#endif

#if defined(_PR_USE_POLL)
static PRInt32 NativeThreadPoll(
    PRPollDesc *pds, PRIntn npds, PRIntervalTime timeout)
{
    /*
     * This function is mostly duplicated from ptio.s's PR_Poll().
     */
    PRInt32 ready = 0;
    /*
     * For restarting poll() if it is interrupted by a signal.
     * We use these variables to figure out how much time has
     * elapsed and how much of the timeout still remains.
     */
    PRIntn index, msecs;
    struct pollfd *syspoll = NULL;
    PRIntervalTime start, elapsed, remaining;

    syspoll = (struct pollfd*)PR_MALLOC(npds * sizeof(struct pollfd));
    if (NULL == syspoll)
    {
        PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
        return -1;
    }
    for (index = 0; index < npds; ++index)
    {
        PRFileDesc *bottom;
        PRInt16 in_flags_read = 0, in_flags_write = 0;
        PRInt16 out_flags_read = 0, out_flags_write = 0;

        if ((NULL != pds[index].fd) && (0 != pds[index].in_flags))
        {
            if (pds[index].in_flags & PR_POLL_READ)
            {
                in_flags_read = (pds[index].fd->methods->poll)(
                    pds[index].fd,
                    pds[index].in_flags & ~PR_POLL_WRITE,
                    &out_flags_read);
            }
            if (pds[index].in_flags & PR_POLL_WRITE)
            {
                in_flags_write = (pds[index].fd->methods->poll)(
                    pds[index].fd,
                    pds[index].in_flags & ~PR_POLL_READ,
                    &out_flags_write);
            }
            if ((0 != (in_flags_read & out_flags_read))
            || (0 != (in_flags_write & out_flags_write)))
            {
                /* this one is ready right now */
                if (0 == ready)
                {
                    /*
                     * We will return without calling the system
                     * poll function.  So zero the out_flags
                     * fields of all the poll descriptors before
                     * this one.
                     */
                    int i;
                    for (i = 0; i < index; i++)
                    {
                        pds[i].out_flags = 0;
                    }
                }
                ready += 1;
                pds[index].out_flags = out_flags_read | out_flags_write;
            }
            else
            {
                pds[index].out_flags = 0;  /* pre-condition */
                /* now locate the NSPR layer at the bottom of the stack */
                bottom = PR_GetIdentitiesLayer(pds[index].fd, PR_NSPR_IO_LAYER);
                PR_ASSERT(NULL != bottom);  /* what to do about that? */
                if ((NULL != bottom)
                && (_PR_FILEDESC_OPEN == bottom->secret->state))
                {
                    if (0 == ready)
                    {
                        syspoll[index].fd = bottom->secret->md.osfd;
                        syspoll[index].events = 0;  /* pre-condition */
                        if (in_flags_read & PR_POLL_READ)
                        {
                            pds[index].out_flags |=
                                _PR_POLL_READ_SYS_READ;
                            syspoll[index].events |= POLLIN;
                        }
                        if (in_flags_read & PR_POLL_WRITE)
                        {
                            pds[index].out_flags |=
                                _PR_POLL_READ_SYS_WRITE;
                            syspoll[index].events |= POLLOUT;
                        }
                        if (in_flags_write & PR_POLL_READ)
                        {
                            pds[index].out_flags |=
                                _PR_POLL_WRITE_SYS_READ;
                            syspoll[index].events |= POLLIN;
                        }
                        if (in_flags_write & PR_POLL_WRITE)
                        {
                            pds[index].out_flags |=
                                _PR_POLL_WRITE_SYS_WRITE;
                            syspoll[index].events |= POLLOUT;
                        }
                        if (pds[index].in_flags & PR_POLL_EXCEPT)
                            syspoll[index].events |= POLLPRI;
                    }
                }
                else
                {
                    if (0 == ready)
                    {
                        int i;
                        for (i = 0; i < index; i++)
                        {
                            pds[i].out_flags = 0;
                        }
                    }
                    ready += 1;  /* this will cause an abrupt return */
                    pds[index].out_flags = PR_POLL_NVAL;  /* bogii */
                }
            }
        }
        else
        {
            /* make poll() ignore this entry */
            syspoll[index].fd = -1;
        }
    }

    if (0 == ready)
    {
        switch (timeout)
        {
            case PR_INTERVAL_NO_WAIT: msecs = 0; break;
            case PR_INTERVAL_NO_TIMEOUT: msecs = -1; break;
            default:
                msecs = PR_IntervalToMilliseconds(timeout);
                start = PR_IntervalNow();
        }

retry:
        ready = _MD_POLL(syspoll, npds, msecs);
        if (-1 == ready)
        {
            PRIntn oserror = errno;

            if (EINTR == oserror)
            {
                if (timeout == PR_INTERVAL_NO_TIMEOUT) goto retry;
                else if (timeout == PR_INTERVAL_NO_WAIT) ready = 0;
                else
                {
                    elapsed = (PRIntervalTime)(PR_IntervalNow() - start);
                    if (elapsed > timeout) ready = 0;  /* timed out */
                    else
                    {
                        remaining = timeout - elapsed;
                        msecs = PR_IntervalToMilliseconds(remaining);
                        goto retry;
                    }
                }
            }
            else _PR_MD_MAP_POLL_ERROR(oserror);
        }
        else if (ready > 0)
        {
            for (index = 0; index < npds; ++index)
            {
                PRInt16 out_flags = 0;
                if ((NULL != pds[index].fd) && (0 != pds[index].in_flags))
                {
                    if (0 != syspoll[index].revents)
                    {
                        /*
                        ** Set up the out_flags so that it contains the
                        ** bits that the highest layer thinks are nice
                        ** to have. Then the client of that layer will
                        ** call the appropriate I/O function and maybe
                        ** the protocol will make progress.
                        */
                        if (syspoll[index].revents & POLLIN)
                        {
                            if (pds[index].out_flags
                            & _PR_POLL_READ_SYS_READ)
                            {
                                out_flags |= PR_POLL_READ;
                            }
                            if (pds[index].out_flags
                            & _PR_POLL_WRITE_SYS_READ)
                            {
                                out_flags |= PR_POLL_WRITE;
                            }
                        }
                        if (syspoll[index].revents & POLLOUT)
                        {
                            if (pds[index].out_flags
                            & _PR_POLL_READ_SYS_WRITE)
                            {
                                out_flags |= PR_POLL_READ;
                            }
                            if (pds[index].out_flags
                            & _PR_POLL_WRITE_SYS_WRITE)
                            {
                                out_flags |= PR_POLL_WRITE;
                            }
                        }
                        if (syspoll[index].revents & POLLPRI)
                            out_flags |= PR_POLL_EXCEPT;
                        if (syspoll[index].revents & POLLERR)
                            out_flags |= PR_POLL_ERR;
                        if (syspoll[index].revents & POLLNVAL)
                            out_flags |= PR_POLL_NVAL;
                        if (syspoll[index].revents & POLLHUP)
                            out_flags |= PR_POLL_HUP;
                    }
                }
                pds[index].out_flags = out_flags;
            }
        }
    }

    PR_DELETE(syspoll);
    return ready;

}  /* NativeThreadPoll */
#endif  /* defined(_PR_USE_POLL) */

#if !defined(_PR_USE_POLL)
static PRInt32 NativeThreadSelect(
    PRPollDesc *pds, PRIntn npds, PRIntervalTime timeout)
{
    /*
     * This code is almost a duplicate of w32poll.c's _PR_MD_PR_POLL().
     */
    fd_set rd, wt, ex;
    PRFileDesc *bottom;
    PRPollDesc *pd, *epd;
    PRInt32 maxfd = -1, ready, err;
    PRIntervalTime remaining, elapsed, start;

    struct timeval tv, *tvp = NULL;

    FD_ZERO(&rd);
    FD_ZERO(&wt);
    FD_ZERO(&ex);

    ready = 0;
    for (pd = pds, epd = pd + npds; pd < epd; pd++)
    {
        PRInt16 in_flags_read = 0, in_flags_write = 0;
        PRInt16 out_flags_read = 0, out_flags_write = 0;

        if ((NULL != pd->fd) && (0 != pd->in_flags))
        {
            if (pd->in_flags & PR_POLL_READ)
            {
                in_flags_read = (pd->fd->methods->poll)(
                    pd->fd, pd->in_flags & ~PR_POLL_WRITE, &out_flags_read);
            }
            if (pd->in_flags & PR_POLL_WRITE)
            {
                in_flags_write = (pd->fd->methods->poll)(
                    pd->fd, pd->in_flags & ~PR_POLL_READ, &out_flags_write);
            }
            if ((0 != (in_flags_read & out_flags_read))
            || (0 != (in_flags_write & out_flags_write)))
            {
                /* this one's ready right now */
                if (0 == ready)
                {
                    /*
                     * We will have to return without calling the
                     * system poll/select function.  So zero the
                     * out_flags fields of all the poll descriptors
                     * before this one.
                     */
                    PRPollDesc *prev;
                    for (prev = pds; prev < pd; prev++)
                    {
                        prev->out_flags = 0;
                    }
                }
                ready += 1;
                pd->out_flags = out_flags_read | out_flags_write;
            }
            else
            {
                pd->out_flags = 0;  /* pre-condition */

                /* make sure this is an NSPR supported stack */
                bottom = PR_GetIdentitiesLayer(pd->fd, PR_NSPR_IO_LAYER);
                PR_ASSERT(NULL != bottom);  /* what to do about that? */
                if ((NULL != bottom)
                && (_PR_FILEDESC_OPEN == bottom->secret->state))
                {
                    if (0 == ready)
                    {
                        PRInt32 osfd = bottom->secret->md.osfd;
                        if (osfd > maxfd) maxfd = osfd;
                        if (in_flags_read & PR_POLL_READ)
                        {
                            pd->out_flags |= _PR_POLL_READ_SYS_READ;