root/win32/select.c

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DEFINITIONS

This source file includes following definitions.
  1. php_select

/*
  +----------------------------------------------------------------------+
  | PHP Version 5                                                        |
  +----------------------------------------------------------------------+
  | Copyright (c) 1997-2013 The PHP Group                                |
  +----------------------------------------------------------------------+
  | This source file is subject to version 3.01 of the PHP license,      |
  | that is bundled with this package in the file LICENSE, and is        |
  | available through the world-wide-web at the following url:           |
  | http://www.php.net/license/3_01.txt                                  |
  | If you did not receive a copy of the PHP license and are unable to   |
  | obtain it through the world-wide-web, please send a note to          |
  | license@php.net so we can mail you a copy immediately.               |
  +----------------------------------------------------------------------+
  | Author: Wez Furlong <wez@thebrainroom.com>                           |
  +----------------------------------------------------------------------+
*/

#include "php.h"
#include "php_network.h"

#ifdef PHP_WIN32

/* $Id$ */

/* Win32 select() will only work with sockets, so we roll our own implementation here.
 * - If you supply only sockets, this simply passes through to winsock select().
 * - If you supply file handles, there is no way to distinguish between
 *   ready for read/write or OOB, so any set in which the handle is found will
 *   be marked as ready.
 * - If you supply a mixture of handles and sockets, the system will interleave
 *   calls between select() and WaitForMultipleObjects(). The time slicing may
 *   cause this function call to take up to 100 ms longer than you specified.
 * - Calling this with NULL sets as a portable way to sleep with sub-second
 *   accuracy is not supported.
 * */
PHPAPI int php_select(int max_fd, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeval *tv)
{
        ULONGLONG ms_total, limit;
        HANDLE handles[MAXIMUM_WAIT_OBJECTS];
        int handle_slot_to_fd[MAXIMUM_WAIT_OBJECTS];
        int n_handles = 0, i;
        fd_set sock_read, sock_write, sock_except;
        fd_set aread, awrite, aexcept;
        int sock_max_fd = -1;
        struct timeval tvslice;
        int retcode;

#define SAFE_FD_ISSET(fd, set)  (set != NULL && FD_ISSET(fd, set))
        
        /* calculate how long we need to wait in milliseconds */
        if (tv == NULL) {
                ms_total = INFINITE;
        } else {
                ms_total = tv->tv_sec * 1000;
                ms_total += tv->tv_usec / 1000;
        }

        FD_ZERO(&sock_read);
        FD_ZERO(&sock_write);
        FD_ZERO(&sock_except);
        
        /* build an array of handles for non-sockets */
        for (i = 0; i < max_fd; i++) {
                if (SAFE_FD_ISSET(i, rfds) || SAFE_FD_ISSET(i, wfds) || SAFE_FD_ISSET(i, efds)) {
                        handles[n_handles] = (HANDLE)(zend_uintptr_t)_get_osfhandle(i);
                        if (handles[n_handles] == INVALID_HANDLE_VALUE) {
                                /* socket */
                                if (SAFE_FD_ISSET(i, rfds)) {
                                        FD_SET((uint)i, &sock_read);
                                }
                                if (SAFE_FD_ISSET(i, wfds)) {
                                        FD_SET((uint)i, &sock_write);
                                }
                                if (SAFE_FD_ISSET(i, efds)) {
                                        FD_SET((uint)i, &sock_except);
                                }
                                if (i > sock_max_fd) {
                                        sock_max_fd = i;
                                }
                        } else {
                                handle_slot_to_fd[n_handles] = i;
                                n_handles++;
                        }
                }
        }

        if (n_handles == 0) {
                /* plain sockets only - let winsock handle the whole thing */
                return select(max_fd, rfds, wfds, efds, tv);
        }
        
        /* mixture of handles and sockets; lets multiplex between
         * winsock and waiting on the handles */

        FD_ZERO(&aread);
        FD_ZERO(&awrite);
        FD_ZERO(&aexcept);
        
        limit = GetTickCount64() + ms_total;
        do {
                retcode = 0;
        
                if (sock_max_fd >= 0) {
                        /* overwrite the zero'd sets here; the select call
                         * will clear those that are not active */
                        aread = sock_read;
                        awrite = sock_write;
                        aexcept = sock_except;

                        tvslice.tv_sec = 0;
                        tvslice.tv_usec = 100000;

                        retcode = select(sock_max_fd+1, &aread, &awrite, &aexcept, &tvslice);
                }
                if (n_handles > 0) {
                        /* check handles */
                        DWORD wret;

                        wret = MsgWaitForMultipleObjects(n_handles, handles, FALSE, retcode > 0 ? 0 : 100, QS_ALLEVENTS);

                        if (wret == WAIT_TIMEOUT) {
                                /* set retcode to 0; this is the default.
                                 * select() may have set it to something else,
                                 * in which case we leave it alone, so this branch
                                 * does nothing */
                                ;
                        } else if (wret == WAIT_FAILED) {
                                if (retcode == 0) {
                                        retcode = -1;
                                }
                        } else {
                                if (retcode < 0) {
                                        retcode = 0;
                                }
                                for (i = 0; i < n_handles; i++) {
                                        if (WAIT_OBJECT_0 == WaitForSingleObject(handles[i], 0)) {
                                                if (SAFE_FD_ISSET(handle_slot_to_fd[i], rfds)) {
                                                        FD_SET((uint)handle_slot_to_fd[i], &aread);
                                                }
                                                if (SAFE_FD_ISSET(handle_slot_to_fd[i], wfds)) {
                                                        FD_SET((uint)handle_slot_to_fd[i], &awrite);
                                                }
                                                if (SAFE_FD_ISSET(handle_slot_to_fd[i], efds)) {
                                                        FD_SET((uint)handle_slot_to_fd[i], &aexcept);
                                                }
                                                retcode++;
                                        }
                                }
                        }
                }
        } while (retcode == 0 && (ms_total == INFINITE || GetTickCount64() < limit));

        if (rfds) {
                *rfds = aread;
        }
        if (wfds) {
                *wfds = awrite;
        }
        if (efds) {
                *efds = aexcept;
        }       
        
        return retcode;
}

#endif

/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 * vim600: noet sw=4 ts=4 fdm=marker
 * vim<600: noet sw=4 ts=4
 */

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