src/core/unix/SDL_poll.c
author Sam Lantinga <slouken@libsdl.org>
Wed, 03 Jan 2018 10:03:25 -0800
changeset 11811 5d94cb6b24d3
parent 11783 c7577c45151a
child 12503 806492103856
permissions -rw-r--r--
Updated copyright for 2018
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 
    22 #include "../../SDL_internal.h"
    23 
    24 #include "SDL_assert.h"
    25 #include "SDL_poll.h"
    26 
    27 #ifdef HAVE_POLL
    28 #include <poll.h>
    29 #else
    30 #include <sys/time.h>
    31 #include <sys/types.h>
    32 #include <unistd.h>
    33 #endif
    34 #include <errno.h>
    35 
    36 
    37 int
    38 SDL_IOReady(int fd, SDL_bool forWrite, int timeoutMS)
    39 {
    40     int result;
    41 
    42     /* Note: We don't bother to account for elapsed time if we get EINTR */
    43     do
    44     {
    45 #ifdef HAVE_POLL
    46         struct pollfd info;
    47 
    48         info.fd = fd;
    49         if (forWrite) {
    50             info.events = POLLOUT;
    51         } else {
    52             info.events = POLLIN | POLLPRI;
    53         }
    54         result = poll(&info, 1, timeoutMS);
    55 #else
    56         fd_set rfdset, *rfdp = NULL;
    57         fd_set wfdset, *wfdp = NULL;
    58         struct timeval tv, *tvp = NULL;
    59 
    60         /* If this assert triggers we'll corrupt memory here */
    61         SDL_assert(fd >= 0 && fd < FD_SETSIZE);
    62 
    63         if (forWrite) {
    64             FD_ZERO(&wfdset);
    65             FD_SET(fd, &wfdset);
    66             wfdp = &wfdset;
    67         } else {
    68             FD_ZERO(&rfdset);
    69             FD_SET(fd, &rfdset);
    70             rfdp = &rfdset;
    71         }
    72 
    73         if (timeoutMS >= 0) {
    74             tv.tv_sec = timeoutMS / 1000;
    75             tv.tv_usec = (timeoutMS % 1000) * 1000;
    76             tvp = &tv;
    77         }
    78 
    79         result = select(fd + 1, rfdp, wfdp, NULL, tvp);
    80 #endif /* HAVE_POLL */
    81 
    82     } while ( result < 0 && errno == EINTR );
    83 
    84     return result;
    85 }
    86 
    87 /* vi: set ts=4 sw=4 expandtab: */