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/* |
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* libev select fd activity backend |
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* |
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* Copyright (c) 2007,2008 Marc Alexander Lehmann <libev@schmorp.de> |
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* All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or without modifica- |
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* tion, are permitted provided that the following conditions are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright notice, |
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* this list of conditions and the following disclaimer. |
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* |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the distribution. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- |
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* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO |
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* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- |
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* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; |
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH- |
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* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
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* OF THE POSSIBILITY OF SUCH DAMAGE. |
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* |
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* Alternatively, the contents of this file may be used under the terms of |
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* the GNU General Public License ("GPL") version 2 or any later version, |
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* in which case the provisions of the GPL are applicable instead of |
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* the above. If you wish to allow the use of your version of this file |
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* only under the terms of the GPL and not to allow others to use your |
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* version of this file under the BSD license, indicate your decision |
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* by deleting the provisions above and replace them with the notice |
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* and other provisions required by the GPL. If you do not delete the |
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* provisions above, a recipient may use your version of this file under |
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* either the BSD or the GPL. |
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*/ |
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|
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#ifndef _WIN32 |
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/* for unix systems */ |
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# include <sys/select.h> |
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# include <inttypes.h> |
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#endif |
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|
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#ifndef EV_SELECT_USE_FD_SET |
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# ifdef NFDBITS |
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# define EV_SELECT_USE_FD_SET 0 |
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# else |
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# define EV_SELECT_USE_FD_SET 1 |
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# endif |
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#endif |
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|
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#if EV_SELECT_IS_WINSOCKET |
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# undef EV_SELECT_USE_FD_SET |
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# define EV_SELECT_USE_FD_SET 1 |
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# undef NFDBITS |
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# define NFDBITS 0 |
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#endif |
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|
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#if !EV_SELECT_USE_FD_SET |
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# define NFDBYTES (NFDBITS / 8) |
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#endif |
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|
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#include <string.h> |
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|
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static void |
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select_modify (EV_P_ int fd, int oev, int nev) |
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{ |
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if (oev == nev) |
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return; |
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|
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{ |
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#if EV_SELECT_USE_FD_SET |
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|
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#if EV_SELECT_IS_WINSOCKET |
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SOCKET handle = anfds [fd].handle; |
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#else |
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int handle = fd; |
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#endif |
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|
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if (nev & EV_READ) |
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FD_SET (handle, (fd_set *)vec_ri); |
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else |
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FD_CLR (handle, (fd_set *)vec_ri); |
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|
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if (nev & EV_WRITE) |
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FD_SET (handle, (fd_set *)vec_wi); |
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else |
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FD_CLR (handle, (fd_set *)vec_wi); |
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|
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#else |
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|
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int word = fd / NFDBITS; |
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fd_mask mask = 1UL << (fd % NFDBITS); |
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|
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if (expect_false (vec_max <= word)) |
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{ |
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int new_max = word + 1; |
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|
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vec_ri = ev_realloc (vec_ri, new_max * NFDBYTES); |
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vec_ro = ev_realloc (vec_ro, new_max * NFDBYTES); /* could free/malloc */ |
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vec_wi = ev_realloc (vec_wi, new_max * NFDBYTES); |
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vec_wo = ev_realloc (vec_wo, new_max * NFDBYTES); /* could free/malloc */ |
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#ifdef _WIN32 |
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vec_eo = ev_realloc (vec_eo, new_max * NFDBYTES); /* could free/malloc */ |
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#endif |
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|
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for (; vec_max < new_max; ++vec_max) |
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((fd_mask *)vec_ri) [vec_max] = |
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((fd_mask *)vec_wi) [vec_max] = 0; |
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} |
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|
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((fd_mask *)vec_ri) [word] |= mask; |
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if (!(nev & EV_READ)) |
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((fd_mask *)vec_ri) [word] &= ~mask; |
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|
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((fd_mask *)vec_wi) [word] |= mask; |
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if (!(nev & EV_WRITE)) |
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((fd_mask *)vec_wi) [word] &= ~mask; |
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#endif |
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} |
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} |
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|
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static void |
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select_poll (EV_P_ ev_tstamp timeout) |
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{ |
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struct timeval tv; |
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int res; |
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int fd_setsize; |
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|
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tv.tv_sec = (long)timeout; |
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tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6); |
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|
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#if EV_SELECT_USE_FD_SET |
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fd_setsize = sizeof (fd_set); |
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#else |
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fd_setsize = vec_max * NFDBYTES; |
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#endif |
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|
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memcpy (vec_ro, vec_ri, fd_setsize); |
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memcpy (vec_wo, vec_wi, fd_setsize); |
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|
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#ifdef _WIN32 |
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/* pass in the write set as except set. |
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* the idea behind this is to work around a windows bug that causes |
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* errors to be reported as an exception and not by setting |
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* the writable bit. this is so uncontrollably lame. |
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*/ |
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memcpy (vec_eo, vec_wi, fd_setsize); |
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res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, (fd_set *)vec_eo, &tv); |
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#else |
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res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv); |
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#endif |
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|
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if (expect_false (res < 0)) |
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{ |
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#if EV_SELECT_IS_WINSOCKET |
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errno = WSAGetLastError (); |
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#endif |
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#ifdef WSABASEERR |
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/* on windows, select returns incompatible error codes, fix this */ |
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if (errno >= WSABASEERR && errno < WSABASEERR + 1000) |
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if (errno == WSAENOTSOCK) |
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errno = EBADF; |
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else |
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errno -= WSABASEERR; |
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#endif |
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|
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#ifdef _WIN32 |
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/* select on windows errornously returns EINVAL when no fd sets have been |
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* provided (this is documented). what microsoft doesn't tell you that this bug |
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* exists even when the fd sets are provided, so we have to check for this bug |
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* here and emulate by sleeping manually. |
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* we also get EINVAL when the timeout is invalid, but we ignore this case here |
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* and assume that EINVAL always means: you have to wait manually. |
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*/ |
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if (errno == EINVAL) |
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{ |
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ev_sleep (timeout); |
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return; |
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} |
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#endif |
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|
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if (errno == EBADF) |
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fd_ebadf (EV_A); |
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else if (errno == ENOMEM && !syserr_cb) |
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fd_enomem (EV_A); |
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else if (errno != EINTR) |
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syserr ("(libev) select"); |
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|
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return; |
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} |
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|
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#if EV_SELECT_USE_FD_SET |
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|
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{ |
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int fd; |
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|
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for (fd = 0; fd < anfdmax; ++fd) |
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if (anfds [fd].events) |
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{ |
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int events = 0; |
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#if EV_SELECT_IS_WINSOCKET |
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SOCKET handle = anfds [fd].handle; |
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#else |
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int handle = fd; |
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#endif |
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|
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if (FD_ISSET (handle, (fd_set *)vec_ro)) events |= EV_READ; |
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if (FD_ISSET (handle, (fd_set *)vec_wo)) events |= EV_WRITE; |
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#ifdef _WIN32 |
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if (FD_ISSET (handle, (fd_set *)vec_eo)) events |= EV_WRITE; |
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#endif |
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|
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if (expect_true (events)) |
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fd_event (EV_A_ fd, events); |
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} |
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} |
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|
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#else |
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|
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{ |
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int word, bit; |
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for (word = vec_max; word--; ) |
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{ |
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fd_mask word_r = ((fd_mask *)vec_ro) [word]; |
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fd_mask word_w = ((fd_mask *)vec_wo) [word]; |
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#ifdef _WIN32 |
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word_w |= ((fd_mask *)vec_eo) [word]; |
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#endif |
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|
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if (word_r || word_w) |
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for (bit = NFDBITS; bit--; ) |
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{ |
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fd_mask mask = 1UL << bit; |
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int events = 0; |
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|
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events |= word_r & mask ? EV_READ : 0; |
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events |= word_w & mask ? EV_WRITE : 0; |
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|
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if (expect_true (events)) |
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fd_event (EV_A_ word * NFDBITS + bit, events); |
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} |
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} |
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} |
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|
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#endif |
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} |
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|
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int inline_size |
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select_init (EV_P_ int flags) |
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{ |
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backend_fudge = 0.; /* posix says this is zero */ |
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backend_modify = select_modify; |
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backend_poll = select_poll; |
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|
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#if EV_SELECT_USE_FD_SET |
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vec_max = FD_SETSIZE / 32; |
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vec_ri = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_ri); |
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vec_ro = ev_malloc (sizeof (fd_set)); |
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vec_wi = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_wi); |
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vec_wo = ev_malloc (sizeof (fd_set)); |
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#ifdef _WIN32 |
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vec_eo = ev_malloc (sizeof (fd_set)); |
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#endif |
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#else |
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vec_max = 0; |
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vec_ri = 0; |
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vec_ri = 0; |
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vec_wo = 0; |
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vec_wo = 0; |
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#endif |
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|
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return EVBACKEND_SELECT; |
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} |
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|
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void inline_size |
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select_destroy (EV_P) |
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{ |
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ev_free (vec_ri); |
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ev_free (vec_ro); |
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ev_free (vec_wi); |
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ev_free (vec_wo); |
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} |
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|
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|
