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편집 파일: ev_select.c

/* * libev select fd activity backend * * Copyright (c) 2007,2008,2009,2010,2011 Marc Alexander Lehmann <libev@schmorp.de> * All rights reserved. * * Redistribution and use in source and binary forms, with or without modifica- * tion, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER- * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE- * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH- * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * * Alternatively, the contents of this file may be used under the terms of * the GNU General Public License ("GPL") version 2 or any later version, * in which case the provisions of the GPL are applicable instead of * the above. If you wish to allow the 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 BSD license, 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 BSD or the GPL. */ #ifndef _WIN32 /* for unix systems */ # include <inttypes.h> # ifndef __hpux /* for REAL unix systems */ # include <sys/select.h> # endif #endif #ifndef EV_SELECT_USE_FD_SET # ifdef NFDBITS # define EV_SELECT_USE_FD_SET 0 # else # define EV_SELECT_USE_FD_SET 1 # endif #endif #if EV_SELECT_IS_WINSOCKET # undef EV_SELECT_USE_FD_SET # define EV_SELECT_USE_FD_SET 1 # undef NFDBITS # define NFDBITS 0 #endif #if !EV_SELECT_USE_FD_SET # define NFDBYTES (NFDBITS / 8) #endif #include <string.h> static void select_modify (EV_P_ int fd, int oev, int nev) { if (oev == nev) return; { #if EV_SELECT_USE_FD_SET #if EV_SELECT_IS_WINSOCKET SOCKET handle = anfds [fd].handle; #else int handle = fd; #endif assert (("libev: fd >= FD_SETSIZE passed to fd_set-based select backend", fd < FD_SETSIZE)); /* FD_SET is broken on windows (it adds the fd to a set twice or more, * which eventually leads to overflows). Need to call it only on changes. */ #if EV_SELECT_IS_WINSOCKET if ((oev ^ nev) & EV_READ) #endif if (nev & EV_READ) FD_SET (handle, (fd_set *)vec_ri); else FD_CLR (handle, (fd_set *)vec_ri); #if EV_SELECT_IS_WINSOCKET if ((oev ^ nev) & EV_WRITE) #endif if (nev & EV_WRITE) FD_SET (handle, (fd_set *)vec_wi); else FD_CLR (handle, (fd_set *)vec_wi); #else int word = fd / NFDBITS; fd_mask mask = 1UL << (fd % NFDBITS); if (expect_false (vec_max <= word)) { int new_max = word + 1; vec_ri = ev_realloc (vec_ri, new_max * NFDBYTES); vec_ro = ev_realloc (vec_ro, new_max * NFDBYTES); /* could free/malloc */ vec_wi = ev_realloc (vec_wi, new_max * NFDBYTES); vec_wo = ev_realloc (vec_wo, new_max * NFDBYTES); /* could free/malloc */ #ifdef _WIN32 vec_eo = ev_realloc (vec_eo, new_max * NFDBYTES); /* could free/malloc */ #endif for (; vec_max < new_max; ++vec_max) ((fd_mask *)vec_ri) [vec_max] = ((fd_mask *)vec_wi) [vec_max] = 0; } ((fd_mask *)vec_ri) [word] |= mask; if (!(nev & EV_READ)) ((fd_mask *)vec_ri) [word] &= ~mask; ((fd_mask *)vec_wi) [word] |= mask; if (!(nev & EV_WRITE)) ((fd_mask *)vec_wi) [word] &= ~mask; #endif } } static void select_poll (EV_P_ ev_tstamp timeout) { struct timeval tv; int res; int fd_setsize; EV_RELEASE_CB; EV_TV_SET (tv, timeout); #if EV_SELECT_USE_FD_SET fd_setsize = sizeof (fd_set); #else fd_setsize = vec_max * NFDBYTES; #endif memcpy (vec_ro, vec_ri, fd_setsize); memcpy (vec_wo, vec_wi, fd_setsize); #ifdef _WIN32 /* pass in the write set as except set. * the idea behind this is to work around a windows bug that causes * errors to be reported as an exception and not by setting * the writable bit. this is so uncontrollably lame. */ memcpy (vec_eo, vec_wi, fd_setsize); res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, (fd_set *)vec_eo, &tv); #elif EV_SELECT_USE_FD_SET fd_setsize = anfdmax < FD_SETSIZE ? anfdmax : FD_SETSIZE; res = select (fd_setsize, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv); #else res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv); #endif EV_ACQUIRE_CB; if (expect_false (res < 0)) { #if EV_SELECT_IS_WINSOCKET errno = WSAGetLastError (); #endif #ifdef WSABASEERR /* on windows, select returns incompatible error codes, fix this */ if (errno >= WSABASEERR && errno < WSABASEERR + 1000) if (errno == WSAENOTSOCK) errno = EBADF; else errno -= WSABASEERR; #endif #ifdef _WIN32 /* select on windows erroneously returns EINVAL when no fd sets have been * provided (this is documented). what microsoft doesn't tell you that this bug * exists even when the fd sets _are_ provided, so we have to check for this bug * here and emulate by sleeping manually. * we also get EINVAL when the timeout is invalid, but we ignore this case here * and assume that EINVAL always means: you have to wait manually. */ if (errno == EINVAL) { if (timeout) { unsigned long ms = timeout * 1e3; Sleep (ms ? ms : 1); } return; } #endif if (errno == EBADF) fd_ebadf (EV_A); else if (errno == ENOMEM && !syserr_cb) fd_enomem (EV_A); else if (errno != EINTR) ev_syserr ("(libev) select"); return; } #if EV_SELECT_USE_FD_SET { int fd; for (fd = 0; fd < anfdmax; ++fd) if (anfds [fd].events) { int events = 0; #if EV_SELECT_IS_WINSOCKET SOCKET handle = anfds [fd].handle; #else int handle = fd; #endif if (FD_ISSET (handle, (fd_set *)vec_ro)) events |= EV_READ; if (FD_ISSET (handle, (fd_set *)vec_wo)) events |= EV_WRITE; #ifdef _WIN32 if (FD_ISSET (handle, (fd_set *)vec_eo)) events |= EV_WRITE; #endif if (expect_true (events)) fd_event (EV_A_ fd, events); } } #else { int word, bit; for (word = vec_max; word--; ) { fd_mask word_r = ((fd_mask *)vec_ro) [word]; fd_mask word_w = ((fd_mask *)vec_wo) [word]; #ifdef _WIN32 word_w |= ((fd_mask *)vec_eo) [word]; #endif if (word_r || word_w) for (bit = NFDBITS; bit--; ) { fd_mask mask = 1UL << bit; int events = 0; events |= word_r & mask ? EV_READ : 0; events |= word_w & mask ? EV_WRITE : 0; if (expect_true (events)) fd_event (EV_A_ word * NFDBITS + bit, events); } } } #endif } inline_size int select_init (EV_P_ int flags) { backend_mintime = 1e-6; backend_modify = select_modify; backend_poll = select_poll; #if EV_SELECT_USE_FD_SET vec_ri = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_ri); vec_ro = ev_malloc (sizeof (fd_set)); vec_wi = ev_malloc (sizeof (fd_set)); FD_ZERO ((fd_set *)vec_wi); vec_wo = ev_malloc (sizeof (fd_set)); #ifdef _WIN32 vec_eo = ev_malloc (sizeof (fd_set)); #endif #else vec_max = 0; vec_ri = 0; vec_ro = 0; vec_wi = 0; vec_wo = 0; #ifdef _WIN32 vec_eo = 0; #endif #endif return EVBACKEND_SELECT; } inline_size void select_destroy (EV_P) { ev_free (vec_ri); ev_free (vec_ro); ev_free (vec_wi); ev_free (vec_wo); #ifdef _WIN32 ev_free (vec_eo); #endif }