X-Git-Url: https://git.llucax.com/software/libev.git/blobdiff_plain/cc75a05531d9d05ac14fdaec7960b1c970c87bbb..0a7b0ac074d9987c6fa23ab20be4842e4514c7b9:/ev_select.c diff --git a/ev_select.c b/ev_select.c index e69de29..1df0953 100644 --- a/ev_select.c +++ b/ev_select.c @@ -0,0 +1,236 @@ +/* + * libev select fd activity backend + * + * Copyright (c) 2007 Marc Alexander Lehmann + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * * 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 COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, 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 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef _WIN32 +/* for unix systems */ +# include +# include +#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 EINTR +# define EINTR WSAEINTR +# undef EBADF +# define EBADF WSAENOTSOCK +# undef ENOMEM +# define ENOMEM (errno + 1) +#endif + +#if !EV_SELECT_USE_FD_SET +# define NFDBYTES (NFDBITS / 8) +#endif + +#include + +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 + + if (nev & EV_READ) + FD_SET (handle, (fd_set *)vec_ri); + else + FD_CLR (handle, (fd_set *)vec_ri); + + if (nev & EV_WRITE) + FD_SET (handle, (fd_set *)vec_wi); + else + FD_CLR (handle, (fd_set *)vec_wi); + +#else + + int word = fd / NFDBITS; + int mask = 1UL << (fd % NFDBITS); + + if (vec_max < word + 1) + { + 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 */ + + 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; + +#if EV_SELECT_USE_FD_SET + memcpy (vec_ro, vec_ri, sizeof (fd_set)); + memcpy (vec_wo, vec_wi, sizeof (fd_set)); +#else + memcpy (vec_ro, vec_ri, vec_max * NFDBYTES); + memcpy (vec_wo, vec_wi, vec_max * NFDBYTES); +#endif + + tv.tv_sec = (long)timeout; + tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6); + + res = select (vec_max * NFDBITS, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv); + + if (res < 0) + { + #if EV_SELECT_IS_WINSOCKET + errno = WSAGetLastError (); + #endif + + if (errno == EBADF) + fd_ebadf (EV_A); + else if (errno == ENOMEM && !syserr_cb) + fd_enomem (EV_A); + else if (errno != EINTR) + 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; + + if (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]; + + 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 (events) + fd_event (EV_A_ word * NFDBITS + bit, events); + } + } + } + +#endif +} + +int inline_size +select_init (EV_P_ int flags) +{ + backend_fudge = 1e-2; /* needed to compensate for select returning early, very conservative */ + backend_modify = select_modify; + backend_poll = select_poll; + +#if EV_SELECT_USE_FD_SET + vec_max = FD_SETSIZE / 32; + 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)); +#else + vec_max = 0; + vec_ri = 0; + vec_ri = 0; + vec_wo = 0; + vec_wo = 0; +#endif + + return EVBACKEND_SELECT; +} + +void inline_size +select_destroy (EV_P) +{ + ev_free (vec_ri); + ev_free (vec_ro); + ev_free (vec_wi); + ev_free (vec_wo); +} + +