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/* |
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* libev select fd activity backend |
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* |
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* Copyright (c) 2007 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 |
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* modification, are permitted provided that the following conditions are |
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* met: |
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* |
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* * Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* |
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* * Redistributions in binary form must reproduce the above |
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* copyright notice, this list of conditions and the following |
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* disclaimer in the documentation and/or other materials provided |
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* with the distribution. |
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* |
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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*/ |
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|
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/* for unix systems */ |
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#ifdef WIN32 |
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typedef unsigned int uint32_t; |
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#else |
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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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#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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int offs = fd >> 3; |
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int mask = 1 << (fd & 7); |
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|
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if (oev == nev) |
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return; |
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|
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if (vec_max < (fd >> 5) + 1) |
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{ |
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int new_max = (fd >> 5) + 1; |
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|
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vec_ri = (unsigned char *)ev_realloc (vec_ri, new_max * 4); |
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vec_ro = (unsigned char *)ev_realloc (vec_ro, new_max * 4); /* could free/malloc */ |
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vec_wi = (unsigned char *)ev_realloc (vec_wi, new_max * 4); |
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vec_wo = (unsigned char *)ev_realloc (vec_wo, new_max * 4); /* could free/malloc */ |
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|
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for (; vec_max < new_max; ++vec_max) |
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((uint32_t *)vec_ri)[vec_max] = |
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((uint32_t *)vec_wi)[vec_max] = 0; |
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} |
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|
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vec_ri [offs] |= mask; |
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if (!(nev & EV_READ)) |
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vec_ri [offs] &= ~mask; |
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|
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vec_wi [offs] |= mask; |
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if (!(nev & EV_WRITE)) |
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vec_wi [offs] &= ~mask; |
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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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int word, offs; |
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struct timeval tv; |
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int res; |
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|
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memcpy (vec_ro, vec_ri, vec_max * 4); |
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memcpy (vec_wo, vec_wi, vec_max * 4); |
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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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res = select (vec_max * 32, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv); |
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|
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if (res < 0) |
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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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for (word = vec_max; word--; ) |
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{ |
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if (((uint32_t *)vec_ro) [word] | ((uint32_t *)vec_wo) [word]) |
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for (offs = 4; offs--; ) |
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{ |
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int idx = word * 4 + offs; |
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unsigned char byte_r = vec_ro [idx]; |
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unsigned char byte_w = vec_wo [idx]; |
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int bit; |
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|
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if (byte_r | byte_w) |
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for (bit = 8; bit--; ) |
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{ |
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int events = 0; |
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events |= byte_r & (1 << bit) ? EV_READ : 0; |
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events |= byte_w & (1 << bit) ? EV_WRITE : 0; |
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|
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if (events) |
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fd_event (EV_A_ idx * 8 + bit, events); |
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} |
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} |
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} |
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} |
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|
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static int |
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select_init (EV_P_ int flags) |
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{ |
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method_fudge = 1e-2; /* needed to compensate for select returning early, very conservative */ |
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method_modify = select_modify; |
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method_poll = select_poll; |
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|
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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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|
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return EVMETHOD_SELECT; |
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} |
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|
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static void |
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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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|
