+/*
+ * libev select fd activity backend
+ *
+ * Copyright (c) 2007 Marc Alexander Lehmann <libev@schmorp.de>
+ * 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.
+ */
+
+/* for unix systems */
+#if WIN32
+typedef unsigned int uint32_t;
+# ifndef EV_SELECT_USE_FD_SET
+# define EV_SELECT_USE_FD_SET 1
+# endif
+#else
+# include <sys/select.h>
+# include <inttypes.h>
+#endif
+
+#if EV_SELECT_USE_WIN32_HANDLES
+# undef EV_SELECT_USE_FD_SET
+# define EV_SELECT_USE_FD_SET 1
+#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_USE_WIN32_HANDLES
+ fd = _get_osfhandle (fd);
+ if (fd < 0)
+ return;
+# endif
+
+ if (nev & EV_READ)
+ FD_SET (fd, (struct fd_set *)vec_ri);
+ else
+ FD_CLR (fd, (struct fd_set *)vec_ri);
+
+ if (nev & EV_WRITE)
+ FD_SET (fd, (struct fd_set *)vec_wi);
+ else
+ FD_CLR (fd, (struct fd_set *)vec_wi);
+#else
+ {
+ int offs = fd >> 3;
+ int mask = 1 << (fd & 7);
+
+ if (vec_max < (fd >> 5) + 1)
+ {
+ int new_max = (fd >> 5) + 1;
+
+ vec_ri = (unsigned char *)ev_realloc (vec_ri, new_max * 4);
+ vec_ro = (unsigned char *)ev_realloc (vec_ro, new_max * 4); /* could free/malloc */
+ vec_wi = (unsigned char *)ev_realloc (vec_wi, new_max * 4);
+ vec_wo = (unsigned char *)ev_realloc (vec_wo, new_max * 4); /* could free/malloc */
+
+ for (; vec_max < new_max; ++vec_max)
+ ((uint32_t *)vec_ri)[vec_max] =
+ ((uint32_t *)vec_wi)[vec_max] = 0;
+ }
+
+ vec_ri [offs] |= mask;
+ if (!(nev & EV_READ))
+ vec_ri [offs] &= ~mask;
+
+ vec_wi [offs] |= mask;
+ if (!(nev & EV_WRITE))
+ vec_wi [offs] &= ~mask;
+ }
+#endif
+}
+
+static void
+select_poll (EV_P_ ev_tstamp timeout)
+{
+ int word, offs;
+ struct timeval tv;
+ int res;
+
+#if EV_SELECT_USE_FD_SET
+ memcpy (vec_ro, vec_ri, sizeof (struct fd_set));
+ memcpy (vec_wo, vec_wi, sizeof (struct fd_set));
+#else
+ memcpy (vec_ro, vec_ri, vec_max * 4);
+ memcpy (vec_wo, vec_wi, vec_max * 4);
+#endif
+
+ tv.tv_sec = (long)timeout;
+ tv.tv_usec = (long)((timeout - (ev_tstamp)tv.tv_sec) * 1e6);
+
+ res = select (vec_max * 32, (fd_set *)vec_ro, (fd_set *)vec_wo, 0, &tv);
+
+ if (res < 0)
+ {
+#ifdef WIN32
+ if (errno == WSAEINTR ) errno = EINTR;
+ if (errno == WSAENOTSOCK) errno = EBADF;
+#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
+# if EV_SELECT_USE_WIN32_HANDLES
+ for (word = 0; word < anfdmax; ++word)
+ {
+ if (!anfd [word].events)
+ {
+ int fd = _get_osfhandle (word);
+
+ if (fd >= 0)
+ {
+ int events = 0;
+
+ if (FD_ISSET (fd, (struct fd_set *)vec_ro)) events |= EV_READ;
+ if (FD_ISSET (fd, (struct fd_set *)vec_wo)) events |= EV_WRITE;
+
+ if (events)
+ fd_event (EV_A_ word, events);
+ }
+ }
+ }
+# else
+ for (word = 0; word < FD_SETSIZE; ++word)
+ {
+ int events = 0;
+ if (FD_ISSET (word, (struct fd_set *)vec_ro)) events |= EV_READ;
+ if (FD_ISSET (word, (struct fd_set *)vec_wo)) events |= EV_WRITE;
+
+ if (events)
+ fd_event (EV_A_ word, events);
+ }
+# endif
+#else
+ for (word = vec_max; word--; )
+ {
+ if (((uint32_t *)vec_ro) [word] | ((uint32_t *)vec_wo) [word])
+ for (offs = 4; offs--; )
+ {
+ int idx = word * 4 + offs;
+ unsigned char byte_r = vec_ro [idx];
+ unsigned char byte_w = vec_wo [idx];
+ int bit;
+
+ if (byte_r | byte_w)
+ for (bit = 8; bit--; )
+ {
+ int events = 0;
+ events |= byte_r & (1 << bit) ? EV_READ : 0;
+ events |= byte_w & (1 << bit) ? EV_WRITE : 0;
+
+ if (events)
+ fd_event (EV_A_ idx * 8 + bit, events);
+ }
+ }
+ }
+#endif
+}
+
+static int
+select_init (EV_P_ int flags)
+{
+ method_fudge = 1e-2; /* needed to compensate for select returning early, very conservative */
+ method_modify = select_modify;
+ method_poll = select_poll;
+
+#if EV_SELECT_USE_FD_SET
+ vec_max = FD_SETSIZE / 32;
+ vec_ri = ev_malloc (sizeof (struct fd_set)); FD_ZERO ((struct fd_set *)vec_ri);
+ vec_ro = ev_malloc (sizeof (struct fd_set));
+ vec_wi = ev_malloc (sizeof (struct fd_set)); FD_ZERO ((struct fd_set *)vec_wi);
+ vec_wo = ev_malloc (sizeof (struct fd_set));
+#else
+ vec_max = 0;
+ vec_ri = 0;
+ vec_ri = 0;
+ vec_wo = 0;
+ vec_wo = 0;
+#endif
+
+ return EVMETHOD_SELECT;
+}
+
+static void
+select_destroy (EV_P)
+{
+ ev_free (vec_ri);
+ ev_free (vec_ro);
+ ev_free (vec_wi);
+ ev_free (vec_wo);
+}
+
+
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