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authorpeter <peter@FreeBSD.org>2008-07-12 05:00:28 +0000
committerpeter <peter@FreeBSD.org>2008-07-12 05:00:28 +0000
commitba8f85b49c38af7bc2a9acdef5dcde2de008d25e (patch)
treeceac31a567976fd5866cb5791b059781f6e045de /lib/bind/isc/ev_files.c
parent0f328cea2580ffb8f9e363be671a517787111472 (diff)
downloadFreeBSD-src-ba8f85b49c38af7bc2a9acdef5dcde2de008d25e.zip
FreeBSD-src-ba8f85b49c38af7bc2a9acdef5dcde2de008d25e.tar.gz
Flatten bind9 vendor work area
Diffstat (limited to 'lib/bind/isc/ev_files.c')
-rw-r--r--lib/bind/isc/ev_files.c277
1 files changed, 277 insertions, 0 deletions
diff --git a/lib/bind/isc/ev_files.c b/lib/bind/isc/ev_files.c
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+++ b/lib/bind/isc/ev_files.c
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+/*
+ * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (c) 1995-1999 by Internet Software Consortium
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+ * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* ev_files.c - implement asynch file IO for the eventlib
+ * vix 11sep95 [initial]
+ */
+
+#if !defined(LINT) && !defined(CODECENTER)
+static const char rcsid[] = "$Id: ev_files.c,v 1.5.18.3 2005/07/28 07:38:09 marka Exp $";
+#endif
+
+#include "port_before.h"
+#include "fd_setsize.h"
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/ioctl.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <isc/eventlib.h>
+#include "eventlib_p.h"
+
+#include "port_after.h"
+
+static evFile *FindFD(const evContext_p *ctx, int fd, int eventmask);
+
+int
+evSelectFD(evContext opaqueCtx,
+ int fd,
+ int eventmask,
+ evFileFunc func,
+ void *uap,
+ evFileID *opaqueID
+) {
+ evContext_p *ctx = opaqueCtx.opaque;
+ evFile *id;
+ int mode;
+
+ evPrintf(ctx, 1,
+ "evSelectFD(ctx %p, fd %d, mask 0x%x, func %p, uap %p)\n",
+ ctx, fd, eventmask, func, uap);
+ if (eventmask == 0 || (eventmask & ~EV_MASK_ALL) != 0)
+ EV_ERR(EINVAL);
+#ifndef USE_POLL
+ if (fd > ctx->highestFD)
+ EV_ERR(EINVAL);
+#endif
+ OK(mode = fcntl(fd, F_GETFL, NULL)); /*%< side effect: validate fd. */
+ /*
+ * The first time we touch a file descriptor, we need to check to see
+ * if the application already had it in O_NONBLOCK mode and if so, all
+ * of our deselect()'s have to leave it in O_NONBLOCK. If not, then
+ * all but our last deselect() has to leave it in O_NONBLOCK.
+ */
+#ifdef USE_POLL
+ /* Make sure both ctx->pollfds[] and ctx->fdTable[] are large enough */
+ if (fd >= ctx->maxnfds && evPollfdRealloc(ctx, 1, fd) != 0)
+ EV_ERR(ENOMEM);
+#endif /* USE_POLL */
+ id = FindFD(ctx, fd, EV_MASK_ALL);
+ if (id == NULL) {
+ if (mode & PORT_NONBLOCK)
+ FD_SET(fd, &ctx->nonblockBefore);
+ else {
+#ifdef USE_FIONBIO_IOCTL
+ int on = 1;
+ OK(ioctl(fd, FIONBIO, (char *)&on));
+#else
+ OK(fcntl(fd, F_SETFL, mode | PORT_NONBLOCK));
+#endif
+ FD_CLR(fd, &ctx->nonblockBefore);
+ }
+ }
+
+ /*
+ * If this descriptor is already in use, search for it again to see
+ * if any of the eventmask bits we want to set are already captured.
+ * We cannot usefully capture the same fd event more than once in the
+ * same context.
+ */
+ if (id != NULL && FindFD(ctx, fd, eventmask) != NULL)
+ EV_ERR(ETOOMANYREFS);
+
+ /* Allocate and fill. */
+ OKNEW(id);
+ id->func = func;
+ id->uap = uap;
+ id->fd = fd;
+ id->eventmask = eventmask;
+
+ /*
+ * Insert at head. Order could be important for performance if we
+ * believe that evGetNext()'s accesses to the fd_sets will be more
+ * serial and therefore more cache-lucky if the list is ordered by
+ * ``fd.'' We do not believe these things, so we don't do it.
+ *
+ * The interesting sequence is where GetNext() has cached a select()
+ * result and the caller decides to evSelectFD() on some descriptor.
+ * Since GetNext() starts at the head, it can miss new entries we add
+ * at the head. This is not a serious problem since the event being
+ * evSelectFD()'d for has to occur before evSelectFD() is called for
+ * the file event to be considered "missed" -- a real corner case.
+ * Maintaining a "tail" pointer for ctx->files would fix this, but I'm
+ * not sure it would be ``more correct.''
+ */
+ if (ctx->files != NULL)
+ ctx->files->prev = id;
+ id->prev = NULL;
+ id->next = ctx->files;
+ ctx->files = id;
+
+ /* Insert into fd table. */
+ if (ctx->fdTable[fd] != NULL)
+ ctx->fdTable[fd]->fdprev = id;
+ id->fdprev = NULL;
+ id->fdnext = ctx->fdTable[fd];
+ ctx->fdTable[fd] = id;
+
+ /* Turn on the appropriate bits in the {rd,wr,ex}Next fd_set's. */
+ if (eventmask & EV_READ)
+ FD_SET(fd, &ctx->rdNext);
+ if (eventmask & EV_WRITE)
+ FD_SET(fd, &ctx->wrNext);
+ if (eventmask & EV_EXCEPT)
+ FD_SET(fd, &ctx->exNext);
+
+ /* Update fdMax. */
+ if (fd > ctx->fdMax)
+ ctx->fdMax = fd;
+
+ /* Remember the ID if the caller provided us a place for it. */
+ if (opaqueID)
+ opaqueID->opaque = id;
+
+ return (0);
+}
+
+int
+evDeselectFD(evContext opaqueCtx, evFileID opaqueID) {
+ evContext_p *ctx = opaqueCtx.opaque;
+ evFile *del = opaqueID.opaque;
+ evFile *cur;
+ int mode, eventmask;
+
+ if (!del) {
+ evPrintf(ctx, 11, "evDeselectFD(NULL) ignored\n");
+ errno = EINVAL;
+ return (-1);
+ }
+
+ evPrintf(ctx, 1, "evDeselectFD(fd %d, mask 0x%x)\n",
+ del->fd, del->eventmask);
+
+ /* Get the mode. Unless the file has been closed, errors are bad. */
+ mode = fcntl(del->fd, F_GETFL, NULL);
+ if (mode == -1 && errno != EBADF)
+ EV_ERR(errno);
+
+ /* Remove from the list of files. */
+ if (del->prev != NULL)
+ del->prev->next = del->next;
+ else
+ ctx->files = del->next;
+ if (del->next != NULL)
+ del->next->prev = del->prev;
+
+ /* Remove from the fd table. */
+ if (del->fdprev != NULL)
+ del->fdprev->fdnext = del->fdnext;
+ else
+ ctx->fdTable[del->fd] = del->fdnext;
+ if (del->fdnext != NULL)
+ del->fdnext->fdprev = del->fdprev;
+
+ /*
+ * If the file descriptor does not appear in any other select() entry,
+ * and if !EV_WASNONBLOCK, and if we got no EBADF when we got the mode
+ * earlier, then: restore the fd to blocking status.
+ */
+ if (!(cur = FindFD(ctx, del->fd, EV_MASK_ALL)) &&
+ !FD_ISSET(del->fd, &ctx->nonblockBefore) &&
+ mode != -1) {
+ /*
+ * Note that we won't return an error status to the caller if
+ * this fcntl() fails since (a) we've already done the work
+ * and (b) the caller didn't ask us anything about O_NONBLOCK.
+ */
+#ifdef USE_FIONBIO_IOCTL
+ int off = 0;
+ (void) ioctl(del->fd, FIONBIO, (char *)&off);
+#else
+ (void) fcntl(del->fd, F_SETFL, mode & ~PORT_NONBLOCK);
+#endif
+ }
+
+ /*
+ * Now find all other uses of this descriptor and OR together an event
+ * mask so that we don't turn off {rd,wr,ex}Next bits that some other
+ * file event is using. As an optimization, stop if the event mask
+ * fills.
+ */
+ eventmask = 0;
+ for ((void)NULL;
+ cur != NULL && eventmask != EV_MASK_ALL;
+ cur = cur->next)
+ if (cur->fd == del->fd)
+ eventmask |= cur->eventmask;
+
+ /* OK, now we know which bits we can clear out. */
+ if (!(eventmask & EV_READ)) {
+ FD_CLR(del->fd, &ctx->rdNext);
+ if (FD_ISSET(del->fd, &ctx->rdLast)) {
+ FD_CLR(del->fd, &ctx->rdLast);
+ ctx->fdCount--;
+ }
+ }
+ if (!(eventmask & EV_WRITE)) {
+ FD_CLR(del->fd, &ctx->wrNext);
+ if (FD_ISSET(del->fd, &ctx->wrLast)) {
+ FD_CLR(del->fd, &ctx->wrLast);
+ ctx->fdCount--;
+ }
+ }
+ if (!(eventmask & EV_EXCEPT)) {
+ FD_CLR(del->fd, &ctx->exNext);
+ if (FD_ISSET(del->fd, &ctx->exLast)) {
+ FD_CLR(del->fd, &ctx->exLast);
+ ctx->fdCount--;
+ }
+ }
+
+ /* If this was the maxFD, find the new one. */
+ if (del->fd == ctx->fdMax) {
+ ctx->fdMax = -1;
+ for (cur = ctx->files; cur; cur = cur->next)
+ if (cur->fd > ctx->fdMax)
+ ctx->fdMax = cur->fd;
+ }
+
+ /* If this was the fdNext, cycle that to the next entry. */
+ if (del == ctx->fdNext)
+ ctx->fdNext = del->next;
+
+ /* Couldn't free it before now since we were using fields out of it. */
+ FREE(del);
+
+ return (0);
+}
+
+static evFile *
+FindFD(const evContext_p *ctx, int fd, int eventmask) {
+ evFile *id;
+
+ for (id = ctx->fdTable[fd]; id != NULL; id = id->fdnext)
+ if (id->fd == fd && (id->eventmask & eventmask) != 0)
+ break;
+ return (id);
+}
+
+/*! \file */
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