* hurd/hurd/signal.h (struct hurd_sigstate): New member `preempters'. cvs/libc-960102

	(hurd_preempt_signals, hurd_unpreempt_signals): Decls removed.
	* hurd/hurd/sigpreempt.h: New file.
	* hurd/preempt-sig.c: Rewritten with new interface.
	* sysdeps/mach/hurd/jmp-unwind.c (_longjmp_unwind): Remove local signal
	preempters being unwound past.

	* db: New directory, 4.4 BSD db package incorporated from BSD db-1.85
	release.

	* sysdeps/unix/sysv/linux/sys/param.h: Several new macros for BSD
	compatibility.

1 files changed, 460 insertions, 0 deletions

diff --git a/db/btree/bt_seq.c b/db/btree/bt_seq.c
new file mode 100644
index 0000000000..303b481903
--- /dev/null
+++ b/db/btree/bt_seq.c
@@ -0,0 +1,460 @@
+/*-
+ * Copyright (c) 1990, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Mike Olson.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)bt_seq.c	8.7 (Berkeley) 7/20/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/types.h>
+
+#include <errno.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <db.h>
+#include "btree.h"
+
+static int __bt_first __P((BTREE *, const DBT *, EPG *, int *));
+static int __bt_seqadv __P((BTREE *, EPG *, int));
+static int __bt_seqset __P((BTREE *, EPG *, DBT *, int));
+
+/*
+ * Sequential scan support.
+ *
+ * The tree can be scanned sequentially, starting from either end of the
+ * tree or from any specific key.  A scan request before any scanning is
+ * done is initialized as starting from the least node.
+ */
+
+/*
+ * __bt_seq --
+ *	Btree sequential scan interface.
+ *
+ * Parameters:
+ *	dbp:	pointer to access method
+ *	key:	key for positioning and return value
+ *	data:	data return value
+ *	flags:	R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV.
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
+ */
+int
+__bt_seq(dbp, key, data, flags)
+	const DB *dbp;
+	DBT *key, *data;
+	u_int flags;
+{
+	BTREE *t;
+	EPG e;
+	int status;
+
+	t = dbp->internal;
+
+	/* Toss any page pinned across calls. */
+	if (t->bt_pinned != NULL) {
+		mpool_put(t->bt_mp, t->bt_pinned, 0);
+		t->bt_pinned = NULL;
+	}
+
+	/*
+	 * If scan unitialized as yet, or starting at a specific record, set
+	 * the scan to a specific key.  Both __bt_seqset and __bt_seqadv pin
+	 * the page the cursor references if they're successful.
+	 */
+	switch (flags) {
+	case R_NEXT:
+	case R_PREV:
+		if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
+			status = __bt_seqadv(t, &e, flags);
+			break;
+		}
+		/* FALLTHROUGH */
+	case R_FIRST:
+	case R_LAST:
+	case R_CURSOR:
+		status = __bt_seqset(t, &e, key, flags);
+		break;
+	default:
+		errno = EINVAL;
+		return (RET_ERROR);
+	}
+
+	if (status == RET_SUCCESS) {
+		__bt_setcur(t, e.page->pgno, e.index);
+
+		status =
+		    __bt_ret(t, &e, key, &t->bt_rkey, data, &t->bt_rdata, 0);
+
+		/*
+		 * If the user is doing concurrent access, we copied the
+		 * key/data, toss the page.
+		 */
+		if (F_ISSET(t, B_DB_LOCK))
+			mpool_put(t->bt_mp, e.page, 0);
+		else
+			t->bt_pinned = e.page;
+	}
+	return (status);
+}
+
+/*
+ * __bt_seqset --
+ *	Set the sequential scan to a specific key.
+ *
+ * Parameters:
+ *	t:	tree
+ *	ep:	storage for returned key
+ *	key:	key for initial scan position
+ *	flags:	R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV
+ *
+ * Side effects:
+ *	Pins the page the cursor references.
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
+ */
+static int
+__bt_seqset(t, ep, key, flags)
+	BTREE *t;
+	EPG *ep;
+	DBT *key;
+	int flags;
+{
+	PAGE *h;
+	pgno_t pg;
+	int exact;
+
+	/*
+	 * Find the first, last or specific key in the tree and point the
+	 * cursor at it.  The cursor may not be moved until a new key has
+	 * been found.
+	 */
+	switch (flags) {
+	case R_CURSOR:				/* Keyed scan. */
+		/*
+		 * Find the first instance of the key or the smallest key
+		 * which is greater than or equal to the specified key.
+		 */
+		if (key->data == NULL || key->size == 0) {
+			errno = EINVAL;
+			return (RET_ERROR);
+		}
+		return (__bt_first(t, key, ep, &exact));
+	case R_FIRST:				/* First record. */
+	case R_NEXT:
+		/* Walk down the left-hand side of the tree. */
+		for (pg = P_ROOT;;) {
+			if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+				return (RET_ERROR);
+
+			/* Check for an empty tree. */
+			if (NEXTINDEX(h) == 0) {
+				mpool_put(t->bt_mp, h, 0);
+				return (RET_SPECIAL);
+			}
+
+			if (h->flags & (P_BLEAF | P_RLEAF))
+				break;
+			pg = GETBINTERNAL(h, 0)->pgno;
+			mpool_put(t->bt_mp, h, 0);
+		}
+		ep->page = h;
+		ep->index = 0;
+		break;
+	case R_LAST:				/* Last record. */
+	case R_PREV:
+		/* Walk down the right-hand side of the tree. */
+		for (pg = P_ROOT;;) {
+			if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+				return (RET_ERROR);
+
+			/* Check for an empty tree. */
+			if (NEXTINDEX(h) == 0) {
+				mpool_put(t->bt_mp, h, 0);
+				return (RET_SPECIAL);
+			}
+
+			if (h->flags & (P_BLEAF | P_RLEAF))
+				break;
+			pg = GETBINTERNAL(h, NEXTINDEX(h) - 1)->pgno;
+			mpool_put(t->bt_mp, h, 0);
+		}
+
+		ep->page = h;
+		ep->index = NEXTINDEX(h) - 1;
+		break;
+	}
+	return (RET_SUCCESS);
+}
+
+/*
+ * __bt_seqadvance --
+ *	Advance the sequential scan.
+ *
+ * Parameters:
+ *	t:	tree
+ *	flags:	R_NEXT, R_PREV
+ *
+ * Side effects:
+ *	Pins the page the new key/data record is on.
+ *
+ * Returns:
+ *	RET_ERROR, RET_SUCCESS or RET_SPECIAL if there's no next key.
+ */
+static int
+__bt_seqadv(t, ep, flags)
+	BTREE *t;
+	EPG *ep;
+	int flags;
+{
+	CURSOR *c;
+	PAGE *h;
+	indx_t index;
+	pgno_t pg;
+	int exact;
+
+	/*
+	 * There are a couple of states that we can be in.  The cursor has
+	 * been initialized by the time we get here, but that's all we know.
+	 */
+	c = &t->bt_cursor;
+
+	/*
+	 * The cursor was deleted where there weren't any duplicate records,
+	 * so the key was saved.  Find out where that key would go in the
+	 * current tree.  It doesn't matter if the returned key is an exact
+	 * match or not -- if it's an exact match, the record was added after
+	 * the delete so we can just return it.  If not, as long as there's
+	 * a record there, return it.
+	 */
+	if (F_ISSET(c, CURS_ACQUIRE))
+		return (__bt_first(t, &c->key, ep, &exact));
+
+	/* Get the page referenced by the cursor. */
+	if ((h = mpool_get(t->bt_mp, c->pg.pgno, 0)) == NULL)
+		return (RET_ERROR);
+
+	/*
+ 	 * Find the next/previous record in the tree and point the cursor at
+	 * it.  The cursor may not be moved until a new key has been found.
+	 */
+	switch (flags) {
+	case R_NEXT:			/* Next record. */
+		/*
+		 * The cursor was deleted in duplicate records, and moved
+		 * forward to a record that has yet to be returned.  Clear
+		 * that flag, and return the record.
+		 */
+		if (F_ISSET(c, CURS_AFTER))
+			goto usecurrent;
+		index = c->pg.index;
+		if (++index == NEXTINDEX(h)) {
+			pg = h->nextpg;
+			mpool_put(t->bt_mp, h, 0);
+			if (pg == P_INVALID)
+				return (RET_SPECIAL);
+			if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+				return (RET_ERROR);
+			index = 0;
+		}
+		break;
+	case R_PREV:			/* Previous record. */
+		/*
+		 * The cursor was deleted in duplicate records, and moved
+		 * backward to a record that has yet to be returned.  Clear
+		 * that flag, and return the record.
+		 */
+		if (F_ISSET(c, CURS_BEFORE)) {
+usecurrent:		F_CLR(c, CURS_AFTER | CURS_BEFORE);
+			ep->page = h;
+			ep->index = c->pg.index;
+			return (RET_SUCCESS);
+		}
+		index = c->pg.index;
+		if (index == 0) {
+			pg = h->prevpg;
+			mpool_put(t->bt_mp, h, 0);
+			if (pg == P_INVALID)
+				return (RET_SPECIAL);
+			if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+				return (RET_ERROR);
+			index = NEXTINDEX(h) - 1;
+		} else
+			--index;
+		break;
+	}
+
+	ep->page = h;
+	ep->index = index;
+	return (RET_SUCCESS);
+}
+
+/*
+ * __bt_first --
+ *	Find the first entry.
+ *
+ * Parameters:
+ *	t:	the tree
+ *    key:	the key
+ *  erval:	return EPG
+ * exactp:	pointer to exact match flag
+ *
+ * Returns:
+ *	The first entry in the tree greater than or equal to key,
+ *	or RET_SPECIAL if no such key exists.
+ */
+static int
+__bt_first(t, key, erval, exactp)
+	BTREE *t;
+	const DBT *key;
+	EPG *erval;
+	int *exactp;
+{
+	PAGE *h;
+	EPG *ep, save;
+	pgno_t pg;
+
+	/*
+	 * Find any matching record; __bt_search pins the page.
+	 *
+	 * If it's an exact match and duplicates are possible, walk backwards
+	 * in the tree until we find the first one.  Otherwise, make sure it's
+	 * a valid key (__bt_search may return an index just past the end of a
+	 * page) and return it.
+	 */
+	if ((ep = __bt_search(t, key, exactp)) == NULL)
+		return (NULL);
+	if (*exactp) {
+		if (F_ISSET(t, B_NODUPS)) {
+			*erval = *ep;
+			return (RET_SUCCESS);
+		}
+			
+		/*
+		 * Walk backwards, as long as the entry matches and there are
+		 * keys left in the tree.  Save a copy of each match in case
+		 * we go too far.
+		 */
+		save = *ep;
+		h = ep->page;
+		do {
+			if (save.page->pgno != ep->page->pgno) {
+				mpool_put(t->bt_mp, save.page, 0);
+				save = *ep;
+			} else
+				save.index = ep->index;
+
+			/*
+			 * Don't unpin the page the last (or original) match
+			 * was on, but make sure it's unpinned if an error
+			 * occurs.
+			 */
+			if (ep->index == 0) {
+				if (h->prevpg == P_INVALID)
+					break;
+				if (h->pgno != save.page->pgno)
+					mpool_put(t->bt_mp, h, 0);
+				if ((h = mpool_get(t->bt_mp,
+				    h->prevpg, 0)) == NULL) {
+					if (h->pgno == save.page->pgno)
+						mpool_put(t->bt_mp,
+						    save.page, 0);
+					return (RET_ERROR);
+				}
+				ep->page = h;
+				ep->index = NEXTINDEX(h);
+			}
+			--ep->index;
+		} while (__bt_cmp(t, key, ep) == 0);
+
+		/*
+		 * Reach here with the last page that was looked at pinned,
+		 * which may or may not be the same as the last (or original)
+		 * match page.  If it's not useful, release it.
+		 */
+		if (h->pgno != save.page->pgno)
+			mpool_put(t->bt_mp, h, 0);
+
+		*erval = save;
+		return (RET_SUCCESS);
+	}
+
+	/* If at the end of a page, find the next entry. */
+	if (ep->index == NEXTINDEX(ep->page)) {
+		h = ep->page;
+		pg = h->nextpg;
+		mpool_put(t->bt_mp, h, 0);
+		if (pg == P_INVALID)
+			return (RET_SPECIAL);
+		if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
+			return (RET_ERROR);
+		ep->index = 0;
+		ep->page = h;
+	}
+	*erval = *ep;
+	return (RET_SUCCESS);
+}
+
+/*
+ * __bt_setcur --
+ *	Set the cursor to an entry in the tree.
+ *
+ * Parameters:
+ *	t:	the tree
+ *   pgno:	page number
+ *  index:	page index
+ */
+void
+__bt_setcur(t, pgno, index)
+	BTREE *t;
+	pgno_t pgno;
+	u_int index;
+{
+	/* Lose any already deleted key. */
+	if (t->bt_cursor.key.data != NULL) {
+		free(t->bt_cursor.key.data);
+		t->bt_cursor.key.size = 0;
+		t->bt_cursor.key.data = NULL;
+	}
+	F_CLR(&t->bt_cursor, CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE);
+
+	/* Update the cursor. */
+	t->bt_cursor.pg.pgno = pgno;
+	t->bt_cursor.pg.index = index;
+	F_SET(&t->bt_cursor, CURS_INIT);
+}