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authorUlrich Drepper <drepper@redhat.com>2000-01-02 06:01:06 +0000
committerUlrich Drepper <drepper@redhat.com>2000-01-02 06:01:06 +0000
commit8d6f1731fcd082e4f744ba9cb4bde4be7c08f1b3 (patch)
tree099a250d7366aef2ab028fdb24f0d692cd784b4a /db2/common/db_region.c
parent9a6450d578556c11e7c173d2f28362345b8f1258 (diff)
downloadglibc-8d6f1731fcd082e4f744ba9cb4bde4be7c08f1b3.tar.gz
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Update.
	* Makeconfig (all-subdirs): Remove db and db2.
	* db/*: Removed.
	* db2/*: Removed.
Diffstat (limited to 'db2/common/db_region.c')
-rw-r--r--db2/common/db_region.c873
1 files changed, 0 insertions, 873 deletions
diff --git a/db2/common/db_region.c b/db2/common/db_region.c
deleted file mode 100644
index 12abfa524d..0000000000
--- a/db2/common/db_region.c
+++ /dev/null
@@ -1,873 +0,0 @@
-/*-
- * See the file LICENSE for redistribution information.
- *
- * Copyright (c) 1996, 1997, 1998
- *	Sleepycat Software.  All rights reserved.
- */
-
-#include "config.h"
-
-#ifndef lint
-static const char sccsid[] = "@(#)db_region.c	10.53 (Sleepycat) 11/10/98";
-#endif /* not lint */
-
-#ifndef NO_SYSTEM_INCLUDES
-#include <sys/types.h>
-
-#include <errno.h>
-#include <string.h>
-#include <unistd.h>
-#endif
-
-#include "db_int.h"
-#include "common_ext.h"
-
-static int __db_growregion __P((REGINFO *, size_t));
-
-/*
- * __db_rattach --
- *	Optionally create and attach to a shared memory region.
- *
- * PUBLIC: int __db_rattach __P((REGINFO *));
- */
-int
-__db_rattach(infop)
-	REGINFO *infop;
-{
-	RLAYOUT *rlp, rl;
-	size_t grow_region, size;
-	ssize_t nr, nw;
-	u_int32_t flags, mbytes, bytes;
-	u_int8_t *p;
-	int malloc_possible, ret, retry_cnt;
-
-	grow_region = 0;
-	malloc_possible = 1;
-	ret = retry_cnt = 0;
-
-	/* Round off the requested size to the next page boundary. */
-	DB_ROUNDOFF(infop->size, DB_VMPAGESIZE);
-
-	/* Some architectures have hard limits on the maximum region size. */
-#ifdef DB_REGIONSIZE_MAX
-	if (infop->size > DB_REGIONSIZE_MAX) {
-		__db_err(infop->dbenv, "__db_rattach: cache size too large");
-		return (EINVAL);
-	}
-#endif
-
-	/* Intialize the return information in the REGINFO structure. */
-loop:	infop->addr = NULL;
-	infop->fd = -1;
-	infop->segid = INVALID_SEGID;
-	if (infop->name != NULL) {
-		__os_freestr(infop->name);
-		infop->name = NULL;
-	}
-	F_CLR(infop, REGION_CANGROW | REGION_CREATED);
-
-#ifndef HAVE_SPINLOCKS
-	/*
-	 * XXX
-	 * Lacking spinlocks, we must have a file descriptor for fcntl(2)
-	 * locking, which implies using mmap(2) to map in a regular file.
-	 * (Theoretically, we could probably get a file descriptor to lock
-	 * other types of shared regions, but I don't see any reason to
-	 * bother.)
-	 *
-	 * Since we may be using shared memory regions, e.g., shmget(2),
-	 * and not mmap of regular files, the backing file may be only a
-	 * few tens of bytes in length.  So, this depends on the ability
-	 * to fcntl lock file offsets much larger than the physical file.
-	 */
-	malloc_possible = 0;
-#endif
-
-#ifdef __hppa
-	/*
-	 * XXX
-	 * HP-UX won't permit mutexes to live in anything but shared memory.
-	 * Instantiate a shared region file on that architecture, regardless.
-	 */
-	malloc_possible = 0;
-#endif
-	/*
-	 * If a region is truly private, malloc the memory.  That's faster
-	 * than either anonymous memory or a shared file.
-	 */
-	if (malloc_possible && F_ISSET(infop, REGION_PRIVATE)) {
-		if ((ret = __os_malloc(infop->size, NULL, &infop->addr)) != 0)
-			return (ret);
-
-		/*
-		 * It's sometimes significantly faster to page-fault in all of
-		 * the region's pages before we run the application, as we see
-		 * nasty side-effects when we page-fault while holding various
-		 * locks, i.e., the lock takes a long time to acquire because
-		 * of the underlying page fault, and the other threads convoy
-		 * behind the lock holder.
-		 */
-		if (DB_GLOBAL(db_region_init))
-			for (p = infop->addr;
-			    p < (u_int8_t *)infop->addr + infop->size;
-			    p += DB_VMPAGESIZE)
-				p[0] = '\0';
-
-		F_SET(infop, REGION_CREATED | REGION_MALLOC);
-		goto region_init;
-	}
-
-	/*
-	 * Get the name of the region (creating the file if a temporary file
-	 * is being used).  The dbenv contains the current DB environment,
-	 * including naming information.  The path argument may be a file or
-	 * a directory.  If path is a directory, it must exist and file is the
-	 * file name to be created inside the directory.  If path is a file,
-	 * then file must be NULL.
-	 */
-	if ((ret = __db_appname(infop->dbenv, infop->appname, infop->path,
-	    infop->file, infop->dbflags, &infop->fd, &infop->name)) != 0)
-		return (ret);
-	if (infop->fd != -1)
-		F_SET(infop, REGION_CREATED);
-
-	/*
-	 * Try to create the file, if we have authority.  We have to make sure
-	 * that multiple threads/processes attempting to simultaneously create
-	 * the region are properly ordered, so we open it using DB_CREATE and
-	 * DB_EXCL, so two attempts to create the region will return failure in
-	 * one.
-	 */
-	if (infop->fd == -1 && infop->dbflags & DB_CREATE) {
-		flags = infop->dbflags;
-		LF_SET(DB_EXCL);
-		if ((ret = __db_open(infop->name,
-		    flags, flags, infop->mode, &infop->fd)) == 0)
-			F_SET(infop, REGION_CREATED);
-		else
-			if (ret != EEXIST)
-				goto errmsg;
-	}
-
-	/* If we couldn't create the file, try and open it. */
-	if (infop->fd == -1) {
-		flags = infop->dbflags;
-		LF_CLR(DB_CREATE | DB_EXCL);
-		if ((ret = __db_open(infop->name,
-		    flags, flags, infop->mode, &infop->fd)) != 0)
-			goto errmsg;
-	}
-
-	/*
-	 * There are three cases we support:
-	 *    1. Named anonymous memory (shmget(2)).
-	 *    2. Unnamed anonymous memory (mmap(2): MAP_ANON/MAP_ANONYMOUS).
-	 *    3. Memory backed by a regular file (mmap(2)).
-	 *
-	 * We instantiate a backing file in all cases, which contains at least
-	 * the RLAYOUT structure, and in case #3, contains the actual region.
-	 * This is necessary for a couple of reasons:
-	 *
-	 * First, the mpool region uses temporary files to name regions, and
-	 * since you may have multiple regions in the same directory, we need
-	 * a filesystem name to ensure that they don't collide.
-	 *
-	 * Second, applications are allowed to forcibly remove regions, even
-	 * if they don't know anything about them other than the name.  If a
-	 * region is backed by anonymous memory, there has to be some way for
-	 * the application to find out that information, and, in some cases,
-	 * determine ID information for the anonymous memory.
-	 */
-	if (F_ISSET(infop, REGION_CREATED)) {
-		/*
-		 * If we're using anonymous memory to back this region, set
-		 * the flag.
-		 */
-		if (DB_GLOBAL(db_region_anon))
-			F_SET(infop, REGION_ANONYMOUS);
-
-		/*
-		 * If we're using a regular file to back a region we created,
-		 * grow it to the specified size.
-		 */
-		if (!DB_GLOBAL(db_region_anon) &&
-		    (ret = __db_growregion(infop, infop->size)) != 0)
-			goto err;
-	} else {
-		/*
-		 * If we're joining a region, figure out what it looks like.
-		 *
-		 * XXX
-		 * We have to figure out if the file is a regular file backing
-		 * a region that we want to map into our address space, or a
-		 * file with the information we need to find a shared anonymous
-		 * region that we want to map into our address space.
-		 *
-		 * All this noise is because some systems don't have a coherent
-		 * VM and buffer cache, and worse, if you mix operations on the
-		 * VM and buffer cache, half the time you hang the system.
-		 *
-		 * There are two possibilities.  If the file is the size of an
-		 * RLAYOUT structure, then we know that the real region is in
-		 * shared memory, because otherwise it would be bigger.  (As
-		 * the RLAYOUT structure size is smaller than a disk sector,
-		 * the only way it can be this size is if deliberately written
-		 * that way.)  In which case, retrieve the information we need
-		 * from the RLAYOUT structure and use it to acquire the shared
-		 * memory.
-		 *
-		 * If the structure is larger than an RLAYOUT structure, then
-		 * the file is backing the shared memory region, and we use
-		 * the current size of the file without reading any information
-		 * from the file itself so that we don't confuse the VM.
-		 *
-		 * And yes, this makes me want to take somebody and kill them,
-		 * but I can't think of any other solution.
-		 */
-		if ((ret = __os_ioinfo(infop->name,
-		    infop->fd, &mbytes, &bytes, NULL)) != 0)
-			goto errmsg;
-		size = mbytes * MEGABYTE + bytes;
-
-		if (size <= sizeof(RLAYOUT)) {
-			/*
-			 * If the size is too small, the read fails or the
-			 * valid flag is incorrect, assume it's because the
-			 * RLAYOUT information hasn't been written out yet,
-			 * and retry.
-			 */
-			if (size < sizeof(RLAYOUT))
-				goto retry;
-			if ((ret =
-			    __os_read(infop->fd, &rl, sizeof(rl), &nr)) != 0)
-				goto retry;
-			if (rl.valid != DB_REGIONMAGIC)
-				goto retry;
-
-			/* Copy the size, memory id and characteristics. */
-			size = rl.size;
-			infop->segid = rl.segid;
-			if (F_ISSET(&rl, REGION_ANONYMOUS))
-				F_SET(infop, REGION_ANONYMOUS);
-		}
-
-		/*
-		 * If the region is larger than we think, that's okay, use the
-		 * current size.  If it's smaller than we think, and we were
-		 * just using the default size, that's okay, use the current
-		 * size.  If it's smaller than we think and we really care,
-		 * save the size and we'll catch that further down -- we can't
-		 * correct it here because we have to have a lock to grow the
-		 * region.
-		 */
-		if (infop->size > size && !F_ISSET(infop, REGION_SIZEDEF))
-			grow_region = infop->size;
-		infop->size = size;
-	}
-
-	/*
-	 * Map the region into our address space.  If we're creating it, the
-	 * underlying routines will make it the right size.
-	 *
-	 * There are at least two cases where we can "reasonably" fail when
-	 * we attempt to map in the region.  On Windows/95, closing the last
-	 * reference to a region causes it to be zeroed out.  On UNIX, when
-	 * using the shmget(2) interfaces, the region will no longer exist
-	 * if the system was rebooted.  In these cases, the underlying map call
-	 * returns EAGAIN, and we *remove* our file and try again.  There are
-	 * obvious races in doing this, but it should eventually settle down
-	 * to a winner and then things should proceed normally.
-	 */
-	if ((ret = __db_mapregion(infop->name, infop)) != 0) {
-		if (ret == EAGAIN) {
-			/*
-			 * Pretend we created the region even if we didn't so
-			 * that our error processing unlinks it.
-			 */
-			F_SET(infop, REGION_CREATED);
-			ret = 0;
-			goto retry;
-		} else
-			goto err;
-	}
-
-region_init:
-	/*
-	 * Initialize the common region information.
-	 *
-	 * !!!
-	 * We have to order the region creates so that two processes don't try
-	 * to simultaneously create the region.  This is handled by using the
-	 * DB_CREATE and DB_EXCL flags when we create the "backing" region file.
-	 *
-	 * We also have to order region joins so that processes joining regions
-	 * never see inconsistent data.  We'd like to play permissions games
-	 * with the backing file, but we can't because WNT filesystems won't
-	 * open a file mode 0.
-	 */
-	rlp = (RLAYOUT *)infop->addr;
-	if (F_ISSET(infop, REGION_CREATED)) {
-		/*
-		 * The process creating the region acquires a lock before it
-		 * sets the valid flag.  Any processes joining the region will
-		 * check the valid flag before acquiring the lock.
-		 *
-		 * Check the return of __db_mutex_init() and __db_mutex_lock(),
-		 * even though we don't usually check elsewhere.  This is the
-		 * first lock we initialize and acquire, and we have to know if
-		 * it fails.  (It CAN fail, e.g., SunOS, when using fcntl(2)
-		 * for locking, with an in-memory filesystem specified as the
-		 * database home.)
-		 */
-		if ((ret = __db_mutex_init(&rlp->lock,
-		    MUTEX_LOCK_OFFSET(rlp, &rlp->lock))) != 0 ||
-		    (ret = __db_mutex_lock(&rlp->lock, infop->fd)) != 0)
-			goto err;
-
-		/* Initialize the remaining region information. */
-		rlp->refcnt = 1;
-		rlp->size = infop->size;
-		db_version(&rlp->majver, &rlp->minver, &rlp->patch);
-		rlp->panic = 0;
-		rlp->segid = infop->segid;
-		rlp->flags = 0;
-		if (F_ISSET(infop, REGION_ANONYMOUS))
-			F_SET(rlp, REGION_ANONYMOUS);
-
-		/*
-		 * Fill in the valid field last -- use a magic number, memory
-		 * may not be zero-filled, and we want to minimize the chance
-		 * for collision.
-		 */
-		rlp->valid = DB_REGIONMAGIC;
-
-		/*
-		 * If the region is anonymous, write the RLAYOUT information
-		 * into the backing file so that future region join and unlink
-		 * calls can find it.
-		 *
-		 * XXX
-		 * We MUST do the seek before we do the write.  On Win95, while
-		 * closing the last reference to an anonymous shared region
-		 * doesn't discard the region, it does zero it out.  So, the
-		 * REGION_CREATED may be set, but the file may have already
-		 * been written and the file descriptor may be at the end of
-		 * the file.
-		 */
-		if (F_ISSET(infop, REGION_ANONYMOUS)) {
-			if ((ret = __os_seek(infop->fd, 0, 0, 0, 0, 0)) != 0)
-				goto err;
-			if ((ret =
-			    __os_write(infop->fd, rlp, sizeof(*rlp), &nw)) != 0)
-				goto err;
-		}
-	} else {
-		/* Check to see if the region has had catastrophic failure. */
-		if (rlp->panic) {
-			ret = DB_RUNRECOVERY;
-			goto err;
-		}
-
-		/*
-		 * Check the valid flag to ensure the region is initialized.
-		 * If the valid flag has not been set, the mutex may not have
-		 * been initialized, and an attempt to get it could lead to
-		 * random behavior.
-		 */
-		if (rlp->valid != DB_REGIONMAGIC)
-			goto retry;
-
-		/* Get the region lock. */
-		(void)__db_mutex_lock(&rlp->lock, infop->fd);
-
-		/*
-		 * We now own the region.  There are a couple of things that
-		 * may have gone wrong, however.
-		 *
-		 * Problem #1: while we were waiting for the lock, the region
-		 * was deleted.  Detected by re-checking the valid flag, since
-		 * it's cleared by the delete region routines.
-		 */
-		if (rlp->valid != DB_REGIONMAGIC) {
-			(void)__db_mutex_unlock(&rlp->lock, infop->fd);
-			goto retry;
-		}
-
-		/*
-		 * Problem #3: when we checked the size of the file, it was
-		 * still growing as part of creation.  Detected by the fact
-		 * that infop->size isn't the same size as the region.
-		 */
-		if (infop->size != rlp->size) {
-			(void)__db_mutex_unlock(&rlp->lock, infop->fd);
-			goto retry;
-		}
-
-		/* Increment the reference count. */
-		++rlp->refcnt;
-	}
-
-	/* Return the region in a locked condition. */
-
-	if (0) {
-errmsg:		__db_err(infop->dbenv, "%s: %s", infop->name, strerror(ret));
-
-err:
-retry:		/* Discard the region. */
-		if (infop->addr != NULL) {
-			(void)__db_unmapregion(infop);
-			infop->addr = NULL;
-		}
-
-		/* Discard the backing file. */
-		if (infop->fd != -1) {
-			(void)__os_close(infop->fd);
-			infop->fd = -1;
-
-			if (F_ISSET(infop, REGION_CREATED))
-				(void)__os_unlink(infop->name);
-		}
-
-		/* Discard the name. */
-		if (infop->name != NULL) {
-			__os_freestr(infop->name);
-			infop->name = NULL;
-		}
-
-		/*
-		 * If we had a temporary error, wait a few seconds and
-		 * try again.
-		 */
-		if (ret == 0) {
-			if (++retry_cnt <= 3) {
-				__os_sleep(retry_cnt * 2, 0);
-				goto loop;
-			}
-			ret = EAGAIN;
-		}
-	}
-
-	/*
-	 * XXX
-	 * HP-UX won't permit mutexes to live in anything but shared memory.
-	 * Instantiate a shared region file on that architecture, regardless.
-	 *
-	 * XXX
-	 * There's a problem in cleaning this up on application exit, or on
-	 * application failure.  If an application opens a database without
-	 * an environment, we create a temporary backing mpool region for it.
-	 * That region is marked REGION_PRIVATE, but as HP-UX won't permit
-	 * mutexes to live in anything but shared memory, we instantiate a
-	 * real file plus a memory region of some form.  If the application
-	 * crashes, the necessary information to delete the backing file and
-	 * any system region (e.g., the shmget(2) segment ID) is no longer
-	 * available.  We can't completely fix the problem, but we try.
-	 *
-	 * The underlying UNIX __db_mapregion() code preferentially uses the
-	 * mmap(2) interface with the MAP_ANON/MAP_ANONYMOUS flags for regions
-	 * that are marked REGION_PRIVATE.  This means that we normally aren't
-	 * holding any system resources when we get here, in which case we can
-	 * delete the backing file.  This results in a short race, from the
-	 * __db_open() call above to here.
-	 *
-	 * If, for some reason, we are holding system resources when we get
-	 * here, we don't have any choice -- we can't delete the backing file
-	 * because we may need it to detach from the resources.  Set the
-	 * REGION_LASTDETACH flag, so that we do all necessary cleanup when
-	 * the application closes the region.
-	 */
-	if (F_ISSET(infop, REGION_PRIVATE) && !F_ISSET(infop, REGION_MALLOC)) {
-		if (F_ISSET(infop, REGION_HOLDINGSYS))
-			F_SET(infop, REGION_LASTDETACH);
-		else {
-			F_SET(infop, REGION_REMOVED);
-			F_CLR(infop, REGION_CANGROW);
-
-			(void)__os_close(infop->fd);
-			(void)__os_unlink(infop->name);
-		}
-	}
-
-	return (ret);
-}
-
-/*
- * __db_rdetach --
- *	De-attach from a shared memory region.
- *
- * PUBLIC: int __db_rdetach __P((REGINFO *));
- */
-int
-__db_rdetach(infop)
-	REGINFO *infop;
-{
-	RLAYOUT *rlp;
-	int detach, ret, t_ret;
-
-	ret = 0;
-
-	/*
-	 * If the region was removed when it was created, no further action
-	 * is required.
-	 */
-	if (F_ISSET(infop, REGION_REMOVED))
-		goto done;
-	/*
-	 * If the region was created in memory returned by malloc, the only
-	 * action required is freeing the memory.
-	 */
-	if (F_ISSET(infop, REGION_MALLOC)) {
-		__os_free(infop->addr, 0);
-		goto done;
-	}
-
-	/* Otherwise, attach to the region and optionally delete it. */
-	rlp = infop->addr;
-
-	/* Get the lock. */
-	(void)__db_mutex_lock(&rlp->lock, infop->fd);
-
-	/* Decrement the reference count. */
-	if (rlp->refcnt == 0)
-		__db_err(infop->dbenv,
-		    "region rdetach: reference count went to zero!");
-	else
-		--rlp->refcnt;
-
-	/*
-	 * If we're going to remove the region, clear the valid flag so
-	 * that any region join that's blocked waiting for us will know
-	 * what happened.
-	 */
-	detach = 0;
-	if (F_ISSET(infop, REGION_LASTDETACH)) {
-		if (rlp->refcnt == 0) {
-			detach = 1;
-			rlp->valid = 0;
-		} else
-			ret = EBUSY;
-	}
-
-	/* Release the lock. */
-	(void)__db_mutex_unlock(&rlp->lock, infop->fd);
-
-	/* Close the backing file descriptor. */
-	(void)__os_close(infop->fd);
-	infop->fd = -1;
-
-	/* Discard our mapping of the region. */
-	if ((t_ret = __db_unmapregion(infop)) != 0 && ret == 0)
-		ret = t_ret;
-
-	/* Discard the region itself. */
-	if (detach) {
-		if ((t_ret =
-		    __db_unlinkregion(infop->name, infop) != 0) && ret == 0)
-			ret = t_ret;
-		if ((t_ret = __os_unlink(infop->name) != 0) && ret == 0)
-			ret = t_ret;
-	}
-
-done:	/* Discard the name. */
-	if (infop->name != NULL) {
-		__os_freestr(infop->name);
-		infop->name = NULL;
-	}
-
-	return (ret);
-}
-
-/*
- * __db_runlink --
- *	Remove a region.
- *
- * PUBLIC: int __db_runlink __P((REGINFO *, int));
- */
-int
-__db_runlink(infop, force)
-	REGINFO *infop;
-	int force;
-{
-	RLAYOUT rl, *rlp;
-	size_t size;
-	ssize_t nr;
-	u_int32_t mbytes, bytes;
-	int fd, ret, t_ret;
-	char *name;
-
-	/*
-	 * XXX
-	 * We assume that we've created a new REGINFO structure for this
-	 * call, not used one that was already initialized.  Regardless,
-	 * if anyone is planning to use it after we're done, they're going
-	 * to be sorely disappointed.
-	 *
-	 * If force isn't set, we attach to the region, set a flag to delete
-	 * the region on last close, and let the region delete code do the
-	 * work.
-	 */
-	if (!force) {
-		if ((ret = __db_rattach(infop)) != 0)
-			return (ret);
-
-		rlp = (RLAYOUT *)infop->addr;
-		(void)__db_mutex_unlock(&rlp->lock, infop->fd);
-
-		F_SET(infop, REGION_LASTDETACH);
-
-		return (__db_rdetach(infop));
-	}
-
-	/*
-	 * Otherwise, we don't want to attach to the region.  We may have been
-	 * called to clean up if a process died leaving a region locked and/or
-	 * corrupted, which could cause the attach to hang.
-	 */
-	if ((ret = __db_appname(infop->dbenv, infop->appname,
-	    infop->path, infop->file, infop->dbflags, NULL, &name)) != 0)
-		return (ret);
-
-	/*
-	 * An underlying file is created for all regions other than private
-	 * (REGION_PRIVATE) ones, regardless of whether or not it's used to
-	 * back the region.  If that file doesn't exist, we're done.
-	 */
-	if (__os_exists(name, NULL) != 0) {
-		__os_freestr(name);
-		return (0);
-	}
-
-	/*
-	 * See the comments in __db_rattach -- figure out if this is a regular
-	 * file backing a region or if it's a regular file with information
-	 * about a region.
-	 */
-	if ((ret = __db_open(name, DB_RDONLY, DB_RDONLY, 0, &fd)) != 0)
-		goto errmsg;
-	if ((ret = __os_ioinfo(name, fd, &mbytes, &bytes, NULL)) != 0)
-		goto errmsg;
-	size = mbytes * MEGABYTE + bytes;
-
-	if (size <= sizeof(RLAYOUT)) {
-		if ((ret = __os_read(fd, &rl, sizeof(rl), &nr)) != 0)
-			goto errmsg;
-		if (rl.valid != DB_REGIONMAGIC) {
-			__db_err(infop->dbenv,
-			    "%s: illegal region magic number", name);
-			ret = EINVAL;
-			goto err;
-		}
-
-		/* Set the size, memory id and characteristics. */
-		infop->size = rl.size;
-		infop->segid = rl.segid;
-		if (F_ISSET(&rl, REGION_ANONYMOUS))
-			F_SET(infop, REGION_ANONYMOUS);
-	} else {
-		infop->size = size;
-		infop->segid = INVALID_SEGID;
-	}
-
-	/* Remove the underlying region. */
-	ret = __db_unlinkregion(name, infop);
-
-	/*
-	 * Unlink the backing file.  Close the open file descriptor first,
-	 * because some architectures (e.g., Win32) won't unlink a file if
-	 * open file descriptors remain.
-	 */
-	(void)__os_close(fd);
-	if ((t_ret = __os_unlink(name)) != 0 && ret == 0)
-		ret = t_ret;
-
-	if (0) {
-errmsg:		__db_err(infop->dbenv, "%s: %s", name, strerror(ret));
-err:		(void)__os_close(fd);
-	}
-
-	__os_freestr(name);
-	return (ret);
-}
-
-/*
- * __db_rgrow --
- *	Extend a region.
- *
- * PUBLIC: int __db_rgrow __P((REGINFO *, size_t));
- */
-int
-__db_rgrow(infop, new_size)
-	REGINFO *infop;
-	size_t new_size;
-{
-	RLAYOUT *rlp;
-	size_t increment;
-	int ret;
-
-	/*
-	 * !!!
-	 * This routine MUST be called with the region already locked.
-	 */
-
-	/* The underlying routines have flagged if this region can grow. */
-	if (!F_ISSET(infop, REGION_CANGROW))
-		return (EINVAL);
-
-	/*
-	 * Round off the requested size to the next page boundary, and
-	 * determine the additional space required.
-	 */
-	rlp = (RLAYOUT *)infop->addr;
-	DB_ROUNDOFF(new_size, DB_VMPAGESIZE);
-	increment = new_size - rlp->size;
-
-	if ((ret = __db_growregion(infop, increment)) != 0)
-		return (ret);
-
-	/* Update the on-disk region size. */
-	rlp->size = new_size;
-
-	/* Detach from and reattach to the region. */
-	return (__db_rreattach(infop, new_size));
-}
-
-/*
- * __db_growregion --
- *	Grow a shared memory region.
- */
-static int
-__db_growregion(infop, increment)
-	REGINFO *infop;
-	size_t increment;
-{
-	db_pgno_t pages;
-	size_t i;
-	ssize_t nr, nw;
-	u_int32_t relative;
-	int ret;
-	char buf[DB_VMPAGESIZE];
-
-	/* Seek to the end of the region. */
-	if ((ret = __os_seek(infop->fd, 0, 0, 0, 0, SEEK_END)) != 0)
-		goto err;
-
-	/* Write nuls to the new bytes. */
-	memset(buf, 0, sizeof(buf));
-
-	/*
-	 * Some systems require that all of the bytes of the region be
-	 * written before it can be mapped and accessed randomly, and
-	 * other systems don't zero out the pages.
-	 */
-	if (__db_mapinit())
-		/* Extend the region by writing each new page. */
-		for (i = 0; i < increment; i += DB_VMPAGESIZE) {
-			if ((ret =
-			    __os_write(infop->fd, buf, sizeof(buf), &nw)) != 0)
-				goto err;
-			if (nw != sizeof(buf))
-				goto eio;
-		}
-	else {
-		/*
-		 * Extend the region by writing the last page.  If the region
-		 * is >4Gb, increment may be larger than the maximum possible
-		 * seek "relative" argument, as it's an unsigned 32-bit value.
-		 * Break the offset into pages of 1MB each so that we don't
-		 * overflow (2^20 + 2^32 is bigger than any memory I expect
-		 * to see for awhile).
-		 */
-		pages = (increment - DB_VMPAGESIZE) / MEGABYTE;
-		relative = (increment - DB_VMPAGESIZE) % MEGABYTE;
-		if ((ret = __os_seek(infop->fd,
-		    MEGABYTE, pages, relative, 0, SEEK_CUR)) != 0)
-			goto err;
-		if ((ret = __os_write(infop->fd, buf, sizeof(buf), &nw)) != 0)
-			goto err;
-		if (nw != sizeof(buf))
-			goto eio;
-
-		/*
-		 * It's sometimes significantly faster to page-fault in all of
-		 * the region's pages before we run the application, as we see
-		 * nasty side-effects when we page-fault while holding various
-		 * locks, i.e., the lock takes a long time to acquire because
-		 * of the underlying page fault, and the other threads convoy
-		 * behind the lock holder.
-		 *
-		 * We also use REGION_INIT to guarantee that there is enough
-		 * disk space for the region, so we also write a byte to each
-		 * page.  Reading the byte is insufficient as some systems
-		 * (e.g., Solaris) do not instantiate disk pages to satisfy
-		 * a read, and so we don't know if there is enough disk space
-		 * or not.
-		 */
-		if (DB_GLOBAL(db_region_init)) {
-			pages = increment / MEGABYTE;
-			relative = increment % MEGABYTE;
-			if ((ret = __os_seek(infop->fd,
-			    MEGABYTE, pages, relative, 1, SEEK_END)) != 0)
-				goto err;
-
-			/* Write a byte to each page. */
-			for (i = 0; i < increment; i += DB_VMPAGESIZE) {
-				if ((ret =
-				    __os_write(infop->fd, buf, 1, &nr)) != 0)
-					goto err;
-				if (nr != 1)
-					goto eio;
-				if ((ret = __os_seek(infop->fd,
-				    0, 0, DB_VMPAGESIZE - 1, 0, SEEK_CUR)) != 0)
-					goto err;
-			}
-		}
-	}
-	return (0);
-
-eio:	ret = EIO;
-err:	__db_err(infop->dbenv, "region grow: %s", strerror(ret));
-	return (ret);
-}
-
-/*
- * __db_rreattach --
- *	Detach from and reattach to a region.
- *
- * PUBLIC: int __db_rreattach __P((REGINFO *, size_t));
- */
-int
-__db_rreattach(infop, new_size)
-	REGINFO *infop;
-	size_t new_size;
-{
-	int ret;
-
-#ifdef DIAGNOSTIC
-	if (infop->name == NULL) {
-		__db_err(infop->dbenv, "__db_rreattach: name was NULL");
-		return (EINVAL);
-	}
-#endif
-	/*
-	 * If we're growing an already mapped region, we have to unmap it
-	 * and get it back.  We have it locked, so nobody else can get in,
-	 * which makes it fairly straight-forward to do, as everybody else
-	 * is going to block while we do the unmap/remap.  NB: if we fail
-	 * to get it back, the pooch is genuinely screwed, because we can
-	 * never release the lock we're holding.
-	 *
-	 * Detach from the region.  We have to do this first so architectures
-	 * that don't permit a file to be mapped into different places in the
-	 * address space simultaneously, e.g., HP's PaRisc, will work.
-	 */
-	if ((ret = __db_unmapregion(infop)) != 0)
-		return (ret);
-
-	/* Update the caller's REGINFO size to the new map size. */
-	infop->size = new_size;
-
-	/* Attach to the region. */
-	ret = __db_mapregion(infop->name, infop);
-
-	return (ret);
-}