From 14a9cdf6005a6a404bd897f3ebfd0b0de28c4137 Mon Sep 17 00:00:00 2001
From: clemahieu <clemahieu@gmail.com>
Date: Sat, 29 Aug 2015 22:17:10 -0500
Subject: [PATCH] Upgrade LMDB to stock 0.9.16

---
 liblmdb/CHANGES        |  33 ++
 liblmdb/COPYRIGHT      |   2 +-
 liblmdb/lmdb.h         |  80 +++--
 liblmdb/mdb.c          | 665 +++++++++++++++++------------------------
 liblmdb/mdb_copy.1     |   2 +-
 liblmdb/mdb_copy.c     |   2 +-
 liblmdb/mdb_dump.1     |   2 +-
 liblmdb/mdb_dump.c     |   2 +-
 liblmdb/mdb_load.1     |   2 +-
 liblmdb/mdb_load.c     |  12 +-
 liblmdb/mdb_stat.1     |   2 +-
 liblmdb/mdb_stat.c     |   2 +-
 liblmdb/midl.c         |   6 +-
 liblmdb/midl.h         |   5 +-
 liblmdb/mtest.c        |  20 +-
 liblmdb/mtest2.c       |  19 +-
 liblmdb/mtest3.c       |  14 +-
 liblmdb/mtest4.c       |  14 +-
 liblmdb/mtest5.c       |  14 +-
 liblmdb/mtest6.c       |  20 +-
 liblmdb/sample-bdb.txt |   2 +-
 liblmdb/sample-mdb.txt |   6 +-
 22 files changed, 421 insertions(+), 505 deletions(-)

diff --git a/liblmdb/CHANGES b/liblmdb/CHANGES
index 34049ba7..bc39d82a 100644
--- a/liblmdb/CHANGES
+++ b/liblmdb/CHANGES
@@ -1,5 +1,38 @@
 LMDB 0.9 Change Log
 
+LMDB 0.9.16 Release (2015/08/14)
+	Fix cursor EOF bug (ITS#8190)
+	Fix handling of subDB records (ITS#8181)
+	Fix mdb_midl_shrink() usage (ITS#8200)
+
+LMDB 0.9.15 Release (2015/06/19)
+	Fix txn init (ITS#7961,#7987)
+	Fix MDB_PREV_DUP (ITS#7955,#7671)
+	Fix compact of empty env (ITS#7956)
+	Fix mdb_copy file mode
+	Fix mdb_env_close() after failed mdb_env_open()
+	Fix mdb_rebalance collapsing root (ITS#8062)
+	Fix mdb_load with large values (ITS#8066)
+	Fix to retry writes on EINTR (ITS#8106)
+	Fix mdb_cursor_del on empty DB (ITS#8109)
+	Fix MDB_INTEGERDUP key compare (ITS#8117)
+	Fix error handling (ITS#7959,#8157,etc.)
+	Fix race conditions (ITS#7969,7970)
+	Added workaround for fdatasync bug in ext3fs
+	Build
+		Don't use -fPIC for static lib
+		Update .gitignore (ITS#7952,#7953)
+		Cleanup for "make test" (ITS#7841), "make clean", mtest*.c
+		Misc. Android/Windows cleanup
+	Documentation
+		Fix MDB_APPEND doc
+		Fix MDB_MAXKEYSIZE doc (ITS#8156)
+		Fix mdb_cursor_put,mdb_cursor_del EACCES description
+		Fix mdb_env_sync(MDB_RDONLY env) doc (ITS#8021)
+		Clarify MDB_WRITEMAP doc (ITS#8021)
+		Clarify mdb_env_open doc
+		Clarify mdb_dbi_open doc
+
 LMDB 0.9.14 Release (2014/09/20)
 	Fix to support 64K page size (ITS#7713)
 	Fix to persist decreased as well as increased mapsizes (ITS#7789)
diff --git a/liblmdb/COPYRIGHT b/liblmdb/COPYRIGHT
index e0eb484c..722d1a51 100644
--- a/liblmdb/COPYRIGHT
+++ b/liblmdb/COPYRIGHT
@@ -1,4 +1,4 @@
-Copyright 2011-2014 Howard Chu, Symas Corp.
+Copyright 2011-2015 Howard Chu, Symas Corp.
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
diff --git a/liblmdb/lmdb.h b/liblmdb/lmdb.h
index 61318ffd..762dba2e 100644
--- a/liblmdb/lmdb.h
+++ b/liblmdb/lmdb.h
@@ -49,15 +49,11 @@
  *	  stale locks can block further operation.
  *
  *	  Fix: Check for stale readers periodically, using the
- *	  #mdb_reader_check function or the \ref mdb_stat_1 "mdb_stat" tool.
- *	  Stale writers will be cleared automatically on most systems:
- *	  - Windows - automatic
- *	  - BSD, systems using SysV semaphores - automatic
- *	  - Linux, systems using POSIX mutexes with Robust option - automatic
- *	  Otherwise just make all programs using the database close it;
- *	  the lockfile is always reset on first open of the environment.
+ *	  #mdb_reader_check function or the \ref mdb_stat_1 "mdb_stat" tool. Or just
+ *	  make all programs using the database close it; the lockfile
+ *	  is always reset on first open of the environment.
  *
- *	- On BSD systems or others configured with MDB_USE_SYSV_SEM,
+ *	- On BSD systems or others configured with MDB_USE_POSIX_SEM,
  *	  startup can fail due to semaphores owned by another userid.
  *
  *	  Fix: Open and close the database as the user which owns the
@@ -110,9 +106,6 @@
  *	  for stale readers is performed or the lockfile is reset,
  *	  since the process may not remove it from the lockfile.
  *
- *	  This does not apply to write transactions if the system clears
- *	  stale writers, see above.
- *
  *	- If you do that anyway, do a periodic check for stale readers. Or
  *	  close the environment once in a while, so the lockfile can get reset.
  *
@@ -126,7 +119,7 @@
  *
  *	@author	Howard Chu, Symas Corporation.
  *
- *	@copyright Copyright 2011-2014 Howard Chu, Symas Corp. All rights reserved.
+ *	@copyright Copyright 2011-2015 Howard Chu, Symas Corp. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted only as authorized by the OpenLDAP
@@ -191,7 +184,7 @@ typedef int mdb_filehandle_t;
 /** Library minor version */
 #define MDB_VERSION_MINOR	9
 /** Library patch version */
-#define MDB_VERSION_PATCH	14
+#define MDB_VERSION_PATCH	16
 
 /** Combine args a,b,c into a single integer for easy version comparisons */
 #define MDB_VERINT(a,b,c)	(((a) << 24) | ((b) << 16) | (c))
@@ -201,7 +194,7 @@ typedef int mdb_filehandle_t;
 	MDB_VERINT(MDB_VERSION_MAJOR,MDB_VERSION_MINOR,MDB_VERSION_PATCH)
 
 /** The release date of this library version */
-#define MDB_VERSION_DATE	"September 20, 2014"
+#define MDB_VERSION_DATE	"August 14, 2015"
 
 /** A stringifier for the version info */
 #define MDB_VERSTR(a,b,c,d)	"LMDB " #a "." #b "." #c ": (" d ")"
@@ -303,12 +296,12 @@ typedef void (MDB_rel_func)(MDB_val *item, void *oldptr, void *newptr, void *rel
 #define MDB_REVERSEKEY	0x02
 	/** use sorted duplicates */
 #define MDB_DUPSORT		0x04
-	/** numeric keys in native byte order.
+	/** numeric keys in native byte order: either unsigned int or size_t.
 	 *  The keys must all be of the same size. */
 #define MDB_INTEGERKEY	0x08
 	/** with #MDB_DUPSORT, sorted dup items have fixed size */
 #define MDB_DUPFIXED	0x10
-	/** with #MDB_DUPSORT, dups are numeric in native byte order */
+	/** with #MDB_DUPSORT, dups are #MDB_INTEGERKEY-style integers */
 #define MDB_INTEGERDUP	0x20
 	/** with #MDB_DUPSORT, use reverse string dups */
 #define MDB_REVERSEDUP	0x40
@@ -398,7 +391,7 @@ typedef enum MDB_cursor_op {
 #define MDB_PAGE_NOTFOUND	(-30797)
 	/** Located page was wrong type */
 #define MDB_CORRUPTED	(-30796)
-	/** Update of meta page failed or environment had fatal error */
+	/** Update of meta page failed, probably I/O error */
 #define MDB_PANIC		(-30795)
 	/** Environment version mismatch */
 #define MDB_VERSION_MISMATCH	(-30794)
@@ -420,7 +413,14 @@ typedef enum MDB_cursor_op {
 #define MDB_PAGE_FULL	(-30786)
 	/** Database contents grew beyond environment mapsize */
 #define MDB_MAP_RESIZED	(-30785)
-	/** MDB_INCOMPATIBLE: Operation and DB incompatible, or DB flags changed */
+	/** Operation and DB incompatible, or DB type changed. This can mean:
+	 *	<ul>
+	 *	<li>The operation expects an #MDB_DUPSORT / #MDB_DUPFIXED database.
+	 *	<li>Opening a named DB when the unnamed DB has #MDB_DUPSORT / #MDB_INTEGERKEY.
+	 *	<li>Accessing a data record as a database, or vice versa.
+	 *	<li>The database was dropped and recreated with different flags.
+	 *	</ul>
+	 */
 #define MDB_INCOMPATIBLE	(-30784)
 	/** Invalid reuse of reader locktable slot */
 #define MDB_BAD_RSLOT		(-30783)
@@ -595,8 +595,8 @@ int  mdb_env_create(MDB_env **env);
 	 *		reserved in that case.
 	 *		This flag may be changed at any time using #mdb_env_set_flags().
 	 * </ul>
-	 * @param[in] mode The UNIX permissions to set on created files. This parameter
-	 * is ignored on Windows.
+	 * @param[in] mode The UNIX permissions to set on created files and semaphores.
+	 * This parameter is ignored on Windows.
 	 * @return A non-zero error value on failure and 0 on success. Some possible
 	 * errors are:
 	 * <ul>
@@ -930,8 +930,6 @@ int  mdb_env_set_assert(MDB_env *env, MDB_assert_func *func);
 	 * <ul>
 	 *	<li>#MDB_RDONLY
 	 *		This transaction will not perform any write operations.
-	 *	<li>#MDB_NOSYNC
-	 *		Don't flush system buffers to disk when committing this transaction.
 	 * </ul>
 	 * @param[out] txn Address where the new #MDB_txn handle will be stored
 	 * @return A non-zero error value on failure and 0 on success. Some possible
@@ -955,17 +953,6 @@ int  mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **
 	 */
 MDB_env *mdb_txn_env(MDB_txn *txn);
 
-	/** @brief Return the transaction's ID.
-	 *
-	 * This returns the identifier associated with this transaction. For a
-	 * read-only transaction, this corresponds to the snapshot being read;
-	 * concurrent readers will frequently have the same transaction ID.
-	 *
-	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
-	 * @return A transaction ID, valid if input is an active transaction.
-	 */
-size_t mdb_txn_id(MDB_txn *txn);
-
 	/** @brief Commit all the operations of a transaction into the database.
 	 *
 	 * The transaction handle is freed. It and its cursors must not be used
@@ -1041,19 +1028,22 @@ int  mdb_txn_renew(MDB_txn *txn);
 	 * The database handle may be discarded by calling #mdb_dbi_close().
 	 * The old database handle is returned if the database was already open.
 	 * The handle may only be closed once.
+	 *
 	 * The database handle will be private to the current transaction until
 	 * the transaction is successfully committed. If the transaction is
 	 * aborted the handle will be closed automatically.
-	 * After a successful commit the
-	 * handle will reside in the shared environment, and may be used
-	 * by other transactions. This function must not be called from
-	 * multiple concurrent transactions in the same process. A transaction
-	 * that uses this function must finish (either commit or abort) before
+	 * After a successful commit the handle will reside in the shared
+	 * environment, and may be used by other transactions.
+	 *
+	 * This function must not be called from multiple concurrent
+	 * transactions in the same process. A transaction that uses
+	 * this function must finish (either commit or abort) before
 	 * any other transaction in the process may use this function.
 	 *
 	 * To use named databases (with name != NULL), #mdb_env_set_maxdbs()
-	 * must be called before opening the environment.  Database names
-	 * are kept as keys in the unnamed database.
+	 * must be called before opening the environment.  Database names are
+	 * keys in the unnamed database, and may be read but not written.
+	 *
 	 * @param[in] txn A transaction handle returned by #mdb_txn_begin()
 	 * @param[in] name The name of the database to open. If only a single
 	 * 	database is needed in the environment, this value may be NULL.
@@ -1070,9 +1060,9 @@ int  mdb_txn_renew(MDB_txn *txn);
 	 *		keys may have multiple data items, stored in sorted order.) By default
 	 *		keys must be unique and may have only a single data item.
 	 *	<li>#MDB_INTEGERKEY
-	 *		Keys are binary integers in native byte order. Setting this option
-	 *		requires all keys to be the same size, typically sizeof(int)
-	 *		or sizeof(size_t).
+	 *		Keys are binary integers in native byte order, either unsigned int
+	 *		or size_t, and will be sorted as such.
+	 *		The keys must all be of the same size.
 	 *	<li>#MDB_DUPFIXED
 	 *		This flag may only be used in combination with #MDB_DUPSORT. This option
 	 *		tells the library that the data items for this database are all the same
@@ -1080,8 +1070,8 @@ int  mdb_txn_renew(MDB_txn *txn);
 	 *		all data items are the same size, the #MDB_GET_MULTIPLE and #MDB_NEXT_MULTIPLE
 	 *		cursor operations may be used to retrieve multiple items at once.
 	 *	<li>#MDB_INTEGERDUP
-	 *		This option specifies that duplicate data items are also integers, and
-	 *		should be sorted as such.
+	 *		This option specifies that duplicate data items are binary integers,
+	 *		similar to #MDB_INTEGERKEY keys.
 	 *	<li>#MDB_REVERSEDUP
 	 *		This option specifies that duplicate data items should be compared as
 	 *		strings in reverse order.
diff --git a/liblmdb/mdb.c b/liblmdb/mdb.c
index 98b69fcc..b5d59bcd 100644
--- a/liblmdb/mdb.c
+++ b/liblmdb/mdb.c
@@ -5,7 +5,7 @@
  *	BerkeleyDB API, but much simplified.
  */
 /*
- * Copyright 2011-2014 Howard Chu, Symas Corp.
+ * Copyright 2011-2015 Howard Chu, Symas Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -110,7 +110,7 @@ extern int cacheflush(char *addr, int nbytes, int cache);
 #endif
 
 #if defined(__APPLE__) || defined (BSD)
-# define MDB_USE_SYSV_SEM	1
+# define MDB_USE_POSIX_SEM	1
 # define MDB_FDATASYNC		fsync
 #elif defined(ANDROID)
 # define MDB_FDATASYNC		fsync
@@ -118,18 +118,11 @@ extern int cacheflush(char *addr, int nbytes, int cache);
 
 #ifndef _WIN32
 #include <pthread.h>
-#ifdef MDB_USE_SYSV_SEM
-#include <sys/ipc.h>
-#include <sys/sem.h>
-#ifdef _SEM_SEMUN_UNDEFINED
-union semun {
-	int val;
-	struct semid_ds *buf;
-	unsigned short *array;
-};
-#endif /* _SEM_SEMUN_UNDEFINED */
-#endif /* MDB_USE_SYSV_SEM */
-#endif /* !_WIN32 */
+#ifdef MDB_USE_POSIX_SEM
+# define MDB_USE_HASH		1
+#include <semaphore.h>
+#endif
+#endif
 
 #ifdef USE_VALGRIND
 #include <valgrind/memcheck.h>
@@ -206,10 +199,6 @@ union semun {
 	/** Features under development */
 #ifndef MDB_DEVEL
 #define MDB_DEVEL 0
-#endif
-
-#if defined(_WIN32) || defined(MDB_USE_SYSV_SEM) || defined(EOWNERDEAD)
-#define MDB_ROBUST_SUPPORTED	1
 #endif
 
 	/** Wrapper around __func__, which is a C99 feature */
@@ -222,16 +211,6 @@ union semun {
 # define mdb_func_	"<mdb_unknown>"
 #endif
 
-/* Internal error codes, not exposed outside liblmdb */
-#define	MDB_NO_ROOT		(MDB_LAST_ERRCODE + 10)
-#ifdef _WIN32
-#define MDB_OWNERDEAD	((int) WAIT_ABANDONED)
-#elif defined MDB_USE_SYSV_SEM
-#define MDB_OWNERDEAD	(MDB_LAST_ERRCODE + 11)
-#else
-#define MDB_OWNERDEAD	EOWNERDEAD
-#endif
-
 #ifdef _WIN32
 #define MDB_USE_HASH	1
 #define MDB_PIDLOCK	0
@@ -239,7 +218,6 @@ union semun {
 #define pthread_t	HANDLE
 #define pthread_mutex_t	HANDLE
 #define pthread_cond_t	HANDLE
-typedef HANDLE mdb_mutex_t;
 #define pthread_key_t	DWORD
 #define pthread_self()	GetCurrentThreadId()
 #define pthread_key_create(x,y)	\
@@ -253,10 +231,10 @@ typedef HANDLE mdb_mutex_t;
 #define pthread_cond_wait(cond,mutex)	do{SignalObjectAndWait(*mutex, *cond, INFINITE, FALSE); WaitForSingleObject(*mutex, INFINITE);}while(0)
 #define THREAD_CREATE(thr,start,arg)	thr=CreateThread(NULL,0,start,arg,0,NULL)
 #define THREAD_FINISH(thr)	WaitForSingleObject(thr, INFINITE)
-#define MDB_MUTEX(env, rw)		((env)->me_##rw##mutex)
-#define LOCK_MUTEX0(mutex)		WaitForSingleObject(mutex, INFINITE)
-#define UNLOCK_MUTEX(mutex)		ReleaseMutex(mutex)
-#define mdb_mutex_consistent(mutex)	0
+#define LOCK_MUTEX_R(env)	pthread_mutex_lock(&(env)->me_rmutex)
+#define UNLOCK_MUTEX_R(env)	pthread_mutex_unlock(&(env)->me_rmutex)
+#define LOCK_MUTEX_W(env)	pthread_mutex_lock(&(env)->me_wmutex)
+#define UNLOCK_MUTEX_W(env)	pthread_mutex_unlock(&(env)->me_wmutex)
 #define getpid()	GetCurrentProcessId()
 #define	MDB_FDATASYNC(fd)	(!FlushFileBuffers(fd))
 #define	MDB_MSYNC(addr,len,flags)	(!FlushViewOfFile(addr,len))
@@ -279,59 +257,38 @@ typedef HANDLE mdb_mutex_t;
 	/** For MDB_LOCK_FORMAT: True if readers take a pid lock in the lockfile */
 #define MDB_PIDLOCK			1
 
-#ifdef MDB_USE_SYSV_SEM
+#ifdef MDB_USE_POSIX_SEM
 
-typedef struct mdb_mutex {
-	int semid;
-	int semnum;
-	int *locked;
-} mdb_mutex_t;
-
-#define MDB_MUTEX(env, rw)		(&(env)->me_##rw##mutex)
-#define LOCK_MUTEX0(mutex)		mdb_sem_wait(mutex)
-#define UNLOCK_MUTEX(mutex)		do { \
-	struct sembuf sb = { 0, 1, SEM_UNDO }; \
-	sb.sem_num = (mutex)->semnum; \
-	*(mutex)->locked = 0; \
-	semop((mutex)->semid, &sb, 1); \
-} while(0)
+#define LOCK_MUTEX_R(env)	mdb_sem_wait((env)->me_rmutex)
+#define UNLOCK_MUTEX_R(env)	sem_post((env)->me_rmutex)
+#define LOCK_MUTEX_W(env)	mdb_sem_wait((env)->me_wmutex)
+#define UNLOCK_MUTEX_W(env)	sem_post((env)->me_wmutex)
 
 static int
-mdb_sem_wait(mdb_mutex_t *sem)
+mdb_sem_wait(sem_t *sem)
 {
-	int rc, *locked = sem->locked;
-	struct sembuf sb = { 0, -1, SEM_UNDO };
-	sb.sem_num = sem->semnum;
-	do {
-		if (!semop(sem->semid, &sb, 1)) {
-			rc = *locked ? MDB_OWNERDEAD : MDB_SUCCESS;
-			*locked = 1;
-			break;
-		}
-	} while ((rc = errno) == EINTR);
-	return rc;
+   int rc;
+   while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ;
+   return rc;
 }
 
-#define mdb_mutex_consistent(mutex)	0
-
 #else
-	/** Pointer/HANDLE type of shared mutex/semaphore.
+	/** Lock the reader mutex.
 	 */
-typedef pthread_mutex_t mdb_mutex_t;
-	/** Mutex for the reader table (rw = r) or write transaction (rw = w).
+#define LOCK_MUTEX_R(env)	pthread_mutex_lock(&(env)->me_txns->mti_mutex)
+	/** Unlock the reader mutex.
 	 */
-#define MDB_MUTEX(env, rw)	(&(env)->me_txns->mti_##rw##mutex)
-	/** Lock the reader or writer mutex.
-	 *	Returns 0 or a code to give #mdb_mutex_failed(), as in #LOCK_MUTEX().
+#define UNLOCK_MUTEX_R(env)	pthread_mutex_unlock(&(env)->me_txns->mti_mutex)
+
+	/** Lock the writer mutex.
+	 *	Only a single write transaction is allowed at a time. Other writers
+	 *	will block waiting for this mutex.
 	 */
-#define LOCK_MUTEX0(mutex)	pthread_mutex_lock(mutex)
-	/** Unlock the reader or writer mutex.
+#define LOCK_MUTEX_W(env)	pthread_mutex_lock(&(env)->me_txns->mti_wmutex)
+	/** Unlock the writer mutex.
 	 */
-#define UNLOCK_MUTEX(mutex)	pthread_mutex_unlock(mutex)
-	/** Mark mutex-protected data as repaired, after death of previous owner.
-	 */
-#define mdb_mutex_consistent(mutex)	pthread_mutex_consistent(mutex)
-#endif	/* MDB_USE_SYSV_SEM */
+#define UNLOCK_MUTEX_W(env)	pthread_mutex_unlock(&(env)->me_txns->mti_wmutex)
+#endif	/* MDB_USE_POSIX_SEM */
 
 	/** Get the error code for the last failed system function.
 	 */
@@ -356,35 +313,14 @@ typedef pthread_mutex_t mdb_mutex_t;
 #define	GET_PAGESIZE(x)	((x) = sysconf(_SC_PAGE_SIZE))
 #endif
 
-#if defined(_WIN32)
+#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
 #define MNAME_LEN	32
-#elif defined(MDB_USE_SYSV_SEM)
-#define MNAME_LEN	(sizeof(int))
 #else
 #define MNAME_LEN	(sizeof(pthread_mutex_t))
 #endif
 
-#ifdef MDB_USE_SYSV_SEM
-#define SYSV_SEM_FLAG	1		/**< SysV sems in lockfile format */
-#else
-#define SYSV_SEM_FLAG	0
-#endif
-
 /** @} */
 
-#ifdef MDB_ROBUST_SUPPORTED
-	/** Lock mutex, handle any error, set rc = result.
-	 *	Return 0 on success, nonzero (not rc) on error.
-	 */
-#define LOCK_MUTEX(rc, env, mutex) \
-	(((rc) = LOCK_MUTEX0(mutex)) && \
-	 ((rc) = mdb_mutex_failed(env, mutex, rc)))
-static int mdb_mutex_failed(MDB_env *env, mdb_mutex_t *mutex, int rc);
-#else
-#define LOCK_MUTEX(rc, env, mutex) ((rc) = LOCK_MUTEX0(mutex))
-#define mdb_mutex_failed(env, mutex, rc) (rc)
-#endif
-
 #ifndef _WIN32
 /**	A flag for opening a file and requesting synchronous data writes.
  *	This is only used when writing a meta page. It's not strictly needed;
@@ -508,14 +444,19 @@ static txnid_t mdb_debug_start;
 	/**	The version number for a database's datafile format. */
 #define MDB_DATA_VERSION	 ((MDB_DEVEL) ? 999 : 1)
 	/**	The version number for a database's lockfile format. */
-#define MDB_LOCK_VERSION	 ((MDB_DEVEL) ? 999 : 1)
+#define MDB_LOCK_VERSION	 1
 
-	/**	@brief The max size of a key we can write, or 0 for dynamic max.
+	/**	@brief The max size of a key we can write, or 0 for computed max.
 	 *
-	 *	Define this as 0 to compute the max from the page size.  511
-	 *	is default for backwards compat: liblmdb <= 0.9.10 can break
-	 *	when modifying a DB with keys/dupsort data bigger than its max.
-	 *	#MDB_DEVEL sets the default to 0.
+	 *	This macro should normally be left alone or set to 0.
+	 *	Note that a database with big keys or dupsort data cannot be
+	 *	reliably modified by a liblmdb which uses a smaller max.
+	 *	The default is 511 for backwards compat, or 0 when #MDB_DEVEL.
+	 *
+	 *	Other values are allowed, for backwards compat.  However:
+	 *	A value bigger than the computed max can break if you do not
+	 *	know what you are doing, and liblmdb <= 0.9.10 can break when
+	 *	modifying a DB with keys/dupsort data bigger than its max.
 	 *
 	 *	Data items in an #MDB_DUPSORT database are also limited to
 	 *	this size, since they're actually keys of a sub-DB.  Keys and
@@ -692,16 +633,13 @@ typedef struct MDB_txbody {
 	uint32_t	mtb_magic;
 		/** Format of this lock file. Must be set to #MDB_LOCK_FORMAT. */
 	uint32_t	mtb_format;
-#if defined(_WIN32)
+#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
 	char	mtb_rmname[MNAME_LEN];
-#elif defined(MDB_USE_SYSV_SEM)
-	int 	mtb_semid;
-	int		mtb_rlocked;
 #else
 		/** Mutex protecting access to this table.
-		 *	This is the #MDB_MUTEX(env,r) reader table lock.
+		 *	This is the reader lock that #LOCK_MUTEX_R acquires.
 		 */
-	pthread_mutex_t	mtb_rmutex;
+	pthread_mutex_t	mtb_mutex;
 #endif
 		/**	The ID of the last transaction committed to the database.
 		 *	This is recorded here only for convenience; the value can always
@@ -721,23 +659,16 @@ typedef struct MDB_txninfo {
 		MDB_txbody mtb;
 #define mti_magic	mt1.mtb.mtb_magic
 #define mti_format	mt1.mtb.mtb_format
-#define mti_rmutex	mt1.mtb.mtb_rmutex
+#define mti_mutex	mt1.mtb.mtb_mutex
 #define mti_rmname	mt1.mtb.mtb_rmname
 #define mti_txnid	mt1.mtb.mtb_txnid
 #define mti_numreaders	mt1.mtb.mtb_numreaders
-#ifdef MDB_USE_SYSV_SEM
-#define	mti_semid	mt1.mtb.mtb_semid
-#define	mti_rlocked	mt1.mtb.mtb_rlocked
-#endif
 		char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)];
 	} mt1;
 	union {
-#if defined(_WIN32)
+#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM)
 		char mt2_wmname[MNAME_LEN];
 #define	mti_wmname	mt2.mt2_wmname
-#elif defined MDB_USE_SYSV_SEM
-		int mt2_wlocked;
-#define mti_wlocked	mt2.mt2_wlocked
 #else
 		pthread_mutex_t	mt2_wmutex;
 #define mti_wmutex	mt2.mt2_wmutex
@@ -752,7 +683,6 @@ typedef struct MDB_txninfo {
 	((uint32_t) \
 	 ((MDB_LOCK_VERSION) \
 	  /* Flags which describe functionality */ \
-	  + (SYSV_SEM_FLAG << 18) \
 	  + (((MDB_PIDLOCK) != 0) << 16)))
 /** @} */
 
@@ -1084,7 +1014,6 @@ struct MDB_txn {
 #define MDB_TXN_ERROR		0x02		/**< txn is unusable after an error */
 #define MDB_TXN_DIRTY		0x04		/**< must write, even if dirty list is empty */
 #define MDB_TXN_SPILLS		0x08		/**< txn or a parent has spilled pages */
-#define MDB_TXN_NOSYNC		0x10		/**< don't sync this txn on commit */
 /** @} */
 	unsigned int	mt_flags;		/**< @ref mdb_txn */
 	/** #dirty_list room: Array size - \#dirty pages visible to this txn.
@@ -1186,8 +1115,7 @@ struct MDB_env {
 	unsigned int	me_psize;	/**< DB page size, inited from me_os_psize */
 	unsigned int	me_os_psize;	/**< OS page size, from #GET_PAGESIZE */
 	unsigned int	me_maxreaders;	/**< size of the reader table */
-	/** Max #MDB_txninfo.%mti_numreaders of interest to #mdb_env_close() */
-	volatile int	me_close_readers;
+	unsigned int	me_numreaders;	/**< max numreaders set by this env */
 	MDB_dbi		me_numdbs;		/**< number of DBs opened */
 	MDB_dbi		me_maxdbs;		/**< size of the DB table */
 	MDB_PID_T	me_pid;		/**< process ID of this env */
@@ -1224,11 +1152,11 @@ struct MDB_env {
 	int		me_live_reader;		/**< have liveness lock in reader table */
 #ifdef _WIN32
 	int		me_pidquery;		/**< Used in OpenProcess */
-#endif
-#if defined(_WIN32) || defined(MDB_USE_SYSV_SEM)
-	/* Windows mutexes/SysV semaphores do not reside in shared mem */
-	mdb_mutex_t	me_rmutex;
-	mdb_mutex_t	me_wmutex;
+	HANDLE		me_rmutex;		/* Windows mutexes don't reside in shared mem */
+	HANDLE		me_wmutex;
+#elif defined(MDB_USE_POSIX_SEM)
+	sem_t		*me_rmutex;		/* Shared mutexes are not supported */
+	sem_t		*me_wmutex;
 #endif
 	void		*me_userctx;	 /**< User-settable context */
 	MDB_assert_func *me_assert_func; /**< Callback for assertion failures */
@@ -1280,7 +1208,7 @@ static int	mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
 static int  mdb_env_read_header(MDB_env *env, MDB_meta *meta);
 static int  mdb_env_pick_meta(const MDB_env *env);
 static int  mdb_env_write_meta(MDB_txn *txn);
-#if !(defined(_WIN32) || defined(MDB_USE_SYSV_SEM)) /* Drop unused excl arg */
+#if !(defined(_WIN32) || defined(MDB_USE_POSIX_SEM)) /* Drop unused excl arg */
 # define mdb_env_close0(env, excl) mdb_env_close1(env)
 #endif
 static void mdb_env_close0(MDB_env *env, int excl);
@@ -1317,12 +1245,18 @@ static void	mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node);
 
 static int	mdb_drop0(MDB_cursor *mc, int subs);
 static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi);
-static int mdb_reader_check0(MDB_env *env, int rlocked, int *dead);
 
 /** @cond */
 static MDB_cmp_func	mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long;
 /** @endcond */
 
+/** Compare two items pointing at size_t's of unknown alignment. */
+#ifdef MISALIGNED_OK
+# define mdb_cmp_clong mdb_cmp_long
+#else
+# define mdb_cmp_clong mdb_cmp_cint
+#endif
+
 #ifdef _WIN32
 static SECURITY_DESCRIPTOR mdb_null_sd;
 static SECURITY_ATTRIBUTES mdb_all_sa;
@@ -1345,7 +1279,7 @@ static char *const mdb_errstr[] = {
 	"MDB_NOTFOUND: No matching key/data pair found",
 	"MDB_PAGE_NOTFOUND: Requested page not found",
 	"MDB_CORRUPTED: Located page was wrong type",
-	"MDB_PANIC: Update of meta page failed or environment had fatal error",
+	"MDB_PANIC: Update of meta page failed",
 	"MDB_VERSION_MISMATCH: Database environment version mismatch",
 	"MDB_INVALID: File is not an LMDB file",
 	"MDB_MAP_FULL: Environment mapsize limit reached",
@@ -1636,7 +1570,12 @@ mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
 int
 mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b)
 {
-	return txn->mt_dbxs[dbi].md_dcmp(a, b);
+	MDB_cmp_func *dcmp = txn->mt_dbxs[dbi].md_dcmp;
+#if UINT_MAX < SIZE_MAX
+	if (dcmp == mdb_cmp_int && a->mv_size == sizeof(size_t))
+		dcmp = mdb_cmp_clong;
+#endif
+	return dcmp(a, b);
 }
 
 /** Allocate memory for a page.
@@ -2564,14 +2503,11 @@ mdb_txn_renew0(MDB_txn *txn)
 	MDB_env *env = txn->mt_env;
 	MDB_txninfo *ti = env->me_txns;
 	MDB_meta *meta;
-	unsigned int i, nr;
+	unsigned int i, nr, flags = txn->mt_flags;
 	uint16_t x;
 	int rc, new_notls = 0;
 
-	if (txn->mt_flags & MDB_TXN_RDONLY) {
-		/* Setup db info */
-		txn->mt_numdbs = env->me_numdbs;
-		txn->mt_dbxs = env->me_dbxs;	/* mostly static anyway */
+	if ((flags &= MDB_TXN_RDONLY) != 0) {
 		if (!ti) {
 			meta = env->me_metas[ mdb_env_pick_meta(env) ];
 			txn->mt_txnid = meta->mm_txnid;
@@ -2585,7 +2521,6 @@ mdb_txn_renew0(MDB_txn *txn)
 			} else {
 				MDB_PID_T pid = env->me_pid;
 				MDB_THR_T tid = pthread_self();
-				mdb_mutex_t *rmutex = MDB_MUTEX(env, r);
 
 				if (!env->me_live_reader) {
 					rc = mdb_reader_pid(env, Pidset, pid);
@@ -2594,32 +2529,24 @@ mdb_txn_renew0(MDB_txn *txn)
 					env->me_live_reader = 1;
 				}
 
-				if (LOCK_MUTEX(rc, env, rmutex))
-					return rc;
+				LOCK_MUTEX_R(env);
 				nr = ti->mti_numreaders;
 				for (i=0; i<nr; i++)
 					if (ti->mti_readers[i].mr_pid == 0)
 						break;
 				if (i == env->me_maxreaders) {
-					UNLOCK_MUTEX(rmutex);
+					UNLOCK_MUTEX_R(env);
 					return MDB_READERS_FULL;
 				}
-				r = &ti->mti_readers[i];
-				/* Claim the reader slot, carefully since other code
-				 * uses the reader table un-mutexed: First reset the
-				 * slot, next publish it in mti_numreaders.  After
-				 * that, it is safe for mdb_env_close() to touch it.
-				 * When it will be closed, we can finally claim it.
-				 */
-				r->mr_pid = 0;
-				r->mr_txnid = (txnid_t)-1;
-				r->mr_tid = tid;
+				ti->mti_readers[i].mr_pid = pid;
+				ti->mti_readers[i].mr_tid = tid;
 				if (i == nr)
 					ti->mti_numreaders = ++nr;
-				env->me_close_readers = nr;
-				r->mr_pid = pid;
-				UNLOCK_MUTEX(rmutex);
+				/* Save numreaders for un-mutexed mdb_env_close() */
+				env->me_numreaders = nr;
+				UNLOCK_MUTEX_R(env);
 
+				r = &ti->mti_readers[i];
 				new_notls = (env->me_flags & MDB_NOTLS);
 				if (!new_notls && (rc=pthread_setspecific(env->me_txkey, r))) {
 					r->mr_pid = 0;
@@ -2633,24 +2560,22 @@ mdb_txn_renew0(MDB_txn *txn)
 			txn->mt_u.reader = r;
 			meta = env->me_metas[txn->mt_txnid & 1];
 		}
+		txn->mt_dbxs = env->me_dbxs;	/* mostly static anyway */
 	} else {
 		if (ti) {
-			if (LOCK_MUTEX(rc, env, MDB_MUTEX(env, w)))
-				return rc;
+			LOCK_MUTEX_W(env);
+
 			txn->mt_txnid = ti->mti_txnid;
 			meta = env->me_metas[txn->mt_txnid & 1];
 		} else {
 			meta = env->me_metas[ mdb_env_pick_meta(env) ];
 			txn->mt_txnid = meta->mm_txnid;
 		}
-		/* Setup db info */
-		txn->mt_numdbs = env->me_numdbs;
 		txn->mt_txnid++;
 #if MDB_DEBUG
 		if (txn->mt_txnid == mdb_debug_start)
 			mdb_debug = 1;
 #endif
-		txn->mt_flags = 0;
 		txn->mt_child = NULL;
 		txn->mt_loose_pgs = NULL;
 		txn->mt_loose_count = 0;
@@ -2670,6 +2595,10 @@ mdb_txn_renew0(MDB_txn *txn)
 	/* Moved to here to avoid a data race in read TXNs */
 	txn->mt_next_pgno = meta->mm_last_pg+1;
 
+	txn->mt_flags = flags;
+
+	/* Setup db info */
+	txn->mt_numdbs = env->me_numdbs;
 	for (i=2; i<txn->mt_numdbs; i++) {
 		x = env->me_dbflags[i];
 		txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;
@@ -2756,8 +2685,6 @@ mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret)
 		txn->mt_dbflags = (unsigned char *)(txn->mt_dbs + env->me_maxdbs);
 		txn->mt_dbiseqs = env->me_dbiseqs;
 	} else {
-		if (flags & MDB_NOSYNC)
-			txn->mt_flags |= MDB_TXN_NOSYNC;
 		txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs);
 		if (parent) {
 			txn->mt_dbiseqs = parent->mt_dbiseqs;
@@ -2832,13 +2759,6 @@ mdb_txn_env(MDB_txn *txn)
 	return txn->mt_env;
 }
 
-size_t
-mdb_txn_id(MDB_txn *txn)
-{
-    if(!txn) return 0;
-    return txn->mt_txnid;
-}
-
 /** Export or close DBI handles opened in this txn. */
 static void
 mdb_dbis_update(MDB_txn *txn, int keep)
@@ -2902,8 +2822,8 @@ mdb_txn_reset0(MDB_txn *txn, const char *act)
 		}
 
 		if (!txn->mt_parent) {
-			if (mdb_midl_shrink(&txn->mt_free_pgs))
-				env->me_free_pgs = txn->mt_free_pgs;
+			mdb_midl_shrink(&txn->mt_free_pgs);
+			env->me_free_pgs = txn->mt_free_pgs;
 			/* me_pgstate: */
 			env->me_pghead = NULL;
 			env->me_pglast = 0;
@@ -2911,7 +2831,7 @@ mdb_txn_reset0(MDB_txn *txn, const char *act)
 			env->me_txn = NULL;
 			/* The writer mutex was locked in mdb_txn_begin. */
 			if (env->me_txns)
-				UNLOCK_MUTEX(MDB_MUTEX(env, w));
+				UNLOCK_MUTEX_W(env);
 		} else {
 			txn->mt_parent->mt_child = NULL;
 			env->me_pgstate = ((MDB_ntxn *)txn)->mnt_pgstate;
@@ -3228,6 +3148,7 @@ mdb_page_flush(MDB_txn *txn, int keep)
 		/* Write up to MDB_COMMIT_PAGES dirty pages at a time. */
 		if (pos!=next_pos || n==MDB_COMMIT_PAGES || wsize+size>MAX_WRITE) {
 			if (n) {
+retry_write:
 				/* Write previous page(s) */
 #ifdef MDB_USE_PWRITEV
 				wres = pwritev(env->me_fd, iov, n, wpos);
@@ -3235,8 +3156,11 @@ mdb_page_flush(MDB_txn *txn, int keep)
 				if (n == 1) {
 					wres = pwrite(env->me_fd, iov[0].iov_base, wsize, wpos);
 				} else {
+retry_seek:
 					if (lseek(env->me_fd, wpos, SEEK_SET) == -1) {
 						rc = ErrCode();
+						if (rc == EINTR)
+							goto retry_seek;
 						DPRINTF(("lseek: %s", strerror(rc)));
 						return rc;
 					}
@@ -3246,6 +3170,8 @@ mdb_page_flush(MDB_txn *txn, int keep)
 				if (wres != wsize) {
 					if (wres < 0) {
 						rc = ErrCode();
+						if (rc == EINTR)
+							goto retry_write;
 						DPRINTF(("Write error: %s", strerror(rc)));
 					} else {
 						rc = EIO; /* TODO: Use which error code? */
@@ -3469,7 +3395,8 @@ mdb_txn_commit(MDB_txn *txn)
 					goto fail;
 				}
 				data.mv_data = &txn->mt_dbs[i];
-				rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, 0);
+				rc = mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data,
+					F_SUBDATA);
 				if (rc)
 					goto fail;
 			}
@@ -3482,19 +3409,16 @@ mdb_txn_commit(MDB_txn *txn)
 
 	mdb_midl_free(env->me_pghead);
 	env->me_pghead = NULL;
-	if (mdb_midl_shrink(&txn->mt_free_pgs))
-		env->me_free_pgs = txn->mt_free_pgs;
+	mdb_midl_shrink(&txn->mt_free_pgs);
+	env->me_free_pgs = txn->mt_free_pgs;
 
 #if (MDB_DEBUG) > 2
 	mdb_audit(txn);
 #endif
 
-	if ((rc = mdb_page_flush(txn, 0)))
-		goto fail;
-	if (!F_ISSET(txn->mt_flags, MDB_TXN_NOSYNC) &&
-		(rc = mdb_env_sync(env, 0)))
-		goto fail;
-	if ((rc = mdb_env_write_meta(txn)))
+	if ((rc = mdb_page_flush(txn, 0)) ||
+		(rc = mdb_env_sync(env, 0)) ||
+		(rc = mdb_env_write_meta(txn)))
 		goto fail;
 
 	/* Free P_LOOSE pages left behind in dirty_list */
@@ -3507,7 +3431,7 @@ done:
 	mdb_dbis_update(txn, 1);
 
 	if (env->me_txns)
-		UNLOCK_MUTEX(MDB_MUTEX(env, w));
+		UNLOCK_MUTEX_W(env);
 	if (txn != env->me_txn0)
 		free(txn);
 
@@ -3582,7 +3506,6 @@ mdb_env_read_header(MDB_env *env, MDB_meta *meta)
 	return 0;
 }
 
-/** Fill in most of the zeroed #MDB_meta for an empty database environment */
 static void ESECT
 mdb_env_init_meta0(MDB_env *env, MDB_meta *meta)
 {
@@ -3599,7 +3522,7 @@ mdb_env_init_meta0(MDB_env *env, MDB_meta *meta)
 
 /** Write the environment parameters of a freshly created DB environment.
  * @param[in] env the environment handle
- * @param[in] meta the #MDB_meta to write
+ * @param[out] meta address of where to store the meta information
  * @return 0 on success, non-zero on failure.
  */
 static int ESECT
@@ -3619,13 +3542,16 @@ mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
 	int len;
 #define DO_PWRITE(rc, fd, ptr, size, len, pos)	do { \
 	len = pwrite(fd, ptr, size, pos);	\
-	rc = (len >= 0); } while(0)
+	if (len == -1 && ErrCode() == EINTR) continue; \
+	rc = (len >= 0); break; } while(1)
 #endif
 
 	DPUTS("writing new meta page");
 
 	psize = env->me_psize;
 
+	mdb_env_init_meta0(env, meta);
+
 	p = calloc(2, psize);
 	p->mp_pgno = 0;
 	p->mp_flags = P_META;
@@ -3683,13 +3609,7 @@ mdb_env_write_meta(MDB_txn *txn)
 		mp->mm_dbs[0] = txn->mt_dbs[0];
 		mp->mm_dbs[1] = txn->mt_dbs[1];
 		mp->mm_last_pg = txn->mt_next_pgno - 1;
-#if !(defined(_MSC_VER) || defined(__i386__) || defined(__x86_64__))
-		/* LY: issue a memory barrier, if not x86. ITS#7969 */
-		__sync_synchronize();
-#endif
 		mp->mm_txnid = txn->mt_txnid;
-		if (F_ISSET(txn->mt_flags, MDB_TXN_NOSYNC))
-			goto done;
 		if (!(env->me_flags & (MDB_NOMETASYNC|MDB_NOSYNC))) {
 			unsigned meta_size = env->me_psize;
 			rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC;
@@ -3726,8 +3646,7 @@ mdb_env_write_meta(MDB_txn *txn)
 	off += PAGEHDRSZ;
 
 	/* Write to the SYNC fd */
-	mfd = ((env->me_flags & (MDB_NOSYNC|MDB_NOMETASYNC)) ||
-		(txn->mt_flags & MDB_TXN_NOSYNC)) ?
+	mfd = env->me_flags & (MDB_NOSYNC|MDB_NOMETASYNC) ?
 		env->me_fd : env->me_mfd;
 #ifdef _WIN32
 	{
@@ -3737,10 +3656,15 @@ mdb_env_write_meta(MDB_txn *txn)
 			rc = -1;
 	}
 #else
+retry_write:
 	rc = pwrite(mfd, ptr, len, off);
 #endif
 	if (rc != len) {
 		rc = rc < 0 ? ErrCode() : EIO;
+#ifndef _WIN32
+		if (rc == EINTR)
+			goto retry_write;
+#endif
 		DPUTS("write failed, disk error?");
 		/* On a failure, the pagecache still contains the new data.
 		 * Write some old data back, to prevent it from being used.
@@ -3799,9 +3723,9 @@ mdb_env_create(MDB_env **env)
 	e->me_fd = INVALID_HANDLE_VALUE;
 	e->me_lfd = INVALID_HANDLE_VALUE;
 	e->me_mfd = INVALID_HANDLE_VALUE;
-#ifdef MDB_USE_SYSV_SEM
-	e->me_rmutex.semid = -1;
-	e->me_wmutex.semid = -1;
+#ifdef MDB_USE_POSIX_SEM
+	e->me_rmutex = SEM_FAILED;
+	e->me_wmutex = SEM_FAILED;
 #endif
 	e->me_pid = getpid();
 	GET_PAGESIZE(e->me_os_psize);
@@ -3902,16 +3826,16 @@ mdb_env_set_mapsize(MDB_env *env, size_t size)
 	 */
 	if (env->me_map) {
 		int rc;
-		MDB_meta *meta;
 		void *old;
 		if (env->me_txn)
 			return EINVAL;
-		meta = env->me_metas[mdb_env_pick_meta(env)];
 		if (!size)
-			size = meta->mm_mapsize;
-		{
-			/* Silently round up to minimum if the size is too small */
-			size_t minsize = (meta->mm_last_pg + 1) * env->me_psize;
+			size = env->me_metas[mdb_env_pick_meta(env)]->mm_mapsize;
+		else if (size < env->me_mapsize) {
+			/* If the configured size is smaller, make sure it's
+			 * still big enough. Silently round up to minimum if not.
+			 */
+			size_t minsize = (env->me_metas[mdb_env_pick_meta(env)]->mm_last_pg + 1) * env->me_psize;
 			if (size < minsize)
 				size = minsize;
 		}
@@ -3998,7 +3922,6 @@ mdb_env_open2(MDB_env *env)
 	else
 		env->me_pidquery = PROCESS_QUERY_INFORMATION;
 #endif /* _WIN32 */
-
 #ifdef BROKEN_FDATASYNC
 	/* ext3/ext4 fdatasync is broken on some older Linux kernels.
 	 * https://lkml.org/lkml/2012/9/3/83
@@ -4047,6 +3970,8 @@ mdb_env_open2(MDB_env *env)
 	}
 #endif
 
+	memset(&meta, 0, sizeof(meta));
+
 	if ((i = mdb_env_read_header(env, &meta)) != 0) {
 		if (i != ENOENT)
 			return i;
@@ -4055,40 +3980,24 @@ mdb_env_open2(MDB_env *env)
 		env->me_psize = env->me_os_psize;
 		if (env->me_psize > MAX_PAGESIZE)
 			env->me_psize = MAX_PAGESIZE;
-		memset(&meta, 0, sizeof(meta));
-		mdb_env_init_meta0(env, &meta);
-		meta.mm_mapsize = DEFAULT_MAPSIZE;
 	} else {
 		env->me_psize = meta.mm_psize;
 	}
 
 	/* Was a mapsize configured? */
 	if (!env->me_mapsize) {
-		env->me_mapsize = meta.mm_mapsize;
-	}
-	{
-		/* Make sure mapsize >= committed data size.  Even when using
-		 * mm_mapsize, which could be broken in old files (ITS#7789).
+		/* If this is a new environment, take the default,
+		 * else use the size recorded in the existing env.
+		 */
+		env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize;
+	} else if (env->me_mapsize < meta.mm_mapsize) {
+		/* If the configured size is smaller, make sure it's
+		 * still big enough. Silently round up to minimum if not.
 		 */
 		size_t minsize = (meta.mm_last_pg + 1) * meta.mm_psize;
 		if (env->me_mapsize < minsize)
 			env->me_mapsize = minsize;
 	}
-	meta.mm_mapsize = env->me_mapsize;
-
-	if (newenv && !(flags & MDB_FIXEDMAP)) {
-		/* mdb_env_map() may grow the datafile.  Write the metapages
-		 * first, so the file will be valid if initialization fails.
-		 * Except with FIXEDMAP, since we do not yet know mm_address.
-		 * We could fill in mm_address later, but then a different
-		 * program might end up doing that - one with a memory layout
-		 * and map address which does not suit the main program.
-		 */
-		rc = mdb_env_init_meta(env, &meta);
-		if (rc)
-			return rc;
-		newenv = 0;
-	}
 
 	rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta.mm_address : NULL);
 	if (rc)
@@ -4272,8 +4181,8 @@ mdb_env_excl_lock(MDB_env *env, int *excl)
 	if (!rc) {
 		*excl = 1;
 	} else
-# ifdef MDB_USE_SYSV_SEM
-	if (*excl < 0) /* always true when !MDB_USE_SYSV_SEM */
+# ifdef MDB_USE_POSIX_SEM
+	if (*excl < 0) /* always true when !MDB_USE_POSIX_SEM */
 # endif
 	{
 		lock_info.l_type = F_RDLCK;
@@ -4398,10 +4307,6 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 	int fdflags;
 #	define MDB_CLOEXEC		0
 #endif
-#endif
-#ifdef MDB_USE_SYSV_SEM
-	int semid;
-	union semun semu;
 #endif
 	int rc;
 	off_t size, rsize;
@@ -4515,28 +4420,50 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 		if (!env->me_rmutex) goto fail_errno;
 		env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_wmname);
 		if (!env->me_wmutex) goto fail_errno;
-#elif defined(MDB_USE_SYSV_SEM)
-		unsigned short vals[2] = {1, 1};
-		semid = semget(IPC_PRIVATE, 2, mode);
-		if (semid < 0)
-			goto fail_errno;
-		semu.array = vals;
-		if (semctl(semid, 0, SETALL, semu) < 0)
-			goto fail_errno;
-		env->me_txns->mti_semid = semid;
-#else	/* MDB_USE_SYSV_SEM */
+#elif defined(MDB_USE_POSIX_SEM)
+		struct stat stbuf;
+		struct {
+			dev_t dev;
+			ino_t ino;
+		} idbuf;
+		MDB_val val;
+		char encbuf[11];
+
+#if defined(__NetBSD__)
+#define	MDB_SHORT_SEMNAMES	1	/* limited to 14 chars */
+#endif
+		if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
+		idbuf.dev = stbuf.st_dev;
+		idbuf.ino = stbuf.st_ino;
+		val.mv_data = &idbuf;
+		val.mv_size = sizeof(idbuf);
+		mdb_hash_enc(&val, encbuf);
+#ifdef MDB_SHORT_SEMNAMES
+		encbuf[9] = '\0';	/* drop name from 15 chars to 14 chars */
+#endif
+		sprintf(env->me_txns->mti_rmname, "/MDBr%s", encbuf);
+		sprintf(env->me_txns->mti_wmname, "/MDBw%s", encbuf);
+		/* Clean up after a previous run, if needed:  Try to
+		 * remove both semaphores before doing anything else.
+		 */
+		sem_unlink(env->me_txns->mti_rmname);
+		sem_unlink(env->me_txns->mti_wmname);
+		env->me_rmutex = sem_open(env->me_txns->mti_rmname,
+			O_CREAT|O_EXCL, mode, 1);
+		if (env->me_rmutex == SEM_FAILED) goto fail_errno;
+		env->me_wmutex = sem_open(env->me_txns->mti_wmname,
+			O_CREAT|O_EXCL, mode, 1);
+		if (env->me_wmutex == SEM_FAILED) goto fail_errno;
+#else	/* MDB_USE_POSIX_SEM */
 		pthread_mutexattr_t mattr;
 
 		if ((rc = pthread_mutexattr_init(&mattr))
 			|| (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED))
-#ifdef MDB_ROBUST_SUPPORTED
-			|| (rc = pthread_mutexattr_setrobust(&mattr, PTHREAD_MUTEX_ROBUST))
-#endif
-			|| (rc = pthread_mutex_init(&env->me_txns->mti_rmutex, &mattr))
+			|| (rc = pthread_mutex_init(&env->me_txns->mti_mutex, &mattr))
 			|| (rc = pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr)))
 			goto fail;
 		pthread_mutexattr_destroy(&mattr);
-#endif	/* _WIN32 || MDB_USE_SYSV_SEM */
+#endif	/* _WIN32 || MDB_USE_POSIX_SEM */
 
 		env->me_txns->mti_magic = MDB_MAGIC;
 		env->me_txns->mti_format = MDB_LOCK_FORMAT;
@@ -4544,9 +4471,6 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 		env->me_txns->mti_numreaders = 0;
 
 	} else {
-#ifdef MDB_USE_SYSV_SEM
-		struct semid_ds buf;
-#endif
 		if (env->me_txns->mti_magic != MDB_MAGIC) {
 			DPUTS("lock region has invalid magic");
 			rc = MDB_INVALID;
@@ -4567,26 +4491,13 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 		if (!env->me_rmutex) goto fail_errno;
 		env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname);
 		if (!env->me_wmutex) goto fail_errno;
-#elif defined(MDB_USE_SYSV_SEM)
-		semid = env->me_txns->mti_semid;
-		semu.buf = &buf;
-		/* check for read access */
-		if (semctl(semid, 0, IPC_STAT, semu) < 0)
-			goto fail_errno;
-		/* check for write access */
-		if (semctl(semid, 0, IPC_SET, semu) < 0)
-			goto fail_errno;
+#elif defined(MDB_USE_POSIX_SEM)
+		env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0);
+		if (env->me_rmutex == SEM_FAILED) goto fail_errno;
+		env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0);
+		if (env->me_wmutex == SEM_FAILED) goto fail_errno;
 #endif
 	}
-#ifdef MDB_USE_SYSV_SEM
-	env->me_rmutex.semid = semid;
-	env->me_wmutex.semid = semid;
-	env->me_rmutex.semnum = 0;
-	env->me_wmutex.semnum = 1;
-	env->me_rmutex.locked = &env->me_txns->mti_rlocked;
-	env->me_wmutex.locked = &env->me_txns->mti_wlocked;
-#endif
-
 	return MDB_SUCCESS;
 
 fail_errno:
@@ -4606,8 +4517,8 @@ fail:
 	 *	environment and re-opening it with the new flags.
 	 */
 #define	CHANGEABLE	(MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC|MDB_NOMEMINIT)
-#define	CHANGELESS	(MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY| \
-	MDB_WRITEMAP|MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)
+#define	CHANGELESS	(MDB_FIXEDMAP|MDB_NOSUBDIR|MDB_RDONLY|MDB_WRITEMAP| \
+	MDB_NOTLS|MDB_NOLOCK|MDB_NORDAHEAD)
 
 #if VALID_FLAGS & PERSISTENT_FLAGS & (CHANGEABLE|CHANGELESS)
 # error "Persistent DB flags & env flags overlap, but both go in mm_flags"
@@ -4682,10 +4593,6 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode
 	mode = FILE_ATTRIBUTE_NORMAL;
 	env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
 		NULL, len, mode, NULL);
-	DWORD actual;
-	if (!DeviceIoControl(env->me_fd, FSCTL_SET_SPARSE, NULL, 0,
-		NULL, 0, &actual, NULL))
-		; // If the file is not sparsed, it will allocate the full environment
 #else
 	if (F_ISSET(flags, MDB_RDONLY))
 		oflags = O_RDONLY;
@@ -4810,12 +4717,8 @@ mdb_env_close0(MDB_env *env, int excl)
 		MDB_PID_T pid = env->me_pid;
 		/* Clearing readers is done in this function because
 		 * me_txkey with its destructor must be disabled first.
-		 *
-		 * We skip the the reader mutex, so we touch only
-		 * data owned by this process (me_close_readers and
-		 * our readers), and clear each reader atomically.
 		 */
-		for (i = env->me_close_readers; --i >= 0; )
+		for (i = env->me_numreaders; --i >= 0; )
 			if (env->me_txns->mti_readers[i].mr_pid == pid)
 				env->me_txns->mti_readers[i].mr_pid = 0;
 #ifdef _WIN32
@@ -4826,15 +4729,20 @@ mdb_env_close0(MDB_env *env, int excl)
 		/* Windows automatically destroys the mutexes when
 		 * the last handle closes.
 		 */
-#elif defined(MDB_USE_SYSV_SEM)
-		if (env->me_rmutex.semid != -1) {
+#elif defined(MDB_USE_POSIX_SEM)
+		if (env->me_rmutex != SEM_FAILED) {
+			sem_close(env->me_rmutex);
+			if (env->me_wmutex != SEM_FAILED)
+				sem_close(env->me_wmutex);
 			/* If we have the filelock:  If we are the
 			 * only remaining user, clean up semaphores.
 			 */
 			if (excl == 0)
 				mdb_env_excl_lock(env, &excl);
-			if (excl > 0)
-				semctl(env->me_rmutex.semid, 0, IPC_RMID);
+			if (excl > 0) {
+				sem_unlink(env->me_txns->mti_rmname);
+				sem_unlink(env->me_txns->mti_wmname);
+			}
 		}
 #endif
 		munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
@@ -4854,6 +4762,7 @@ mdb_env_close0(MDB_env *env, int excl)
 	env->me_flags &= ~(MDB_ENV_ACTIVE|MDB_ENV_TXKEY);
 }
 
+
 void ESECT
 mdb_env_close(MDB_env *env)
 {
@@ -4881,7 +4790,11 @@ mdb_cmp_long(const MDB_val *a, const MDB_val *b)
 		*(size_t *)a->mv_data > *(size_t *)b->mv_data;
 }
 
-/** Compare two items pointing at aligned unsigned int's */
+/** Compare two items pointing at aligned unsigned int's.
+ *
+ *	This is also set as #MDB_INTEGERDUP|#MDB_DUPFIXED's #MDB_dbx.%md_dcmp,
+ *	but #mdb_cmp_clong() is called instead if the data type is size_t.
+ */
 static int
 mdb_cmp_int(const MDB_val *a, const MDB_val *b)
 {
@@ -4919,13 +4832,6 @@ mdb_cmp_cint(const MDB_val *a, const MDB_val *b)
 #endif
 }
 
-/** Compare two items pointing at size_t's of unknown alignment. */
-#ifdef MISALIGNED_OK
-# define mdb_cmp_clong mdb_cmp_long
-#else
-# define mdb_cmp_clong mdb_cmp_cint
-#endif
-
 /** Compare two items lexically */
 static int
 mdb_cmp_memn(const MDB_val *a, const MDB_val *b)
@@ -5311,6 +5217,8 @@ mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags)
 						&mc->mc_dbx->md_name, &exact);
 					if (!exact)
 						return MDB_NOTFOUND;
+					if ((leaf->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
+						return MDB_INCOMPATIBLE; /* not a named DB */
 					rc = mdb_node_read(mc->mc_txn, leaf, &data);
 					if (rc)
 						return rc;
@@ -5822,8 +5730,10 @@ set2:
 
 	if (leaf == NULL) {
 		DPUTS("===> inexact leaf not found, goto sibling");
-		if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS)
+		if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) {
+			mc->mc_flags |= C_EOF;
 			return rc;		/* no entries matched */
+		}
 		mp = mc->mc_pg[mc->mc_top];
 		mdb_cassert(mc, IS_LEAF(mp));
 		leaf = NODEPTR(mp, 0);
@@ -5861,15 +5771,21 @@ set1:
 					return rc;
 			}
 		} else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) {
-			MDB_val d2;
-			if ((rc = mdb_node_read(mc->mc_txn, leaf, &d2)) != MDB_SUCCESS)
+			MDB_val olddata;
+			MDB_cmp_func *dcmp;
+			if ((rc = mdb_node_read(mc->mc_txn, leaf, &olddata)) != MDB_SUCCESS)
 				return rc;
-			rc = mc->mc_dbx->md_dcmp(data, &d2);
+			dcmp = mc->mc_dbx->md_dcmp;
+#if UINT_MAX < SIZE_MAX
+			if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
+				dcmp = mdb_cmp_clong;
+#endif
+			rc = dcmp(data, &olddata);
 			if (rc) {
 				if (op == MDB_GET_BOTH || rc > 0)
 					return MDB_NOTFOUND;
 				rc = 0;
-				*data = d2;
+				*data = olddata;
 			}
 
 		} else {
@@ -6188,6 +6104,7 @@ int
 mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data,
     unsigned int flags)
 {
+	enum { MDB_NO_ROOT = MDB_LAST_ERRCODE+10 }; /* internal code */
 	MDB_env		*env;
 	MDB_node	*leaf = NULL;
 	MDB_page	*fp, *mp;
@@ -6378,16 +6295,17 @@ more:
 
 			/* Was a single item before, must convert now */
 			if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+				MDB_cmp_func *dcmp;
 				/* Just overwrite the current item */
 				if (flags == MDB_CURRENT)
 					goto current;
-
+				dcmp = mc->mc_dbx->md_dcmp;
 #if UINT_MAX < SIZE_MAX
-				if (mc->mc_dbx->md_dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
-					mc->mc_dbx->md_dcmp = mdb_cmp_clong;
+				if (dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
+					dcmp = mdb_cmp_clong;
 #endif
 				/* does data match? */
-				if (!mc->mc_dbx->md_dcmp(data, &olddata)) {
+				if (!dcmp(data, &olddata)) {
 					if (flags & MDB_NODUPDATA)
 						return MDB_KEYEXIST;
 					/* overwrite it */
@@ -6493,6 +6411,9 @@ prep_subDB:
 			goto new_sub;
 		}
 current:
+		/* LMDB passes F_SUBDATA in 'flags' to write a DB record */
+		if ((leaf->mn_flags ^ flags) & F_SUBDATA)
+			return MDB_INCOMPATIBLE;
 		/* overflow page overwrites need special handling */
 		if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
 			MDB_page *omp;
@@ -6763,6 +6684,11 @@ mdb_cursor_del(MDB_cursor *mc, unsigned int flags)
 				goto fail;
 		}
 	}
+	/* LMDB passes F_SUBDATA in 'flags' to delete a DB record */
+	else if ((leaf->mn_flags ^ flags) & F_SUBDATA) {
+		rc = MDB_INCOMPATIBLE;
+		goto fail;
+	}
 
 	/* add overflow pages to free list */
 	if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
@@ -7207,6 +7133,7 @@ mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx)
 	mc->mc_snum = 0;
 	mc->mc_top = 0;
 	mc->mc_pg[0] = 0;
+	mc->mc_ki[0] = 0;
 	mc->mc_flags = 0;
 	if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) {
 		mdb_tassert(txn, mx != NULL);
@@ -7836,12 +7763,12 @@ mdb_rebalance(MDB_cursor *mc)
 						m3 = m2;
 					if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
 					if (m3->mc_pg[0] == mp) {
-						m3->mc_snum--;
-						m3->mc_top--;
 						for (i=0; i<m3->mc_snum; i++) {
 							m3->mc_pg[i] = m3->mc_pg[i+1];
 							m3->mc_ki[i] = m3->mc_ki[i+1];
 						}
+						m3->mc_snum--;
+						m3->mc_top--;
 					}
 				}
 			}
@@ -7909,9 +7836,23 @@ mdb_rebalance(MDB_cursor *mc)
 		if (mc->mc_ki[ptop] == 0) {
 			rc = mdb_page_merge(&mn, mc);
 		} else {
+			MDB_cursor dummy;
 			oldki += NUMKEYS(mn.mc_pg[mn.mc_top]);
 			mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
+			/* We want mdb_rebalance to find mn when doing fixups */
+			if (mc->mc_flags & C_SUB) {
+				dummy.mc_next = mc->mc_txn->mt_cursors[mc->mc_dbi];
+				mc->mc_txn->mt_cursors[mc->mc_dbi] = &dummy;
+				dummy.mc_xcursor = (MDB_xcursor *)&mn;
+			} else {
+				mn.mc_next = mc->mc_txn->mt_cursors[mc->mc_dbi];
+				mc->mc_txn->mt_cursors[mc->mc_dbi] = &mn;
+			}
 			rc = mdb_page_merge(mc, &mn);
+			if (mc->mc_flags & C_SUB)
+				mc->mc_txn->mt_cursors[mc->mc_dbi] = dummy.mc_next;
+			else
+				mc->mc_txn->mt_cursors[mc->mc_dbi] = mn.mc_next;
 			mdb_cursor_copy(&mn, mc);
 		}
 		mc->mc_flags &= ~C_EOF;
@@ -7938,6 +7879,13 @@ mdb_cursor_del0(MDB_cursor *mc)
 		MDB_cursor *m2, *m3;
 		MDB_dbi dbi = mc->mc_dbi;
 
+		/* DB is totally empty now, just bail out.
+		 * Other cursors adjustments were already done
+		 * by mdb_rebalance and aren't needed here.
+		 */
+		if (!mc->mc_snum)
+			return rc;
+
 		mp = mc->mc_pg[mc->mc_top];
 		nkeys = NUMKEYS(mp);
 
@@ -8846,7 +8794,6 @@ static int ESECT
 mdb_env_copyfd0(MDB_env *env, HANDLE fd)
 {
 	MDB_txn *txn = NULL;
-	mdb_mutex_t *wmutex = NULL;
 	int rc;
 	size_t wsize;
 	char *ptr;
@@ -8871,13 +8818,11 @@ mdb_env_copyfd0(MDB_env *env, HANDLE fd)
 		mdb_txn_reset0(txn, "reset-stage1");
 
 		/* Temporarily block writers until we snapshot the meta pages */
-		wmutex = MDB_MUTEX(env, w);
-		if (LOCK_MUTEX(rc, env, wmutex))
-			goto leave;
+		LOCK_MUTEX_W(env);
 
 		rc = mdb_txn_renew0(txn);
 		if (rc) {
-			UNLOCK_MUTEX(wmutex);
+			UNLOCK_MUTEX_W(env);
 			goto leave;
 		}
 	}
@@ -8901,8 +8846,8 @@ mdb_env_copyfd0(MDB_env *env, HANDLE fd)
 			break;
 		}
 	}
-	if (wmutex)
-		UNLOCK_MUTEX(wmutex);
+	if (env->me_txns)
+		UNLOCK_MUTEX_W(env);
 
 	if (rc)
 		goto leave;
@@ -9134,7 +9079,11 @@ mdb_env_info(MDB_env *env, MDB_envinfo *arg)
 	arg->me_mapaddr = env->me_metas[toggle]->mm_address;
 	arg->me_mapsize = env->me_mapsize;
 	arg->me_maxreaders = env->me_maxreaders;
-	arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : 0;
+
+	/* me_numreaders may be zero if this process never used any readers. Use
+	 * the shared numreader count if it exists.
+	 */
+	arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : env->me_numreaders;
 
 	arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg;
 	arg->me_last_txnid = env->me_metas[toggle]->mm_txnid;
@@ -9235,7 +9184,7 @@ int mdb_dbi_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *db
 	if (rc == MDB_SUCCESS) {
 		/* make sure this is actually a DB */
 		MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]);
-		if (!(node->mn_flags & F_SUBDATA))
+		if ((node->mn_flags & (F_DUPDATA|F_SUBDATA)) != F_SUBDATA)
 			return MDB_INCOMPATIBLE;
 	} else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) {
 		/* Create if requested */
@@ -9428,7 +9377,7 @@ int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del)
 
 	/* Can't delete the main DB */
 	if (del && dbi > MAIN_DBI) {
-		rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, 0);
+		rc = mdb_del0(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL, F_SUBDATA);
 		if (!rc) {
 			txn->mt_dbflags[dbi] = DB_STALE;
 			mdb_dbi_close(txn->mt_env, dbi);
@@ -9575,22 +9524,17 @@ mdb_pid_insert(MDB_PID_T *ids, MDB_PID_T pid)
 int ESECT
 mdb_reader_check(MDB_env *env, int *dead)
 {
+	unsigned int i, j, rdrs;
+	MDB_reader *mr;
+	MDB_PID_T *pids, pid;
+	int count = 0;
+
 	if (!env)
 		return EINVAL;
 	if (dead)
 		*dead = 0;
-	return env->me_txns ? mdb_reader_check0(env, 0, dead) : MDB_SUCCESS;
-}
-
-/** As #mdb_reader_check(). rlocked = <caller locked the reader mutex>. */
-static int mdb_reader_check0(MDB_env *env, int rlocked, int *dead)
-{
-	mdb_mutex_t *rmutex = rlocked ? NULL : MDB_MUTEX(env, r);
-	unsigned int i, j, rdrs;
-	MDB_reader *mr;
-	MDB_PID_T *pids, pid;
-	int rc = MDB_SUCCESS, count = 0;
-
+	if (!env->me_txns)
+		return MDB_SUCCESS;
 	rdrs = env->me_txns->mti_numreaders;
 	pids = malloc((rdrs+1) * sizeof(MDB_PID_T));
 	if (!pids)
@@ -9598,32 +9542,22 @@ static int mdb_reader_check0(MDB_env *env, int rlocked, int *dead)
 	pids[0] = 0;
 	mr = env->me_txns->mti_readers;
 	for (i=0; i<rdrs; i++) {
-		pid = mr[i].mr_pid;
-		if (pid && pid != env->me_pid) {
+		if (mr[i].mr_pid && mr[i].mr_pid != env->me_pid) {
+			pid = mr[i].mr_pid;
 			if (mdb_pid_insert(pids, pid) == 0) {
 				if (!mdb_reader_pid(env, Pidcheck, pid)) {
-					/* Stale reader found */
-					j = i;
-					if (rmutex) {
-						if ((rc = LOCK_MUTEX0(rmutex)) != 0) {
-							if ((rc = mdb_mutex_failed(env, rmutex, rc)))
-								break;
-							rdrs = 0; /* the above checked all readers */
-						} else {
-							/* Recheck, a new process may have reused pid */
-							if (mdb_reader_pid(env, Pidcheck, pid))
-								j = rdrs;
-						}
-					}
-					for (; j<rdrs; j++)
+					LOCK_MUTEX_R(env);
+					/* Recheck, a new process may have reused pid */
+					if (!mdb_reader_pid(env, Pidcheck, pid)) {
+						for (j=i; j<rdrs; j++)
 							if (mr[j].mr_pid == pid) {
 								DPRINTF(("clear stale reader pid %u txn %"Z"d",
 									(unsigned) pid, mr[j].mr_txnid));
 								mr[j].mr_pid = 0;
 								count++;
 							}
-					if (rmutex)
-						UNLOCK_MUTEX(rmutex);
+					}
+					UNLOCK_MUTEX_R(env);
 				}
 			}
 		}
@@ -9631,55 +9565,6 @@ static int mdb_reader_check0(MDB_env *env, int rlocked, int *dead)
 	free(pids);
 	if (dead)
 		*dead = count;
-	return rc;
+	return MDB_SUCCESS;
 }
-
-#ifdef MDB_ROBUST_SUPPORTED
-/** Handle #LOCK_MUTEX0() failure.
- * Try to repair the lock file if the mutex owner died.
- * @param[in] env	the environment handle
- * @param[in] mutex	LOCK_MUTEX0() mutex
- * @param[in] rc	LOCK_MUTEX0() error (nonzero)
- * @return 0 on success with the mutex locked, or an error code on failure.
- */
-static int mdb_mutex_failed(MDB_env *env, mdb_mutex_t *mutex, int rc)
-{
-	int toggle, rlocked, rc2;
-
-	if (rc == MDB_OWNERDEAD) {
-		/* We own the mutex. Clean up after dead previous owner. */
-		rc = MDB_SUCCESS;
-		rlocked = (mutex == MDB_MUTEX(env, r));
-		if (!rlocked) {
-			/* Keep mti_txnid updated, otherwise next writer can
-			 * overwrite data which latest meta page refers to.
-			 */
-			toggle = mdb_env_pick_meta(env);
-			env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
-			/* env is hosed if the dead thread was ours */
-			if (env->me_txn) {
-				env->me_flags |= MDB_FATAL_ERROR;
-				env->me_txn = NULL;
-				rc = MDB_PANIC;
-			}
-		}
-		DPRINTF(("%cmutex owner died, %s", (rlocked ? 'r' : 'w'),
-			(rc ? "this process' env is hosed" : "recovering")));
-		rc2 = mdb_reader_check0(env, rlocked, NULL);
-		if (rc2 == 0)
-			rc2 = mdb_mutex_consistent(mutex);
-		if (rc || (rc = rc2)) {
-			DPRINTF(("LOCK_MUTEX recovery failed, %s", mdb_strerror(rc)));
-			UNLOCK_MUTEX(mutex);
-		}
-	} else {
-#ifdef _WIN32
-		rc = ErrCode();
-#endif
-		DPRINTF(("LOCK_MUTEX failed, %s", mdb_strerror(rc)));
-	}
-
-	return rc;
-}
-#endif	/* MDB_ROBUST_SUPPORTED */
 /** @} */
diff --git a/liblmdb/mdb_copy.1 b/liblmdb/mdb_copy.1
index 094b2605..1e2a9769 100644
--- a/liblmdb/mdb_copy.1
+++ b/liblmdb/mdb_copy.1
@@ -1,5 +1,5 @@
 .TH MDB_COPY 1 "2014/06/20" "LMDB 0.9.14"
-.\" Copyright 2012-2014 Howard Chu, Symas Corp. All Rights Reserved.
+.\" Copyright 2012-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
 .SH NAME
 mdb_copy \- LMDB environment copy tool
diff --git a/liblmdb/mdb_copy.c b/liblmdb/mdb_copy.c
index af0a9411..f37ccbcc 100644
--- a/liblmdb/mdb_copy.c
+++ b/liblmdb/mdb_copy.c
@@ -1,6 +1,6 @@
 /* mdb_copy.c - memory-mapped database backup tool */
 /*
- * Copyright 2012 Howard Chu, Symas Corp.
+ * Copyright 2012-2015 Howard Chu, Symas Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/liblmdb/mdb_dump.1 b/liblmdb/mdb_dump.1
index 6fcc9308..dd545049 100644
--- a/liblmdb/mdb_dump.1
+++ b/liblmdb/mdb_dump.1
@@ -1,5 +1,5 @@
 .TH MDB_DUMP 1 "2014/06/20" "LMDB 0.9.14"
-.\" Copyright 2014 Howard Chu, Symas Corp. All Rights Reserved.
+.\" Copyright 2014-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
 .SH NAME
 mdb_dump \- LMDB environment export tool
diff --git a/liblmdb/mdb_dump.c b/liblmdb/mdb_dump.c
index 0eb85fd2..7202d865 100644
--- a/liblmdb/mdb_dump.c
+++ b/liblmdb/mdb_dump.c
@@ -1,6 +1,6 @@
 /* mdb_dump.c - memory-mapped database dump tool */
 /*
- * Copyright 2011-2014 Howard Chu, Symas Corp.
+ * Copyright 2011-2015 Howard Chu, Symas Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/liblmdb/mdb_load.1 b/liblmdb/mdb_load.1
index 72802401..511ec552 100644
--- a/liblmdb/mdb_load.1
+++ b/liblmdb/mdb_load.1
@@ -1,5 +1,5 @@
 .TH MDB_LOAD 1 "2014/06/20" "LMDB 0.9.14"
-.\" Copyright 2014 Howard Chu, Symas Corp. All Rights Reserved.
+.\" Copyright 2014-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
 .SH NAME
 mdb_load \- LMDB environment import tool
diff --git a/liblmdb/mdb_load.c b/liblmdb/mdb_load.c
index e0d95e13..1f6ce0b7 100644
--- a/liblmdb/mdb_load.c
+++ b/liblmdb/mdb_load.c
@@ -1,6 +1,6 @@
 /* mdb_load.c - memory-mapped database load tool */
 /*
- * Copyright 2011-2014 Howard Chu, Symas Corp.
+ * Copyright 2011-2015 Howard Chu, Symas Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -176,7 +176,7 @@ static int unhex(unsigned char *c2)
 static int readline(MDB_val *out, MDB_val *buf)
 {
 	unsigned char *c1, *c2, *end;
-	size_t len;
+	size_t len, l2;
 	int c;
 
 	if (!(mode & NOHDR)) {
@@ -206,6 +206,7 @@ badend:
 
 	c1 = buf->mv_data;
 	len = strlen((char *)c1);
+	l2 = len;
 
 	/* Is buffer too short? */
 	while (c1[len-1] != '\n') {
@@ -217,17 +218,18 @@ badend:
 			return EOF;
 		}
 		c1 = buf->mv_data;
-		c1 += buf->mv_size;
-		if (fgets((char *)c1, buf->mv_size, stdin) == NULL) {
+		c1 += l2;
+		if (fgets((char *)c1, buf->mv_size+1, stdin) == NULL) {
 			Eof = 1;
 			badend();
 			return EOF;
 		}
 		buf->mv_size *= 2;
 		len = strlen((char *)c1);
+		l2 += len;
 	}
 	c1 = c2 = buf->mv_data;
-	len = strlen((char *)c1);
+	len = l2;
 	c1[--len] = '\0';
 	end = c1 + len;
 
diff --git a/liblmdb/mdb_stat.1 b/liblmdb/mdb_stat.1
index 3d8d461d..e6ee5ad5 100644
--- a/liblmdb/mdb_stat.1
+++ b/liblmdb/mdb_stat.1
@@ -1,5 +1,5 @@
 .TH MDB_STAT 1 "2014/06/20" "LMDB 0.9.14"
-.\" Copyright 2012-2014 Howard Chu, Symas Corp. All Rights Reserved.
+.\" Copyright 2012-2015 Howard Chu, Symas Corp. All Rights Reserved.
 .\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
 .SH NAME
 mdb_stat \- LMDB environment status tool
diff --git a/liblmdb/mdb_stat.c b/liblmdb/mdb_stat.c
index 1e922929..210609b3 100644
--- a/liblmdb/mdb_stat.c
+++ b/liblmdb/mdb_stat.c
@@ -1,6 +1,6 @@
 /* mdb_stat.c - memory-mapped database status tool */
 /*
- * Copyright 2011-2013 Howard Chu, Symas Corp.
+ * Copyright 2011-2015 Howard Chu, Symas Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/liblmdb/midl.c b/liblmdb/midl.c
index 88a3aff1..57a9d492 100644
--- a/liblmdb/midl.c
+++ b/liblmdb/midl.c
@@ -3,7 +3,7 @@
 /* $OpenLDAP$ */
 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
  *
- * Copyright 2000-2014 The OpenLDAP Foundation.
+ * Copyright 2000-2015 The OpenLDAP Foundation.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -116,7 +116,7 @@ void mdb_midl_free(MDB_IDL ids)
 		free(ids-1);
 }
 
-int mdb_midl_shrink( MDB_IDL *idp )
+void mdb_midl_shrink( MDB_IDL *idp )
 {
 	MDB_IDL ids = *idp;
 	if (*(--ids) > MDB_IDL_UM_MAX &&
@@ -124,9 +124,7 @@ int mdb_midl_shrink( MDB_IDL *idp )
 	{
 		*ids++ = MDB_IDL_UM_MAX;
 		*idp = ids;
-		return 1;
 	}
-	return 0;
 }
 
 static int mdb_midl_grow( MDB_IDL *idp, int num )
diff --git a/liblmdb/midl.h b/liblmdb/midl.h
index a7f25026..2331e783 100644
--- a/liblmdb/midl.h
+++ b/liblmdb/midl.h
@@ -11,7 +11,7 @@
 /* $OpenLDAP$ */
 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
  *
- * Copyright 2000-2014 The OpenLDAP Foundation.
+ * Copyright 2000-2015 The OpenLDAP Foundation.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -98,9 +98,8 @@ void mdb_midl_free(MDB_IDL ids);
 	/** Shrink an IDL.
 	 * Return the IDL to the default size if it has grown larger.
 	 * @param[in,out] idp	Address of the IDL to shrink.
-	 * @return	0 on no change, non-zero if shrunk.
 	 */
-int mdb_midl_shrink(MDB_IDL *idp);
+void mdb_midl_shrink(MDB_IDL *idp);
 
 	/** Make room for num additional elements in an IDL.
 	 * @param[in,out] idp	Address of the IDL.
diff --git a/liblmdb/mtest.c b/liblmdb/mtest.c
index 79b4175e..9d15088b 100644
--- a/liblmdb/mtest.c
+++ b/liblmdb/mtest.c
@@ -1,6 +1,6 @@
 /* mtest.c - memory-mapped database tester/toy */
 /*
- * Copyright 2011-2014 Howard Chu, Symas Corp.
+ * Copyright 2011-2015 Howard Chu, Symas Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -45,19 +45,22 @@ int main(int argc,char * argv[])
 	    }
     
 		E(mdb_env_create(&env));
+		E(mdb_env_set_maxreaders(env, 1));
 		E(mdb_env_set_mapsize(env, 10485760));
 		E(mdb_env_open(env, "./testdb", MDB_FIXEDMAP /*|MDB_NOSYNC*/, 0664));
+
 		E(mdb_txn_begin(env, NULL, 0, &txn));
-		E(mdb_open(txn, NULL, 0, &dbi));
+		E(mdb_dbi_open(txn, NULL, 0, &dbi));
    
 		key.mv_size = sizeof(int);
 		key.mv_data = sval;
-		data.mv_size = sizeof(sval);
-		data.mv_data = sval;
 
 		printf("Adding %d values\n", count);
 	    for (i=0;i<count;i++) {	
 			sprintf(sval, "%03x %d foo bar", values[i], values[i]);
+			/* Set <data> in each iteration, since MDB_NOOVERWRITE may modify it */
+			data.mv_size = sizeof(sval);
+			data.mv_data = sval;
 			if (RES(MDB_KEYEXIST, mdb_put(txn, dbi, &key, &data, MDB_NOOVERWRITE))) {
 				j++;
 				data.mv_size = sizeof(sval);
@@ -68,7 +71,7 @@ int main(int argc,char * argv[])
 		E(mdb_txn_commit(txn));
 		E(mdb_env_stat(env, &mst));
 
-		E(mdb_txn_begin(env, NULL, 1, &txn));
+		E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
 		E(mdb_cursor_open(txn, dbi, &cursor));
 		while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
 			printf("key: %p %.*s, data: %p %.*s\n",
@@ -97,7 +100,7 @@ int main(int argc,char * argv[])
 		printf("Deleted %d values\n", j);
 
 		E(mdb_env_stat(env, &mst));
-		E(mdb_txn_begin(env, NULL, 1, &txn));
+		E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
 		E(mdb_cursor_open(txn, dbi, &cursor));
 		printf("Cursor next\n");
 		while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
@@ -128,6 +131,7 @@ int main(int argc,char * argv[])
 				(int) key.mv_size,  (char *) key.mv_data,
 				(int) data.mv_size, (char *) data.mv_data);
 
+		mdb_cursor_close(cursor);
 		mdb_txn_abort(txn);
 
 		printf("Deleting with cursor\n");
@@ -164,9 +168,9 @@ int main(int argc,char * argv[])
 				data.mv_data, (int) data.mv_size, (char *) data.mv_data);
 		}
 		mdb_cursor_close(cursor);
-		mdb_close(env, dbi);
-
 		mdb_txn_abort(txn);
+
+		mdb_dbi_close(env, dbi);
 		mdb_env_close(env);
 
 	return 0;
diff --git a/liblmdb/mtest2.c b/liblmdb/mtest2.c
index f1a3dbd6..eacbe59d 100644
--- a/liblmdb/mtest2.c
+++ b/liblmdb/mtest2.c
@@ -1,6 +1,6 @@
 /* mtest2.c - memory-mapped database tester/toy */
 /*
- * Copyright 2011-2014 Howard Chu, Symas Corp.
+ * Copyright 2011-2015 Howard Chu, Symas Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -47,20 +47,22 @@ int main(int argc,char * argv[])
 	}
 
 	E(mdb_env_create(&env));
+	E(mdb_env_set_maxreaders(env, 1));
 	E(mdb_env_set_mapsize(env, 10485760));
 	E(mdb_env_set_maxdbs(env, 4));
 	E(mdb_env_open(env, "./testdb", MDB_FIXEDMAP|MDB_NOSYNC, 0664));
+
 	E(mdb_txn_begin(env, NULL, 0, &txn));
-	E(mdb_open(txn, "id1", MDB_CREATE, &dbi));
+	E(mdb_dbi_open(txn, "id1", MDB_CREATE, &dbi));
    
 	key.mv_size = sizeof(int);
 	key.mv_data = sval;
-	data.mv_size = sizeof(sval);
-	data.mv_data = sval;
 
 	printf("Adding %d values\n", count);
 	for (i=0;i<count;i++) {	
 		sprintf(sval, "%03x %d foo bar", values[i], values[i]);
+		data.mv_size = sizeof(sval);
+		data.mv_data = sval;
 		if (RES(MDB_KEYEXIST, mdb_put(txn, dbi, &key, &data, MDB_NOOVERWRITE)))
 			j++;
 	}
@@ -68,7 +70,7 @@ int main(int argc,char * argv[])
 	E(mdb_txn_commit(txn));
 	E(mdb_env_stat(env, &mst));
 
-	E(mdb_txn_begin(env, NULL, 1, &txn));
+	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
 	E(mdb_cursor_open(txn, dbi, &cursor));
 	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
 		printf("key: %p %.*s, data: %p %.*s\n",
@@ -97,7 +99,7 @@ int main(int argc,char * argv[])
 	printf("Deleted %d values\n", j);
 
 	E(mdb_env_stat(env, &mst));
-	E(mdb_txn_begin(env, NULL, 1, &txn));
+	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
 	E(mdb_cursor_open(txn, dbi, &cursor));
 	printf("Cursor next\n");
 	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
@@ -114,10 +116,9 @@ int main(int argc,char * argv[])
 	}
 	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
 	mdb_cursor_close(cursor);
-	mdb_close(env, dbi);
-
 	mdb_txn_abort(txn);
-	mdb_env_close(env);
 
+	mdb_dbi_close(env, dbi);
+	mdb_env_close(env);
 	return 0;
 }
diff --git a/liblmdb/mtest3.c b/liblmdb/mtest3.c
index f705c52d..9db79e62 100644
--- a/liblmdb/mtest3.c
+++ b/liblmdb/mtest3.c
@@ -1,6 +1,6 @@
 /* mtest3.c - memory-mapped database tester/toy */
 /*
- * Copyright 2011-2014 Howard Chu, Symas Corp.
+ * Copyright 2011-2015 Howard Chu, Symas Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -53,8 +53,9 @@ int main(int argc,char * argv[])
 	E(mdb_env_set_mapsize(env, 10485760));
 	E(mdb_env_set_maxdbs(env, 4));
 	E(mdb_env_open(env, "./testdb", MDB_FIXEDMAP|MDB_NOSYNC, 0664));
+
 	E(mdb_txn_begin(env, NULL, 0, &txn));
-	E(mdb_open(txn, "id2", MDB_CREATE|MDB_DUPSORT, &dbi));
+	E(mdb_dbi_open(txn, "id2", MDB_CREATE|MDB_DUPSORT, &dbi));
 
 	key.mv_size = sizeof(int);
 	key.mv_data = kval;
@@ -73,7 +74,7 @@ int main(int argc,char * argv[])
 	E(mdb_txn_commit(txn));
 	E(mdb_env_stat(env, &mst));
 
-	E(mdb_txn_begin(env, NULL, 1, &txn));
+	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
 	E(mdb_cursor_open(txn, dbi, &cursor));
 	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
 		printf("key: %p %.*s, data: %p %.*s\n",
@@ -107,7 +108,7 @@ int main(int argc,char * argv[])
 	printf("Deleted %d values\n", j);
 
 	E(mdb_env_stat(env, &mst));
-	E(mdb_txn_begin(env, NULL, 1, &txn));
+	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
 	E(mdb_cursor_open(txn, dbi, &cursor));
 	printf("Cursor next\n");
 	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
@@ -124,10 +125,9 @@ int main(int argc,char * argv[])
 	}
 	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
 	mdb_cursor_close(cursor);
-	mdb_close(env, dbi);
-
 	mdb_txn_abort(txn);
-	mdb_env_close(env);
 
+	mdb_dbi_close(env, dbi);
+	mdb_env_close(env);
 	return 0;
 }
diff --git a/liblmdb/mtest4.c b/liblmdb/mtest4.c
index da5a9530..6df890e2 100644
--- a/liblmdb/mtest4.c
+++ b/liblmdb/mtest4.c
@@ -1,6 +1,6 @@
 /* mtest4.c - memory-mapped database tester/toy */
 /*
- * Copyright 2011-2014 Howard Chu, Symas Corp.
+ * Copyright 2011-2015 Howard Chu, Symas Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -51,8 +51,9 @@ int main(int argc,char * argv[])
 	E(mdb_env_set_mapsize(env, 10485760));
 	E(mdb_env_set_maxdbs(env, 4));
 	E(mdb_env_open(env, "./testdb", MDB_FIXEDMAP|MDB_NOSYNC, 0664));
+
 	E(mdb_txn_begin(env, NULL, 0, &txn));
-	E(mdb_open(txn, "id4", MDB_CREATE|MDB_DUPSORT|MDB_DUPFIXED, &dbi));
+	E(mdb_dbi_open(txn, "id4", MDB_CREATE|MDB_DUPSORT|MDB_DUPFIXED, &dbi));
 
 	key.mv_size = sizeof(int);
 	key.mv_data = kval;
@@ -72,7 +73,7 @@ int main(int argc,char * argv[])
 
 	/* there should be one full page of dups now.
 	 */
-	E(mdb_txn_begin(env, NULL, 1, &txn));
+	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
 	E(mdb_cursor_open(txn, dbi, &cursor));
 	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
 		printf("key: %p %.*s, data: %p %.*s\n",
@@ -142,7 +143,7 @@ int main(int argc,char * argv[])
 	printf("Deleted %d values\n", j);
 
 	E(mdb_env_stat(env, &mst));
-	E(mdb_txn_begin(env, NULL, 1, &txn));
+	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
 	E(mdb_cursor_open(txn, dbi, &cursor));
 	printf("Cursor next\n");
 	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
@@ -159,10 +160,9 @@ int main(int argc,char * argv[])
 	}
 	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
 	mdb_cursor_close(cursor);
-	mdb_close(env, dbi);
-
 	mdb_txn_abort(txn);
-	mdb_env_close(env);
 
+	mdb_dbi_close(env, dbi);
+	mdb_env_close(env);
 	return 0;
 }
diff --git a/liblmdb/mtest5.c b/liblmdb/mtest5.c
index 39a8c728..14e3c0da 100644
--- a/liblmdb/mtest5.c
+++ b/liblmdb/mtest5.c
@@ -1,6 +1,6 @@
 /* mtest5.c - memory-mapped database tester/toy */
 /*
- * Copyright 2011-2014 Howard Chu, Symas Corp.
+ * Copyright 2011-2015 Howard Chu, Symas Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -53,8 +53,9 @@ int main(int argc,char * argv[])
 	E(mdb_env_set_mapsize(env, 10485760));
 	E(mdb_env_set_maxdbs(env, 4));
 	E(mdb_env_open(env, "./testdb", MDB_FIXEDMAP|MDB_NOSYNC, 0664));
+
 	E(mdb_txn_begin(env, NULL, 0, &txn));
-	E(mdb_open(txn, "id2", MDB_CREATE|MDB_DUPSORT, &dbi));
+	E(mdb_dbi_open(txn, "id2", MDB_CREATE|MDB_DUPSORT, &dbi));
 	E(mdb_cursor_open(txn, dbi, &cursor));
 
 	key.mv_size = sizeof(int);
@@ -75,7 +76,7 @@ int main(int argc,char * argv[])
 	E(mdb_txn_commit(txn));
 	E(mdb_env_stat(env, &mst));
 
-	E(mdb_txn_begin(env, NULL, 1, &txn));
+	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
 	E(mdb_cursor_open(txn, dbi, &cursor));
 	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
 		printf("key: %p %.*s, data: %p %.*s\n",
@@ -109,7 +110,7 @@ int main(int argc,char * argv[])
 	printf("Deleted %d values\n", j);
 
 	E(mdb_env_stat(env, &mst));
-	E(mdb_txn_begin(env, NULL, 1, &txn));
+	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
 	E(mdb_cursor_open(txn, dbi, &cursor));
 	printf("Cursor next\n");
 	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
@@ -126,10 +127,9 @@ int main(int argc,char * argv[])
 	}
 	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
 	mdb_cursor_close(cursor);
-	mdb_close(env, dbi);
-
 	mdb_txn_abort(txn);
-	mdb_env_close(env);
 
+	mdb_dbi_close(env, dbi);
+	mdb_env_close(env);
 	return 0;
 }
diff --git a/liblmdb/mtest6.c b/liblmdb/mtest6.c
index 07d57589..ae3c7f26 100644
--- a/liblmdb/mtest6.c
+++ b/liblmdb/mtest6.c
@@ -1,6 +1,6 @@
 /* mtest6.c - memory-mapped database tester/toy */
 /*
- * Copyright 2011-2014 Howard Chu, Symas Corp.
+ * Copyright 2011-2015 Howard Chu, Symas Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,7 +31,7 @@ int main(int argc,char * argv[])
 	int i = 0, j = 0, rc;
 	MDB_env *env;
 	MDB_dbi dbi;
-	MDB_val key, data;
+	MDB_val key, data, sdata;
 	MDB_txn *txn;
 	MDB_stat mst;
 	MDB_cursor *cursor;
@@ -46,33 +46,37 @@ int main(int argc,char * argv[])
 	E(mdb_env_set_mapsize(env, 10485760));
 	E(mdb_env_set_maxdbs(env, 4));
 	E(mdb_env_open(env, "./testdb", MDB_FIXEDMAP|MDB_NOSYNC, 0664));
+
 	E(mdb_txn_begin(env, NULL, 0, &txn));
-	E(mdb_open(txn, "id6", MDB_CREATE|MDB_INTEGERKEY, &dbi));
+	E(mdb_dbi_open(txn, "id6", MDB_CREATE|MDB_INTEGERKEY, &dbi));
 	E(mdb_cursor_open(txn, dbi, &cursor));
 	E(mdb_stat(txn, dbi, &mst));
 
 	sval = calloc(1, mst.ms_psize / 4);
 	key.mv_size = sizeof(long);
 	key.mv_data = &kval;
-	data.mv_size = mst.ms_psize / 4 - 30;
-	data.mv_data = sval;
+	sdata.mv_size = mst.ms_psize / 4 - 30;
+	sdata.mv_data = sval;
 
 	printf("Adding 12 values, should yield 3 splits\n");
 	for (i=0;i<12;i++) {
 		kval = i*5;
 		sprintf(sval, "%08x", kval);
+		data = sdata;
 		(void)RES(MDB_KEYEXIST, mdb_cursor_put(cursor, &key, &data, MDB_NOOVERWRITE));
 	}
 	printf("Adding 12 more values, should yield 3 splits\n");
 	for (i=0;i<12;i++) {
 		kval = i*5+4;
 		sprintf(sval, "%08x", kval);
+		data = sdata;
 		(void)RES(MDB_KEYEXIST, mdb_cursor_put(cursor, &key, &data, MDB_NOOVERWRITE));
 	}
 	printf("Adding 12 more values, should yield 3 splits\n");
 	for (i=0;i<12;i++) {
 		kval = i*5+1;
 		sprintf(sval, "%08x", kval);
+		data = sdata;
 		(void)RES(MDB_KEYEXIST, mdb_cursor_put(cursor, &key, &data, MDB_NOOVERWRITE));
 	}
 	E(mdb_cursor_get(cursor, &key, &data, MDB_FIRST));
@@ -110,7 +114,7 @@ int main(int argc,char * argv[])
 	printf("Deleted %d values\n", j);
 
 	E(mdb_env_stat(env, &mst));
-	E(mdb_txn_begin(env, NULL, 1, &txn));
+	E(mdb_txn_begin(env, NULL, MDB_RDONLY, &txn));
 	E(mdb_cursor_open(txn, dbi, &cursor));
 	printf("Cursor next\n");
 	while ((rc = mdb_cursor_get(cursor, &key, &data, MDB_NEXT)) == 0) {
@@ -127,9 +131,9 @@ int main(int argc,char * argv[])
 	}
 	CHECK(rc == MDB_NOTFOUND, "mdb_cursor_get");
 	mdb_cursor_close(cursor);
-	mdb_close(env, dbi);
-
 	mdb_txn_abort(txn);
+
+	mdb_dbi_close(env, dbi);
 #endif
 	mdb_env_close(env);
 
diff --git a/liblmdb/sample-bdb.txt b/liblmdb/sample-bdb.txt
index 6a959bd6..563807a2 100644
--- a/liblmdb/sample-bdb.txt
+++ b/liblmdb/sample-bdb.txt
@@ -3,7 +3,7 @@
  * Do a line-by-line comparison of this and sample-mdb.txt
  */
 /*
- * Copyright 2012 Howard Chu, Symas Corp.
+ * Copyright 2012-2015 Howard Chu, Symas Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/liblmdb/sample-mdb.txt b/liblmdb/sample-mdb.txt
index a233ec5d..10a25687 100644
--- a/liblmdb/sample-mdb.txt
+++ b/liblmdb/sample-mdb.txt
@@ -3,7 +3,7 @@
  * Do a line-by-line comparison of this and sample-bdb.txt
  */
 /*
- * Copyright 2012 Howard Chu, Symas Corp.
+ * Copyright 2012-2015 Howard Chu, Symas Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -32,7 +32,7 @@ int main(int argc,char * argv[])
 	rc = mdb_env_create(&env);
 	rc = mdb_env_open(env, "./testdb", 0, 0664);
 	rc = mdb_txn_begin(env, NULL, 0, &txn);
-	rc = mdb_open(txn, NULL, 0, &dbi);
+	rc = mdb_dbi_open(txn, NULL, 0, &dbi);
 
 	key.mv_size = sizeof(int);
 	key.mv_data = sval;
@@ -56,7 +56,7 @@ int main(int argc,char * argv[])
 	mdb_cursor_close(cursor);
 	mdb_txn_abort(txn);
 leave:
-	mdb_close(env, dbi);
+	mdb_dbi_close(env, dbi);
 	mdb_env_close(env);
 	return 0;
 }