From 447f552756c4e388aca2789ffe56043f4c412fd2 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@openldap.org>
Date: Sat, 31 Oct 2015 02:11:47 +0000
Subject: [PATCH] Add MDB_NO_ROBUST to disable Robust Mutexes

---
 libraries/liblmdb/Makefile |  1 +
 libraries/liblmdb/mdb.c    | 20 +++++++++++++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/libraries/liblmdb/Makefile b/libraries/liblmdb/Makefile
index 62b52a9..afd0cd8 100644
--- a/libraries/liblmdb/Makefile
+++ b/libraries/liblmdb/Makefile
@@ -13,6 +13,7 @@
 # - MDB_FDATASYNC
 # - MDB_FDATASYNC_WORKS
 # - MDB_USE_PWRITEV
+# - MDB_NO_ROBUST
 #
 # There may be other macros in mdb.c of interest. You should
 # read mdb.c before changing any of them.
diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 7a21b50..ac3ec2b 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -238,7 +238,25 @@ typedef SSIZE_T	ssize_t;
 #define MDB_OWNERDEAD	EOWNERDEAD	/**< #LOCK_MUTEX0() result if dead owner */
 #endif
 
-#ifdef MDB_OWNERDEAD
+/* Android currently lacks Robust Mutex support */
+#if defined(ANDROID) && defined(MDB_USE_POSIX_MUTEX)
+#define MDB_NO_ROBUST	1
+#endif
+
+/** Some platforms define the EOWNERDEAD error code
+ * even though they don't support Robust Mutexes.
+ * Compile with -DMDB_NO_ROBUST, or use some other
+ * mechanism like -DMDB_USE_SYSV_SEM instead of
+ * -DMDB_USE_POSIX_MUTEX. (SysV semaphores are
+ * also Robust, but some systems don't support them
+ * either.)
+ */
+
+#ifndef MDB_NO_ROBUST
+#define MDB_NO_ROBUST	0
+#endif
+
+#if defined(MDB_OWNERDEAD) && !(MDB_NO_ROBUST)
 #define MDB_ROBUST_SUPPORTED	1
 #endif