Import wiredtiger: 3818fb14bd816a5fa2b9e8d50b0c2f93a3bfb9ca from branch mongodb-4.4

ref: e0041ca53c..3818fb14bd
for: 4.3.1

WT-5083       Add mips64el support
WT-5118       Remove incorrect assert that there are no hazard references to discarded WT_REF
WT-5134       Fix leaf-page only search and search-near operations
WT-5148       Switch little-endian test to use ubuntu1808 distro
WT-5149       Clear the debugging field value so it cannot get stale
WT-5156       Lookaside table cursors not operating at isolation level WT_ISO_READ_UNCOMMITTED
WT-5160       Stop requiring a checkpoint before calling rollback_to_stable

10 files changed, 65 insertions, 29 deletions

diff --git a/src/third_party/wiredtiger/build_posix/configure.ac.in b/src/third_party/wiredtiger/build_posix/configure.ac.in
index 7c829f86f80..c50d86678e6 100644
--- a/src/third_party/wiredtiger/build_posix/configure.ac.in
+++ b/src/third_party/wiredtiger/build_posix/configure.ac.in
@@ -56,7 +56,7 @@ AS_CASE([$host_cpu],
 	[wt_cv_powerpc="no"])
 AM_CONDITIONAL([POWERPC_HOST], [test "$wt_cv_powerpc" = "yes"])
 AS_CASE([$host_cpu],
-	[amd*|i[[3456]]86*|pentium|x86*], [wt_cv_x86="yes"], [wt_cv_x86="no"])
+	[amd*|i[[3456]]86*|pentium|x86*|mips64el*], [wt_cv_x86="yes"], [wt_cv_x86="no"])
 AM_CONDITIONAL([X86_HOST], [test "$wt_cv_x86" = "yes"])
 AS_CASE([$host_cpu],
 	[s390x*], [wt_cv_zseries="yes"],
@@ -66,6 +66,10 @@ AS_CASE([$host_cpu],
 	[aarch64*], [wt_cv_arm64="yes"],
 	[wt_cv_arm64="no"])
 AM_CONDITIONAL([ARM64_HOST], [test "$wt_cv_arm64" = "yes"])
+AS_CASE([$host_cpu],
+       [mips64el*], [wt_cv_mips64el="yes"],
+       [wt_cv_mips64el="no"])
+AM_CONDITIONAL([MIPS64EL_HOST], [test "$wt_cv_mips64el" = "yes"])
 AS_CASE([$host_os], [*solaris*], [wt_cv_solaris="yes"], [wt_cv_solaris="no"])
 
 # This is a workaround as part of WT-2459. Currently, clang (v3.7) does not
diff --git a/src/third_party/wiredtiger/import.data b/src/third_party/wiredtiger/import.data
index 427cb8cd696..32cdae47322 100644
--- a/src/third_party/wiredtiger/import.data
+++ b/src/third_party/wiredtiger/import.data
@@ -1,5 +1,5 @@
 {
-    "commit": "e0041ca53c1c1a4a23cc7aaa7ef8137dc1c61117", 
+    "commit": "3818fb14bd816a5fa2b9e8d50b0c2f93a3bfb9ca", 
     "github": "wiredtiger/wiredtiger.git", 
     "vendor": "wiredtiger", 
     "branch": "mongodb-4.4"
diff --git a/src/third_party/wiredtiger/src/btree/bt_cursor.c b/src/third_party/wiredtiger/src/btree/bt_cursor.c
index c45d9ed8b6b..bc70a9d389f 100644
--- a/src/third_party/wiredtiger/src/btree/bt_cursor.c
+++ b/src/third_party/wiredtiger/src/btree/bt_cursor.c
@@ -54,7 +54,7 @@ __cursor_state_restore(WT_CURSOR *cursor, WT_CURFILE_STATE *state)
  *     Return if we have a page pinned.
  */
 static inline bool
-__cursor_page_pinned(WT_CURSOR_BTREE *cbt)
+__cursor_page_pinned(WT_CURSOR_BTREE *cbt, bool search_operation)
 {
     WT_CURSOR *cursor;
     WT_SESSION_IMPL *session;
@@ -72,11 +72,25 @@ __cursor_page_pinned(WT_CURSOR_BTREE *cbt)
     }
 
     /*
-     * Check if the key references the page. When returning from search, the page is active and the
-     * key is internal. After the application sets a key, the key is external, and the page is
-     * useless.
+     * Check if the key references an item on a page. When returning from search, the page is pinned
+     * and the key is internal. After the application sets a key, the key becomes external. For the
+     * search and search-near operations, we assume locality and check any pinned page first on each
+     * new search operation. For operations other than search and search-near, check if we have an
+     * internal key. If the page is pinned and we're pointing into the page, we don't need to search
+     * at all, we can proceed with the operation. However, if the key has been set, that is, it's an
+     * external key, we're going to have to do a full search.
      */
-    if (!F_ISSET(cursor, WT_CURSTD_KEY_INT))
+    if (!search_operation && !F_ISSET(cursor, WT_CURSTD_KEY_INT))
+        return (false);
+
+    /*
+     * XXX No fast-path searches at read-committed isolation. Underlying transactional functions
+     * called by the fast and slow path search code handle transaction IDs differently, resulting in
+     * different search results at read-committed isolation. This makes no difference for the update
+     * functions, but in the case of a search, we will see different results based on the cursor's
+     * initial location. See WT-5134 for the details.
+     */
+    if (search_operation && session->txn.isolation == WT_ISO_READ_COMMITTED)
         return (false);
 
     /*
@@ -541,7 +555,7 @@ __wt_btcur_search(WT_CURSOR_BTREE *cbt)
      * pinned page doesn't find an exact match, search from the root.
      */
     valid = false;
-    if (__cursor_page_pinned(cbt)) {
+    if (__cursor_page_pinned(cbt, true)) {
         __wt_txn_cursor_op(session);
 
         WT_ERR(btree->type == BTREE_ROW ? __cursor_row_search(session, cbt, cbt->ref, false) :
@@ -642,7 +656,7 @@ __wt_btcur_search_near(WT_CURSOR_BTREE *cbt, int *exactp)
      * existing record.
      */
     valid = false;
-    if (btree->type == BTREE_ROW && __cursor_page_pinned(cbt)) {
+    if (btree->type == BTREE_ROW && __cursor_page_pinned(cbt, true)) {
         __wt_txn_cursor_op(session);
 
         WT_ERR(__cursor_row_search(session, cbt, cbt->ref, true));
@@ -793,7 +807,7 @@ __wt_btcur_insert(WT_CURSOR_BTREE *cbt)
      * because the cursor may not be positioned to the correct record in the
      * case of implicit records in the append list.
      */
-    if (btree->type != BTREE_COL_FIX && __cursor_page_pinned(cbt) &&
+    if (btree->type != BTREE_COL_FIX && __cursor_page_pinned(cbt, false) &&
       F_ISSET(cursor, WT_CURSTD_OVERWRITE) && !append_key) {
         WT_ERR(__wt_txn_autocommit_check(session));
         /*
@@ -1019,7 +1033,7 @@ __wt_btcur_remove(WT_CURSOR_BTREE *cbt, bool positioned)
      * because the cursor may not be positioned to the correct record in the
      * case of implicit records in the append list.
      */
-    if (btree->type != BTREE_COL_FIX && __cursor_page_pinned(cbt)) {
+    if (btree->type != BTREE_COL_FIX && __cursor_page_pinned(cbt, false)) {
         WT_ERR(__wt_txn_autocommit_check(session));
 
         /*
@@ -1201,7 +1215,7 @@ __btcur_update(WT_CURSOR_BTREE *cbt, WT_ITEM *value, u_int modify_type)
      * because the cursor may not be positioned to the correct record in the
      * case of implicit records in the append list.
      */
-    if (btree->type != BTREE_COL_FIX && __cursor_page_pinned(cbt)) {
+    if (btree->type != BTREE_COL_FIX && __cursor_page_pinned(cbt, false)) {
         WT_ERR(__wt_txn_autocommit_check(session));
 
         /*
diff --git a/src/third_party/wiredtiger/src/btree/bt_split.c b/src/third_party/wiredtiger/src/btree/bt_split.c
index 141eb78d8b4..ee373192a40 100644
--- a/src/third_party/wiredtiger/src/btree/bt_split.c
+++ b/src/third_party/wiredtiger/src/btree/bt_split.c
@@ -837,7 +837,6 @@ __split_parent(WT_SESSION_IMPL *session, WT_REF *ref, WT_REF **ref_new, uint32_t
         /* Free the backing block and address. */
         WT_TRET(__wt_ref_block_free(session, next_ref));
 
-        WT_ASSERT(session, __wt_hazard_check_assert(session, next_ref, false));
         WT_TRET(__split_safe_free(session, split_gen, exclusive, next_ref, sizeof(WT_REF)));
         parent_decr += sizeof(WT_REF);
     }
diff --git a/src/third_party/wiredtiger/src/cache/cache_las.c b/src/third_party/wiredtiger/src/cache/cache_las.c
index aa05724b406..20a8f3df3b6 100644
--- a/src/third_party/wiredtiger/src/cache/cache_las.c
+++ b/src/third_party/wiredtiger/src/cache/cache_las.c
@@ -502,6 +502,7 @@ __las_remove_block(WT_CURSOR *cursor, uint64_t pageid, bool lock_wait, uint64_t
     bool local_txn;
 
     *remove_cntp = 0;
+    saved_isolation = 0; /*[-Wconditional-uninitialized] */
 
     session = (WT_SESSION_IMPL *)cursor->session;
     conn = S2C(session);
@@ -513,8 +514,8 @@ __las_remove_block(WT_CURSOR *cursor, uint64_t pageid, bool lock_wait, uint64_t
     else
         WT_RET(__wt_try_writelock(session, &conn->cache->las_sweepwalk_lock));
 
-    __las_set_isolation(session, &saved_isolation);
     WT_ERR(__wt_txn_begin(session, NULL));
+    __las_set_isolation(session, &saved_isolation);
     local_txn = true;
 
     /*
@@ -539,9 +540,9 @@ err:
             ret = __wt_txn_commit(session, NULL);
         else
             WT_TRET(__wt_txn_rollback(session, NULL));
+        __las_restore_isolation(session, saved_isolation);
     }
 
-    __las_restore_isolation(session, saved_isolation);
     __wt_writeunlock(session, &conn->cache->las_sweepwalk_lock);
     return (ret);
 }
@@ -628,6 +629,7 @@ __wt_las_insert_block(
     session = (WT_SESSION_IMPL *)cursor->session;
     conn = S2C(session);
     WT_CLEAR(las_value);
+    saved_isolation = 0; /*[-Wconditional-uninitialized] */
     insert_cnt = prepared_insert_cnt = 0;
     btree_id = btree->id;
     local_txn = false;
@@ -649,8 +651,8 @@ __wt_las_insert_block(
 #endif
 
     /* Wrap all the updates in a transaction. */
-    __las_set_isolation(session, &saved_isolation);
     WT_ERR(__wt_txn_begin(session, NULL));
+    __las_set_isolation(session, &saved_isolation);
     local_txn = true;
 
     /* Enter each update in the boundary's list into the lookaside store. */
@@ -775,6 +777,7 @@ err:
             ret = __wt_txn_commit(session, NULL);
         else
             WT_TRET(__wt_txn_rollback(session, NULL));
+        __las_restore_isolation(session, saved_isolation);
 
         /* Adjust the entry count. */
         if (ret == 0) {
@@ -784,8 +787,6 @@ err:
         }
     }
 
-    __las_restore_isolation(session, saved_isolation);
-
     if (ret == 0 && insert_cnt > 0) {
         multi->page_las.las_pageid = las_pageid;
         multi->page_las.has_prepares = prepared_insert_cnt > 0;
@@ -1039,6 +1040,7 @@ __wt_las_sweep(WT_SESSION_IMPL *session)
     cache = S2C(session)->cache;
     cursor = NULL;
     sweep_key = &cache->las_sweep_key;
+    saved_isolation = 0; /*[-Wconditional-uninitialized] */
     remove_cnt = 0;
     session_flags = 0; /* [-Werror=maybe-uninitialized] */
     local_txn = locked = removing_key_block = false;
@@ -1058,8 +1060,8 @@ __wt_las_sweep(WT_SESSION_IMPL *session)
      */
     __wt_las_cursor(session, &cursor, &session_flags);
     WT_ASSERT(session, cursor->session == &session->iface);
-    __las_set_isolation(session, &saved_isolation);
     WT_ERR(__wt_txn_begin(session, NULL));
+    __las_set_isolation(session, &saved_isolation);
     local_txn = true;
 
     /* Encourage a race */
@@ -1241,11 +1243,11 @@ err:
             ret = __wt_txn_commit(session, NULL);
         else
             WT_TRET(__wt_txn_rollback(session, NULL));
+        __las_restore_isolation(session, saved_isolation);
         if (ret == 0)
             (void)__wt_atomic_add64(&cache->las_remove_count, remove_cnt);
     }
 
-    __las_restore_isolation(session, saved_isolation);
     WT_TRET(__wt_las_cursor_close(session, &cursor, session_flags));
 
     if (locked)
diff --git a/src/third_party/wiredtiger/src/include/gcc.h b/src/third_party/wiredtiger/src/include/gcc.h
index 052fb35d3a7..184d08c01d6 100644
--- a/src/third_party/wiredtiger/src/include/gcc.h
+++ b/src/third_party/wiredtiger/src/include/gcc.h
@@ -180,6 +180,21 @@ WT_ATOMIC_FUNC(size, size_t, size_t *vp, size_t v)
 #define WT_READ_BARRIER() WT_FULL_BARRIER()
 #define WT_WRITE_BARRIER() WT_FULL_BARRIER()
 
+#elif defined(__mips64el__) || defined(__mips__) || defined(__mips64__) || defined(__mips64)
+#define WT_PAUSE() __asm__ volatile("pause\n" ::: "memory")
+#define WT_FULL_BARRIER()                                                                  \
+    do {                                                                                   \
+        __asm__ volatile("sync; ld $0, %0" ::"m"(*(long *)0xffffffff80000000) : "memory"); \
+    } while (0)
+#define WT_READ_BARRIER()                                                                  \
+    do {                                                                                   \
+        __asm__ volatile("sync; ld $0, %0" ::"m"(*(long *)0xffffffff80000000) : "memory"); \
+    } while (0)
+#define WT_WRITE_BARRIER()                                                                 \
+    do {                                                                                   \
+        __asm__ volatile("sync; ld $0, %0" ::"m"(*(long *)0xffffffff80000000) : "memory"); \
+    } while (0)
+
 #elif defined(__PPC64__) || defined(PPC64)
 /* ori 0,0,0 is the PPC64 noop instruction */
 #define WT_PAUSE() __asm__ volatile("ori 0,0,0" ::: "memory")
diff --git a/src/third_party/wiredtiger/src/include/time.i b/src/third_party/wiredtiger/src/include/time.i
index bad2f0417ad..0dd6781216e 100644
--- a/src/third_party/wiredtiger/src/include/time.i
+++ b/src/third_party/wiredtiger/src/include/time.i
@@ -161,6 +161,14 @@ static inline void
 __wt_op_timer_start(WT_SESSION_IMPL *session)
 {
     session->operation_start_us = session->operation_timeout_us == 0 ? 0 : __wt_clock(session);
+#ifdef HAVE_DIAGNOSTIC
+    /*
+     * This is called at the beginning of each API call. We need to clear out any old values from
+     * this debugging field so that we don't leave a stale value in there that may then give a false
+     * positive.
+     */
+    session->op_5043_seconds = 0;
+#endif
 }
 
 /*
diff --git a/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c b/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c
index 0b2ec12a47a..7b6463f6f2e 100644
--- a/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c
+++ b/src/third_party/wiredtiger/src/txn/txn_rollback_to_stable.c
@@ -432,9 +432,8 @@ __txn_rollback_to_stable_check(WT_SESSION_IMPL *session)
     conn = S2C(session);
     txn_global = &conn->txn_global;
 
-    if (!txn_global->has_stable_timestamp || txn_global->last_ckpt_timestamp == WT_TS_NONE)
-        WT_RET_MSG(
-          session, EINVAL, "rollback_to_stable requires a checkpoint with a stable timestamp");
+    if (!txn_global->has_stable_timestamp)
+        WT_RET_MSG(session, EINVAL, "rollback_to_stable requires a stable timestamp");
 
     /*
      * Help the user comply with the requirement that there are no concurrent operations. Protect
diff --git a/src/third_party/wiredtiger/test/evergreen.yml b/src/third_party/wiredtiger/test/evergreen.yml
index c6131ac0e77..578bddc84b7 100755
--- a/src/third_party/wiredtiger/test/evergreen.yml
+++ b/src/third_party/wiredtiger/test/evergreen.yml
@@ -1320,7 +1320,7 @@ buildvariants:
 - name: little-endian
   display_name: Little-endian (x86)
   run_on:
-  - ubuntu1404-test
+  - ubuntu1804-test
   batchtime: 10080 # 7 days
   expansions:
     smp_command: -j $(grep -c ^processor /proc/cpuinfo)
diff --git a/src/third_party/wiredtiger/test/suite/test_txn20.py b/src/third_party/wiredtiger/test/suite/test_txn20.py
index 381435ff472..f824d85ff45 100644
--- a/src/third_party/wiredtiger/test/suite/test_txn20.py
+++ b/src/third_party/wiredtiger/test/suite/test_txn20.py
@@ -83,10 +83,5 @@ class test_txn20(wttest.WiredTigerTestCase):
             # 'read-uncommitted' will still see the new value.
             self.assertEqual(cursor[self.key], self.new_value)
 
-        # Cleanup.
-        self.session.close()
-        s.rollback_transaction()
-        s.close()
-
 if __name__ == '__main__':
     wttest.run()