Import wiredtiger: 154719f3ff736872f67f2b3e9f4d8b396d2d8adf from branch mongodb-4.4r4.4.0-rc9

ref: bf1d78126c..154719f3ff
for: 4.4.0-rc9

WT-6185       Insert full updates into the history store in some corner cases and add a history store c test
WT-6257       Fix rows out-of-order in history store file
WT-6339       Stop creating snapshots for history store cursors
WT-6396       Fix wrong assert when inserting updates to the history store

1 files changed, 25 insertions, 18 deletions

diff --git a/src/third_party/wiredtiger/src/include/cursor.i b/src/third_party/wiredtiger/src/include/cursor.i
index 362efea63a9..99354198433 100644
--- a/src/third_party/wiredtiger/src/include/cursor.i
+++ b/src/third_party/wiredtiger/src/include/cursor.i
@@ -173,13 +173,9 @@ __cursor_enter(WT_SESSION_IMPL *session)
 static inline void
 __cursor_leave(WT_SESSION_IMPL *session)
 {
-    /*
-     * Decrement the count of active cursors in the session. When that goes to zero, there are no
-     * active cursors, and we can release any snapshot we're holding for read committed isolation.
-     */
+    /* Decrement the count of active cursors in the session. */
     WT_ASSERT(session, session->ncursors > 0);
-    if (--session->ncursors == 0)
-        __wt_txn_read_last(session);
+    --session->ncursors;
 }
 
 /*
@@ -189,20 +185,32 @@ __cursor_leave(WT_SESSION_IMPL *session)
 static inline int
 __cursor_reset(WT_CURSOR_BTREE *cbt)
 {
+    WT_CURSOR *cursor;
     WT_DECL_RET;
     WT_SESSION_IMPL *session;
 
+    cursor = &cbt->iface;
     session = CUR2S(cbt);
 
+#ifdef HAVE_DIAGNOSTIC
+    __wt_cursor_key_order_reset(cbt); /* Clear key-order checks. */
+#endif
     __cursor_pos_clear(cbt);
 
     /* If the cursor was active, deactivate it. */
     if (F_ISSET(cbt, WT_CBT_ACTIVE)) {
-        if (!F_ISSET(cbt, WT_CBT_NO_TXN))
+        if (!F_ISSET(cbt, WT_CBT_NO_TRACKING))
             __cursor_leave(session);
         F_CLR(cbt, WT_CBT_ACTIVE);
     }
 
+    /*
+     * When the count of active cursors in the session goes to zero, there are no active cursors,
+     * and we can release any snapshot we're holding for read committed isolation.
+     */
+    if (session->ncursors == 0 && !F_ISSET(cbt, WT_CBT_NO_TXN))
+        __wt_txn_read_last(session);
+
     /* If we're not holding a cursor reference, we're done. */
     if (cbt->ref == NULL)
         return (0);
@@ -223,12 +231,15 @@ __cursor_reset(WT_CURSOR_BTREE *cbt)
     cbt->page_deleted_count = 0;
 
     /*
-     * Release any page references we're holding. This can trigger eviction (e.g., forced eviction
-     * of big pages), so it's important to do after releasing our snapshot above.
-     *
-     * Clear the reference regardless, so we don't try the release twice.
+     * Release any page references we're holding. This can trigger eviction (for example, forced
+     * eviction of big pages), so it must happen after releasing our snapshot above. Additionally,
+     * there's a debug mode where an application can force the eviction in order to test or stress
+     * the system. Clear the reference so we never try the release twice.
      */
-    ret = __wt_page_release(session, cbt->ref, 0);
+    if (F_ISSET(cursor, WT_CURSTD_DEBUG_RESET_EVICT))
+        WT_TRET_BUSY_OK(__wt_page_release_evict(session, cbt->ref, 0));
+    else
+        ret = __wt_page_release(session, cbt->ref, 0);
     cbt->ref = NULL;
 
     return (ret);
@@ -377,12 +388,8 @@ __cursor_func_init(WT_CURSOR_BTREE *cbt, bool reenter)
 
     session = CUR2S(cbt);
 
-    if (reenter) {
-#ifdef HAVE_DIAGNOSTIC
-        __wt_cursor_key_order_reset(cbt);
-#endif
+    if (reenter)
         WT_RET(__cursor_reset(cbt));
-    }
 
     /*
      * Any old insert position is now invalid. We rely on this being cleared to detect if a new
@@ -395,7 +402,7 @@ __cursor_func_init(WT_CURSOR_BTREE *cbt, bool reenter)
 
     /* Activate the file cursor. */
     if (!F_ISSET(cbt, WT_CBT_ACTIVE)) {
-        if (!F_ISSET(cbt, WT_CBT_NO_TXN))
+        if (!F_ISSET(cbt, WT_CBT_NO_TRACKING))
             WT_RET(__cursor_enter(session));
         F_SET(cbt, WT_CBT_ACTIVE);
     }