1 files changed, 15 insertions, 9 deletions
diff --git a/src/mongo/db/storage/recovery_unit.h b/src/mongo/db/storage/recovery_unit.h
index a67d1f090f5..04101ad66dc 100644
--- a/src/mongo/db/storage/recovery_unit.h
+++ b/src/mongo/db/storage/recovery_unit.h
@@ -129,9 +129,12 @@ public:
      * Marks the beginning of a unit of work. Each call must be matched with exactly one call to
      * either commitUnitOfWork or abortUnitOfWork.
      *
+     * When called with readOnly=true, no unit of work is started. Calling commitUnitOfWork or
+     * abortUnitOfWork will invariant.
+     *
      * Should be called through WriteUnitOfWork rather than directly.
      */
-    virtual void beginUnitOfWork(OperationContext* opCtx) = 0;
+    void beginUnitOfWork(bool readOnly);
 
     /**
      * Marks the end of a unit of work and commits all changes registered by calls to onCommit or
@@ -139,10 +142,7 @@ public:
      *
      * Should be called through WriteUnitOfWork rather than directly.
      */
-    void commitUnitOfWork() {
-        doCommitUnitOfWork();
-        assignNextSnapshotId();
-    }
+    void commitUnitOfWork();
 
     /**
      * Marks the end of a unit of work and rolls back all changes registered by calls to onRollback
@@ -151,10 +151,14 @@ public:
      *
      * Should be called through WriteUnitOfWork rather than directly.
      */
-    void abortUnitOfWork() {
-        doAbortUnitOfWork();
-        assignNextSnapshotId();
-    }
+    void abortUnitOfWork();
+
+    /**
+     * Cleans up any state set for this unit of work.
+     *
+     * Should be called through WriteUnitOfWork rather than directly.
+     */
+    void endReadOnlyUnitOfWork();
 
     /**
      * Transitions the active unit of work to the "prepared" state. Must be called after
@@ -803,6 +807,7 @@ private:
     // Sets the snapshot associated with this RecoveryUnit to a new globally unique id number.
     void assignNextSnapshotId();
 
+    virtual void doBeginUnitOfWork() = 0;
     virtual void doAbandonSnapshot() = 0;
     virtual void doCommitUnitOfWork() = 0;
     virtual void doAbortUnitOfWork() = 0;
@@ -816,6 +821,7 @@ private:
     std::unique_ptr<Change> _changeForCatalogVisibility;
     State _state = State::kInactive;
     uint64_t _mySnapshotId;
+    bool _readOnly = false;
 };
 
 /**