Revert "SERVER-35890 refactor User cache into InvalidatingLRUCache and UserHandle"

This reverts commit 78dec3622268ad27bb855eda4c6a4ed345412fd9.

1 files changed, 30 insertions, 7 deletions

diff --git a/src/mongo/db/auth/user.h b/src/mongo/db/auth/user.h
index a22bdca7231..b974a0a3a7c 100644
--- a/src/mongo/db/auth/user.h
+++ b/src/mongo/db/auth/user.h
@@ -101,6 +101,7 @@ public:
     typedef stdx::unordered_map<ResourcePattern, Privilege> ResourcePrivilegeMap;
 
     explicit User(const UserName& name);
+    ~User();
 
     /**
      * Returns the user name for this user.
@@ -161,6 +162,12 @@ public:
      */
     bool isValid() const;
 
+    /**
+     * This returns the reference count for this User.  The AuthorizationManager should be the
+     * only caller of this.
+     */
+    uint32_t getRefCount() const;
+
     // Mutators below.  Mutation functions should *only* be called by the AuthorizationManager
 
     /**
@@ -217,15 +224,30 @@ public:
     }
     void getRestrictions() && = delete;
 
-protected:
-    friend class AuthorizationManagerImpl;
     /**
      * Marks this instance of the User object as invalid, most likely because information about
      * the user has been updated and needs to be reloaded from the AuthorizationManager.
      *
      * This method should *only* be called by the AuthorizationManager.
      */
-    void _invalidate();
+    void invalidate();
+
+    /**
+     * Increments the reference count for this User object, which records how many threads have
+     * a reference to it.
+     *
+     * This method should *only* be called by the AuthorizationManager.
+     */
+    void incrementRefCount();
+
+    /**
+     * Decrements the reference count for this User object, which records how many threads have
+     * a reference to it.  Once the reference count goes to zero, the AuthorizationManager is
+     * allowed to destroy this instance.
+     *
+     * This method should *only* be called by the AuthorizationManager.
+     */
+    void decrementRefCount();
 
 private:
     UserName _name;
@@ -248,10 +270,11 @@ private:
     // Restrictions which must be met by a Client in order to authenticate as this user.
     RestrictionDocuments _restrictions;
 
-    // Indicates whether the user has been marked as invalid by the AuthorizationManager.
-    AtomicBool _isValid{true};
+    // _refCount and _isInvalidated are modified exclusively by the AuthorizationManager
+    // _isInvalidated can be read by any consumer of User, but _refCount can only be
+    // meaningfully read by the AuthorizationManager, as _refCount is guarded by the AM's _lock
+    uint32_t _refCount;
+    AtomicUInt32 _isValid;  // Using as a boolean
 };
 
-using UserHandle = std::shared_ptr<User>;
-
 }  // namespace mongo