---
description: "Learn more about: Warning C26115"
title: Warning C26115
ms.date: 11/04/2016
f1_keywords: ["C26115"]
helpviewer_keywords: ["C26115"]
ms.assetid: 3977a2bb-d1fe-4510-89dd-07fdc69e911c
---
# Warning C26115

> Failing to release lock '*lock*' in function '*func*'.

Enforcement of syntactically scoped lock *acquire* and lock *release* pairs in C/C++ programs isn't performed by the language. A function may introduce a locking side effect by making an observable modification to the concurrency state. For example, a lock wrapper function increments the number of lock acquisitions, or lock count, for a given lock.

You can annotate a function that has a side effect from a lock acquire or lock release by using `_Acquires_lock_` or `_Releases_lock_`, respectively. Without such annotations, a function is expected not to change any lock count after it returns. If acquires and releases aren't balanced, they're considered to be *orphaned*. Warning C26115 is issued when a function introduces an orphaned lock.

## Example

The following example generates warning C26115 because there's an orphaned lock in a function that isn't annotated with `_Acquires_lock_`.

```cpp
typedef struct _DATA
{
    CRITICAL_SECTION cs;
} DATA;

void FailToReleaseLock(int flag, DATA* p)
{
    EnterCriticalSection(&p->cs);

    if (flag)
        return; // Warning C26115

    LeaveCriticalSection(&p->cs);
}
```