c26130.md

description	title	ms.date	f1_keywords	helpviewer_keywords	ms.assetid
Learn more about: Warning C26130	Warning C26130	11/04/2016	C26130	C26130	535e2356-bc84-4549-983d-7d29aee2249c

Warning C26130

Missing annotation _Requires_lock_held_('lock') or _No_competing_thread_ at function 'func'. Otherwise it could be a race condition. Variable 'var' should be protected by lock 'lock'.

Warning C26130 is issued when the analyzer detects a potential race condition but infers that the function is likely to be run in a single threaded mode. For example, when the function is in the initialization stage, based on certain heuristics.

Examples

In the following example, warning C26130 is generated because a _Guarded_by_ member is being modified without a lock.

typedef struct _DATA
{
    CRITICAL_SECTION cs;
    _Guarded_by_(cs) int data;
} DATA;

void Init(DATA* p)
{
    p->data = 0; // Warning C26130
}

If the previous code is guaranteed to operate in single-threaded mode, annotate the function by using _No_competing_thread_, as shown in the following example.

typedef struct _DATA
{
    CRITICAL_SECTION cs;
    _Guarded_by_(cs) int data;
} DATA;

_No_competing_thread_ void Init(DATA* p)
{
    p->data = 0; // Warning C26130 will be resolved
}

Alternatively, you can annotate a code fragment by using _No_competing_thread_begin_ and _No_competing_thread_end_, as follows.

typedef struct _DATA
{
    CRITICAL_SECTION cs;
    _Guarded_by_(cs) int data;
} DATA;

void Init(DATA* p)
{
    _No_competing_thread_begin_
    p->data = 0; // Warning C26130 will be resolved
    _No_competing_thread_end_
}