Locking the ‘this’ object in a lock statement¶
ID: cs/lock-this
Kind: problem
Security severity:
Severity: warning
Precision: high
Tags:
- reliability
- maintainability
- modularity
- external/cwe/cwe-662
Query suites:
- csharp-security-and-quality.qls
Click to see the query in the CodeQL repository
It is inadvisable to use this in a lock statement, because other classes could also attempt to lock the object, resulting in inefficiency or deadlock.
Recommendation¶
Create a private readonly Object which is used exclusively for locking. This ensures that no other classes can use the same lock.
Example¶
The following example uses a private readonly variable called mutex to use in the lock statement.
class ThreadSafe
{
private readonly Object mutex = new Object();
int value = 0;
public void Inc()
{
lock (mutex) // Correct
{
++value;
}
}
}
References¶
MSDN, C# Reference: lock Statement.
Common Weakness Enumeration: CWE-662.