CONCURRENCY.LOCK.NESTED : Nested Locks

JavaScript is not currently enabled, but is required for full CodeSonar manual search and browse functionality.

If you are viewing this file in your hub's Web GUI, enable JavaScript in your browser: you will also need it for GUI functionality.

If you opened this file directly from disk, your browser may be directly suppressing JavaScript functionality: certain browsers perform this suppression on local files (but not files delivered by web servers) for security reasons.

If you access the manual through the hub's Web GUI, the functionality will not be suppressed because the hub is a web server.
Alternatively, your browser may allow you to explicitly disable the security setting that suppresses functionality. See the CodeSonar FAQ for more information.

CodeSonar^® 9.2p0

CONFIDENTIAL

CodeSecure Inc

C and C++

CONCURRENCY.LOCK.NESTED : Nested Locks

Summary

A lock is acquired while another lock is held.

Properties

Class Name

Nested Locks

Significance

style

Mnemonic

CONCURRENCY.LOCK.NESTED

Triggering Functions

Nested Locks warnings can be triggered by the following functions.

Any function treated as a lock acquisition function by CodeSonar:
- any library function that is recognized as a lock acquisition function because CodeSonar ships with a library model that identifies it as such, and
- any function for which you have added a library model identifying it as a lock acquisition function.
Any function specified with the LOCK_FUNCTIONS configuration file parameter.

Example

#include <pthread.h>

pthread_mutex_t LockA;
pthread_mutex_t LockB;

void nested_locks(void){
    pthread_mutex_lock(&LockA);
    pthread_mutex_lock(&LockB);    /* 'Nested Locks' warning issued here */
    /* ... operate on locked data */
    pthread_mutex_unlock(&LockB);
    pthread_mutex_unlock(&LockA);
}

Notes

Deadlock cannot occur if no thread ever holds more than one lock at a time.

Relevant Configuration File Parameters

The following configuration file parameters affect checks for this warning class.

To report problems with this documentation, please visit https://support.codesecure.com/.