CONCURRENCY.STARVE.BLOCKING : Blocking in Critical

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CONCURRENCY.STARVE.BLOCKING : Blocking in Critical Section

A blocking function is called while a lock is held.

Class Name

Blocking in Critical Section

Significance

reliability

Mnemonic

CONCURRENCY.STARVE.BLOCKING

Categories

CWE	CWE:662	Improper Synchronization
CERT-C	CERT-C:CON05-C	Do not perform operations that can block while holding a lock
	CERT-C:POS52-C	Do not perform operations that can block while holding a POSIX lock

Availability

Available for C and C++.

Enabling

Checks for this warning class are enabled by default. To disable them, add the following WARNING_FILTER rule to the project configuration file.

WARNING_FILTER += discard class="Blocking in Critical Section"

The code calls a blocking function while holding one or more locks, where:

a blocking function	Any function treated as a blocking function by CodeSonar: any library function that is recognized as a blocking 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 blocking function.
a thread holds lock L	if it has acquired L with one of the following, but not yet released it. 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,

a blocking function

Any function treated as a blocking function by CodeSonar:

any library function that is recognized as a blocking 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 blocking function.

a thread holds lock L

if it has acquired L with one of the following, but not yet released it.

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,

#include <pthread.h>
#include <unistd.h>
#include <stdlib.h>

void concurrency_starve_blocking(pthread_mutex_t lock){
    sleep(2);                              /* ok: No lock held at this time */
    if( pthread_mutex_lock(&lock) != 0 ){
        abort();
    }
    sleep(3);               /* 'Blocking in Critical Section' warning issued here
                             * - a lock is held while the thread blocks.
                             */
    if( pthread_mutex_unlock(&lock) != 0 ) abort();
    sleep(4);                              /* ok: No lock held at this time */
}

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

CONCURRENCY.STARVE.BLOCKING : Blocking in Critical Section

Summary

Properties

Triggered When

Example

Relevant Configuration File Parameters