Question

I am writing a C UNIX program that is threaded and shares one variable across all threads. What would be the easiest way to acquire a lock on this variable? I can’t find any small libraries just for locking in UNIX.

Any suggestions how to do this?

Thanks, Boda Cydo.

Answer 1

There’s pthread_mutex_lock, if you’re already using pthreads.

Quick example, where counter is the shared variable and mutex is a mutex variable of type pthread_mutex_t:

/* Function C */
void functionC()
{
   pthread_mutex_lock( &mutex );
   counter++;
   pthread_mutex_unlock( &mutex );
}