Thread: How to generalize this while loop?

I have two blocks of code that I feel can be generalized. I have a reader_acquire_segment function and a writer_acquire_segment function and I feel that the bulk of the code could be generalized to an "acquire_segment" function with different parameters passed in. Here's the relevant code:

Code:

#define SEGMENT_INITIALIZED 1 
#define SEGMENT_READ 2                                                             
#define SEGMENT_WRITTEN 3    

void
reader_acquire_segment(shared_segment_t *seg)                     
{                                                                                                  
    lock_segment(seg);
    int current_status = read_segment_status(seg);                                        
    while ((current_status != SEGMENT_WRITTEN) {                                                
        wait_segment(seg);                                                               
        current_status = read_segment_status(seg);
    }                                                                                              
}  


void                                                                                                                                                                                                        
writer_acquire_segment(shared_segment_t *seg)                                             
{                                                                                                  
    lock_segment(seg);                                                                      
    int current_status = read_segment_status(seg);                                      
    while (current_status == SEGMENT_WRITTEN) {                                            
        wait_segment(seg);                                                              
        current_status = read_segment_status(seg);                            }                                                                                                                                                       
}

I feel like I could just have writer_acquire_segment call a generic acquire_segment with the appropriate parameters, and have reader_acquire_segment also call acquire_segment with the appropriate parameters, but I am little confused how to generalize the while condition. Any suggestions?

Or you could make writer_acquire_segment(seg); call aquire_segment(seg, 1); and reader_acquire_segment(seg); call acquire_segment(seg, 0);

This way all of the similar code is in acquire_segment() and the outside functions don't even have to change their signatures. From a client programmer perspective it is like nothing changed.

> while ((current_status != SEGMENT_WRITTEN)
Well is there a difference between this and say
while ((current_status == SEGMENT_READ)

Because if you can make the loops the same syntactically, apart from the value you test against, then parameterising it is a doddle.