Return to readme CVS log

Up to [WindowsNT SDKs] / q_a / samples / mutex

Annotation of q_a/samples/mutex/readme, revision 1.1.1.1

1.1       root        1:  Sample: Using Named Mutexes Between Independent Processes
                      2: 
                      3: Summary:
                      4: 
                      5: MUTEX demonstrates using a named mutex between independent
                      6: processes.
                      7: 
                      8: More Information:
                      9: 
                     10: A mutex is often more appropriate to use between processes
                     11: than a semaphore.  A potential drawback to the semaphore is
                     12: that any thread, even a thread not having control of the
                     13: semaphore, can call the ReleaseSemaphore function and change
                     14: it's use count.  Another drawback is that if a thread gains
                     15: control of a semaphore, modifying the semaphore's use count
                     16: denies access to the semaphore by other threads or
                     17: processes; if that thread dies before calling
                     18: ReleaseSemaphore and changing the use count back, no other
                     19: thread or process will be able to gain access to the
                     20: semaphore.  On the other hand, when a thread having control
                     21: of a mutex dies, the use count on the mutex is automatically
                     22: modified to allow other threads and processes access to it.
                     23: 
                     24: To Use:
                     25: 
                     26: Start any number of instances of this application.  Each
                     27: instance will start a thread which will request access to
                     28: the mutex. when the thread has the mutex, it will print a
                     29: message in the application window "I HAVE CONTROL OF THE
                     30: MUTEX!", and then sleep for two seconds.  It will then wake
                     31: up, erase the message, release the mutex; and then sleep for
                     32: another two seconds before asking for control again.  By
                     33: starting several instances, you will see that each instance
                     34: will often have to wait longer than it's two seconds before
                     35: it gets control.
                     36: 
                     37: 
                     38: 

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.