Return to readme1.txt CVS log

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

Annotation of q_a/samples/readwrit/readme1.txt, revision 1.1

1.1     ! root        1: Summary:
        !             2: 
        !             3: This article refers to the file Database.c which is one
        !             4: variation of the classical synchronization problem
        !             5: Reader/Writers. The Reader/Writer problem first stated and
        !             6: solved by Courtois revolves around a shared resource a DataBase
        !             7: typically. The issue here is to allow both readers and writers
        !             8: access to the database without corrupting it. Typically one allows
        !             9: multiple Readers to access the database as long as a Writer is not
        !            10: in there. However when a Writer is in the database no one else is
        !            11: allowed in either Reader or Writer. There are several variations
        !            12: of this problem around the simplest will favor Readers to the
        !            13: exclusion of Writers or visa versa.
        !            14: 
        !            15: The implementation I used I believe was modeled after Dijkstra;
        !            16: however I've long since misplaced my operating systems book so can't
        !            17: verify it. His method would allow as many readers in the database
        !            18: at one time until a Writer wished entrance in. Then no other Reader
        !            19: can enter the database until this Writer is finished. All Readers
        !            20: currently in the database however can finish. This way no starvation
        !            21: of either the Readers or Writers which is inherent in the simpler
        !            22: methods will happen.
        !            23: 
        !            24: More Information: 
        !            25: 
        !            26: In order to keep this sample focused, I've left the user interface
        !            27: simple; to run this sample at the command prompt type
        !            28: 
        !            29:    ReadWrit
        !            30: 
        !            31: What you will see are the values the Readers put on the screen. These
        !            32: are the running total of the threads that wrote to the database.
        !            33: 
        !            34: Enjoy

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