Consistency Semantics for File Sharing

• Determines how modification of data is observable to other users.

• Unix Semantics:

  • Writes to a file by a user are immediately visible to other users that have this file open.
  • Supports a mode of sharing where users share even the current location pointer into the file.

• Session Semantics (Andrew File System):

  • Writes to a file by a user is not visible to other users.
  • Once the file is closed, the changes are visible only to new sessions.

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