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The increment operation and the increment lock

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• The increment operation
  • The increment operation:

    INC(A, c): performs the following steps atomically READ(A, t)     // t is a local variable in the transaction t = t + c WRITE(A, t) Note: c can be negative !!!

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  • Fact:

    Many applications make use of the increment operation: Banking: transfer sum: A = A + c B = B + (-c) Booking: #seats = #seats + (-1)