PPT Slide
Figure 7.2 & table on page 234 demonstrate how the ordering of the read() and write() events between the users can potentially cause the loss of one of the user’s editing sessions.
This is called the mutual exclusion problem - either one of the two can edit, but not both at the same time (think of Exclusive OR Boolean operator).
Critical section - sequence of actions that must be done one at a time.
Serially reusable resource - a resource that can only be used by one process as a time.