Long description

The horizontal direction represents time. The image consists of two parts labeled Process "A" and Process B. A straight horizontal line labeled Process "A" has a horizontal rectangular block placed on it nearly at the center. An arrow "A" enters the critical region points to the left end of the block. Another arrow labeled "A" leaves the critical region points to the right end of the block. A straight horizontal line labeled Process B has a horizontal rectangular block placed on it exactly at the point where the rectangular block of Process "A" ends. An arrow labeled B enters the critical region points to the left end of the block. Another arrow labeled B leaves the critical region points to the right end of the block. There are four time intervals labeled T1, T2, T3, and T4 from left to right. The T1 time cycle is marked from where A enters the critical region, enters process B, and exits. The T2 time cycle is marked from where the Process "A" block, attempts to enter process B, and exits. The T3 time cycle is marked from where "A" leaves the critical region, enters process B. The T4 time cycle is marked from process A end of the line enters B where B leaves the critical region. The area between T2 and T3 is labeled B attempts to enter the critical region, line of Process B at this point is a dotted line and marked as B blocked.