39     printf("frontFd=%d\n", frontFd);  in main()
42     printf("rearFd=%d\n", rearFd);  in main()
45     printf("dataFd=%d\n", dataFd);  in main()
51     printf("parent frontIndex=%p\n", frontIndex);  in main()
56     printf("parent rearIndex=%p\n", rearIndex);  in main()
61     printf("parent data=%p\n", data);  in main()
65     printf("page size=%d\n", pageSize);  in main()
69     printf("fork writer:\n");  in main()
78         printf("writer unmap front ok=%d\n", ok);  in main()
80         printf("writer prot read front ok=%d\n", ok);  in main()
85         printf("writer frontIndex=%p\n", frontIndex);  in main()
94             printf("writing %d\n", value);  in main()
97                 printf("wrote unexpected actual = %zd\n", actual);  in main()
132     printf("fork reader:\n");  in main()
141         printf("reader unmap rear ok=%d\n", ok);  in main()
143         printf("reader prot read rear ok=%d\n", ok);  in main()
148         printf("reader rearIndex=%p\n", rearIndex);  in main()
152         printf("reader unmap data ok=%d\n", ok);  in main()
154         printf("reader prot read data ok=%d\n", ok);  in main()
158         printf("reader data=%p\n", data);  in main()
175                 printf("read %d\n", value);  in main()
181                 printf("read timed out\n");  in main()
184                 printf("read unexpected actual = %zd\n", actual);  in main()
200         printf("writer exited with status %d\n", status);  in main()
202         printf("waitpid on writer = %d\n", pid);  in main()
206         printf("reader exited with status %d\n", status);  in main()
208         printf("waitpid on reader = %d\n", pid);  in main()
216     printf("parent unmap front ok=%d\n", ok);  in main()
218     printf("parent unmap rear ok=%d\n", ok);  in main()
220     printf("parent unmap data ok=%d\n", ok);  in main()