OS/161 Reference Manual


usemtest - test semfs (sem:) semaphores




usemtest forks some subprocesses and uses the semfs semaphores to do coordinated printing. It is somewhat similar to the sy1 in-kernel test for the in-kernel semaphores.

The first parts of the test open each semaphore separately in each process, so locking issues in the filetable and open-file code should not keep it from running. The last part opens the semaphores once and inherits the file descriptors through fork; it is likely to hang (including sometimes in fork) if the filetable and open-file locking is not just so.


usemtest uses the following system calls:

usemtest should run successfully once the basic system calls are complete. Until you implement the remove() system call the semaphores from the test will be left lying around afterwards, but this should not keep it from running.