A spin lock on the test subsystem. The spinlock is used as follows. Before starting a test, a manager-station should make sure that a test is not in progress as follows: try_again: get (upsTestSpinLock) while (upsTestResultsSummary == inProgress) { /* loop while a test is running for another manager */ short delay get (upsTestSpinLock) } lock_value = upsTestSpinLock /* no test in progress, start the test */ set (upsTestSpinLock = lock_value, upsTestId = requested_test) if (error_index == 1) { /* (upsTestSpinLock failed) */ /* if problem is not access control, then some other manager slipped in ahead of us */ goto try_again } if (error_index == 2) { /* (upsTestId) */ /* cannot perform the test */ give up } /* test started ok */ /* wait for test completion by polling upsTestResultsSummary */ get (upsTestSpinLock, upsTestResultsSummary, upsTestResultsDetail) while (upsTestResultsSummary == inProgress) { short delay get (upsTestSpinLock, upsTestResultsSummary, upsTestResultsDetail) } /* when test completes, retrieve any additional test results */ /* if upsTestSpinLock == lock_value + 1, then these are our test */ /* results (as opposed to another manager's */ The initial value of upsTestSpinLock at agent initialization shall be 1.