lib, tests: fix some b0rked tests, then fix TSAN warnings #16258
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seqlock_bump() used to return the value before bumping, but that's unhelpful if you were to actually need it. I had changed it to return the value after, but the update to the test got lost at some point. The return value is not in fact used anywhere in FRR, so while it is a bug, it has zero impact. NB: yes, test_seqlock is not run, which sounds wrong. The problem here is that (a) the test itself uses sleeps and is timing sensitive, which would raise false positives. And (b), the test is meaningless if executed once. It needs to be run millions of times under various conditions (e.g. load) to catch rare races, and it needs to be run on machines with "odd" memory models (in this case I used BE ppc32 and ppc64 systems as test platforms.) Fixes: 6046b69 ("lib/seqlock: avoid syscalls in no-waiter cases") Signed-off-by: David Lamparter <[email protected]>
I lost an underscore somewhere along the way. Which never caused issues because we don't use that function macro. It is, however, useful for testing, so fix it. Signed-off-by: David Lamparter <[email protected]>
TSAN warns about leaving the second thread dangling. Doesn't really matter, but just add a pthread_join to get rid of the warning. Signed-off-by: David Lamparter <[email protected]>
TSAN doesn't understand the OS specific "fast" seqlock code. Use the pthread mutex/condvar based path when TSAN is enabled. Signed-off-by: David Lamparter <[email protected]>
The atomlist test consists of a sequence of (MT) sub-tests, from which counters are collected and verified. TSAN doesn't know that these counters are synchronized by way of the sub-test starting and finishing, so it complains. Just use atomics to get rid of the warning. (This is solely an issue with the test, not the atomlist code. There are no warnings from that.) Signed-off-by: David Lamparter <[email protected]>
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First go around and fix a bunch of mixups in test_seqlock, then make TSAN understand that the world is not on fire.
Fixes: #16244 (hopefully)