* log buffer: wake the interval loop on shutdown instead of sleeping through it
loopInterval parked in time.Sleep(flushInterval) and only re-checked
IsStopping when it woke, so a buffer shut down early kept both loop
goroutines - and the PreviousBufferCount+1 slabs of BufferSize they
reach - alive for up to a full interval afterwards. Select on shutdownCh
against a ticker instead, and give the loops a WaitGroup so a test can
observe that they exit.
* test: release the filers the server tests build
Every helper here left its filer's meta log buffer running, so each test
pinned PreviousBufferCount+1 buffers of BufferSize for the rest of the
run: ~3.5GB of live heap across the package, which overruns the address
space on linux/386 and kills the 32-bit job with an out-of-memory throw.
Thread the test through the helpers so the buffer is shut down on
cleanup, and shut the subscribe harness's filer down outright - its
deletion loop keeps the whole filer reachable otherwise. That harness
quiesces its flush path first, since Filer.Shutdown closes the store a
flush still in flight would write through.
CreateEntry is a FindEntry-then-write with no lock, so concurrent creates to the
same path race: OExcl can admit two creators, and a conditional check-then-act
has no atomicity. Add a per-path exclusive lock (util.LockTable, which evicts
idle keys so it stays bounded) on the FilerServer and take it in CreateEntry, so
the existence check and the write are atomic on this filer.
This is the local serialization point that lets callers route a key's writes to
its owner filer and drop the distributed lock for that key. AppendToEntry keeps
its distributed lock for now; it can move to the per-path lock once its callers
route to the owner.
Chris Lu