Background ledger acquisition reads and writes SHAMap::state_, SHAMap::full_, SHAMap::ledgerSeq_ and
SHAMapInnerNode::fullBelowGen_ concurrently with the thread driving it, so all four are std::atomic.
state_ is read through state() and written through setInvalid() and the existing setters, and
SHAMapState carries an explicit std::uint8_t underlying type. finishFetch() withdraws full_ with an
exchange behind a relaxed load, so exactly one of the reader threads that miss reports the gap, and a
map that is already not full stays off the exclusive-write path: full_ shares a cache line with
state_ and ledgerSeq_, and a walk posts up to 512 reads per pass. ledgerSeq_ is read through
ledgerSeq() and relaxed both ways, since it only serves as a lookup hint for a nodestore keyed by
hash.
Ledger::setFull() sets each map's ledger sequence before its full flag. A release store publishes
only what is sequenced before it, and the finishFetch() thread that wins the exchange on the flag
reads the sequence after that, so this is the order that makes the sequence visible to the once-only
gap report.
Static assertions pin the three SHAMap members lock-free, and pin fullBelowGen_'s size and alignment
to those of a plain std::uint32_t, so SHAMapInnerNode's packed layout stays byte-identical and
isFullBelow() takes no mutex once per node of every walk. Its accessors are relaxed, since a
generation is only ever compared for equality and the children it vouches for are published through
the node's own child lock. Three tests cover this: sixteen unresolvable branches posted at a backed
map with four nodestore reader threads, so finishFetch() runs concurrently for one map and the single
gap report is observable; that Ledger::setFull() publishes the sequence that report names; and that
every node the sync path hands to a filter carries it.
SHAMapAddNode gains getBad() and getDuplicate() beside getGood(), so a verdict can be read as
counts. Every accessor, mutator and factory is documented, and reset(), get() and operator+= move
after the static factories, so the counters and the ways to read or combine them stay grouped. get()
is a log format, and src/tests/libxrpl/shamap/SHAMapAddNode.cpp is the one place that depends on its
wording: it pins that format, the counts the three accessors report, and the way one tally
accumulates into another.
* upstream/release/3.3.x: (41 commits)
chore: Bump version to 3.3.0
chore: Bump version to 3.3.0-rc7
fix: Increase manifest protocol message size cap and fix manifests relay
fix: Cap untrusted manifests per message and drop oversized ones
chore: Bump version to 3.2.1
chore: Bump version to 3.2.1-rc1
fix: Cap untrusted manifests per message and drop oversized ones
fix: Reject oversized validator manifest before decoding
fix: Reduce untrusted manifest cache cap to 100
fix: Bound untrusted manifest cache
chore: Bump version to 3.3.0-rc6
feat: Package validator-keys inside rippled
chore: Bump version to 3.3.0-rc5
fix: Switch SponsorshipSet to use a delta for sfFeeAmount
fix: Re-revert "fix: Set request size limits and differential pricing for get-object-by-hash calls"
chore: Bump version to 3.3.0-rc4
fix: Revert "fix: Set request size limits and differential pricing for get-object-by-hash calls"
chore: Bump version to 3.3.0-rc3
fix: Reduce untrusted manifest cache cap to 100
fix: Revert "fix: Reject oversized SHAMap nodes in gotStaleData and fetch-pack path"
...
