void ClientCursor::invalidate(const StringData& ns) {
Lock::assertWriteLocked(ns);
size_t dot = ns.find( '.' );
verify( dot != string::npos );
// first (and only) dot is the last char
bool isDB = dot == ns.size() - 1;
Database *db = cc().database();
verify(db);
verify(ns.startsWith(db->name()));
recursive_scoped_lock cclock(ccmutex);
// Look at all active non-cached Runners. These are the runners that are in auto-yield mode
// that are not attached to the the client cursor. For example, all internal runners don't
// need to be cached -- there will be no getMore.
for (set<Runner*>::iterator it = nonCachedRunners.begin(); it != nonCachedRunners.end();
++it) {
Runner* runner = *it;
const string& runnerNS = runner->ns();
if ( ( isDB && StringData(runnerNS).startsWith(ns) ) || ns == runnerNS ) {
runner->kill();
}
}
// Look at all cached ClientCursor(s). The CC may have a Runner, a Cursor, or nothing (see
// sharding_block.h).
CCById::const_iterator it = clientCursorsById.begin();
while (it != clientCursorsById.end()) {
ClientCursor* cc = it->second;
// We're only interested in cursors over one db.
if (cc->_db != db) {
++it;
continue;
}
// Note that a valid ClientCursor state is "no cursor no runner." This is because
// the set of active cursor IDs in ClientCursor is used as representation of query
// state. See sharding_block.h. TODO(greg,hk): Move this out.
if (NULL == cc->c() && NULL == cc->_runner.get()) {
++it;
continue;
}
bool shouldDelete = false;
// We will only delete CCs with runners that are not actively in use. The runners that
// are actively in use are instead kill()-ed.
if (NULL != cc->_runner.get()) {
verify(NULL == cc->c());
if (isDB || cc->_runner->ns() == ns) {
// If there is a pinValue >= 100, somebody is actively using the CC and we do
// not delete it. Instead we notify the holder that we killed it. The holder
// will then delete the CC.
if (cc->_pinValue >= 100) {
cc->_runner->kill();
}
else {
// pinvalue is <100, so there is nobody actively holding the CC. We can
// safely delete it as nobody is holding the CC.
shouldDelete = true;
}
}
}
// Begin cursor-only DEPRECATED
else if (cc->c()->shouldDestroyOnNSDeletion()) {
verify(NULL == cc->_runner.get());
if (isDB) {
// already checked that db matched above
dassert( StringData(cc->_ns).startsWith( ns ) );
shouldDelete = true;
}
else {
if ( ns == cc->_ns ) {
shouldDelete = true;
}
}
}
// End cursor-only DEPRECATED
if (shouldDelete) {
ClientCursor* toDelete = it->second;
CursorId id = toDelete->cursorid();
delete toDelete;
// We're not following the usual paradigm of saving it, ++it, and deleting the saved
// 'it' because deleting 'it' might invalidate the next thing in clientCursorsById.
// TODO: Why?
it = clientCursorsById.upper_bound(id);
}
else {
++it;
}
}
}
