func (self *logRetainer) logsQueue(category string, createIfAbsent bool) *queue.Queue {
isReadLocked := true
self.lock.RLock()
defer func() {
if isReadLocked {
self.lock.RUnlock()
}
}()
q, found := self.logsByCategory[category]
if !found && createIfAbsent {
q = queue.New(self.queueCapacity, nil)
// escalate to write lock and add q to logsByCategory
self.lock.RUnlock()
isReadLocked = false
self.lock.Lock()
defer self.lock.Unlock()
// check again as we lost all locks briefly
q2, found := self.logsByCategory[category]
if found {
q = q2
} else {
self.logsByCategory[category] = q
}
}
// Warning if you are adding new code here. We may have either a
// read lock or a write lock at this point.
return q
}
func New(capacity int) *QueuedSet {
qs := &QueuedSet{}
qs.q = queue.New(capacity, qs.delete)
qs.set = make(map[interface{}]int)
return qs
}