redis/internal/pool/conn_list.go

101 lines
1.7 KiB
Go

package pool
import (
"sync"
"sync/atomic"
)
type connList struct {
cns []*Conn
mx sync.Mutex
len int32 // atomic
size int32
}
func newConnList(size int) *connList {
return &connList{
cns: make([]*Conn, 0, size),
size: int32(size),
}
}
func (l *connList) Len() int {
return int(atomic.LoadInt32(&l.len))
}
// Reserve reserves place in the list and returns true on success. The
// caller must add or remove connection if place was reserved.
func (l *connList) Reserve() bool {
len := atomic.AddInt32(&l.len, 1)
reserved := len <= l.size
if !reserved {
atomic.AddInt32(&l.len, -1)
}
return reserved
}
// Add adds connection to the list. The caller must reserve place first.
func (l *connList) Add(cn *Conn) {
l.mx.Lock()
l.cns = append(l.cns, cn)
l.mx.Unlock()
}
// Remove closes connection and removes it from the list.
func (l *connList) Remove(cn *Conn) error {
defer l.mx.Unlock()
l.mx.Lock()
if cn == nil {
atomic.AddInt32(&l.len, -1)
return nil
}
for i, c := range l.cns {
if c == cn {
l.cns = append(l.cns[:i], l.cns[i+1:]...)
atomic.AddInt32(&l.len, -1)
return cn.Close()
}
}
if l.closed() {
return nil
}
panic("conn not found in the list")
}
func (l *connList) Replace(cn, newcn *Conn) error {
defer l.mx.Unlock()
l.mx.Lock()
for i, c := range l.cns {
if c == cn {
l.cns[i] = newcn
return cn.Close()
}
}
if l.closed() {
return newcn.Close()
}
panic("conn not found in the list")
}
func (l *connList) Close() (retErr error) {
l.mx.Lock()
for _, c := range l.cns {
if err := c.Close(); err != nil {
retErr = err
}
}
l.cns = nil
atomic.StoreInt32(&l.len, 0)
l.mx.Unlock()
return retErr
}
func (l *connList) closed() bool {
return l.cns == nil
}