redis/internal/pool/conn_list.go

85 lines
1.4 KiB
Go

package pool
import (
"sync"
"sync/atomic"
)
type connList struct {
cns []*Conn
mu sync.Mutex
len int32 // atomic
size int32
}
func newConnList(size int) *connList {
return &connList{
cns: make([]*Conn, 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.mu.Lock()
for i, c := range l.cns {
if c == nil {
cn.idx = i
l.cns[i] = cn
l.mu.Unlock()
return
}
}
panic("not reached")
}
// Remove closes connection and removes it from the list.
func (l *connList) Remove(cn *Conn) error {
atomic.AddInt32(&l.len, -1)
if cn == nil { // free reserved place
return nil
}
l.mu.Lock()
if l.cns != nil {
l.cns[cn.idx] = nil
cn.idx = -1
}
l.mu.Unlock()
return nil
}
func (l *connList) Close() error {
var retErr error
l.mu.Lock()
for _, c := range l.cns {
if c == nil {
continue
}
if err := c.Close(); err != nil && retErr == nil {
retErr = err
}
}
l.cns = nil
atomic.StoreInt32(&l.len, 0)
l.mu.Unlock()
return retErr
}