github.com/lirm/aeron-go@v0.0.0-20230415210743-920325491dc4/aeron/imagelist.go (about) 1 /* 2 Copyright 2016 Stanislav Liberman 3 4 Licensed under the Apache License, Version 2.0 (the "License"); 5 you may not use this file except in compliance with the License. 6 You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10 Unless required by applicable law or agreed to in writing, software 11 distributed under the License is distributed on an "AS IS" BASIS, 12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 See the License for the specific language governing permissions and 14 limitations under the License. 15 */ 16 17 package aeron 18 19 import ( 20 "sync/atomic" 21 "unsafe" 22 ) 23 24 // ImageList is a helper class to manage list of images atomically without locks 25 type ImageList struct { 26 img unsafe.Pointer 27 } 28 29 // NewImageList is a factory method for ImageList 30 func NewImageList() *ImageList { 31 list := new(ImageList) 32 33 var images []Image 34 list.img = unsafe.Pointer(&images) 35 36 return list 37 } 38 39 // Get returns a pointer to the underlying image array loaded atomically 40 func (l *ImageList) Get() []Image { 41 return *(*[]Image)(atomic.LoadPointer(&l.img)) 42 } 43 44 // Set atomically sets the reference to the underlying array 45 func (l *ImageList) Set(imgs []Image) { 46 atomic.StorePointer(&l.img, unsafe.Pointer(&imgs)) 47 } 48 49 // Empty is a convenience method to reset the contents of the list 50 func (l *ImageList) Empty() (oldList []Image) { 51 oldList = l.Get() 52 l.Set(make([]Image, 0)) 53 return 54 }