XeLabs/100-go-mistakes
2
0
Fork 0
mirror of https://github.com/teivah/100-go-mistakes.git synced 2026-06-25 10:56:52 +08:00
Code Issues Projects Releases Packages Wiki Activity

Reviews

Browse source
This commit is contained in:
teivah 2022-02-05 14:07:04 +01:00
parent f3f5d06bcf
commit ab22488bb0
No known key found for this signature in database
GPG key ID: 07E4A13FB8F8DF63
1 changed files with 45 additions and 37 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

82
08-concurrency-foundations/56-faster/main.go
View file

@ -1,18 +1,54 @@
package main package main
import "sync" import (
"sync"
)
func sequentialMergesort(s []int) { func sequentialMergesort(s []int) {
if len(s) > 1 { if len(s) <= 1 {
middle := len(s) / 2 return
sequentialMergesort(s[:middle])
sequentialMergesort(s[middle:])
merge(s, middle)
} }
middle := len(s) / 2
sequentialMergesort(s[:middle])
sequentialMergesort(s[middle:])
merge(s, middle)
} }
func parallelMergesortV1(s []int) { func parallelMergesortV1(s []int) {
if len(s) > 1 { if len(s) <= 1 {
return
}
middle := len(s) / 2
var wg sync.WaitGroup
wg.Add(2)
go func() {
defer wg.Done()
parallelMergesortV1(s[:middle])
}()
go func() {
defer wg.Done()
parallelMergesortV1(s[middle:])
}()
wg.Wait()
merge(s, middle)
}
const max = 2048
func parallelMergesortV2(s []int) {
if len(s) <= 1 {
return
}
if len(s) <= max {
sequentialMergesort(s)
} else {
middle := len(s) / 2 middle := len(s) / 2
var wg sync.WaitGroup var wg sync.WaitGroup
@ -20,12 +56,12 @@ func parallelMergesortV1(s []int) {
go func() { go func() {
defer wg.Done() defer wg.Done()
parallelMergesortV1(s[:middle]) parallelMergesortV2(s[:middle])
}() }()
go func() { go func() {
defer wg.Done() defer wg.Done()
parallelMergesortV1(s[middle:]) parallelMergesortV2(s[middle:])
}() }()
wg.Wait() wg.Wait()
@ -33,34 +69,6 @@ func parallelMergesortV1(s []int) {
} }
} }
const max = 2048
func parallelMergesortV2(s []int) {
if len(s) > 1 {
if len(s) <= max {
sequentialMergesort(s)
} else {
middle := len(s) / 2
var wg sync.WaitGroup
wg.Add(2)
go func() {
defer wg.Done()
parallelMergesortV2(s[:middle])
}()
go func() {
defer wg.Done()
parallelMergesortV2(s[middle:])
}()
wg.Wait()
merge(s, middle)
}
}
}
func merge(s []int, middle int) { func merge(s []int, middle int) {
helper := make([]int, len(s)) helper := make([]int, len(s))
copy(helper, s) copy(helper, s)