From 12de3f78e0bf9dde7f29d48102cce40dc0f59820 Mon Sep 17 00:00:00 2001
From: Gregory Eremin <g@erem.in>
Date: Mon, 12 Oct 2015 01:28:58 +0300
Subject: [PATCH] Implemented sleep sort algorithm

---
 sort/sleep_sort.go      | 37 +++++++++++++++++++++++++++++++++++++
 sort/sleep_sort_test.go | 12 ++++++++++++
 2 files changed, 49 insertions(+)
 create mode 100644 sort/sleep_sort.go
 create mode 100644 sort/sleep_sort_test.go

diff --git a/sort/sleep_sort.go b/sort/sleep_sort.go
new file mode 100644
index 0000000..d76da2c
--- /dev/null
+++ b/sort/sleep_sort.go
@@ -0,0 +1,37 @@
+package sort
+
+import (
+	"time"
+)
+
+const (
+	// SleepSortTimeout is the default sleep sort timeout in millisecond.
+	SleepSortTimeout = 5
+)
+
+// SleepSort is an implementation of sleep sort algorithm.
+func SleepSort(a []int) []int {
+	return SleepSortWithTimeout(a, SleepSortTimeout)
+}
+
+// SleepSortWithTimeout is an implementation of sleep sort algorithm with user
+// defined sleep timeout.
+func SleepSortWithTimeout(a []int, timeout time.Duration) []int {
+	start := make(chan struct{})
+	results := make(chan int, len(a))
+
+	for _, val := range a {
+		go func(val int) {
+			<-start
+			<-time.After(time.Duration(val) * time.Millisecond)
+			results <- val
+		}(val)
+	}
+	close(start)
+
+	for i := range a {
+		a[i] = <-results
+	}
+
+	return a
+}
diff --git a/sort/sleep_sort_test.go b/sort/sleep_sort_test.go
new file mode 100644
index 0000000..b7790b2
--- /dev/null
+++ b/sort/sleep_sort_test.go
@@ -0,0 +1,12 @@
+package sort
+
+import (
+	"testing"
+)
+
+func TestSleepSort(t *testing.T) {
+	testSort(t, SleepSort,
+		[]int{5, 3, 1, 4, 2},
+		[]int{1, 2, 3, 4, 5},
+	)
+}