From 7a9ad0c8ccbe0cdd4210dada7b52c54c04428714 Mon Sep 17 00:00:00 2001
From: Arceliar <Arceliar@users.noreply.github.com>
Date: Sat, 3 Aug 2019 23:10:37 -0500
Subject: [PATCH] add workerpool to util

---
 src/util/workerpool.go | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 src/util/workerpool.go

diff --git a/src/util/workerpool.go b/src/util/workerpool.go
new file mode 100644
index 00000000..fd37f397
--- /dev/null
+++ b/src/util/workerpool.go
@@ -0,0 +1,29 @@
+package util
+
+import "runtime"
+
+var workerPool chan func()
+
+func init() {
+	maxProcs := runtime.GOMAXPROCS(0)
+	if maxProcs < 1 {
+		maxProcs = 1
+	}
+	workerPool = make(chan func(), maxProcs)
+	for idx := 0; idx < maxProcs; idx++ {
+		go func() {
+			for f := range workerPool {
+				f()
+			}
+		}()
+	}
+}
+
+// WorkerGo submits a job to a pool of GOMAXPROCS worker goroutines.
+// This is meant for short non-blocking functions f() where you could just go f(),
+// but you want some kind of backpressure to prevent spawning endless goroutines.
+// WorkerGo returns as soon as the function is queued to run, not when it finishes.
+// In Yggdrasil, these workers are used for certain cryptographic operations.
+func WorkerGo(f func()) {
+	workerPool <- f
+}