From 26ee4cb6c8a2248f0f7c99d8c622c86a52bf197a Mon Sep 17 00:00:00 2001
From: Max Romanov <max.romanov@nginx.com>
Date: Tue, 24 Dec 2019 18:04:21 +0300
Subject: Go: introducing SHM_ACK observer.

Each request processed in a separate goroutine.  In case of OOSM state,
during response write, request goroutine blocks on channel which waits
event from main thread about SHM_ACK message from router.
---
 go/observable.go | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 go/observable.go

(limited to 'go/observable.go')

diff --git a/go/observable.go b/go/observable.go
new file mode 100644
index 00000000..9a38802c
--- /dev/null
+++ b/go/observable.go
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) NGINX, Inc.
+ */
+
+package unit
+
+import (
+	"sync"
+)
+
+type observable struct {
+	sync.Mutex
+	observers []chan int
+}
+
+func (o *observable) attach(c chan int) {
+	o.Lock()
+	defer o.Unlock()
+
+	o.observers = append(o.observers, c)
+}
+
+func (o *observable) notify(e int) {
+	o.Lock()
+	defer o.Unlock()
+
+	for _, v := range o.observers {
+		v <- e
+	}
+
+	o.observers = nil
+}
-- 
cgit