From f9ab3f4b8157a42d657735101bc2c768c663e814 Mon Sep 17 00:00:00 2001
From: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Mon, 28 Jun 2021 13:31:21 +0100
Subject: [PATCH 1/2] Tweaks

---
 roomserver/internal/input/input_fifo.go | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/roomserver/internal/input/input_fifo.go b/roomserver/internal/input/input_fifo.go
index d8c075d2..d6f4b6d1 100644
--- a/roomserver/internal/input/input_fifo.go
+++ b/roomserver/internal/input/input_fifo.go
@@ -5,7 +5,7 @@ import (
 )
 
 type fifoQueue struct {
-	frames []*inputTask
+	tasks  []*inputTask
 	count  int
 	mutex  sync.Mutex
 	notifs chan struct{}
@@ -18,16 +18,15 @@ func newFIFOQueue() *fifoQueue {
 	return q
 }
 
-func (q *fifoQueue) push(frame *inputTask) bool {
+func (q *fifoQueue) push(frame *inputTask) {
 	q.mutex.Lock()
 	defer q.mutex.Unlock()
-	q.frames = append(q.frames, frame)
+	q.tasks = append(q.tasks, frame)
 	q.count++
 	select {
 	case q.notifs <- struct{}{}:
 	default:
 	}
-	return true
 }
 
 func (q *fifoQueue) pop() (*inputTask, bool) {
@@ -36,14 +35,14 @@ func (q *fifoQueue) pop() (*inputTask, bool) {
 	if q.count == 0 {
 		return nil, false
 	}
-	frame := q.frames[0]
-	q.frames[0] = nil
-	q.frames = q.frames[1:]
+	frame := q.tasks[0]
+	q.tasks[0] = nil
+	q.tasks = q.tasks[1:]
 	q.count--
 	if q.count == 0 {
 		// Force a GC of the underlying array, since it might have
 		// grown significantly if the queue was hammered for some reason
-		q.frames = nil
+		q.tasks = nil
 	}
 	return frame, true
 }
@@ -51,7 +50,7 @@ func (q *fifoQueue) pop() (*inputTask, bool) {
 func (q *fifoQueue) wait() <-chan struct{} {
 	q.mutex.Lock()
 	defer q.mutex.Unlock()
-	if q.count > 0 {
+	if q.count > 0 && len(q.notifs) == 0 {
 		ch := make(chan struct{})
 		close(ch)
 		return ch

From 4a37b19a8f6fe8af02e979827253d22a0ccdedb8 Mon Sep 17 00:00:00 2001
From: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Mon, 28 Jun 2021 13:34:54 +0100
Subject: [PATCH 2/2] Add comments

---
 roomserver/internal/input/input_fifo.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/roomserver/internal/input/input_fifo.go b/roomserver/internal/input/input_fifo.go
index d6f4b6d1..694b1724 100644
--- a/roomserver/internal/input/input_fifo.go
+++ b/roomserver/internal/input/input_fifo.go
@@ -29,6 +29,9 @@ func (q *fifoQueue) push(frame *inputTask) {
 	}
 }
 
+// pop returns the first item of the queue, if there is one.
+// The second return value will indicate if a task was returned.
+// You must check this value, even after calling wait().
 func (q *fifoQueue) pop() (*inputTask, bool) {
 	q.mutex.Lock()
 	defer q.mutex.Unlock()
@@ -47,6 +50,8 @@ func (q *fifoQueue) pop() (*inputTask, bool) {
 	return frame, true
 }
 
+// wait returns a channel which can be used to detect when an
+// item is waiting in the queue.
 func (q *fifoQueue) wait() <-chan struct{} {
 	q.mutex.Lock()
 	defer q.mutex.Unlock()