From b68ad4ced2ce985c4e53b1469681ed3ec807d2b6 Mon Sep 17 00:00:00 2001
From: sudden6 <sudden6@gmx.at>
Date: Wed, 12 Apr 2017 00:10:55 +0200
Subject: [PATCH] feat(audio): don't use dynamic memory allocation and remove
 resource leak

---
 src/audio/audio.cpp | 46 +++++++++++++++++++++++++++++++--------------
 1 file changed, 32 insertions(+), 14 deletions(-)

diff --git a/src/audio/audio.cpp b/src/audio/audio.cpp
index 71c588597..a98b812cf 100644
--- a/src/audio/audio.cpp
+++ b/src/audio/audio.cpp
@@ -119,8 +119,13 @@ private:
  *
  * @var Audio::AUDIO_CHANNELS
  * @brief Ideally, we'd auto-detect, but that's a sane default
+ *
+ * @var BUFFER_COUNT
+ * @brief Number of buffers to use per audio source
  */
 
+static const unsigned int BUFFER_COUNT = 16;
+
 /**
  * @brief Returns the singleton instance.
  */
@@ -480,32 +485,35 @@ void Audio::playAudioBuffer(ALuint alSource, const int16_t* data, int samples, u
     if (!(alOutDev && outputInitialized))
         return;
 
-    ALuint bufid;
-    ALint processed = 0, queued = 16;
+    ALuint bufids[BUFFER_COUNT];
+    ALint processed = 0, queued = 0;
     alGetSourcei(alSource, AL_BUFFERS_PROCESSED, &processed);
     alGetSourcei(alSource, AL_BUFFERS_QUEUED, &queued);
     alSourcei(alSource, AL_LOOPING, AL_FALSE);
 
-    if (processed) {
-        ALuint* bufids = new ALuint[processed];
-        alSourceUnqueueBuffers(alSource, processed, bufids);
-        alDeleteBuffers(processed - 1, bufids + 1);
-        bufid = bufids[0];
-        delete[] bufids;
-    } else if (queued < 16) {
-        alGenBuffers(1, &bufid);
+    if (processed == 0) {
+        if (queued >= BUFFER_COUNT) {
+            // reached limit, drop audio
+            return;
+        }
+        // create new buffer if none got free and we're below the limit
+        alGenBuffers(1, bufids);
     } else {
-        return;
+        // unqueue all processed buffers
+        alSourceUnqueueBuffers(alSource, processed, bufids);
+        // delete all but the first buffer, reuse first for new data
+        alDeleteBuffers(processed - 1, bufids + 1);
     }
 
-    alBufferData(bufid, (channels == 1) ? AL_FORMAT_MONO16 : AL_FORMAT_STEREO16, data,
+    alBufferData(bufids[0], (channels == 1) ? AL_FORMAT_MONO16 : AL_FORMAT_STEREO16, data,
                  samples * 2 * channels, sampleRate);
-    alSourceQueueBuffers(alSource, 1, &bufid);
+    alSourceQueueBuffers(alSource, 1, bufids);
 
     ALint state;
     alGetSourcei(alSource, AL_SOURCE_STATE, &state);
-    if (state != AL_PLAYING)
+    if (state != AL_PLAYING) {
         alSourcePlay(alSource);
+    }
 }
 
 /**
@@ -671,6 +679,16 @@ void Audio::unsubscribeOutput(ALuint& sid)
 
     if (sid) {
         if (alIsSource(sid)) {
+            // stop playing, marks all buffers as processed
+            alSourceStop(sid);
+            // unqueue all buffers from the source
+            ALint processed = 0;
+            alGetSourcei(sid, AL_BUFFERS_PROCESSED, &processed);
+            ALuint* bufids = new ALuint[processed];
+            alSourceUnqueueBuffers(sid, processed, bufids);
+            // delete all buffers
+            alDeleteBuffers(processed, bufids);
+            delete[] bufids;
             alDeleteSources(1, &sid);
             qDebug() << "Audio source" << sid << "deleted. Sources active:" << outSources.size();
         } else {