Improve searching for the next voice when playing multiple sources

Instead of searching from the beginning of the voice list for each source, just
continue searching from the last source's voice.

1 files changed, 5 insertions, 4 deletions

diff --git a/al/source.cpp b/al/source.cpp
index 229a6d66..aa850e5e 100644
--- a/al/source.cpp
+++ b/al/source.cpp
@@ -2712,6 +2712,8 @@ START_API_FUNC
         voicelist = context->getVoicesSpan();
     }
 
+    auto voiceiter = voicelist.begin();
+    ALuint vidx{0};
     VoiceChange *tail{}, *cur{};
     for(ALsource *source : srchandles)
     {
@@ -2777,10 +2779,10 @@ START_API_FUNC
             break;
         }
 
-        /* Look for an unused voice to play this source with. */
-        ALuint vidx{0};
-        for(ALvoice *v : voicelist)
+        /* Find the next unused voice to play this source with. */
+        for(;voiceiter != voicelist.end();++voiceiter,++vidx)
         {
+            ALvoice *v{*voiceiter};
             if(v->mPlayState.load(std::memory_order_acquire) == ALvoice::Stopped
                 && v->mSourceID.load(std::memory_order_relaxed) == 0u
                 && v->mPendingStop.load(std::memory_order_relaxed) == false)
@@ -2788,7 +2790,6 @@ START_API_FUNC
                 voice = v;
                 break;
             }
-            ++vidx;
         };
 
         /* A source that's not playing or paused has any offset applied when it