Add RWLock when accessing tee patches.

Bug: 314041707
Test: atest AudioPlaybackCaptureTest
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:73f9705e6ede00d224047736a8cb31e7790f2f7d)
Merged-In: I3d6e7d434a983c869e3523687e5fb5cb67a253af
Change-Id: I3d6e7d434a983c869e3523687e5fb5cb67a253af
diff --git a/services/audioflinger/PlaybackTracks.h b/services/audioflinger/PlaybackTracks.h
index ae60ed0..2577ca8 100644
--- a/services/audioflinger/PlaybackTracks.h
+++ b/services/audioflinger/PlaybackTracks.h
@@ -23,6 +23,7 @@
 #include <audio_utils/mutex.h>
 #include <audio_utils/LinearMap.h>
 #include <binder/AppOpsManager.h>
+#include <utils/RWLock.h>
 
 namespace android {
 
@@ -352,6 +353,7 @@
     // Must hold thread lock to access tee patches
     template <class F>
     void                forEachTeePatchTrack_l(F f) {
+        RWLock::AutoRLock readLock(mTeePatchesRWLock);
         for (auto& tp : mTeePatches) { f(tp.patchTrack); }
     };
 
@@ -387,6 +389,7 @@
     audio_output_flags_t mFlags;
     TeePatches mTeePatches;
     std::optional<TeePatches> mTeePatchesToUpdate;
+    RWLock              mTeePatchesRWLock;
     const float         mSpeed;
     const bool          mIsSpatialized;
     const bool          mIsBitPerfect;
diff --git a/services/audioflinger/Tracks.cpp b/services/audioflinger/Tracks.cpp
index 224c65b..4fe5b84 100644
--- a/services/audioflinger/Tracks.cpp
+++ b/services/audioflinger/Tracks.cpp
@@ -1081,7 +1081,13 @@
         // Additionally PatchProxyBufferProvider::obtainBuffer (called by PathTrack::getNextBuffer)
         // does not allow 0 frame size request contrary to getNextBuffer
     }
-    for (auto& teePatch : mTeePatches) {
+    TeePatches teePatches;
+    if (mTeePatchesRWLock.tryReadLock() == NO_ERROR) {
+        // Cache a copy of tee patches in case it is updated while using.
+        teePatches = mTeePatches;
+        mTeePatchesRWLock.unlock();
+    }
+    for (auto& teePatch : teePatches) {
         IAfPatchRecord* patchRecord = teePatch.patchRecord.get();
         const size_t framesWritten = patchRecord->writeFrames(
                 sourceBuffer.i8, frameCount, mFrameSize);
@@ -1094,7 +1100,7 @@
     using namespace std::chrono_literals;
     // Average is ~20us per track, this should virtually never be logged (Logging takes >200us)
     ALOGD_IF(spent > 500us, "%s: took %lldus to intercept %zu tracks", __func__,
-             spent.count(), mTeePatches.size());
+             spent.count(), teePatches.size());
 }
 
 // ExtendedAudioBufferProvider interface
@@ -1616,7 +1622,10 @@
 void Track::updateTeePatches_l() {
     if (mTeePatchesToUpdate.has_value()) {
         forEachTeePatchTrack_l([](const auto& patchTrack) { patchTrack->destroy(); });
-        mTeePatches = mTeePatchesToUpdate.value();
+        {
+            RWLock::AutoWLock writeLock(mTeePatchesRWLock);
+            mTeePatches = std::move(mTeePatchesToUpdate.value());
+        }
         if (mState == TrackBase::ACTIVE || mState == TrackBase::RESUMING ||
                 mState == TrackBase::STOPPING_1) {
             forEachTeePatchTrack_l([](const auto& patchTrack) { patchTrack->start(); });