diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 7a5cf66..0be91e4 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -328,7 +328,6 @@
       mTotalMemory(0),
       mClientSharedHeapSize(kMinimumClientSharedHeapSizeBytes),
       mGlobalEffectEnableTime(0),
-      mPatchPanel(this),
       mPatchCommandThread(sp<PatchCommandThread>::make()),
       mDeviceEffectManager(sp<DeviceEffectManager>::make(*this)),
       mMelReporter(sp<MelReporter>::make(*this)),
@@ -934,7 +933,7 @@
             dev->dump(fd, args);
         }
 
-        mPatchPanel.dump(fd);
+        mPatchPanel->dump(fd);
 
         mDeviceEffectManager->dump(fd);
 
@@ -1822,8 +1821,8 @@
         audio_io_handle_t upStream, const String8& keyValuePairs,
         const std::function<bool(const sp<IAfPlaybackThread>&)>& useThread)
 {
-    std::vector<PatchPanel::SoftwarePatch> swPatches;
-    if (mPatchPanel.getDownstreamSoftwarePatches(upStream, &swPatches) != OK) return;
+    std::vector<SoftwarePatch> swPatches;
+    if (mPatchPanel->getDownstreamSoftwarePatches(upStream, &swPatches) != OK) return;
     ALOGV_IF(!swPatches.empty(), "%s found %zu downstream patches for stream ID %d",
             __func__, swPatches.size(), upStream);
     for (const auto& swPatch : swPatches) {
@@ -3077,7 +3076,7 @@
             }
             mPlaybackThreads.add(*output, thread);
             struct audio_patch patch;
-            mPatchPanel.notifyStreamOpened(outHwDev, *output, &patch);
+            mPatchPanel->notifyStreamOpened(outHwDev, *output, &patch);
             if (thread->isMsdDevice()) {
                 thread->setDownStreamPatch(&patch);
             }
@@ -3240,7 +3239,7 @@
             ALOGD("closing mmapThread %p", mmapThread.get());
         }
         ioConfigChanged(AUDIO_OUTPUT_CLOSED, sp<AudioIoDescriptor>::make(output));
-        mPatchPanel.notifyStreamClosed(output);
+        mPatchPanel->notifyStreamClosed(output);
     }
     // The thread entity (active unit of execution) is no longer running here,
     // but the IAfThreadBase container still exists.
@@ -4329,7 +4328,7 @@
             sp<Client> client = registerPid(currentPid);
             ALOGV("%s device type %#x address %s", __func__, device.mType, device.getAddress());
             handle = mDeviceEffectManager->createEffect_l(
-                    &descOut, device, client, effectClient, mPatchPanel.patches_l(),
+                    &descOut, device, client, effectClient, mPatchPanel->patches_l(),
                     &enabledOut, &lStatus, probe, request.notifyFramesProcessed);
             if (lStatus != NO_ERROR && lStatus != ALREADY_EXISTS) {
                 // remove local strong reference to Client with mClientLock held
diff --git a/services/audioflinger/AudioFlinger.h b/services/audioflinger/AudioFlinger.h
index 7067c83..a062ac6 100644
--- a/services/audioflinger/AudioFlinger.h
+++ b/services/audioflinger/AudioFlinger.h
@@ -124,6 +124,7 @@
 #include "ResamplerBufferProvider.h"
 
 // include AudioFlinger component interfaces
+#include "IAfPatchPanel.h"  // this should be listed before other IAf* interfaces.
 #include "IAfEffect.h"
 #include "IAfThread.h"
 #include "IAfTrack.h"
@@ -879,7 +880,8 @@
     nsecs_t mGlobalEffectEnableTime;  // when a global effect was last enabled
 
     // protected by mLock
-    PatchPanel mPatchPanel;
+    const sp<IAfPatchPanel> mPatchPanel = IAfPatchPanel::create(this);
+
 public:
     // TODO(b/288339104) access by getter.
     sp<EffectsFactoryHalInterface> mEffectsFactoryHal;
diff --git a/services/audioflinger/IAfPatchPanel.h b/services/audioflinger/IAfPatchPanel.h
new file mode 100644
index 0000000..29bd4ab
--- /dev/null
+++ b/services/audioflinger/IAfPatchPanel.h
@@ -0,0 +1,251 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+namespace android {
+
+class IAfPatchPanel;
+class IAfPatchRecord;
+class IAfPatchTrack;
+class IAfPlaybackThread;
+class IAfRecordThread;
+class IAfThreadBase;
+
+class SoftwarePatch {
+public:
+    SoftwarePatch(
+            const sp<const IAfPatchPanel>& patchPanel,
+            audio_patch_handle_t patchHandle,
+            audio_io_handle_t playbackThreadHandle,
+            audio_io_handle_t recordThreadHandle)
+        : mPatchPanel(patchPanel),
+          mPatchHandle(patchHandle),
+          mPlaybackThreadHandle(playbackThreadHandle),
+          mRecordThreadHandle(recordThreadHandle) {}
+    SoftwarePatch(const SoftwarePatch&) = default;
+
+    // Must be called under AudioFlinger::mLock
+    status_t getLatencyMs_l(double* latencyMs) const;
+    audio_patch_handle_t getPatchHandle() const { return mPatchHandle; };
+    audio_io_handle_t getPlaybackThreadHandle() const { return mPlaybackThreadHandle; };
+    audio_io_handle_t getRecordThreadHandle() const { return mRecordThreadHandle; };
+
+private:
+    const sp<const IAfPatchPanel> mPatchPanel;
+    const audio_patch_handle_t mPatchHandle;
+    const audio_io_handle_t mPlaybackThreadHandle;
+    const audio_io_handle_t mRecordThreadHandle;
+};
+
+class IAfPatchPanel : public virtual RefBase {
+public:
+    static sp<IAfPatchPanel> create(AudioFlinger* audioFlinger);
+
+    // Extraction of inner Endpoint and Patch classes would require interfaces
+    // (in the Endpoint case a templated interface) but that seems
+    // excessive for now.  We keep them as inner classes until extraction
+    // is needed.
+    template <typename ThreadType, typename TrackType>
+    class Endpoint final {
+    public:
+        Endpoint() = default;
+        Endpoint(const Endpoint&) = delete;
+        Endpoint& operator=(const Endpoint& other) noexcept {
+            mThread = other.mThread;
+            mCloseThread = other.mCloseThread;
+            mHandle = other.mHandle;
+            mTrack = other.mTrack;
+            return *this;
+        }
+        Endpoint(Endpoint&& other) noexcept { swap(other); }
+        Endpoint& operator=(Endpoint&& other) noexcept {
+            swap(other);
+            return *this;
+        }
+        ~Endpoint() {
+            ALOGE_IF(
+                    mHandle != AUDIO_PATCH_HANDLE_NONE,
+                    "A non empty Patch Endpoint leaked, handle %d", mHandle);
+        }
+
+        status_t checkTrack(TrackType* trackOrNull) const {
+            if (trackOrNull == nullptr) return NO_MEMORY;
+            return trackOrNull->initCheck();
+        }
+        audio_patch_handle_t handle() const { return mHandle; }
+        sp<ThreadType> thread() const { return mThread; }
+        sp<TrackType> track() const { return mTrack; }
+        sp<const ThreadType> const_thread() const { return mThread; }
+        sp<const TrackType> const_track() const { return mTrack; }
+
+        void closeConnections(const sp<IAfPatchPanel>& panel) {
+            if (mHandle != AUDIO_PATCH_HANDLE_NONE) {
+                panel->releaseAudioPatch(mHandle);
+                mHandle = AUDIO_PATCH_HANDLE_NONE;
+            }
+            if (mThread != nullptr) {
+                if (mTrack != nullptr) {
+                    mThread->deletePatchTrack(mTrack);
+                }
+                if (mCloseThread) {
+                    panel->closeThreadInternal_l(mThread);
+                }
+            }
+        }
+        audio_patch_handle_t* handlePtr() { return &mHandle; }
+        void setThread(const sp<ThreadType>& thread, bool closeThread = true) {
+            mThread = thread;
+            mCloseThread = closeThread;
+        }
+        template <typename T>
+        void setTrackAndPeer(const sp<TrackType>& track, const sp<T>& peer, bool holdReference) {
+            mTrack = track;
+            mThread->addPatchTrack(mTrack);
+            mTrack->setPeerProxy(peer, holdReference);
+            mClearPeerProxy = holdReference;
+        }
+        void clearTrackPeer() {
+            if (mClearPeerProxy && mTrack) mTrack->clearPeerProxy();
+        }
+        void stopTrack() {
+            if (mTrack) mTrack->stop();
+        }
+
+        void swap(Endpoint& other) noexcept {
+            using std::swap;
+            swap(mThread, other.mThread);
+            swap(mCloseThread, other.mCloseThread);
+            swap(mClearPeerProxy, other.mClearPeerProxy);
+            swap(mHandle, other.mHandle);
+            swap(mTrack, other.mTrack);
+        }
+
+        friend void swap(Endpoint& a, Endpoint& b) noexcept { a.swap(b); }
+
+    private:
+        sp<ThreadType> mThread;
+        bool mCloseThread = true;
+        bool mClearPeerProxy = true;
+        audio_patch_handle_t mHandle = AUDIO_PATCH_HANDLE_NONE;
+        sp<TrackType> mTrack;
+    };
+
+    class Patch final {
+    public:
+        Patch(const struct audio_patch& patch, bool endpointPatch)
+            : mAudioPatch(patch), mIsEndpointPatch(endpointPatch) {}
+        Patch() = default;
+        ~Patch();
+        Patch(const Patch& other) noexcept {
+            mAudioPatch = other.mAudioPatch;
+            mHalHandle = other.mHalHandle;
+            mPlayback = other.mPlayback;
+            mRecord = other.mRecord;
+            mThread = other.mThread;
+            mIsEndpointPatch = other.mIsEndpointPatch;
+        }
+        Patch(Patch&& other) noexcept { swap(other); }
+        Patch& operator=(Patch&& other) noexcept {
+            swap(other);
+            return *this;
+        }
+
+        void swap(Patch& other) noexcept {
+            using std::swap;
+            swap(mAudioPatch, other.mAudioPatch);
+            swap(mHalHandle, other.mHalHandle);
+            swap(mPlayback, other.mPlayback);
+            swap(mRecord, other.mRecord);
+            swap(mThread, other.mThread);
+            swap(mIsEndpointPatch, other.mIsEndpointPatch);
+        }
+
+        friend void swap(Patch& a, Patch& b) noexcept { a.swap(b); }
+
+        status_t createConnections(const sp<IAfPatchPanel>& panel);
+        void clearConnections(const sp<IAfPatchPanel>& panel);
+        bool isSoftware() const {
+            return mRecord.handle() != AUDIO_PATCH_HANDLE_NONE ||
+                   mPlayback.handle() != AUDIO_PATCH_HANDLE_NONE;
+        }
+
+        void setThread(const sp<IAfThreadBase>& thread) { mThread = thread; }
+        wp<IAfThreadBase> thread() const { return mThread; }
+
+        // returns the latency of the patch (from record to playback).
+        status_t getLatencyMs(double* latencyMs) const;
+
+        String8 dump(audio_patch_handle_t myHandle) const;
+
+        // Note that audio_patch::id is only unique within a HAL module
+        struct audio_patch mAudioPatch;
+        // handle for audio HAL patch handle present only when the audio HAL version is >= 3.0
+        audio_patch_handle_t mHalHandle = AUDIO_PATCH_HANDLE_NONE;
+        // below members are used by a software audio patch connecting a source device from a
+        // given audio HW module to a sink device on an other audio HW module.
+        // the objects are created by createConnections() and released by clearConnections()
+        // playback thread is created if no existing playback thread can be used
+        // connects playback thread output to sink device
+        Endpoint<IAfPlaybackThread, IAfPatchTrack> mPlayback;
+        // connects source device to record thread input
+        Endpoint<IAfRecordThread, IAfPatchRecord> mRecord;
+
+        wp<IAfThreadBase> mThread;
+        bool mIsEndpointPatch;
+    };
+
+    /* List connected audio ports and their attributes */
+    virtual status_t listAudioPorts(unsigned int* num_ports, struct audio_port* ports) = 0;
+
+    /* Get supported attributes for a given audio port */
+    virtual status_t getAudioPort(struct audio_port_v7* port) = 0;
+
+    /* Create a patch between several source and sink ports */
+    virtual status_t createAudioPatch(
+            const struct audio_patch* patch,
+            audio_patch_handle_t* handle,
+            bool endpointPatch = false) = 0;
+
+    /* Release a patch */
+    virtual status_t releaseAudioPatch(audio_patch_handle_t handle) = 0;
+
+    /* List connected audio devices and they attributes */
+    virtual status_t listAudioPatches(unsigned int* num_patches, struct audio_patch* patches) = 0;
+
+    // Retrieves all currently estrablished software patches for a stream
+    // opened on an intermediate module.
+    virtual status_t getDownstreamSoftwarePatches(
+            audio_io_handle_t stream, std::vector<SoftwarePatch>* patches) const = 0;
+
+    // Notifies patch panel about all opened and closed streams.
+    virtual void notifyStreamOpened(
+            AudioHwDevice* audioHwDevice, audio_io_handle_t stream, struct audio_patch* patch) = 0;
+
+    virtual void notifyStreamClosed(audio_io_handle_t stream) = 0;
+
+    virtual void dump(int fd) const = 0;
+
+    // Must be called under AudioFlinger::mLock
+
+    virtual const std::map<audio_patch_handle_t, Patch>& patches_l() const = 0;
+
+    virtual status_t getLatencyMs_l(audio_patch_handle_t patchHandle, double* latencyMs) const = 0;
+
+    virtual void closeThreadInternal_l(const sp<IAfThreadBase>& thread) const = 0;
+};
+
+}  // namespace android
diff --git a/services/audioflinger/PatchPanel.cpp b/services/audioflinger/PatchPanel.cpp
index 7b4bc37..ac1455c 100644
--- a/services/audioflinger/PatchPanel.cpp
+++ b/services/audioflinger/PatchPanel.cpp
@@ -52,7 +52,7 @@
                                 struct audio_port *ports)
 {
     Mutex::Autolock _l(mLock);
-    return mPatchPanel.listAudioPorts(num_ports, ports);
+    return mPatchPanel->listAudioPorts(num_ports, ports);
 }
 
 /* Get supported attributes for a given audio port */
@@ -63,7 +63,7 @@
     }
 
     Mutex::Autolock _l(mLock);
-    return mPatchPanel.getAudioPort(port);
+    return mPatchPanel->getAudioPort(port);
 }
 
 /* Connect a patch between several source and sink ports */
@@ -76,14 +76,14 @@
     }
 
     Mutex::Autolock _l(mLock);
-    return mPatchPanel.createAudioPatch(patch, handle);
+    return mPatchPanel->createAudioPatch(patch, handle);
 }
 
 /* Disconnect a patch */
 status_t AudioFlinger::releaseAudioPatch(audio_patch_handle_t handle)
 {
     Mutex::Autolock _l(mLock);
-    return mPatchPanel.releaseAudioPatch(handle);
+    return mPatchPanel->releaseAudioPatch(handle);
 }
 
 /* List connected audio ports and they attributes */
@@ -91,19 +91,44 @@
                                   struct audio_patch *patches)
 {
     Mutex::Autolock _l(mLock);
-    return mPatchPanel.listAudioPatches(num_patches, patches);
+    return mPatchPanel->listAudioPatches(num_patches, patches);
 }
 
-status_t AudioFlinger::PatchPanel::SoftwarePatch::getLatencyMs_l(double *latencyMs) const
+/* static */
+sp<IAfPatchPanel> IAfPatchPanel::create(AudioFlinger* audioFlinger) {
+    return sp<AudioFlinger::PatchPanel>::make(audioFlinger);
+}
+
+status_t SoftwarePatch::getLatencyMs_l(double* latencyMs) const {
+    return mPatchPanel->getLatencyMs_l(mPatchHandle, latencyMs);
+}
+
+status_t AudioFlinger::PatchPanel::getLatencyMs_l(
+        audio_patch_handle_t patchHandle, double* latencyMs) const
 {
-    const auto& iter = mPatchPanel.mPatches.find(mPatchHandle);
-    if (iter != mPatchPanel.mPatches.end()) {
+    const auto& iter = mPatches.find(patchHandle);
+    if (iter != mPatches.end()) {
         return iter->second.getLatencyMs(latencyMs);
     } else {
         return BAD_VALUE;
     }
 }
 
+void AudioFlinger::PatchPanel::closeThreadInternal_l(const sp<IAfThreadBase>& thread) const
+{
+    if (const auto recordThread = thread->asIAfRecordThread();
+            recordThread) {
+        mAudioFlinger.closeThreadInternal_l(recordThread);
+    } else if (const auto playbackThread = thread->asIAfPlaybackThread();
+            playbackThread) {
+        mAudioFlinger.closeThreadInternal_l(playbackThread);
+    } else {
+        LOG_ALWAYS_FATAL("%s: Endpoints only accept IAfPlayback and IAfRecord threads, "
+                "invalid thread, id: %d  type: %d",
+                __func__, thread->id(), thread->type());
+    }
+}
+
 /* List connected audio ports and their attributes */
 status_t AudioFlinger::PatchPanel::listAudioPorts(unsigned int *num_ports __unused,
                                 struct audio_port *ports __unused)
@@ -482,7 +507,7 @@
             mRecord.handle(), mPlayback.handle());
 }
 
-status_t AudioFlinger::PatchPanel::Patch::createConnections(PatchPanel *panel)
+status_t AudioFlinger::PatchPanel::Patch::createConnections(const sp<IAfPatchPanel>& panel)
 {
     // create patch from source device to record thread input
     status_t status = panel->createAudioPatch(
@@ -646,7 +671,7 @@
     return status;
 }
 
-void AudioFlinger::PatchPanel::Patch::clearConnections(PatchPanel *panel)
+void AudioFlinger::PatchPanel::Patch::clearConnections(const sp<IAfPatchPanel>& panel)
 {
     ALOGV("%s() mRecord.handle %d mPlayback.handle %d",
             __func__, mRecord.handle(), mPlayback.handle());
@@ -839,7 +864,7 @@
 
 status_t AudioFlinger::PatchPanel::getDownstreamSoftwarePatches(
         audio_io_handle_t stream,
-        std::vector<AudioFlinger::PatchPanel::SoftwarePatch> *patches) const
+        std::vector<SoftwarePatch>* patches) const
 {
     for (const auto& module : mInsertedModules) {
         if (module.second.streams.count(stream)) {
@@ -847,7 +872,8 @@
                 const auto& patch_iter = mPatches.find(patchHandle);
                 if (patch_iter != mPatches.end()) {
                     const Patch &patch = patch_iter->second;
-                    patches->emplace_back(*this, patchHandle,
+                    patches->emplace_back(sp<const IAfPatchPanel>::fromExisting(this),
+                            patchHandle,
                             patch.mPlayback.const_thread()->id(),
                             patch.mRecord.const_thread()->id());
                 } else {
diff --git a/services/audioflinger/PatchPanel.h b/services/audioflinger/PatchPanel.h
index 497ba2d..b3c8a11 100644
--- a/services/audioflinger/PatchPanel.h
+++ b/services/audioflinger/PatchPanel.h
@@ -21,211 +21,48 @@
 
 public: // TODO(b/288339104) extract out of AudioFlinger class
 // PatchPanel is concealed within AudioFlinger, their lifetimes are the same.
-class PatchPanel {
+class PatchPanel : public IAfPatchPanel {
 public:
-    class SoftwarePatch {
-      public:
-        SoftwarePatch(const PatchPanel &patchPanel, audio_patch_handle_t patchHandle,
-                audio_io_handle_t playbackThreadHandle, audio_io_handle_t recordThreadHandle)
-                : mPatchPanel(patchPanel), mPatchHandle(patchHandle),
-                  mPlaybackThreadHandle(playbackThreadHandle),
-                  mRecordThreadHandle(recordThreadHandle) {}
-        SoftwarePatch(const SoftwarePatch&) = default;
-
-        // Must be called under AudioFlinger::mLock
-        status_t getLatencyMs_l(double *latencyMs) const;
-        audio_patch_handle_t getPatchHandle() const { return mPatchHandle; };
-        audio_io_handle_t getPlaybackThreadHandle() const { return mPlaybackThreadHandle; };
-        audio_io_handle_t getRecordThreadHandle() const { return mRecordThreadHandle; };
-      private:
-        const PatchPanel &mPatchPanel;
-        const audio_patch_handle_t mPatchHandle;
-        const audio_io_handle_t mPlaybackThreadHandle;
-        const audio_io_handle_t mRecordThreadHandle;
-    };
-
     explicit PatchPanel(AudioFlinger* audioFlinger) : mAudioFlinger(*audioFlinger) {}
 
     /* List connected audio ports and their attributes */
     status_t listAudioPorts(unsigned int *num_ports,
-                                    struct audio_port *ports);
+        struct audio_port* ports) final;
 
     /* Get supported attributes for a given audio port */
-    status_t getAudioPort(struct audio_port_v7 *port);
+    status_t getAudioPort(struct audio_port_v7* port) final;
 
     /* Create a patch between several source and sink ports */
     status_t createAudioPatch(const struct audio_patch *patch,
                               audio_patch_handle_t *handle,
-                              bool endpointPatch = false);
+                              bool endpointPatch = false) final;
 
     /* Release a patch */
-    status_t releaseAudioPatch(audio_patch_handle_t handle);
+    status_t releaseAudioPatch(audio_patch_handle_t handle) final;
 
     /* List connected audio devices and they attributes */
     status_t listAudioPatches(unsigned int *num_patches,
-                                      struct audio_patch *patches);
+            struct audio_patch* patches) final;
 
     // Retrieves all currently estrablished software patches for a stream
     // opened on an intermediate module.
     status_t getDownstreamSoftwarePatches(audio_io_handle_t stream,
-            std::vector<SoftwarePatch> *patches) const;
+            std::vector<SoftwarePatch>* patches) const final;
 
     // Notifies patch panel about all opened and closed streams.
     void notifyStreamOpened(AudioHwDevice *audioHwDevice, audio_io_handle_t stream,
-                            struct audio_patch *patch);
-    void notifyStreamClosed(audio_io_handle_t stream);
+                            struct audio_patch* patch) final;
+    void notifyStreamClosed(audio_io_handle_t stream) final;
 
-    void dump(int fd) const;
-
-    template<typename ThreadType, typename TrackType>
-    class Endpoint final {
-    public:
-        Endpoint() = default;
-        Endpoint(const Endpoint&) = delete;
-        Endpoint& operator=(const Endpoint& other) noexcept {
-            mThread = other.mThread;
-            mCloseThread = other.mCloseThread;
-            mHandle = other.mHandle;
-            mTrack = other.mTrack;
-            return *this;
-        }
-        Endpoint(Endpoint&& other) noexcept { swap(other); }
-        Endpoint& operator=(Endpoint&& other) noexcept {
-            swap(other);
-            return *this;
-        }
-        ~Endpoint() {
-            ALOGE_IF(mHandle != AUDIO_PATCH_HANDLE_NONE,
-                    "A non empty Patch Endpoint leaked, handle %d", mHandle);
-        }
-
-        status_t checkTrack(TrackType *trackOrNull) const {
-            if (trackOrNull == nullptr) return NO_MEMORY;
-            return trackOrNull->initCheck();
-        }
-        audio_patch_handle_t handle() const { return mHandle; }
-        sp<ThreadType> thread() const { return mThread; }
-        sp<TrackType> track() const { return mTrack; }
-        sp<const ThreadType> const_thread() const { return mThread; }
-        sp<const TrackType> const_track() const { return mTrack; }
-
-        void closeConnections(PatchPanel *panel) {
-            if (mHandle != AUDIO_PATCH_HANDLE_NONE) {
-                panel->releaseAudioPatch(mHandle);
-                mHandle = AUDIO_PATCH_HANDLE_NONE;
-            }
-            if (mThread != 0) {
-                if (mTrack != 0) {
-                    mThread->deletePatchTrack(mTrack);
-                }
-                if (mCloseThread) {
-                    panel->mAudioFlinger.closeThreadInternal_l(mThread);
-                }
-            }
-        }
-        audio_patch_handle_t* handlePtr() { return &mHandle; }
-        void setThread(const sp<ThreadType>& thread, bool closeThread = true) {
-            mThread = thread;
-            mCloseThread = closeThread;
-        }
-        template <typename T>
-        void setTrackAndPeer(const sp<TrackType>& track, const sp<T> &peer, bool holdReference) {
-            mTrack = track;
-            mThread->addPatchTrack(mTrack);
-            mTrack->setPeerProxy(peer, holdReference);
-            mClearPeerProxy = holdReference;
-        }
-        void clearTrackPeer() { if (mClearPeerProxy && mTrack) mTrack->clearPeerProxy(); }
-        void stopTrack() { if (mTrack) mTrack->stop(); }
-
-        void swap(Endpoint &other) noexcept {
-            using std::swap;
-            swap(mThread, other.mThread);
-            swap(mCloseThread, other.mCloseThread);
-            swap(mClearPeerProxy, other.mClearPeerProxy);
-            swap(mHandle, other.mHandle);
-            swap(mTrack, other.mTrack);
-        }
-
-        friend void swap(Endpoint &a, Endpoint &b) noexcept {
-            a.swap(b);
-        }
-
-    private:
-        sp<ThreadType> mThread;
-        bool mCloseThread = true;
-        bool mClearPeerProxy = true;
-        audio_patch_handle_t mHandle = AUDIO_PATCH_HANDLE_NONE;
-        sp<TrackType> mTrack;
-    };
-
-    class Patch final {
-    public:
-        Patch(const struct audio_patch &patch, bool endpointPatch) :
-            mAudioPatch(patch), mIsEndpointPatch(endpointPatch) {}
-        Patch() = default;
-        ~Patch();
-        Patch(const Patch& other) noexcept {
-            mAudioPatch = other.mAudioPatch;
-            mHalHandle = other.mHalHandle;
-            mPlayback = other.mPlayback;
-            mRecord = other.mRecord;
-            mThread = other.mThread;
-            mIsEndpointPatch = other.mIsEndpointPatch;
-        }
-        Patch(Patch&& other) noexcept { swap(other); }
-        Patch& operator=(Patch&& other) noexcept {
-            swap(other);
-            return *this;
-        }
-
-        void swap(Patch &other) noexcept {
-            using std::swap;
-            swap(mAudioPatch, other.mAudioPatch);
-            swap(mHalHandle, other.mHalHandle);
-            swap(mPlayback, other.mPlayback);
-            swap(mRecord, other.mRecord);
-            swap(mThread, other.mThread);
-            swap(mIsEndpointPatch, other.mIsEndpointPatch);
-        }
-
-        friend void swap(Patch &a, Patch &b) noexcept {
-            a.swap(b);
-        }
-
-        status_t createConnections(PatchPanel *panel);
-        void clearConnections(PatchPanel *panel);
-        bool isSoftware() const {
-            return mRecord.handle() != AUDIO_PATCH_HANDLE_NONE ||
-                    mPlayback.handle() != AUDIO_PATCH_HANDLE_NONE; }
-
-        void setThread(const sp<IAfThreadBase>& thread) { mThread = thread; }
-        wp<IAfThreadBase> thread() const { return mThread; }
-
-        // returns the latency of the patch (from record to playback).
-        status_t getLatencyMs(double *latencyMs) const;
-
-        String8 dump(audio_patch_handle_t myHandle) const;
-
-        // Note that audio_patch::id is only unique within a HAL module
-        struct audio_patch              mAudioPatch;
-        // handle for audio HAL patch handle present only when the audio HAL version is >= 3.0
-        audio_patch_handle_t            mHalHandle = AUDIO_PATCH_HANDLE_NONE;
-        // below members are used by a software audio patch connecting a source device from a
-        // given audio HW module to a sink device on an other audio HW module.
-        // the objects are created by createConnections() and released by clearConnections()
-        // playback thread is created if no existing playback thread can be used
-        // connects playback thread output to sink device
-        Endpoint<IAfPlaybackThread, IAfPatchTrack> mPlayback;
-        // connects source device to record thread input
-        Endpoint<IAfRecordThread, IAfPatchRecord> mRecord;
-
-        wp<IAfThreadBase> mThread;
-        bool mIsEndpointPatch;
-    };
+    void dump(int fd) const final;
 
     // Call with AudioFlinger mLock held
-    std::map<audio_patch_handle_t, Patch>& patches_l() { return mPatches; }
+    const std::map<audio_patch_handle_t, Patch>& patches_l() const final { return mPatches; }
+
+    // Must be called under AudioFlinger::mLock
+    status_t getLatencyMs_l(audio_patch_handle_t patchHandle, double* latencyMs) const final;
+
+    void closeThreadInternal_l(const sp<IAfThreadBase>& thread) const final;
 
 private:
     AudioHwDevice* findAudioHwDeviceByModule(audio_module_handle_t module);
diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index 76c9169..ca2dd47 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -3876,11 +3876,12 @@
             // Here, we try for the AF lock, but do not block on it as the latency
             // is more informational.
             if (mAudioFlinger->mLock.tryLock() == NO_ERROR) {
-                std::vector<AudioFlinger::PatchPanel::SoftwarePatch> swPatches;
+                std::vector<SoftwarePatch> swPatches;
                 double latencyMs = 0.; // not required; initialized for clang-tidy
                 status_t status = INVALID_OPERATION;
                 audio_patch_handle_t downstreamPatchHandle = AUDIO_PATCH_HANDLE_NONE;
-                if (mAudioFlinger->mPatchPanel.getDownstreamSoftwarePatches(id(), &swPatches) == OK
+                if (mAudioFlinger->mPatchPanel->getDownstreamSoftwarePatches(
+                                id(), &swPatches) == OK
                         && swPatches.size() > 0) {
                         status = swPatches[0].getLatencyMs_l(&latencyMs);
                         downstreamPatchHandle = swPatches[0].getPatchHandle();