Refactor DrmSession part into a separate class to prepare for multi session scenario. NO_SQ=flaky

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=165497666

library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSession.java

+/*
+ * Copyright (C) 2016 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.
+ */
+package com.google.android.exoplayer2.drm;
+
+import android.annotation.SuppressLint;
+import android.annotation.TargetApi;
+import android.media.DeniedByServerException;
+import android.media.MediaDrm;
+import android.media.NotProvisionedException;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.Looper;
+import android.os.Message;
+import android.util.Log;
+import android.util.Pair;
+import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.drm.DrmInitData.SchemeData;
+import com.google.android.exoplayer2.drm.ExoMediaDrm.KeyRequest;
+import com.google.android.exoplayer2.drm.ExoMediaDrm.OnEventListener;
+import com.google.android.exoplayer2.drm.ExoMediaDrm.ProvisionRequest;
+import com.google.android.exoplayer2.extractor.mp4.PsshAtomUtil;
+import com.google.android.exoplayer2.util.MimeTypes;
+import com.google.android.exoplayer2.util.Util;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+/**
+ * A {@link DrmSession} that supports playbacks using {@link MediaDrm}.
+ */
+@TargetApi(18)
+/* package */ class DefaultDrmSession<T extends ExoMediaCrypto> implements DrmSession<T> {
+  private static final String TAG = "DefaultDrmSession";
+
+  private static final String CENC_SCHEME_MIME_TYPE = "cenc";
+
+  private static final int MSG_PROVISION = 0;
+  private static final int MSG_KEYS = 1;
+
+  private static final int MAX_LICENSE_DURATION_TO_RENEW = 60;
+
+  private final Handler eventHandler;
+  private final DefaultDrmSessionManager.EventListener eventListener;
+  private final ExoMediaDrm<T> mediaDrm;
+  private final HashMap<String, String> optionalKeyRequestParameters;
+  /* package */ final MediaDrmCallback callback;
+  /* package */ final UUID uuid;
+  /* package */ MediaDrmHandler mediaDrmHandler;
+  /* package */ PostResponseHandler postResponseHandler;
+  private HandlerThread requestHandlerThread;
+  private Handler postRequestHandler;
+
+  @DefaultDrmSessionManager.Mode
+  private final int mode;
+  private int openCount;
+  private boolean provisioningInProgress;
+  @DrmSession.State
+  private int state;
+  private T mediaCrypto;
+  private DrmSessionException lastException;
+  private final byte[] schemeInitData;
+  private final String schemeMimeType;
+  private byte[] sessionId;
+  private byte[] offlineLicenseKeySetId;
+
+  /**
+   * Instantiates a new DRM session.
+   *
+   * @param uuid The UUID of the drm scheme.
+   * @param mediaDrm The media DRM.
+   * @param initData The DRM init data.
+   * @param mode The DRM mode.
+   * @param offlineLicenseKeySetId The offlineLicense KeySetId.
+   * @param optionalKeyRequestParameters The optional key request parameters.
+   * @param callback The media DRM callback.
+   * @param playbackLooper The playback looper.
+   * @param eventHandler The handler to post listener events.
+   * @param eventListener The DRM session manager event listener.
+   */
+  public DefaultDrmSession(UUID uuid, ExoMediaDrm<T> mediaDrm, DrmInitData initData,
+      @DefaultDrmSessionManager.Mode int mode, byte[] offlineLicenseKeySetId,
+      HashMap<String, String> optionalKeyRequestParameters, MediaDrmCallback callback,
+      Looper playbackLooper, Handler eventHandler,
+      DefaultDrmSessionManager.EventListener eventListener) {
+    this.uuid = uuid;
+    this.mediaDrm = mediaDrm;
+    this.mode = mode;
+    this.offlineLicenseKeySetId = offlineLicenseKeySetId;
+    this.optionalKeyRequestParameters = optionalKeyRequestParameters;
+    this.callback = callback;
+
+    this.eventHandler = eventHandler;
+    this.eventListener = eventListener;
+    state = STATE_OPENING;
+
+    mediaDrmHandler = new MediaDrmHandler(playbackLooper);
+    mediaDrm.setOnEventListener(new MediaDrmEventListener());
+    postResponseHandler = new PostResponseHandler(playbackLooper);
+    requestHandlerThread = new HandlerThread("DrmRequestHandler");
+    requestHandlerThread.start();
+    postRequestHandler = new PostRequestHandler(requestHandlerThread.getLooper());
+
+    // Parse init data.
+    byte[] schemeInitData = null;
+    String schemeMimeType = null;
+    if (offlineLicenseKeySetId == null) {
+      SchemeData data = getSchemeData(initData, uuid);
+      if (data == null) {
+        onError(new IllegalStateException("Media does not support uuid: " + uuid));
+      } else {
+        schemeInitData = data.data;
+        schemeMimeType = data.mimeType;
+        if (Util.SDK_INT < 21) {
+          // Prior to L the Widevine CDM required data to be extracted from the PSSH atom.
+          byte[] psshData = PsshAtomUtil.parseSchemeSpecificData(schemeInitData, uuid);
+          if (psshData == null) {
+            // Extraction failed. schemeData isn't a Widevine PSSH atom, so leave it unchanged.
+          } else {
+            schemeInitData = psshData;
+          }
+        }
+        if (Util.SDK_INT < 26 && C.CLEARKEY_UUID.equals(uuid)
+            && (MimeTypes.VIDEO_MP4.equals(schemeMimeType)
+            || MimeTypes.AUDIO_MP4.equals(schemeMimeType))) {
+          // Prior to API level 26 the ClearKey CDM only accepted "cenc" as the scheme for MP4.
+          schemeMimeType = CENC_SCHEME_MIME_TYPE;
+        }
+      }
+    }
+    this.schemeInitData = schemeInitData;
+    this.schemeMimeType = schemeMimeType;
+  }
+
+  // Life cycle.
+
+  public void acquire() {
+    if (++openCount == 1) {
+      if (state == STATE_ERROR) {
+        return;
+      }
+      if (openInternal(true)) {
+        doLicense();
+      }
+    }
+  }
+
+  /**
+   * @return True if the session is closed and cleaned up, false otherwise.
+   */
+  public boolean release() {
+    if (--openCount == 0) {
+      state = STATE_RELEASED;
+      provisioningInProgress = false;
+      mediaDrmHandler.removeCallbacksAndMessages(null);
+      mediaDrmHandler = null;
+      postResponseHandler.removeCallbacksAndMessages(null);
+      postRequestHandler.removeCallbacksAndMessages(null);
+      postRequestHandler = null;
+      requestHandlerThread.quit();
+      requestHandlerThread = null;
+      mediaCrypto = null;
+      lastException = null;
+      if (sessionId != null) {
+        mediaDrm.closeSession(sessionId);
+        sessionId = null;
+      }
+      return true;
+    }
+    return false;
+  }
+
+  // DrmSession Implementation.
+
+  @Override
+  @DrmSession.State
+  public final int getState() {
+    return state;
+  }
+
+  @Override
+  public final DrmSessionException getError() {
+    return state == STATE_ERROR ? lastException : null;
+  }
+
+  @Override
+  public final T getMediaCrypto() {
+    return mediaCrypto;
+  }
+
+  @Override
+  public Map<String, String> queryKeyStatus() {
+    return sessionId == null ? null : mediaDrm.queryKeyStatus(sessionId);
+  }
+
+  @Override
+  public byte[] getOfflineLicenseKeySetId() {
+    return offlineLicenseKeySetId;
+  }
+
+  // Internal methods.
+
+  /**
+   *  Try to open a session, do provisioning if necessary.
+   *  @param allowProvisioning if provisioning is allowed, set this to false when calling from
+   *      processing provision response.
+   *  @return true on success, false otherwise.
+   */
+  private boolean openInternal(boolean allowProvisioning) {
+    if (isOpen()) {
+      // Already opened
+      return true;
+    }
+
+    try {
+      sessionId = mediaDrm.openSession();
+      mediaCrypto = mediaDrm.createMediaCrypto(uuid, sessionId);
+      state = STATE_OPENED;
+      return true;
+    } catch (NotProvisionedException e) {
+      if (allowProvisioning) {
+        postProvisionRequest();
+      } else {
+        onError(e);
+      }
+    } catch (Exception e) {
+      // MediaCryptoException
+      // ResourceBusyException only available on 19+
+      onError(e);
+    }
+
+    return false;
+  }
+
+  private void postProvisionRequest() {
+    if (provisioningInProgress) {
+      return;
+    }
+    provisioningInProgress = true;
+    ProvisionRequest request = mediaDrm.getProvisionRequest();
+    postRequestHandler.obtainMessage(MSG_PROVISION, request).sendToTarget();
+  }
+
+  private void onProvisionResponse(Object response) {
+    provisioningInProgress = false;
+    if (state != STATE_OPENING && !isOpen()) {
+      // This event is stale.
+      return;
+    }
+
+    if (response instanceof Exception) {
+      onError((Exception) response);
+      return;
+    }
+
+    try {
+      mediaDrm.provideProvisionResponse((byte[]) response);
+      if (openInternal(false)) {
+        doLicense();
+      }
+    } catch (DeniedByServerException e) {
+      onError(e);
+    }
+  }
+
+  private void doLicense() {
+    switch (mode) {
+      case DefaultDrmSessionManager.MODE_PLAYBACK:
+      case DefaultDrmSessionManager.MODE_QUERY:
+        if (offlineLicenseKeySetId == null) {
+          postKeyRequest(MediaDrm.KEY_TYPE_STREAMING);
+        } else {
+          if (restoreKeys()) {
+            long licenseDurationRemainingSec = getLicenseDurationRemainingSec();
+            if (mode == DefaultDrmSessionManager.MODE_PLAYBACK
+                && licenseDurationRemainingSec <= MAX_LICENSE_DURATION_TO_RENEW) {
+              Log.d(TAG, "Offline license has expired or will expire soon. "
+                  + "Remaining seconds: " + licenseDurationRemainingSec);
+              postKeyRequest(MediaDrm.KEY_TYPE_OFFLINE);
+            } else if (licenseDurationRemainingSec <= 0) {
+              onError(new KeysExpiredException());
+            } else {
+              state = STATE_OPENED_WITH_KEYS;
+              if (eventHandler != null && eventListener != null) {
+                eventHandler.post(new Runnable() {
+                  @Override
+                  public void run() {
+                    eventListener.onDrmKeysRestored();
+                  }
+                });
+              }
+            }
+          }
+        }
+        break;
+      case DefaultDrmSessionManager.MODE_DOWNLOAD:
+        if (offlineLicenseKeySetId == null) {
+          postKeyRequest(MediaDrm.KEY_TYPE_OFFLINE);
+        } else {
+          // Renew
+          if (restoreKeys()) {
+            postKeyRequest(MediaDrm.KEY_TYPE_OFFLINE);
+          }
+        }
+        break;
+      case DefaultDrmSessionManager.MODE_RELEASE:
+        // It's not necessary to restore the key (and open a session to do that) before releasing it
+        // but this serves as a good sanity/fast-failure check.
+        if (restoreKeys()) {
+          postKeyRequest(MediaDrm.KEY_TYPE_RELEASE);
+        }
+        break;
+    }
+  }
+
+  private boolean restoreKeys() {
+    try {
+      mediaDrm.restoreKeys(sessionId, offlineLicenseKeySetId);
+      return true;
+    } catch (Exception e) {
+      Log.e(TAG, "Error trying to restore Widevine keys.", e);
+      onError(e);
+    }
+    return false;
+  }
+
+  private long getLicenseDurationRemainingSec() {
+    if (!C.WIDEVINE_UUID.equals(uuid)) {
+      return Long.MAX_VALUE;
+    }
+    Pair<Long, Long> pair = WidevineUtil.getLicenseDurationRemainingSec(this);
+    return Math.min(pair.first, pair.second);
+  }
+
+  private void postKeyRequest(int type) {
+    byte[] scope = type == MediaDrm.KEY_TYPE_RELEASE ? offlineLicenseKeySetId : sessionId;
+    try {
+      KeyRequest request = mediaDrm.getKeyRequest(scope, schemeInitData, schemeMimeType, type,
+          optionalKeyRequestParameters);
+      postRequestHandler.obtainMessage(MSG_KEYS, request).sendToTarget();
+    } catch (Exception e) {
+      onKeysError(e);
+    }
+  }
+
+  private void onKeyResponse(Object response) {
+    if (!isOpen()) {
+      // This event is stale.
+      return;
+    }
+
+    if (response instanceof Exception) {
+      onKeysError((Exception) response);
+      return;
+    }
+
+    try {
+      if (mode == DefaultDrmSessionManager.MODE_RELEASE) {
+        mediaDrm.provideKeyResponse(offlineLicenseKeySetId, (byte[]) response);
+        if (eventHandler != null && eventListener != null) {
+          eventHandler.post(new Runnable() {
+            @Override
+            public void run() {
+              eventListener.onDrmKeysRemoved();
+            }
+          });
+        }
+      } else {
+        byte[] keySetId = mediaDrm.provideKeyResponse(sessionId, (byte[]) response);
+        if ((mode == DefaultDrmSessionManager.MODE_DOWNLOAD
+            || (mode == DefaultDrmSessionManager.MODE_PLAYBACK && offlineLicenseKeySetId != null))
+            && keySetId != null && keySetId.length != 0) {
+          offlineLicenseKeySetId = keySetId;
+        }
+        state = STATE_OPENED_WITH_KEYS;
+        if (eventHandler != null && eventListener != null) {
+          eventHandler.post(new Runnable() {
+            @Override
+            public void run() {
+              eventListener.onDrmKeysLoaded();
+            }
+          });
+        }
+      }
+    } catch (Exception e) {
+      onKeysError(e);
+    }
+  }
+
+  private void onKeysExpired() {
+    if (state == STATE_OPENED_WITH_KEYS) {
+      state = STATE_OPENED;
+      onError(new KeysExpiredException());
+    }
+  }
+
+  private void onKeysError(Exception e) {
+    if (e instanceof NotProvisionedException) {
+      postProvisionRequest();
+    } else {
+      onError(e);
+    }
+  }
+
+  private void onError(final Exception e) {
+    lastException = new DrmSessionException(e);
+    if (eventHandler != null && eventListener != null) {
+      eventHandler.post(new Runnable() {
+        @Override
+        public void run() {
+          eventListener.onDrmSessionManagerError(e);
+        }
+      });
+    }
+    if (state != STATE_OPENED_WITH_KEYS) {
+      state = STATE_ERROR;
+    }
+  }
+
+  private boolean isOpen() {
+    return state == STATE_OPENED || state == STATE_OPENED_WITH_KEYS;
+  }
+
+  @SuppressLint("HandlerLeak")
+  private class MediaDrmHandler extends Handler {
+
+    public MediaDrmHandler(Looper looper) {
+      super(looper);
+    }
+
+    @SuppressWarnings("deprecation")
+    @Override
+    public void handleMessage(Message msg) {
+      if (!isOpen()) {
+        return;
+      }
+      switch (msg.what) {
+        case MediaDrm.EVENT_KEY_REQUIRED:
+          doLicense();
+          break;
+        case MediaDrm.EVENT_KEY_EXPIRED:
+          // When an already expired key is loaded MediaDrm sends this event immediately. Ignore
+          // this event if the state isn't STATE_OPENED_WITH_KEYS yet which means we're still
+          // waiting for key response.
+          onKeysExpired();
+          break;
+        case MediaDrm.EVENT_PROVISION_REQUIRED:
+          state = STATE_OPENED;
+          postProvisionRequest();
+          break;
+      }
+    }
+
+  }
+
+  private class MediaDrmEventListener implements OnEventListener<T> {
+
+    @Override
+    public void onEvent(ExoMediaDrm<? extends T> md, byte[] sessionId, int event, int extra,
+        byte[] data) {
+      if (mode == DefaultDrmSessionManager.MODE_PLAYBACK) {
+        mediaDrmHandler.sendEmptyMessage(event);
+      }
+    }
+
+  }
+
+  @SuppressLint("HandlerLeak")
+  private class PostResponseHandler extends Handler {
+
+    public PostResponseHandler(Looper looper) {
+      super(looper);
+    }
+
+    @Override
+    public void handleMessage(Message msg) {
+      switch (msg.what) {
+        case MSG_PROVISION:
+          onProvisionResponse(msg.obj);
+          break;
+        case MSG_KEYS:
+          onKeyResponse(msg.obj);
+          break;
+      }
+    }
+
+  }
+
+  @SuppressLint("HandlerLeak")
+  private class PostRequestHandler extends Handler {
+
+    public PostRequestHandler(Looper backgroundLooper) {
+      super(backgroundLooper);
+    }
+
+    @Override
+    public void handleMessage(Message msg) {
+      Object response;
+      try {
+        switch (msg.what) {
+          case MSG_PROVISION:
+            response = callback.executeProvisionRequest(uuid, (ProvisionRequest) msg.obj);
+            break;
+          case MSG_KEYS:
+            response = callback.executeKeyRequest(uuid, (KeyRequest) msg.obj);
+            break;
+          default:
+            throw new RuntimeException();
+        }
+      } catch (Exception e) {
+        response = e;
+      }
+      postResponseHandler.obtainMessage(msg.what, response).sendToTarget();
+    }
+
+  }
+
+  /**
+   * Extracts {@link SchemeData} suitable for the given DRM scheme {@link UUID}.
+   *
+   * @param drmInitData The {@link DrmInitData} from which to extract the {@link SchemeData}.
+   * @param uuid The UUID of the scheme.
+   * @return The extracted {@link SchemeData}, or null if no suitable data is present.
+   */
+  public static SchemeData getSchemeData(DrmInitData drmInitData, UUID uuid) {
+    SchemeData schemeData = drmInitData.get(uuid);
+    if (schemeData == null && C.CLEARKEY_UUID.equals(uuid)) {
+      // If present, the Common PSSH box should be used for ClearKey.
+      schemeData = drmInitData.get(C.COMMON_PSSH_UUID);
+    }
+    return schemeData;
+  }
+
+}

library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSessionManager.java

@@ -15,41 +15,27 @@
  */
  */
 package com.google.android.exoplayer2.drm;
 package com.google.android.exoplayer2.drm;
 
 
-import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
 import android.annotation.TargetApi;
-import android.media.DeniedByServerException;
 import android.media.MediaDrm;
 import android.media.MediaDrm;
-import android.media.NotProvisionedException;
 import android.os.Handler;
 import android.os.Handler;
-import android.os.HandlerThread;
 import android.os.Looper;
 import android.os.Looper;
-import android.os.Message;
 import android.support.annotation.IntDef;
 import android.support.annotation.IntDef;
 import android.support.annotation.NonNull;
 import android.support.annotation.NonNull;
 import android.text.TextUtils;
 import android.text.TextUtils;
-import android.util.Log;
-import android.util.Pair;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.drm.DrmInitData.SchemeData;
 import com.google.android.exoplayer2.drm.DrmInitData.SchemeData;
-import com.google.android.exoplayer2.drm.ExoMediaDrm.KeyRequest;
-import com.google.android.exoplayer2.drm.ExoMediaDrm.OnEventListener;
-import com.google.android.exoplayer2.drm.ExoMediaDrm.ProvisionRequest;
-import com.google.android.exoplayer2.extractor.mp4.PsshAtomUtil;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Assertions;
-import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.util.Util;
 import java.lang.annotation.Retention;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.RetentionPolicy;
 import java.util.HashMap;
 import java.util.HashMap;
-import java.util.Map;
 import java.util.UUID;
 import java.util.UUID;
 
 
 /**
 /**
  * A {@link DrmSessionManager} that supports playbacks using {@link MediaDrm}.
  * A {@link DrmSessionManager} that supports playbacks using {@link MediaDrm}.
  */
  */
 @TargetApi(18)
 @TargetApi(18)
-public class DefaultDrmSessionManager<T extends ExoMediaCrypto> implements DrmSessionManager<T>,
-    DrmSession<T> {
+public class DefaultDrmSessionManager<T extends ExoMediaCrypto> implements DrmSessionManager<T> {
 
 
   /**
   /**
    * Listener of {@link DefaultDrmSessionManager} events.
    * Listener of {@link DefaultDrmSessionManager} events.
@@ -95,8 +81,7 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto> implements DrmSe
    */
    */
   public static final int MODE_PLAYBACK = 0;
   public static final int MODE_PLAYBACK = 0;
   /**
   /**
-   * Restores an offline license to allow its status to be queried. If the offline license is
-   * expired sets state to {@link #STATE_ERROR}.
+   * Restores an offline license to allow its status to be queried.
    */
    */
   public static final int MODE_QUERY = 1;
   public static final int MODE_QUERY = 1;
   /** Downloads an offline license or renews an existing one. */
   /** Downloads an offline license or renews an existing one. */
@@ -104,40 +89,18 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto> implements DrmSe
   /** Releases an existing offline license. */
   /** Releases an existing offline license. */
   public static final int MODE_RELEASE = 3;
   public static final int MODE_RELEASE = 3;
 
 
-  private static final String TAG = "OfflineDrmSessionMngr";
-  private static final String CENC_SCHEME_MIME_TYPE = "cenc";
-
-  private static final int MSG_PROVISION = 0;
-  private static final int MSG_KEYS = 1;
-
-  private static final int MAX_LICENSE_DURATION_TO_RENEW = 60;
-
   private final Handler eventHandler;
   private final Handler eventHandler;
   private final EventListener eventListener;
   private final EventListener eventListener;
   private final ExoMediaDrm<T> mediaDrm;
   private final ExoMediaDrm<T> mediaDrm;
   private final HashMap<String, String> optionalKeyRequestParameters;
   private final HashMap<String, String> optionalKeyRequestParameters;
 
 
-  /* package */ final MediaDrmCallback callback;
-  /* package */ final UUID uuid;
-
-  /* package */ MediaDrmHandler mediaDrmHandler;
-  /* package */ PostResponseHandler postResponseHandler;
+  private final MediaDrmCallback callback;
+  private final UUID uuid;
 
 
   private Looper playbackLooper;
   private Looper playbackLooper;
-  private HandlerThread requestHandlerThread;
-  private Handler postRequestHandler;
-
   private int mode;
   private int mode;
-  private int openCount;
-  private boolean provisioningInProgress;
-  @DrmSession.State
-  private int state;
-  private T mediaCrypto;
-  private DrmSessionException lastException;
-  private byte[] schemeInitData;
-  private String schemeMimeType;
-  private byte[] sessionId;
   private byte[] offlineLicenseKeySetId;
   private byte[] offlineLicenseKeySetId;
+  private DefaultDrmSession<T> session;
 
 
   /**
   /**
    * Instantiates a new instance using the Widevine scheme.
    * Instantiates a new instance using the Widevine scheme.
@@ -224,7 +187,6 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto> implements DrmSe
     this.optionalKeyRequestParameters = optionalKeyRequestParameters;
     this.optionalKeyRequestParameters = optionalKeyRequestParameters;
     this.eventHandler = eventHandler;
     this.eventHandler = eventHandler;
     this.eventListener = eventListener;
     this.eventListener = eventListener;
-    mediaDrm.setOnEventListener(new MediaDrmEventListener());
     mode = MODE_PLAYBACK;
     mode = MODE_PLAYBACK;
   }
   }
 
 
@@ -299,7 +261,7 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto> implements DrmSe
    * @param offlineLicenseKeySetId The key set id of the license to be used with the given mode.
    * @param offlineLicenseKeySetId The key set id of the license to be used with the given mode.
    */
    */
   public void setMode(@Mode int mode, byte[] offlineLicenseKeySetId) {
   public void setMode(@Mode int mode, byte[] offlineLicenseKeySetId) {
-    Assertions.checkState(openCount == 0);
+    Assertions.checkState(session == null);
     if (mode == MODE_QUERY || mode == MODE_RELEASE) {
     if (mode == MODE_QUERY || mode == MODE_RELEASE) {
       Assertions.checkNotNull(offlineLicenseKeySetId);
       Assertions.checkNotNull(offlineLicenseKeySetId);
     }
     }
@@ -311,7 +273,7 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto> implements DrmSe
 
 
   @Override
   @Override
   public boolean canAcquireSession(@NonNull DrmInitData drmInitData) {
   public boolean canAcquireSession(@NonNull DrmInitData drmInitData) {
-    SchemeData schemeData = getSchemeData(drmInitData);
+    SchemeData schemeData = DefaultDrmSession.getSchemeData(drmInitData, uuid);
     if (schemeData == null) {
     if (schemeData == null) {
       // No data for this manager's scheme.
       // No data for this manager's scheme.
       return false;
       return false;
@@ -332,407 +294,22 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto> implements DrmSe
   @Override
   @Override
   public DrmSession<T> acquireSession(Looper playbackLooper, DrmInitData drmInitData) {
   public DrmSession<T> acquireSession(Looper playbackLooper, DrmInitData drmInitData) {
     Assertions.checkState(this.playbackLooper == null || this.playbackLooper == playbackLooper);
     Assertions.checkState(this.playbackLooper == null || this.playbackLooper == playbackLooper);
-    if (++openCount != 1) {
-      return this;
-    }
-
-    if (this.playbackLooper == null) {
+    if (session == null) {
       this.playbackLooper = playbackLooper;
       this.playbackLooper = playbackLooper;
-      mediaDrmHandler = new MediaDrmHandler(playbackLooper);
-      postResponseHandler = new PostResponseHandler(playbackLooper);
+      session = new DefaultDrmSession<T>(uuid, mediaDrm, drmInitData, mode, offlineLicenseKeySetId,
+          optionalKeyRequestParameters, callback, playbackLooper, eventHandler, eventListener);
     }
     }
 
 
-    requestHandlerThread = new HandlerThread("DrmRequestHandler");
-    requestHandlerThread.start();
-    postRequestHandler = new PostRequestHandler(requestHandlerThread.getLooper());
-
-    if (offlineLicenseKeySetId == null) {
-      SchemeData schemeData = getSchemeData(drmInitData);
-      if (schemeData == null) {
-        onError(new IllegalStateException("Media does not support uuid: " + uuid));
-        return this;
-      }
-      schemeInitData = schemeData.data;
-      schemeMimeType = schemeData.mimeType;
-      if (Util.SDK_INT < 21) {
-        // Prior to L the Widevine CDM required data to be extracted from the PSSH atom.
-        byte[] psshData = PsshAtomUtil.parseSchemeSpecificData(schemeInitData, C.WIDEVINE_UUID);
-        if (psshData == null) {
-          // Extraction failed. schemeData isn't a Widevine PSSH atom, so leave it unchanged.
-        } else {
-          schemeInitData = psshData;
-        }
-      }
-      if (Util.SDK_INT < 26 && C.CLEARKEY_UUID.equals(uuid)
-          && (MimeTypes.VIDEO_MP4.equals(schemeMimeType)
-          || MimeTypes.AUDIO_MP4.equals(schemeMimeType))) {
-        // Prior to API level 26 the ClearKey CDM only accepted "cenc" as the scheme for MP4.
-        schemeMimeType = CENC_SCHEME_MIME_TYPE;
-      }
-    }
-    state = STATE_OPENING;
-    openInternal(true);
-    return this;
+    session.acquire();
+    return session;
   }
   }
 
 
   @Override
   @Override
   public void releaseSession(DrmSession<T> session) {
   public void releaseSession(DrmSession<T> session) {
-    if (--openCount != 0) {
-      return;
-    }
-    state = STATE_RELEASED;
-    provisioningInProgress = false;
-    mediaDrmHandler.removeCallbacksAndMessages(null);
-    postResponseHandler.removeCallbacksAndMessages(null);
-    postRequestHandler.removeCallbacksAndMessages(null);
-    postRequestHandler = null;
-    requestHandlerThread.quit();
-    requestHandlerThread = null;
-    schemeInitData = null;
-    schemeMimeType = null;
-    mediaCrypto = null;
-    lastException = null;
-    if (sessionId != null) {
-      mediaDrm.closeSession(sessionId);
-      sessionId = null;
-    }
-  }
-
-  // DrmSession implementation.
-
-  @Override
-  @DrmSession.State
-  public final int getState() {
-    return state;
-  }
-
-  @Override
-  public final DrmSessionException getError() {
-    return state == STATE_ERROR ? lastException : null;
-  }
-
-  @Override
-  public final T getMediaCrypto() {
-    return mediaCrypto;
-  }
-
-  @Override
-  public Map<String, String> queryKeyStatus() {
-    return sessionId == null ? null : mediaDrm.queryKeyStatus(sessionId);
-  }
-
-  @Override
-  public byte[] getOfflineLicenseKeySetId() {
-    return offlineLicenseKeySetId;
-  }
-
-  // Internal methods.
-
-  private void openInternal(boolean allowProvisioning) {
-    try {
-      sessionId = mediaDrm.openSession();
-      mediaCrypto = mediaDrm.createMediaCrypto(uuid, sessionId);
-      state = STATE_OPENED;
-      doLicense();
-    } catch (NotProvisionedException e) {
-      if (allowProvisioning) {
-        postProvisionRequest();
-      } else {
-        onError(e);
-      }
-    } catch (Exception e) {
-      onError(e);
-    }
-  }
-
-  private void postProvisionRequest() {
-    if (provisioningInProgress) {
-      return;
-    }
-    provisioningInProgress = true;
-    ProvisionRequest request = mediaDrm.getProvisionRequest();
-    postRequestHandler.obtainMessage(MSG_PROVISION, request).sendToTarget();
-  }
-
-  private void onProvisionResponse(Object response) {
-    provisioningInProgress = false;
-    if (state != STATE_OPENING && state != STATE_OPENED && state != STATE_OPENED_WITH_KEYS) {
-      // This event is stale.
-      return;
-    }
-
-    if (response instanceof Exception) {
-      onError((Exception) response);
-      return;
-    }
-
-    try {
-      mediaDrm.provideProvisionResponse((byte[]) response);
-      if (state == STATE_OPENING) {
-        openInternal(false);
-      } else {
-        doLicense();
-      }
-    } catch (DeniedByServerException e) {
-      onError(e);
-    }
-  }
-
-  private void doLicense() {
-    switch (mode) {
-      case MODE_PLAYBACK:
-      case MODE_QUERY:
-        if (offlineLicenseKeySetId == null) {
-          postKeyRequest(sessionId, MediaDrm.KEY_TYPE_STREAMING);
-        } else {
-          if (restoreKeys()) {
-            long licenseDurationRemainingSec = getLicenseDurationRemainingSec();
-            if (mode == MODE_PLAYBACK
-                && licenseDurationRemainingSec <= MAX_LICENSE_DURATION_TO_RENEW) {
-              Log.d(TAG, "Offline license has expired or will expire soon. "
-                  + "Remaining seconds: " + licenseDurationRemainingSec);
-              postKeyRequest(sessionId, MediaDrm.KEY_TYPE_OFFLINE);
-            } else if (licenseDurationRemainingSec <= 0) {
-              onError(new KeysExpiredException());
-            } else {
-              state = STATE_OPENED_WITH_KEYS;
-              if (eventHandler != null && eventListener != null) {
-                eventHandler.post(new Runnable() {
-                  @Override
-                  public void run() {
-                    eventListener.onDrmKeysRestored();
-                  }
-                });
-              }
-            }
-          }
-        }
-        break;
-      case MODE_DOWNLOAD:
-        if (offlineLicenseKeySetId == null) {
-          postKeyRequest(sessionId, MediaDrm.KEY_TYPE_OFFLINE);
-        } else {
-          // Renew
-          if (restoreKeys()) {
-            postKeyRequest(sessionId, MediaDrm.KEY_TYPE_OFFLINE);
-          }
-        }
-        break;
-      case MODE_RELEASE:
-        // It's not necessary to restore the key (and open a session to do that) before releasing it
-        // but this serves as a good sanity/fast-failure check.
-        if (restoreKeys()) {
-          postKeyRequest(offlineLicenseKeySetId, MediaDrm.KEY_TYPE_RELEASE);
-        }
-        break;
-    }
-  }
-
-  private boolean restoreKeys() {
-    try {
-      mediaDrm.restoreKeys(sessionId, offlineLicenseKeySetId);
-      return true;
-    } catch (Exception e) {
-      Log.e(TAG, "Error trying to restore Widevine keys.", e);
-      onError(e);
-    }
-    return false;
-  }
-
-  private long getLicenseDurationRemainingSec() {
-    if (!C.WIDEVINE_UUID.equals(uuid)) {
-      return Long.MAX_VALUE;
+    Assertions.checkState(session == this.session);
+    if (this.session.release()) {
+      this.session = null;
     }
     }
-    Pair<Long, Long> pair = WidevineUtil.getLicenseDurationRemainingSec(this);
-    return Math.min(pair.first, pair.second);
-  }
-
-  private void postKeyRequest(byte[] scope, int keyType) {
-    try {
-      KeyRequest keyRequest = mediaDrm.getKeyRequest(scope, schemeInitData, schemeMimeType, keyType,
-          optionalKeyRequestParameters);
-      postRequestHandler.obtainMessage(MSG_KEYS, keyRequest).sendToTarget();
-    } catch (Exception e) {
-      onKeysError(e);
-    }
-  }
-
-  private void onKeyResponse(Object response) {
-    if (state != STATE_OPENED && state != STATE_OPENED_WITH_KEYS) {
-      // This event is stale.
-      return;
-    }
-
-    if (response instanceof Exception) {
-      onKeysError((Exception) response);
-      return;
-    }
-
-    try {
-      if (mode == MODE_RELEASE) {
-        mediaDrm.provideKeyResponse(offlineLicenseKeySetId, (byte[]) response);
-        if (eventHandler != null && eventListener != null) {
-          eventHandler.post(new Runnable() {
-            @Override
-            public void run() {
-              eventListener.onDrmKeysRemoved();
-            }
-          });
-        }
-      } else {
-        byte[] keySetId = mediaDrm.provideKeyResponse(sessionId, (byte[]) response);
-        if ((mode == MODE_DOWNLOAD || (mode == MODE_PLAYBACK && offlineLicenseKeySetId != null))
-            && keySetId != null && keySetId.length != 0) {
-          offlineLicenseKeySetId = keySetId;
-        }
-        state = STATE_OPENED_WITH_KEYS;
-        if (eventHandler != null && eventListener != null) {
-          eventHandler.post(new Runnable() {
-            @Override
-            public void run() {
-              eventListener.onDrmKeysLoaded();
-            }
-          });
-        }
-      }
-    } catch (Exception e) {
-      onKeysError(e);
-    }
-  }
-
-  private void onKeysError(Exception e) {
-    if (e instanceof NotProvisionedException) {
-      postProvisionRequest();
-    } else {
-      onError(e);
-    }
-  }
-
-  private void onError(final Exception e) {
-    lastException = new DrmSessionException(e);
-    if (eventHandler != null && eventListener != null) {
-      eventHandler.post(new Runnable() {
-        @Override
-        public void run() {
-          eventListener.onDrmSessionManagerError(e);
-        }
-      });
-    }
-    if (state != STATE_OPENED_WITH_KEYS) {
-      state = STATE_ERROR;
-    }
-  }
-
-  /**
-   * Extracts {@link SchemeData} suitable for this manager.
-   *
-   * @param drmInitData The {@link DrmInitData} from which to extract the {@link SchemeData}.
-   * @return The extracted {@link SchemeData}, or null if no suitable data is present.
-   */
-  private SchemeData getSchemeData(DrmInitData drmInitData) {
-    SchemeData schemeData = drmInitData.get(uuid);
-    if (schemeData == null && C.CLEARKEY_UUID.equals(uuid)) {
-      // If present, the Common PSSH box should be used for ClearKey.
-      schemeData = drmInitData.get(C.COMMON_PSSH_UUID);
-    }
-    return schemeData;
-  }
-
-  @SuppressLint("HandlerLeak")
-  private class MediaDrmHandler extends Handler {
-
-    public MediaDrmHandler(Looper looper) {
-      super(looper);
-    }
-
-    @SuppressWarnings("deprecation")
-    @Override
-    public void handleMessage(Message msg) {
-      if (openCount == 0 || (state != STATE_OPENED && state != STATE_OPENED_WITH_KEYS)) {
-        return;
-      }
-      switch (msg.what) {
-        case MediaDrm.EVENT_KEY_REQUIRED:
-          doLicense();
-          break;
-        case MediaDrm.EVENT_KEY_EXPIRED:
-          // When an already expired key is loaded MediaDrm sends this event immediately. Ignore
-          // this event if the state isn't STATE_OPENED_WITH_KEYS yet which means we're still
-          // waiting for key response.
-          if (state == STATE_OPENED_WITH_KEYS) {
-            state = STATE_OPENED;
-            onError(new KeysExpiredException());
-          }
-          break;
-        case MediaDrm.EVENT_PROVISION_REQUIRED:
-          state = STATE_OPENED;
-          postProvisionRequest();
-          break;
-      }
-    }
-
-  }
-
-  private class MediaDrmEventListener implements OnEventListener<T> {
-
-    @Override
-    public void onEvent(ExoMediaDrm<? extends T> md, byte[] sessionId, int event, int extra,
-        byte[] data) {
-      if (mode == MODE_PLAYBACK) {
-        mediaDrmHandler.sendEmptyMessage(event);
-      }
-    }
-
-  }
-
-  @SuppressLint("HandlerLeak")
-  private class PostResponseHandler extends Handler {
-
-    public PostResponseHandler(Looper looper) {
-      super(looper);
-    }
-
-    @Override
-    public void handleMessage(Message msg) {
-      switch (msg.what) {
-        case MSG_PROVISION:
-          onProvisionResponse(msg.obj);
-          break;
-        case MSG_KEYS:
-          onKeyResponse(msg.obj);
-          break;
-      }
-    }
-
-  }
-
-  @SuppressLint("HandlerLeak")
-  private class PostRequestHandler extends Handler {
-
-    public PostRequestHandler(Looper backgroundLooper) {
-      super(backgroundLooper);
-    }
-
-    @Override
-    public void handleMessage(Message msg) {
-      Object response;
-      try {
-        switch (msg.what) {
-          case MSG_PROVISION:
-            response = callback.executeProvisionRequest(uuid, (ProvisionRequest) msg.obj);
-            break;
-          case MSG_KEYS:
-            response = callback.executeKeyRequest(uuid, (KeyRequest) msg.obj);
-            break;
-          default:
-            throw new RuntimeException();
-        }
-      } catch (Exception e) {
-        response = e;
-      }
-      postResponseHandler.obtainMessage(msg.what, response).sendToTarget();
-    }
-
   }
   }
 
 
 }
 }