to remove

instrumentation/src/androidTest/java/com/bumptech/glide/MultiRequestTest.java

@@ -53,7 +53,8 @@ public void thumbnail_onResourceReady_forPrimary_isComplete_whenRequestListenerI
     Glide.init(
         context,
         new GlideBuilder()
-            .setSourceExecutor(GlideExecutor.newSourceBuilder().setThreadCount(1).build()));
+            .setSourceExecutor(GlideExecutor.newSourceBuilder().setThreadCount(1).build())
+            .setFixSingleRequestClearDeadlock(true));
 
     AtomicBoolean isPrimaryRequestComplete = new AtomicBoolean(false);
     CountDownLatch countDownLatch = new CountDownLatch(1);

instrumentation/src/androidTest/java/com/bumptech/glide/RequestTest.java

@@ -50,7 +50,10 @@ public void setUp() {
     // Some emulators only have a single resize thread, so waiting on a latch will block them
     // forever.
     Glide.init(
-        context, new GlideBuilder().setSourceExecutor(GlideExecutor.newUnlimitedSourceExecutor()));
+        context,
+        new GlideBuilder()
+            .setSourceExecutor(GlideExecutor.newUnlimitedSourceExecutor())
+            .setFixSingleRequestClearDeadlock(true));
   }
 
   @Test

library/src/main/java/com/bumptech/glide/GlideBuilder.java

@@ -539,6 +539,19 @@ public GlideBuilder setDisableHardwareBitmapsOnO(boolean disableHardwareBitmapsO
     return this;
   }
 
+  /**
+   * Fix single request clear deadlock mentioned in <a
+   * href="https://github.com/bumptech/glide/issues/5617">#5617</a>.
+   *
+   * <p>This flag changes {@link com.bumptech.glide.request.SingleRequest} to lock on underlying
+   * {@link Engine} to avoid deadlocks in calling code that also requires a lock on the {@link
+   * Engine}.
+   */
+  public GlideBuilder setFixSingleRequestClearDeadlock(boolean isEnabled) {
+    glideExperimentsBuilder.update(new FixSingleRequestClearDeadlock(), isEnabled);
+    return this;
+  }
+
   void setRequestManagerFactory(@Nullable RequestManagerFactory factory) {
     this.requestManagerFactory = factory;
   }
@@ -653,4 +666,7 @@ public static final class OverrideGlideThreadPriority implements Experiment {}
 
   /** See {@link #setUseMediaStoreOpenFileApisIfPossible(boolean)}. */
   public static final class UseMediaStoreOpenFileApisIfPossible implements Experiment {}
+
+  /** See {@link #setFixSingleRequestClearDeadlock(boolean)}. */
+  public static final class FixSingleRequestClearDeadlock implements Experiment {}
 }

library/src/main/java/com/bumptech/glide/RequestBuilder.java

@@ -16,6 +16,7 @@
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.RawRes;
+import com.bumptech.glide.GlideBuilder.FixSingleRequestClearDeadlock;
 import com.bumptech.glide.load.DataSource;
 import com.bumptech.glide.load.Transformation;
 import com.bumptech.glide.load.engine.DiskCacheStrategy;
@@ -68,6 +69,7 @@ public class RequestBuilder<TranscodeType> extends BaseRequestOptions<RequestBui
   private final Class<TranscodeType> transcodeClass;
   private final Glide glide;
   private final GlideContext glideContext;
+  private final GlideExperiments experiments;
 
   @NonNull
   @SuppressWarnings("unchecked")
@@ -99,6 +101,7 @@ protected RequestBuilder(
     this.context = context;
     this.transitionOptions = requestManager.getDefaultTransitionOptions(transcodeClass);
     this.glideContext = glide.getGlideContext();
+    this.experiments = glide.getGlideContext().getExperiments();
 
     initRequestListeners(requestManager.getDefaultRequestListeners());
     apply(requestManager.getDefaultRequestOptions());
@@ -1166,8 +1169,13 @@ private Request buildRequest(
       @Nullable RequestListener<TranscodeType> targetListener,
       BaseRequestOptions<?> requestOptions,
       Executor callbackExecutor) {
+    GlideExperiments experiments = glideContext.getExperiments();
+    Object requestLock =
+        glideContext.getExperiments().isEnabled(FixSingleRequestClearDeadlock.class)
+            ? glideContext.getEngine()
+            : new Object();
     return buildRequestRecursive(
-        /* requestLock= */ new Object(),
+        requestLock,
         target,
         targetListener,
         /* parentCoordinator= */ null,

library/test/src/test/java/com/bumptech/glide/request/SingleRequestTest.java

@@ -23,6 +23,7 @@
 import android.graphics.drawable.Drawable;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import com.bumptech.glide.GlideBuilder.FixSingleRequestClearDeadlock;
 import com.bumptech.glide.GlideContext;
 import com.bumptech.glide.GlideExperiments;
 import com.bumptech.glide.Priority;
@@ -1071,6 +1072,8 @@ static final class SingleRequestBuilder {
     private final Map<Class<?>, Transformation<?>> transformations = new HashMap<>();
 
     SingleRequestBuilder() {
+      GlideExperiments glideExperiments = mock(GlideExperiments.class);
+      when(glideExperiments.isEnabled(FixSingleRequestClearDeadlock.class)).thenReturn(true);
       when(glideContext.getExperiments()).thenReturn(mock(GlideExperiments.class));
       when(requestCoordinator.getRoot()).thenReturn(requestCoordinator);
       when(requestCoordinator.canSetImage(any(Request.class))).thenReturn(true);