Rollback of commit 2891ec527eed27d0c6460d66f51cb66a43373b6a.

*** Reason for rollback ***

Causes our integration tests on Darwin to time out

*** Original change description ***

Make --watchfs a common command option.

Adding an options parameter to DiffAwareness#getCurrentView seems like the
simplest way to achieve that.

Alternatives considered:
1. Making the diff awareness modules stateful. However, I did not want to do so
as I've also been working on improving the module API to reduce state, or at
least to have a proper lifecycle management for any necessary state.

2. Making the watchFs flag a constructor parameter. However, that would also
invalidate any implement...

***

--
MOS_MIGRATED_REVID=136070807

16 files changed, 92 insertions, 207 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/bazel/BazelDiffAwarenessModule.java b/src/main/java/com/google/devtools/build/lib/bazel/BazelDiffAwarenessModule.java
index b5a85d3c4f..4140a7d5e7 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/BazelDiffAwarenessModule.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/BazelDiffAwarenessModule.java
@@ -19,7 +19,6 @@ import com.google.devtools.build.lib.runtime.BlazeModule;
 import com.google.devtools.build.lib.runtime.WorkspaceBuilder;
 import com.google.devtools.build.lib.skyframe.DiffAwareness;
 import com.google.devtools.build.lib.skyframe.LocalDiffAwareness;
-import com.google.devtools.common.options.OptionsBase;
 
 /**
  * Provides the {@link DiffAwareness} implementation that uses the Java watch service.
@@ -27,12 +26,8 @@ import com.google.devtools.common.options.OptionsBase;
 public class BazelDiffAwarenessModule extends BlazeModule {
   @Override
   public void workspaceInit(BlazeDirectories directories, WorkspaceBuilder builder) {
-    // Order here is important - LocalDiffAwareness creation always succeeds, so it must be last.
-    builder.addDiffAwarenessFactory(new LocalDiffAwareness.Factory(ImmutableList.<String>of()));
-  }
-
-  @Override
-  public Iterable<Class<? extends OptionsBase>> getCommonCommandOptions() {
-    return ImmutableList.<Class<? extends OptionsBase>>of(LocalDiffAwareness.Options.class);
+    if (builder.enableWatchFs()) {
+      builder.addDiffAwarenessFactory(new LocalDiffAwareness.Factory(ImmutableList.<String>of()));
+    }
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/commands/FetchCommand.java b/src/main/java/com/google/devtools/build/lib/bazel/commands/FetchCommand.java
index 0d78adcb5f..6f6d48a5ea 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/commands/FetchCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/commands/FetchCommand.java
@@ -71,7 +71,9 @@ public final class FetchCommand implements BlazeCommand {
     }
 
     try {
-      env.setupPackageCache(options, runtime.getDefaultsPackageContent());
+      env.setupPackageCache(
+          options.getOptions(PackageCacheOptions.class),
+          runtime.getDefaultsPackageContent());
     } catch (InterruptedException e) {
       env.getReporter().handle(Event.error("fetch interrupted"));
       return ExitCode.INTERRUPTED;
diff --git a/src/main/java/com/google/devtools/build/lib/buildtool/BuildTool.java b/src/main/java/com/google/devtools/build/lib/buildtool/BuildTool.java
index 9857283f62..e0f9682061 100644
--- a/src/main/java/com/google/devtools/build/lib/buildtool/BuildTool.java
+++ b/src/main/java/com/google/devtools/build/lib/buildtool/BuildTool.java
@@ -134,7 +134,8 @@ public final class BuildTool {
     validateOptions(request);
     BuildOptions buildOptions = runtime.createBuildOptions(request);
     // Sync the package manager before sending the BuildStartingEvent in runLoadingPhase()
-    env.setupPackageCache(request, DefaultsPackage.getDefaultsPackageContent(buildOptions));
+    env.setupPackageCache(request.getPackageCacheOptions(),
+        DefaultsPackage.getDefaultsPackageContent(buildOptions));
 
     ExecutionTool executionTool = null;
     LoadingResult loadingResult = null;
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java b/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
index dc67a17f9d..27e2ecc6d6 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BlazeRuntime.java
@@ -189,7 +189,9 @@ public final class BlazeRuntime {
   public void initWorkspace(BlazeDirectories directories, BinTools binTools)
       throws AbruptExitException {
     Preconditions.checkState(this.workspace == null);
-    WorkspaceBuilder builder = new WorkspaceBuilder(directories, binTools);
+    boolean watchFS = startupOptionsProvider != null
+        && startupOptionsProvider.getOptions(BlazeServerStartupOptions.class).watchFS;
+    WorkspaceBuilder builder = new WorkspaceBuilder(directories, binTools, watchFS);
     for (BlazeModule module : blazeModules) {
       module.workspaceInit(directories, builder);
     }
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/CommandEnvironment.java b/src/main/java/com/google/devtools/build/lib/runtime/CommandEnvironment.java
index e22b09b007..a68226d446 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/CommandEnvironment.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/CommandEnvironment.java
@@ -51,7 +51,6 @@ import com.google.devtools.build.lib.vfs.FileSystemUtils;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.common.options.OptionPriority;
-import com.google.devtools.common.options.OptionsClassProvider;
 import com.google.devtools.common.options.OptionsParser;
 import com.google.devtools.common.options.OptionsParsingException;
 import com.google.devtools.common.options.OptionsProvider;
@@ -471,7 +470,7 @@ public final class CommandEnvironment {
    *
    * @see DefaultsPackage
    */
-  public void setupPackageCache(OptionsClassProvider options,
+  public void setupPackageCache(PackageCacheOptions packageCacheOptions,
       String defaultsPackageContents) throws InterruptedException, AbruptExitException {
     SkyframeExecutor skyframeExecutor = getSkyframeExecutor();
     if (!skyframeExecutor.hasIncrementalState()) {
@@ -479,7 +478,7 @@ public final class CommandEnvironment {
     }
     skyframeExecutor.sync(
         reporter,
-        options.getOptions(PackageCacheOptions.class),
+        packageCacheOptions,
         getOutputBase(),
         getWorkingDirectory(),
         defaultsPackageContents,
@@ -487,8 +486,7 @@ public final class CommandEnvironment {
         // TODO(bazel-team): this optimization disallows rule-specified additional dependencies
         // on the client environment!
         getWhitelistedClientEnv(),
-        timestampGranularityMonitor,
-        options);
+        timestampGranularityMonitor);
   }
 
   public void recordLastExecutionTime() {
@@ -518,15 +516,6 @@ public final class CommandEnvironment {
       CommonCommandOptions options, long execStartTimeNanos, long waitTimeInMs)
       throws AbruptExitException {
     commandStartTime -= options.startupTime;
-    if (runtime.getStartupOptionsProvider().getOptions(BlazeServerStartupOptions.class).watchFS) {
-      try {
-        // TODO(ulfjack): Get rid of the startup option and drop this code.
-        optionsParser.parse("--watchfs");
-      } catch (OptionsParsingException e) {
-        // This should never happen.
-        throw new IllegalStateException(e);
-      }
-    }
 
     eventBus.post(new GotOptionsEvent(runtime.getStartupOptionsProvider(), optionsParser));
     throwPendingException();
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/WorkspaceBuilder.java b/src/main/java/com/google/devtools/build/lib/runtime/WorkspaceBuilder.java
index 241d5690a1..d7f0bfd2f2 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/WorkspaceBuilder.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/WorkspaceBuilder.java
@@ -36,6 +36,7 @@ import com.google.devtools.build.lib.util.Preconditions;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.build.skyframe.SkyFunction;
 import com.google.devtools.build.skyframe.SkyFunctionName;
+
 import java.util.Map;
 
 /**
@@ -45,6 +46,7 @@ import java.util.Map;
 public final class WorkspaceBuilder {
   private final BlazeDirectories directories;
   private final BinTools binTools;
+  private final boolean watchFs;
 
   private SkyframeExecutorFactory skyframeExecutorFactory;
   private WorkspaceStatusAction.Factory workspaceStatusActionFactory;
@@ -61,9 +63,10 @@ public final class WorkspaceBuilder {
   private final ImmutableList.Builder<SkyValueDirtinessChecker> customDirtinessCheckers =
       ImmutableList.builder();
 
-  WorkspaceBuilder(BlazeDirectories directories, BinTools binTools) {
+  WorkspaceBuilder(BlazeDirectories directories, BinTools binTools, boolean watchFs) {
     this.directories = directories;
     this.binTools = binTools;
+    this.watchFs = watchFs;
   }
 
   BlazeWorkspace build(
@@ -101,6 +104,10 @@ public final class WorkspaceBuilder {
         workspaceStatusActionFactory, binTools);
   }
 
+  public boolean enableWatchFs() {
+    return watchFs;
+  }
+
   /**
    * Sets a factory for creating {@link SkyframeExecutor} objects. Note that only one factory per
    * workspace is allowed.
@@ -129,9 +136,7 @@ public final class WorkspaceBuilder {
 
   /**
    * Add a {@link DiffAwareness} factory. These will be used to determine which files, if any,
-   * changed between Blaze commands. Note that these factories are attempted in the order in which
-   * they are added to this class, so order matters - in order to guarantee a specific order, only
-   * a single module should add such factories.
+   * changed between Blaze commands.
    */
   public WorkspaceBuilder addDiffAwarenessFactory(DiffAwareness.Factory factory) {
     this.diffAwarenessFactories.add(Preconditions.checkNotNull(factory));
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/InfoCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/InfoCommand.java
index 38c7d78ea8..b5e596fb88 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/InfoCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/InfoCommand.java
@@ -20,6 +20,7 @@ import com.google.devtools.build.lib.analysis.NoBuildEvent;
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
 import com.google.devtools.build.lib.analysis.config.InvalidConfigurationException;
 import com.google.devtools.build.lib.events.Event;
+import com.google.devtools.build.lib.pkgcache.PackageCacheOptions;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
 import com.google.devtools.build.lib.runtime.BlazeRuntime;
 import com.google.devtools.build.lib.runtime.Command;
@@ -113,7 +114,8 @@ public class InfoCommand implements BlazeCommand {
           // package path. Since info inherits all the build options, all the necessary information
           // is available here.
           env.setupPackageCache(
-              optionsProvider, runtime.getDefaultsPackageContent(optionsProvider));
+              optionsProvider.getOptions(PackageCacheOptions.class),
+              runtime.getDefaultsPackageContent(optionsProvider));
           // TODO(bazel-team): What if there are multiple configurations? [multi-config]
           configuration = env
               .getConfigurations(optionsProvider)
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java
index c52a3fe0d9..6c689d2baa 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/QueryCommand.java
@@ -83,7 +83,9 @@ public final class QueryCommand implements BlazeCommand {
     QueryOptions queryOptions = options.getOptions(QueryOptions.class);
 
     try {
-      env.setupPackageCache(options, runtime.getDefaultsPackageContent());
+      env.setupPackageCache(
+          options.getOptions(PackageCacheOptions.class),
+          runtime.getDefaultsPackageContent());
     } catch (InterruptedException e) {
       env.getReporter().handle(Event.error("query interrupted"));
       return ExitCode.INTERRUPTED;
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/DiffAwareness.java b/src/main/java/com/google/devtools/build/lib/skyframe/DiffAwareness.java
index 64c90338d0..f51cdfe281 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/DiffAwareness.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/DiffAwareness.java
@@ -15,8 +15,9 @@ package com.google.devtools.build.lib.skyframe;
 
 import com.google.devtools.build.lib.vfs.ModifiedFileSet;
 import com.google.devtools.build.lib.vfs.Path;
-import com.google.devtools.common.options.OptionsClassProvider;
+
 import java.io.Closeable;
+
 import javax.annotation.Nullable;
 
 /**
@@ -54,7 +55,7 @@ public interface DiffAwareness extends Closeable {
    *     {@link DiffAwareness} instance. The {@link DiffAwareness} is expected to close itself in
    *     this case.
    */
-  View getCurrentView(OptionsClassProvider options) throws BrokenDiffAwarenessException;
+  View getCurrentView() throws BrokenDiffAwarenessException;
 
   /**
    * Returns the set of files of interest that have been modified between the given two views.
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/DiffAwarenessManager.java b/src/main/java/com/google/devtools/build/lib/skyframe/DiffAwarenessManager.java
index 76f00a7fb4..02870970d4 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/DiffAwarenessManager.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/DiffAwarenessManager.java
@@ -13,16 +13,17 @@
 // limitations under the License.
 package com.google.devtools.build.lib.skyframe;
 
-import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Maps;
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.events.EventHandler;
 import com.google.devtools.build.lib.skyframe.DiffAwareness.View;
 import com.google.devtools.build.lib.vfs.ModifiedFileSet;
 import com.google.devtools.build.lib.vfs.Path;
-import com.google.devtools.common.options.OptionsClassProvider;
+
 import java.util.Map;
 import java.util.logging.Logger;
+
 import javax.annotation.Nullable;
 
 /**
@@ -33,13 +34,11 @@ public final class DiffAwarenessManager {
 
   private static final Logger LOG = Logger.getLogger(DiffAwarenessManager.class.getName());
 
-  // The manager attempts to instantiate these in the order in which they are passed to the
-  // constructor; this is critical in the case where a factory always succeeds.
-  private final ImmutableList<? extends DiffAwareness.Factory> diffAwarenessFactories;
+  private final ImmutableSet<? extends DiffAwareness.Factory> diffAwarenessFactories;
   private Map<Path, DiffAwarenessState> currentDiffAwarenessStates = Maps.newHashMap();
 
   public DiffAwarenessManager(Iterable<? extends DiffAwareness.Factory> diffAwarenessFactories) {
-    this.diffAwarenessFactories = ImmutableList.copyOf(diffAwarenessFactories);
+    this.diffAwarenessFactories = ImmutableSet.copyOf(diffAwarenessFactories);
   }
 
   private static class DiffAwarenessState {
@@ -80,8 +79,7 @@ public final class DiffAwarenessManager {
    * Gets the set of changed files since the last call with this path entry, or
    * {@code ModifiedFileSet.EVERYTHING_MODIFIED} if this is the first such call.
    */
-  public ProcessableModifiedFileSet getDiff(
-      EventHandler eventHandler, Path pathEntry, OptionsClassProvider options) {
+  public ProcessableModifiedFileSet getDiff(EventHandler eventHandler, Path pathEntry) {
     DiffAwarenessState diffAwarenessState = maybeGetDiffAwarenessState(pathEntry);
     if (diffAwarenessState == null) {
       return BrokenProcessableModifiedFileSet.INSTANCE;
@@ -89,7 +87,7 @@ public final class DiffAwarenessManager {
     DiffAwareness diffAwareness = diffAwarenessState.diffAwareness;
     View newView;
     try {
-      newView = diffAwareness.getCurrentView(options);
+      newView = diffAwareness.getCurrentView();
     } catch (BrokenDiffAwarenessException e) {
       handleBrokenDiffAwareness(eventHandler, pathEntry, e);
       return BrokenProcessableModifiedFileSet.INSTANCE;
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/LocalDiffAwareness.java b/src/main/java/com/google/devtools/build/lib/skyframe/LocalDiffAwareness.java
index 753f920cab..cae5cdebd4 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/LocalDiffAwareness.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/LocalDiffAwareness.java
@@ -14,20 +14,18 @@
 
 package com.google.devtools.build.lib.skyframe;
 
-import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Function;
 import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.devtools.build.lib.util.OS;
 import com.google.devtools.build.lib.util.Preconditions;
 import com.google.devtools.build.lib.vfs.ModifiedFileSet;
 import com.google.devtools.build.lib.vfs.PathFragment;
-import com.google.devtools.common.options.Option;
-import com.google.devtools.common.options.OptionsBase;
+
 import java.io.IOException;
 import java.nio.file.FileSystems;
 import java.nio.file.Path;
+import java.nio.file.WatchService;
 import java.util.Set;
 
 /**
@@ -40,19 +38,6 @@ import java.util.Set;
  * {@link WatchServiceDiffAwareness}.
  */
 public abstract class LocalDiffAwareness implements DiffAwareness {
-  /**
-   * Option to enable / disable local diff awareness.
-   */
-  public static final class Options extends OptionsBase {
-    @Option(
-        name = "watchfs",
-        defaultValue = "false",
-        category = "server startup",
-        help = "If true, %{product} tries to use the operating system's file watch service for "
-            + "local changes instead of scanning every file for a change."
-    )
-    public boolean watchFS;
-  }
 
   /** Factory for creating {@link LocalDiffAwareness} instances. */
   public static class Factory implements DiffAwareness.Factory {
@@ -88,26 +73,16 @@ public abstract class LocalDiffAwareness implements DiffAwareness {
         return new MacOSXFsEventsDiffAwareness(resolvedPathEntryFragment.toString());
       }
 
-      return new WatchServiceDiffAwareness(resolvedPathEntryFragment.toString());
+      WatchService watchService;
+      try {
+        watchService = FileSystems.getDefault().newWatchService();
+      } catch (IOException e) {
+        return null;
+      }
+      return new WatchServiceDiffAwareness(resolvedPathEntryFragment.toString(), watchService);
     }
   }
 
-  /**
-   * A view that results in any subsequent getDiff calls returning
-   * {@link ModifiedFileSet#EVERYTHING_MODIFIED}. Use this if --watchFs is disabled.
-   *
-   * <p>The position is set to -2 in order for {@link #areInSequence} below to always return false
-   * if this view is passed to it. Any negative number would work; we don't use -1 as the other
-   * view may have a position of 0.
-   */
-  protected static final View EVERYTHING_MODIFIED =
-      new SequentialView(/*owner=*/null, /*position=*/-2, ImmutableSet.<Path>of());
-
-  public static boolean areInSequence(SequentialView oldView, SequentialView newView) {
-    // Keep this in sync with the EVERYTHING_MODIFIED View above.
-    return oldView.owner == newView.owner && (oldView.position + 1) == newView.position;
-  }
-
   private int numGetCurrentViewCalls = 0;
 
   /** Root directory to watch. This is an absolute path. */
@@ -121,8 +96,7 @@ public abstract class LocalDiffAwareness implements DiffAwareness {
    * The WatchService is inherently sequential and side-effectful, so we enforce this by only
    * supporting {@link #getDiff} calls that happen to be sequential.
    */
-  @VisibleForTesting
-  static class SequentialView implements DiffAwareness.View {
+  private static class SequentialView implements DiffAwareness.View {
     private final LocalDiffAwareness owner;
     private final int position;
     private final Set<Path> modifiedAbsolutePaths;
@@ -133,6 +107,10 @@ public abstract class LocalDiffAwareness implements DiffAwareness {
       this.modifiedAbsolutePaths = modifiedAbsolutePaths;
     }
 
+    public static boolean areInSequence(SequentialView oldView, SequentialView newView) {
+      return oldView.owner == newView.owner && (oldView.position + 1) == newView.position;
+    }
+
     @Override
     public String toString() {
       return String.format("SequentialView[owner=%s, position=%d, modifiedAbsolutePaths=%s]", owner,
@@ -141,7 +119,7 @@ public abstract class LocalDiffAwareness implements DiffAwareness {
   }
 
   /**
-   * Returns true on any call before first call to {@link #newView}.
+   * Returns true on any call before first call to {@link #newView(Set<Path>)}.
    */
   protected boolean isFirstCall() {
     return numGetCurrentViewCalls == 0;
@@ -151,7 +129,8 @@ public abstract class LocalDiffAwareness implements DiffAwareness {
    * Create a new views using a list of modified absolute paths. This will increase the view
    * counter.
    */
-  protected SequentialView newView(Set<Path> modifiedAbsolutePaths) {
+  protected SequentialView newView(Set<Path> modifiedAbsolutePaths)
+      throws BrokenDiffAwarenessException {
     numGetCurrentViewCalls++;
     return new SequentialView(this, numGetCurrentViewCalls, modifiedAbsolutePaths);
   }
@@ -167,7 +146,7 @@ public abstract class LocalDiffAwareness implements DiffAwareness {
     } catch (ClassCastException e) {
       throw new IncompatibleViewException("Given views are not from LocalDiffAwareness");
     }
-    if (!areInSequence(oldSequentialView, newSequentialView)) {
+    if (!SequentialView.areInSequence(oldSequentialView, newSequentialView)) {
       return ModifiedFileSet.EVERYTHING_MODIFIED;
     }
     return ModifiedFileSet.builder()
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/MacOSXFsEventsDiffAwareness.java b/src/main/java/com/google/devtools/build/lib/skyframe/MacOSXFsEventsDiffAwareness.java
index f56611aca3..cf0fc621b5 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/MacOSXFsEventsDiffAwareness.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/MacOSXFsEventsDiffAwareness.java
@@ -17,7 +17,7 @@ package com.google.devtools.build.lib.skyframe;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableSet;
 import com.google.devtools.build.lib.UnixJniLoader;
-import com.google.devtools.common.options.OptionsClassProvider;
+
 import java.io.File;
 import java.nio.file.Path;
 
@@ -25,11 +25,11 @@ import java.nio.file.Path;
  * A {@link DiffAwareness} that use fsevents to watch the filesystem to use in lieu of
  * {@link LocalDiffAwareness}.
  *
- * <p>On OS X, the local diff awareness cannot work because WatchService is dummy and do polling,
- * which is slow (https://bugs.openjdk.java.net/browse/JDK-7133447).
+ * <p>
+ * On OS X, the local diff awareness cannot work because WatchService is dummy and do polling, which
+ * is slow (https://bugs.openjdk.java.net/browse/JDK-7133447).
  */
 public final class MacOSXFsEventsDiffAwareness extends LocalDiffAwareness {
-  private final double latency;
 
   private boolean closed;
 
@@ -37,15 +37,23 @@ public final class MacOSXFsEventsDiffAwareness extends LocalDiffAwareness {
   // structure).
   private long nativePointer;
 
-  private boolean opened;
-
   /**
    * Watch changes on the file system under <code>watchRoot</code> with a granularity of
    * <code>delay</code> seconds.
    */
   MacOSXFsEventsDiffAwareness(String watchRoot, double latency) {
     super(watchRoot);
-    this.latency = latency;
+    create(new String[] {watchRootPath.toAbsolutePath().toString()}, latency);
+
+    // Start a thread that just contains the OS X run loop.
+    new Thread(
+            new Runnable() {
+              @Override
+              public void run() {
+                MacOSXFsEventsDiffAwareness.this.run();
+              }
+            })
+        .start();
   }
 
   /**
@@ -65,35 +73,15 @@ public final class MacOSXFsEventsDiffAwareness extends LocalDiffAwareness {
    */
   private native void run();
 
-  private void init() {
-    // The code below is based on the assumption that init() can never fail, which is currently the
-    // case; if you change init(), then you also need to update {@link #getCurrentView}.
-    Preconditions.checkState(!opened);
-    opened = true;
-    create(new String[] {watchRootPath.toAbsolutePath().toString()}, latency);
-    // Start a thread that just contains the OS X run loop.
-    new Thread(
-            new Runnable() {
-              @Override
-              public void run() {
-                MacOSXFsEventsDiffAwareness.this.run();
-              }
-            })
-        .start();
-  }
-
   /**
    * Close this watch service, this service should not be used any longer after closing.
    */
-  @Override
   public synchronized void close() {
     Preconditions.checkState(!closed);
     closed = true;
     doClose();
   }
 
-  private static final boolean JNI_AVAILABLE;
-
   /**
    * JNI code stopping the main loop and shutting down listening to FSEvents.
    */
@@ -105,36 +93,11 @@ public final class MacOSXFsEventsDiffAwareness extends LocalDiffAwareness {
   private native String[] poll();
 
   static {
-    boolean loadJniWorked = false;
-    try {
-      UnixJniLoader.loadJni();
-      loadJniWorked = true;
-    } catch (UnsatisfiedLinkError ignored) {
-      // Unfortunately, we compile this class into the Bazel bootstrap binary, which doesn't have
-      // access to the JNI code (to simplify bootstrap). This is the quick and dirty way to
-      // hard-disable --watchfs in the bootstrap binary.
-    }
-    JNI_AVAILABLE = loadJniWorked;
+    UnixJniLoader.loadJni();
   }
 
   @Override
-  public synchronized View getCurrentView(OptionsClassProvider options)
-      throws BrokenDiffAwarenessException {
-    if (!JNI_AVAILABLE) {
-      return EVERYTHING_MODIFIED;
-    }
-    // See WatchServiceDiffAwareness#getCurrentView for an explanation of this logic.
-    boolean watchFs = options.getOptions(Options.class).watchFS;
-    if (watchFs && !opened) {
-      init();
-    } else if (!watchFs && opened) {
-      close();
-      throw new BrokenDiffAwarenessException("Switched off --watchfs again");
-    } else if (!opened) {
-      // The only difference with WatchServiceDiffAwareness#getCurrentView is this if; the init()
-      // call above can never fail, so we don't need to re-check the opened flag after init().
-      return EVERYTHING_MODIFIED;
-    }
+  public synchronized View getCurrentView() throws BrokenDiffAwarenessException {
     Preconditions.checkState(!closed);
     ImmutableSet.Builder<Path> paths = ImmutableSet.builder();
     for (String path : poll()) {
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutor.java b/src/main/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutor.java
index 7a45eeded1..3b0bbb4562 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutor.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutor.java
@@ -67,7 +67,6 @@ import com.google.devtools.build.skyframe.SkyFunction;
 import com.google.devtools.build.skyframe.SkyFunctionName;
 import com.google.devtools.build.skyframe.SkyKey;
 import com.google.devtools.build.skyframe.SkyValue;
-import com.google.devtools.common.options.OptionsClassProvider;
 import java.io.PrintStream;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -267,12 +266,11 @@ public final class SequencedSkyframeExecutor extends SkyframeExecutor {
       String defaultsPackageContents,
       UUID commandId,
       Map<String, String> clientEnv,
-      TimestampGranularityMonitor tsgm,
-      OptionsClassProvider options)
+      TimestampGranularityMonitor tsgm)
       throws InterruptedException, AbruptExitException {
     super.sync(eventHandler, packageCacheOptions, outputBase, workingDirectory,
-        defaultsPackageContents, commandId, clientEnv, tsgm, options);
-    handleDiffs(eventHandler, packageCacheOptions.checkOutputFiles, options);
+        defaultsPackageContents, commandId, clientEnv, tsgm);
+    handleDiffs(eventHandler, packageCacheOptions.checkOutputFiles);
   }
 
   /**
@@ -327,12 +325,11 @@ public final class SequencedSkyframeExecutor extends SkyframeExecutor {
    */
   @VisibleForTesting
   public void handleDiffs(EventHandler eventHandler) throws InterruptedException {
-    handleDiffs(eventHandler, /*checkOutputFiles=*/false, OptionsClassProvider.EMPTY);
+    handleDiffs(eventHandler, /*checkOutputFiles=*/ false);
   }
 
-  private void handleDiffs(
-      EventHandler eventHandler, boolean checkOutputFiles, OptionsClassProvider options)
-          throws InterruptedException {
+  private void handleDiffs(EventHandler eventHandler, boolean checkOutputFiles)
+      throws InterruptedException {
     if (lastAnalysisDiscarded) {
       // Values were cleared last build, but they couldn't be deleted because they were needed for
       // the execution phase. We can delete them now.
@@ -347,7 +344,7 @@ public final class SequencedSkyframeExecutor extends SkyframeExecutor {
         pathEntriesWithoutDiffInformation = Sets.newHashSet();
     for (Path pathEntry : pkgLocator.get().getPathEntries()) {
       DiffAwarenessManager.ProcessableModifiedFileSet modifiedFileSet =
-          diffAwarenessManager.getDiff(eventHandler, pathEntry, options);
+          diffAwarenessManager.getDiff(eventHandler, pathEntry);
       if (modifiedFileSet.getModifiedFileSet().treatEverythingAsModified()) {
         pathEntriesWithoutDiffInformation.add(Pair.of(pathEntry, modifiedFileSet));
       } else {
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java
index 146c468aaf..f2bdf9cb48 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java
@@ -1673,8 +1673,7 @@ public abstract class SkyframeExecutor implements WalkableGraphFactory {
       String defaultsPackageContents,
       UUID commandId,
       Map<String, String> clientEnv,
-      TimestampGranularityMonitor tsgm,
-      OptionsClassProvider options)
+      TimestampGranularityMonitor tsgm)
       throws InterruptedException, AbruptExitException {
     preparePackageLoading(
         createPackageLocator(
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/WatchServiceDiffAwareness.java b/src/main/java/com/google/devtools/build/lib/skyframe/WatchServiceDiffAwareness.java
index e425648825..b6d274dc5a 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/WatchServiceDiffAwareness.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/WatchServiceDiffAwareness.java
@@ -17,10 +17,9 @@ package com.google.devtools.build.lib.skyframe;
 import com.google.common.collect.HashBiMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.devtools.build.lib.util.Preconditions;
-import com.google.devtools.common.options.OptionsClassProvider;
+
 import java.io.IOException;
 import java.nio.file.ClosedWatchServiceException;
-import java.nio.file.FileSystems;
 import java.nio.file.FileVisitResult;
 import java.nio.file.Files;
 import java.nio.file.LinkOption;
@@ -40,6 +39,7 @@ import java.util.Set;
  * two consecutive calls. Uses the standard Java WatchService, which uses 'inotify' on Linux.
  */
 public final class WatchServiceDiffAwareness extends LocalDiffAwareness {
+
   /**
    * Bijection from WatchKey to the (absolute) Path being watched. WatchKeys don't have this
    * functionality built-in so we do it ourselves.
@@ -49,52 +49,13 @@ public final class WatchServiceDiffAwareness extends LocalDiffAwareness {
   /** Every directory is registered under this watch service. */
   private WatchService watchService;
 
-  WatchServiceDiffAwareness(String watchRoot) {
+  WatchServiceDiffAwareness(String watchRoot, WatchService watchService) {
     super(watchRoot);
-  }
-
-  private void init() {
-    Preconditions.checkState(watchService == null);
-    try {
-      watchService = FileSystems.getDefault().newWatchService();
-    } catch (IOException ignored) {
-      // According to the docs, this can never happen with the default file system provider.
-    }
+    this.watchService = watchService;
   }
 
   @Override
-  public View getCurrentView(OptionsClassProvider options) throws BrokenDiffAwarenessException {
-    // We need to consider 4 cases for watchFs:
-    // previous view    current view
-    //  disabled         disabled  -> EVERYTHING_MODIFIED
-    //  disabled         enabled   -> valid View (1)
-    //  enabled          disabled  -> throw BrokenDiffAwarenessException
-    //  enabled          enabled   -> valid View
-    //
-    // (1) When watchFs gets enabled, we need to consider both the delta from the previous view
-    //     to the current view (1a), and from the current view to the next view (1b).
-    // (1a) If watchFs was previously disabled, then previous view was either EVERYTHING_MODIFIED,
-    //      or we threw a BrokenDiffAwarenessException. The first is safe because comparing it to
-    //      any view results in ModifiedFileSet.EVERYTHING_MODIFIED. The second is safe because
-    //      the previous diff awareness gets closed and we're now in a new instance; comparisons
-    //      between views with different owners always results in
-    //      ModifiedFileSet.EVERYTHING_MODIFIED.
-    // (1b) On the next run, we want to see the files that were modified between the current and the
-    //      next run. For that, the view we return needs to be valid; however, it's ok for it to
-    //      contain files that are modified between init() and poll() below, because those are
-    //      already taken into account for the current build, as we ended up with
-    //      ModifiedFileSet.EVERYTHING_MODIFIED in the current build.
-    boolean watchFs = options.getOptions(Options.class).watchFS;
-    if (watchFs && watchService == null) {
-      init();
-    } else if (!watchFs && (watchService != null)) {
-      close();
-      throw new BrokenDiffAwarenessException("Switched off --watchfs again");
-    }
-    // If init() failed, then this if also applies.
-    if (watchService == null) {
-      return EVERYTHING_MODIFIED;
-    }
+  public View getCurrentView() throws BrokenDiffAwarenessException {
     Set<Path> modifiedAbsolutePaths;
     if (isFirstCall()) {
       try {
@@ -125,12 +86,10 @@ public final class WatchServiceDiffAwareness extends LocalDiffAwareness {
 
   @Override
   public void close() {
-    if (watchService != null) {
-      try {
-        watchService.close();
-      } catch (IOException ignored) {
-        // Nothing we can do here.
-      }
+    try {
+      watchService.close();
+    } catch (IOException ignored) {
+      // Nothing we can do here.
     }
   }
 
diff --git a/src/main/java/com/google/devtools/common/options/OptionsClassProvider.java b/src/main/java/com/google/devtools/common/options/OptionsClassProvider.java
index b28c29d3dc..90e7d48d1c 100644
--- a/src/main/java/com/google/devtools/common/options/OptionsClassProvider.java
+++ b/src/main/java/com/google/devtools/common/options/OptionsClassProvider.java
@@ -13,20 +13,11 @@
 // limitations under the License.
 package com.google.devtools.common.options;
 
-import javax.annotation.Nullable;
-
 /**
  * A read-only interface for options parser results, which only allows to query the options of
  * a specific class, but not e.g. the residue any other information pertaining to the command line.
  */
 public interface OptionsClassProvider {
-  public static final OptionsClassProvider EMPTY = new OptionsClassProvider() {
-    @Override @Nullable
-    public <O extends OptionsBase> O getOptions(Class<O> optionsClass) {
-      return null;
-    }
-  };
-
   /**
    * Returns the options instance for the given {@code optionsClass}, that is,
    * the parsed options, or null if it is not among those available.
@@ -34,5 +25,5 @@ public interface OptionsClassProvider {
    * <p>The returned options should be treated by library code as immutable and
    * a provider is permitted to return the same options instance multiple times.
    */
-  @Nullable <O extends OptionsBase> O getOptions(Class<O> optionsClass);
+  <O extends OptionsBase> O getOptions(Class<O> optionsClass);
 }