Add a flag --rewind_lost_inputs to toggle action rewinding.

The flag value is ignored unless other rewinding prerequisites are met. PiperOrigin-RevId: 444281575
bazelbuild · Apr 25, 2022 · e13958c · e13958c
1 parent 4e6153e
commit e13958c
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Showing 3 changed files with 29 additions and 11 deletions.
diff --git a/src/main/java/com/google/devtools/build/lib/buildtool/BuildRequestOptions.java b/src/main/java/com/google/devtools/build/lib/buildtool/BuildRequestOptions.java
@@ -420,6 +420,16 @@ public boolean useTopLevelTargetsForSymlinks() {
       help = "Whether to store output metadata in the action cache")
   public boolean actionCacheStoreOutputMetadata;
 
+  @Option(
+      name = "rewind_lost_inputs",
+      defaultValue = "false",
+      documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
+      effectTags = {OptionEffectTag.EXECUTION},
+      help =
+          "Whether to use action rewinding to recover from lost inputs. Ignored unless"
+              + " prerequisites for rewinding are met (no incrementality, no action cache).")
+  public boolean rewindLostInputs;
+
   @Option(
       name = "discard_actions_after_execution",
       defaultValue = "true",

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
@@ -273,11 +273,10 @@ public WorkspaceInfoFromDiff sync(
       OptionsProvider options)
       throws InterruptedException, AbruptExitException {
     if (evaluatorNeedsReset) {
-      // Rewinding is only supported with no incremental state and no action cache.
       inconsistencyReceiver =
-          trackIncrementalState || useActionCache(options)
-              ? GraphInconsistencyReceiver.THROWING
-              : new RewindableGraphInconsistencyReceiver();
+          rewindingPermitted(options)
+              ? new RewindableGraphInconsistencyReceiver()
+              : GraphInconsistencyReceiver.THROWING;
       // Recreate MemoizingEvaluator so that graph is recreated with correct edge-clearing status,
       // or if the graph doesn't have edges, so that a fresh graph can be used.
       resetEvaluator();
@@ -300,9 +299,15 @@ public WorkspaceInfoFromDiff sync(
     return workspaceInfo;
   }
 
-  private static boolean useActionCache(OptionsProvider options) {
+  private boolean rewindingPermitted(OptionsProvider options) {
+    // Rewinding is only supported with no incremental state and no action cache.
+    if (trackIncrementalState) {
+      return false;
+    }
     BuildRequestOptions buildRequestOptions = options.getOptions(BuildRequestOptions.class);
-    return buildRequestOptions != null && buildRequestOptions.useActionCache;
+    return buildRequestOptions != null
+        && !buildRequestOptions.useActionCache
+        && buildRequestOptions.rewindLostInputs;
   }
 
   /**

diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutorTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutorTest.java
@@ -2478,20 +2478,23 @@ public NestedSet<Artifact> discoverInputs(ActionExecutionContext actionExecution
 
   @Test
   public void usesCorrectGraphInconsistencyReceiver(
-      @TestParameter boolean trackIncrementalState, @TestParameter boolean useActionCache)
+      @TestParameter boolean trackIncrementalState,
+      @TestParameter boolean useActionCache,
+      @TestParameter boolean rewindLostInputs)
       throws Exception {
     extraSkyFunctions.put(
         SkyFunctionName.FOR_TESTING,
         (key, env) -> {
-          if (trackIncrementalState || useActionCache) {
-            assertThat(env.restartPermitted()).isFalse();
-          } else {
+          if (!trackIncrementalState && !useActionCache && rewindLostInputs) {
             assertThat(env.restartPermitted()).isTrue();
+          } else {
+            assertThat(env.restartPermitted()).isFalse();
           }
           return new SkyValue() {};
         });
     initializeSkyframeExecutor();
-    options.parse("--use_action_cache=" + useActionCache);
+    options.parse(
+        "--use_action_cache=" + useActionCache, "--rewind_lost_inputs=" + rewindLostInputs);
 
     skyframeExecutor.setActive(false);
     skyframeExecutor.decideKeepIncrementalState(