From 3afe0c561adfa2dc4bbdf5b1cc8eec21345465ad Mon Sep 17 00:00:00 2001
From: Tobias Werth <twerth@google.com>
Date: Mon, 13 Nov 2023 03:03:32 -0800
Subject: [PATCH] Revert "Remove `--experimental_throttle_action_cache_check`
 flag."

This reverts commit 1e17348da7e45c00cb474390a3b8ed3103b6b5cf.

This was requested in #19924.

Closes #20162.

PiperOrigin-RevId: 581897901
Change-Id: Ifea2330c45c97db4454ffdcc31b7b7af640cd659
---
 .../build/lib/analysis/config/CoreOptions.java        | 10 ++++++++++
 .../build/lib/bazel/rules/BazelRulesModule.java       | 11 -----------
 .../build/lib/skyframe/SkyframeActionExecutor.java    |  5 ++++-
 3 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/CoreOptions.java b/src/main/java/com/google/devtools/build/lib/analysis/config/CoreOptions.java
index 2075543cad53c9..25970a6c038059 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/config/CoreOptions.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/CoreOptions.java
@@ -919,6 +919,16 @@ public OutputPathsConverter() {
               + " of failing. This is to help use cquery diagnose failures in select.")
   public boolean debugSelectsAlwaysSucceed;
 
+  @Option(
+      name = "experimental_throttle_action_cache_check",
+      defaultValue = "true",
+      converter = BooleanConverter.class,
+      documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
+      metadataTags = OptionMetadataTag.EXPERIMENTAL,
+      effectTags = {OptionEffectTag.EXECUTION},
+      help = "Whether to throttle the check whether an action is cached.")
+  public boolean throttleActionCacheCheck;
+
   /** Ways configured targets may provide the {@link Fragment}s they require. */
   public enum IncludeConfigFragmentsEnum {
     /**
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRulesModule.java b/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRulesModule.java
index 36d110f654a6a7..6130ab02df9a3b 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRulesModule.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRulesModule.java
@@ -25,7 +25,6 @@
 import com.google.devtools.build.lib.runtime.Command;
 import com.google.devtools.build.lib.runtime.CommandEnvironment;
 import com.google.devtools.build.lib.util.ResourceFileLoader;
-import com.google.devtools.common.options.Converters.BooleanConverter;
 import com.google.devtools.common.options.Option;
 import com.google.devtools.common.options.OptionDocumentationCategory;
 import com.google.devtools.common.options.OptionEffectTag;
@@ -253,16 +252,6 @@ public static class BuildGraveyardOptions extends OptionsBase {
         help = "This option is deprecated and has no effect and will be removed in the future.")
     public boolean deferParamFiles;
 
-    @Option(
-        name = "experimental_throttle_action_cache_check",
-        defaultValue = "true",
-        converter = BooleanConverter.class,
-        documentationCategory = OptionDocumentationCategory.UNDOCUMENTED,
-        metadataTags = OptionMetadataTag.EXPERIMENTAL,
-        effectTags = {OptionEffectTag.EXECUTION},
-        help = "no-op")
-    public boolean throttleActionCacheCheck;
-
     @Option(
         name = "check_fileset_dependencies_recursively",
         defaultValue = "true",
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeActionExecutor.java b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeActionExecutor.java
index b75b2cebdde2fb..81a2ef092f6ecf 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeActionExecutor.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeActionExecutor.java
@@ -310,7 +310,10 @@ void prepareForExecution(
     freeDiscoveredInputsAfterExecution =
         !trackIncrementalState && options.getOptions(CoreOptions.class).actionListeners.isEmpty();
 
-    this.cacheHitSemaphore = new Semaphore(ResourceUsage.getAvailableProcessors());
+    this.cacheHitSemaphore =
+        options.getOptions(CoreOptions.class).throttleActionCacheCheck
+            ? new Semaphore(ResourceUsage.getAvailableProcessors())
+            : null;
 
     this.actionExecutionSemaphore =
         buildRequestOptions.useSemaphoreForJobs ? new Semaphore(buildRequestOptions.jobs) : null;