RELNOTES: --keep_incrementality_data flag allows Bazel servers to be run in memory-saving non-incremental mode independent of --batch and --discard_analysis_cache.

A command run with --nokeep_incrementality_data will discard data that would be needed for incremental builds. Subsequent commands can be sent to the same server, but they will not get the benefit of incrementality from this command. However, if --keep_incrementality_data is specified on a subsequent command, the commands after that will get the benefits of incrementality.

There are two benefits to not being dependent on --batch. First, this allows Bazel servers to be run in extreme memory-saving mode without the startup penalties (JVM startup, JITting) that --batch execution imposes. Second, this allows Bazel developers to inspect the state of a Bazel server after an extreme memory-saving build.

In order to avoid discarding data unnecessarily (for instance, on a "bazel info used-heap-size-after-gc" or "bazel dump --skyframe=summary") the actual resetting of the graph is done lazily, right before its use in SequencedSkyframeExecutor#sync. This is morally a partial rollback of https://github.com/bazelbuild/bazel/commit/98cd82cbdcac7c48164a611c5a9aa8fc2f1720ef.

For now, our tests specify all of the flags. After this change sticks, I plan to get rid of the --batch flag from these tests, which should allow for some clean-ups. Eventually --batch and --discard_analysis_cache may not imply that we don't keep incremental state: we can require that it be specified explicitly.

PiperOrigin-RevId: 175335075

4 files changed, 10 insertions, 8 deletions

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 d8e5a51876..54552a6c5f 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
@@ -21,7 +21,6 @@ import com.google.common.eventbus.EventBus;
 import com.google.devtools.build.lib.actions.PackageRootResolver;
 import com.google.devtools.build.lib.actions.cache.ActionCache;
 import com.google.devtools.build.lib.analysis.BlazeDirectories;
-import com.google.devtools.build.lib.analysis.BuildView;
 import com.google.devtools.build.lib.analysis.SkyframePackageRootResolver;
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
 import com.google.devtools.build.lib.analysis.config.DefaultsPackage;
@@ -607,9 +606,10 @@ public final class CommandEnvironment {
     // Fail fast in the case where a Blaze command forgets to install the package path correctly.
     skyframeExecutor.setActive(false);
     // Let skyframe figure out if it needs to store graph edges for this build.
-    skyframeExecutor.decideKeepIncrementalStateAndResetEvaluatorIfNecessary(
+    skyframeExecutor.decideKeepIncrementalState(
         runtime.getStartupOptionsProvider().getOptions(BlazeServerStartupOptions.class).batch,
-        options.getOptions(BuildView.Options.class));
+        options,
+        reporter);
 
     // Start the performance and memory profilers.
     runtime.beforeCommand(this, commonOptions, execStartTimeNanos);
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/BuildCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/BuildCommand.java
index 5f8077f2e6..d0aa57bb81 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/BuildCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/BuildCommand.java
@@ -15,7 +15,7 @@ package com.google.devtools.build.lib.runtime.commands;
 
 import com.google.devtools.build.lib.analysis.BuildView;
 import com.google.devtools.build.lib.buildtool.BuildRequest;
-import com.google.devtools.build.lib.buildtool.BuildRequest.BuildRequestOptions;
+import com.google.devtools.build.lib.buildtool.BuildRequestOptions;
 import com.google.devtools.build.lib.buildtool.BuildTool;
 import com.google.devtools.build.lib.exec.ExecutionOptions;
 import com.google.devtools.build.lib.exec.local.LocalExecutionOptions;
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/CleanCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/CleanCommand.java
index 88ff555570..ba0ca599ba 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/CleanCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/CleanCommand.java
@@ -15,7 +15,7 @@ package com.google.devtools.build.lib.runtime.commands;
 
 import com.google.devtools.build.lib.actions.ExecException;
 import com.google.devtools.build.lib.analysis.NoBuildEvent;
-import com.google.devtools.build.lib.buildtool.BuildRequest;
+import com.google.devtools.build.lib.buildtool.BuildRequestOptions;
 import com.google.devtools.build.lib.buildtool.OutputDirectoryLinksUtils;
 import com.google.devtools.build.lib.events.Event;
 import com.google.devtools.build.lib.runtime.BlazeCommand;
@@ -182,8 +182,10 @@ public final class CleanCommand implements BlazeCommand {
     env.getReporter().handle(Event.info(null/*location*/, cleanBanner));
 
     try {
-      String symlinkPrefix = options.getOptions(BuildRequest.BuildRequestOptions.class)
-          .getSymlinkPrefix(env.getRuntime().getProductName());
+      String symlinkPrefix =
+          options
+              .getOptions(BuildRequestOptions.class)
+              .getSymlinkPrefix(env.getRuntime().getProductName());
       actuallyClean(env, env.getOutputBase(), expunge, expungeAsync, async, symlinkPrefix);
       return ExitCode.SUCCESS;
     } catch (IOException e) {
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/RunCommand.java b/src/main/java/com/google/devtools/build/lib/runtime/commands/RunCommand.java
index 17f204ae8f..aee56d498a 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/commands/RunCommand.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/RunCommand.java
@@ -28,7 +28,7 @@ import com.google.devtools.build.lib.analysis.actions.CommandLine;
 import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
 import com.google.devtools.build.lib.analysis.config.RunUnder;
 import com.google.devtools.build.lib.buildtool.BuildRequest;
-import com.google.devtools.build.lib.buildtool.BuildRequest.BuildRequestOptions;
+import com.google.devtools.build.lib.buildtool.BuildRequestOptions;
 import com.google.devtools.build.lib.buildtool.BuildResult;
 import com.google.devtools.build.lib.buildtool.BuildTool;
 import com.google.devtools.build.lib.buildtool.OutputDirectoryLinksUtils;