Make references to syscall caches less confusing.

`PerBuildSyscallCache` is renamed `DefaultSyscallCache`. It is server-scoped, not per-build scoped, although `clear()` is called between builds (this is now documented on `SyscallCache`).

Variables named `perBuild` or `perCommand` are adjusted accordingly.

PiperOrigin-RevId: 493672664
Change-Id: Ifa70d8c636fec4b9bc9e194691f865569de3ff2a

src/main/java/com/google/devtools/build/lib/BUILD

@@ -362,14 +362,14 @@ java_library(
         "//src/main/java/com/google/devtools/build/lib/skyframe:configuration_phase_started_event",
         "//src/main/java/com/google/devtools/build/lib/skyframe:configured_target_key",
         "//src/main/java/com/google/devtools/build/lib/skyframe:configured_target_progress_receiver",
+        "//src/main/java/com/google/devtools/build/lib/skyframe:default_syscall_cache",
         "//src/main/java/com/google/devtools/build/lib/skyframe:diff_awareness",
         "//src/main/java/com/google/devtools/build/lib/skyframe:execution_finished_event",
         "//src/main/java/com/google/devtools/build/lib/skyframe:incremental_package_roots",
         "//src/main/java/com/google/devtools/build/lib/skyframe:loading_phase_started_event",
         "//src/main/java/com/google/devtools/build/lib/skyframe:package_progress_receiver",
         "//src/main/java/com/google/devtools/build/lib/skyframe:package_roots_no_symlink_creation",
         "//src/main/java/com/google/devtools/build/lib/skyframe:package_value",
-        "//src/main/java/com/google/devtools/build/lib/skyframe:per_build_syscall_cache",
         "//src/main/java/com/google/devtools/build/lib/skyframe:precomputed_value",
         "//src/main/java/com/google/devtools/build/lib/skyframe:repository_mapping_value",
         "//src/main/java/com/google/devtools/build/lib/skyframe:sky_functions",

src/main/java/com/google/devtools/build/lib/runtime/BlazeWorkspace.java

@@ -63,7 +63,7 @@ public final class BlazeWorkspace {
 
   private final BlazeDirectories directories;
   private final SkyframeExecutor skyframeExecutor;
-  private final SyscallCache perCommandSyscallCache;
+  private final SyscallCache syscallCache;
 
   /**
    * Loaded lazily on the first build command that enables the action cache. Cleared on a build
@@ -84,7 +84,7 @@ public BlazeWorkspace(
       WorkspaceStatusAction.Factory workspaceStatusActionFactory,
       BinTools binTools,
       @Nullable AllocationTracker allocationTracker,
-      SyscallCache perCommandSyscallCache) {
+      SyscallCache syscallCache) {
     this.runtime = runtime;
     this.eventBusExceptionHandler = Preconditions.checkNotNull(eventBusExceptionHandler);
     this.workspaceStatusActionFactory = workspaceStatusActionFactory;
@@ -93,7 +93,7 @@ public BlazeWorkspace(
 
     this.directories = directories;
     this.skyframeExecutor = skyframeExecutor;
-    this.perCommandSyscallCache = perCommandSyscallCache;
+    this.syscallCache = syscallCache;
 
     if (directories.inWorkspace()) {
       writeOutputBaseReadmeFile();
@@ -211,7 +211,7 @@ public CommandEnvironment initCommand(
             Thread.currentThread(),
             command,
             options,
-            perCommandSyscallCache,
+            syscallCache,
             warnings,
             waitTimeInMs,
             commandStartTime,

src/main/java/com/google/devtools/build/lib/runtime/WorkspaceBuilder.java

@@ -23,8 +23,8 @@
 import com.google.devtools.build.lib.exec.BinTools;
 import com.google.devtools.build.lib.packages.PackageFactory;
 import com.google.devtools.build.lib.profiler.memory.AllocationTracker;
+import com.google.devtools.build.lib.skyframe.DefaultSyscallCache;
 import com.google.devtools.build.lib.skyframe.DiffAwareness;
-import com.google.devtools.build.lib.skyframe.PerBuildSyscallCache;
 import com.google.devtools.build.lib.skyframe.SequencedSkyframeExecutorFactory;
 import com.google.devtools.build.lib.skyframe.SkyframeExecutor;
 import com.google.devtools.build.lib.skyframe.SkyframeExecutorFactory;
@@ -60,7 +60,7 @@ public final class WorkspaceBuilder {
   private SkyframeExecutorRepositoryHelpersHolder skyframeExecutorRepositoryHelpersHolder = null;
 
   @Nullable private SkyframeExecutor.SkyKeyStateReceiver skyKeyStateReceiver = null;
-  private SyscallCache perCommandSyscallCache;
+  private SyscallCache syscallCache;
 
   WorkspaceBuilder(BlazeDirectories directories, BinTools binTools) {
     this.directories = directories;
@@ -88,12 +88,6 @@ public static int getSyscallCacheInitialCapacity() {
     return (int) scaledMemory;
   }
 
-  public static PerBuildSyscallCache createPerBuildSyscallCache() {
-    return PerBuildSyscallCache.newBuilder()
-        .setInitialCapacity(getSyscallCacheInitialCapacity())
-        .build();
-  }
-
   BlazeWorkspace build(
       BlazeRuntime runtime,
       PackageFactory packageFactory,
@@ -103,12 +97,15 @@ BlazeWorkspace build(
     if (skyframeExecutorFactory == null) {
       skyframeExecutorFactory = new SequencedSkyframeExecutorFactory();
     }
-    if (perCommandSyscallCache == null) {
-      perCommandSyscallCache = createPerBuildSyscallCache();
+    if (syscallCache == null) {
+      syscallCache =
+          DefaultSyscallCache.newBuilder()
+              .setInitialCapacity(getSyscallCacheInitialCapacity())
+              .build();
     }
 
     SingleFileSystemSyscallCache singleFsSyscallCache =
-        new SingleFileSystemSyscallCache(perCommandSyscallCache, runtime.getFileSystem());
+        new SingleFileSystemSyscallCache(syscallCache, runtime.getFileSystem());
 
     SkyframeExecutor skyframeExecutor =
         skyframeExecutorFactory.create(
@@ -173,13 +170,10 @@ public WorkspaceBuilder setAllocationTracker(AllocationTracker allocationTracker
   }
 
   @CanIgnoreReturnValue
-  public WorkspaceBuilder setPerCommandSyscallCache(SyscallCache perCommandSyscallCache) {
+  public WorkspaceBuilder setSyscallCache(SyscallCache syscallCache) {
     Preconditions.checkState(
-        this.perCommandSyscallCache == null,
-        "Set twice: %s %s",
-        this.perCommandSyscallCache,
-        perCommandSyscallCache);
-    this.perCommandSyscallCache = Preconditions.checkNotNull(perCommandSyscallCache);
+        this.syscallCache == null, "Set twice: %s %s", this.syscallCache, syscallCache);
+    this.syscallCache = Preconditions.checkNotNull(syscallCache);
     return this;
   }
 

src/main/java/com/google/devtools/build/lib/skyframe/BUILD

@@ -1814,8 +1814,8 @@ java_library(
 )
 
 java_library(
-    name = "per_build_syscall_cache",
-    srcs = ["PerBuildSyscallCache.java"],
+    name = "default_syscall_cache",
+    srcs = ["DefaultSyscallCache.java"],
     deps = [
         "//src/main/java/com/google/devtools/build/lib/util",
         "//src/main/java/com/google/devtools/build/lib/vfs",

src/main/java/com/google/devtools/build/lib/skyframe/PerBuildSyscallCache.java → src/main/java/com/google/devtools/build/lib/skyframe/DefaultSyscallCache.java

@@ -30,13 +30,15 @@
 import javax.annotation.Nullable;
 
 /**
- * A per-build cache of filesystem operations.
+ * A basic implementation of {@link SyscallCache} that caches stat and readdir operations, used if
+ * no custom cache is set in {@link
+ * com.google.devtools.build.lib.runtime.WorkspaceBuilder#setSyscallCache}.
  *
  * <p>Allows non-Skyframe operations (like non-Skyframe globbing) to share a filesystem cache with
  * Skyframe operations, and may be able to answer questions (like the type of a file) based on
  * existing data (like the directory listing of a parent) without filesystem access.
  */
-public final class PerBuildSyscallCache implements SyscallCache {
+public final class DefaultSyscallCache implements SyscallCache {
   private final Supplier<LoadingCache<Pair<Path, Symlinks>, Object>> statCacheSupplier;
   private final Supplier<LoadingCache<Path, Object>> readdirCacheSupplier;
 
@@ -47,7 +49,7 @@ public final class PerBuildSyscallCache implements SyscallCache {
 
   private static final FileStatus NO_STATUS = new FakeFileStatus();
 
-  private PerBuildSyscallCache(
+  private DefaultSyscallCache(
       Supplier<LoadingCache<Pair<Path, Symlinks>, Object>> statCacheSupplier,
       Supplier<LoadingCache<Path, Object>> readdirCacheSupplier) {
     this.statCacheSupplier = statCacheSupplier;
@@ -89,7 +91,7 @@ public Builder setInitialCapacity(int initialCapacity) {
       return this;
     }
 
-    public PerBuildSyscallCache build() {
+    public DefaultSyscallCache build() {
       Caffeine<Object, Object> statCacheBuilder = Caffeine.newBuilder();
       if (maxStats != UNSET) {
         statCacheBuilder.maximumSize(maxStats);
@@ -102,9 +104,9 @@ public PerBuildSyscallCache build() {
         statCacheBuilder.initialCapacity(initialCapacity);
         readdirCacheBuilder.initialCapacity(initialCapacity);
       }
-      return new PerBuildSyscallCache(
-          () -> statCacheBuilder.build(PerBuildSyscallCache::statImpl),
-          () -> readdirCacheBuilder.build(PerBuildSyscallCache::readdirImpl));
+      return new DefaultSyscallCache(
+          () -> statCacheBuilder.build(DefaultSyscallCache::statImpl),
+          () -> readdirCacheBuilder.build(DefaultSyscallCache::readdirImpl));
     }
   }
 

src/main/java/com/google/devtools/build/lib/skyframe/DirectoryListingStateFunction.java

@@ -34,7 +34,7 @@ public class DirectoryListingStateFunction implements SkyFunction {
   private final ExternalFilesHelper externalFilesHelper;
 
   /**
-   * A file-system abstraction to use. This can e.g. be a {@link PerBuildSyscallCache} which helps
+   * A file-system abstraction to use. This can e.g. be a {@link DefaultSyscallCache} which helps
    * re-use the results of expensive readdir() operations, that are likely already executed for
    * evaluating globs.
    */

src/main/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutor.java

@@ -172,7 +172,7 @@ private SequencedSkyframeExecutor(
       Iterable<? extends DiffAwareness.Factory> diffAwarenessFactories,
       WorkspaceInfoFromDiffReceiver workspaceInfoFromDiffReceiver,
       ImmutableMap<SkyFunctionName, SkyFunction> extraSkyFunctions,
-      SyscallCache perCommandSyscallCache,
+      SyscallCache syscallCache,
       SkyFunction ignoredPackagePrefixesFunction,
       CrossRepositoryLabelViolationStrategy crossRepositoryLabelViolationStrategy,
       ImmutableList<BuildFileName> buildFilesByPriority,
@@ -189,14 +189,14 @@ private SequencedSkyframeExecutor(
         actionKeyContext,
         workspaceStatusActionFactory,
         extraSkyFunctions,
-        perCommandSyscallCache,
+        syscallCache,
         ExternalFileAction.DEPEND_ON_EXTERNAL_PKG_FOR_EXTERNAL_REPO_PATHS,
         ignoredPackagePrefixesFunction,
         crossRepositoryLabelViolationStrategy,
         buildFilesByPriority,
         externalPackageHelper,
         actionOnIOExceptionReadingBuildFile,
-        /*shouldUnblockCpuWorkWhenFetchingDeps=*/ false,
+        /* shouldUnblockCpuWorkWhenFetchingDeps= */ false,
         new PackageProgressReceiver(),
         new ConfiguredTargetProgressReceiver(),
         skyKeyStateReceiver,
@@ -487,8 +487,7 @@ private void handleDiffsWithMissingDiffInformation(
               .build();
       memoizingEvaluator.evaluate(ImmutableList.of(), evaluationContext);
 
-      FilesystemValueChecker fsvc =
-          new FilesystemValueChecker(tsgm, perCommandSyscallCache, fsvcThreads);
+      FilesystemValueChecker fsvc = new FilesystemValueChecker(tsgm, syscallCache, fsvcThreads);
       // We need to manually check for changes to known files. This entails finding all dirty file
       // system values under package roots for which we don't have diff information. If at least
       // one path entry doesn't have diff information, then we're going to have to iterate over
@@ -558,8 +557,7 @@ private void handleDiffsWithMissingDiffInformation(
       logger.atInfo().log(
           "About to scan %d external files",
           externalFilesKnowledge.nonOutputExternalFilesSeen.size());
-      FilesystemValueChecker fsvc =
-          new FilesystemValueChecker(tsgm, perCommandSyscallCache, fsvcThreads);
+      FilesystemValueChecker fsvc = new FilesystemValueChecker(tsgm, syscallCache, fsvcThreads);
       ImmutableBatchDirtyResult batchDirtyResult;
       try (SilentCloseable c = Profiler.instance().profile("fsvc.getDirtyExternalKeys")) {
         Map<SkyKey, SkyValue> externalDirtyNodes = new ConcurrentHashMap<>();
@@ -730,7 +728,7 @@ protected void invalidateFilesUnderPathForTestingImpl(
     Differencer.Diff diff;
     if (modifiedFileSet.treatEverythingAsModified()) {
       diff =
-          new FilesystemValueChecker(tsgm, perCommandSyscallCache, /*numThreads=*/ 200)
+          new FilesystemValueChecker(tsgm, syscallCache, /* numThreads= */ 200)
               .getDirtyKeys(memoizingEvaluator.getValues(), new BasicFilesystemDirtinessChecker());
     } else {
       diff = getDiff(tsgm, modifiedFileSet, pathEntry, /* fsvcThreads= */ 200);
@@ -757,7 +755,7 @@ public void detectModifiedOutputFiles(
     long startTime = System.nanoTime();
     FilesystemValueChecker fsvc =
         new FilesystemValueChecker(
-            Preconditions.checkNotNull(tsgm.get()), perCommandSyscallCache, fsvcThreads);
+            Preconditions.checkNotNull(tsgm.get()), syscallCache, fsvcThreads);
     BatchStat batchStatter = outputService == null ? null : outputService.getBatchStatter();
     recordingDiffer.invalidate(
         fsvc.getDirtyActionValues(
@@ -977,7 +975,7 @@ public static final class Builder {
     private SkyFunction ignoredPackagePrefixesFunction;
     private BugReporter bugReporter = BugReporter.defaultInstance();
     private SkyKeyStateReceiver skyKeyStateReceiver = SkyKeyStateReceiver.NULL_INSTANCE;
-    private SyscallCache perCommandSyscallCache = null;
+    private SyscallCache syscallCache = null;
 
     private Builder() {}
 
@@ -1004,7 +1002,7 @@ public SequencedSkyframeExecutor build() {
               diffAwarenessFactories,
               workspaceInfoFromDiffReceiver,
               extraSkyFunctions,
-              Preconditions.checkNotNull(perCommandSyscallCache),
+              Preconditions.checkNotNull(syscallCache),
               ignoredPackagePrefixesFunction,
               crossRepositoryLabelViolationStrategy,
               buildFilesByPriority,
@@ -1127,8 +1125,8 @@ public Builder setSkyKeyStateReceiver(SkyKeyStateReceiver skyKeyStateReceiver) {
     }
 
     @CanIgnoreReturnValue
-    public Builder setPerCommandSyscallCache(SyscallCache perCommandSyscallCache) {
-      this.perCommandSyscallCache = perCommandSyscallCache;
+    public Builder setSyscallCache(SyscallCache syscallCache) {
+      this.syscallCache = syscallCache;
       return this;
     }
   }

src/main/java/com/google/devtools/build/lib/skyframe/SequencedSkyframeExecutorFactory.java

@@ -27,6 +27,7 @@
 
 /** A factory of SkyframeExecutors that returns SequencedSkyframeExecutor. */
 public final class SequencedSkyframeExecutorFactory implements SkyframeExecutorFactory {
+
   @Override
   public SkyframeExecutor create(
       PackageFactory pkgFactory,
@@ -36,7 +37,7 @@ public SkyframeExecutor create(
       Factory workspaceStatusActionFactory,
       Iterable<? extends DiffAwareness.Factory> diffAwarenessFactories,
       ImmutableMap<SkyFunctionName, SkyFunction> extraSkyFunctions,
-      SyscallCache perCommandSyscallCache,
+      SyscallCache syscallCache,
       @Nullable SkyframeExecutorRepositoryHelpersHolder repositoryHelpersHolder,
       SkyframeExecutor.SkyKeyStateReceiver skyKeyStateReceiver,
       BugReporter bugReporter) {
@@ -48,7 +49,7 @@ public SkyframeExecutor create(
         .setWorkspaceStatusActionFactory(workspaceStatusActionFactory)
         .setDiffAwarenessFactories(diffAwarenessFactories)
         .setExtraSkyFunctions(extraSkyFunctions)
-        .setPerCommandSyscallCache(perCommandSyscallCache)
+        .setSyscallCache(syscallCache)
         .setRepositoryHelpersHolder(repositoryHelpersHolder)
         .setSkyKeyStateReceiver(skyKeyStateReceiver)
         .setBugReporter(bugReporter)