Run the analysis phase with as many threads as the user wants. In order to avoid memory blow-up intra-configured-target analysis, use a semaphore to ensure that CPU-bound work only occurs on #CPU-many threads.
RELNOTES: Use --loading_phase_threads to control the number of threads used during the loading/analysis phase.
--
MOS_MIGRATED_REVID=139477645
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java
index 71a938a..38db025 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/ConfiguredTargetFunction.java
@@ -87,6 +87,7 @@
import java.util.Map.Entry;
import java.util.Objects;
import java.util.Set;
+import java.util.concurrent.Semaphore;
import javax.annotation.Nullable;
/**
@@ -131,11 +132,15 @@
private final BuildViewProvider buildViewProvider;
private final RuleClassProvider ruleClassProvider;
+ private final Semaphore cpuBoundSemaphore;
- ConfiguredTargetFunction(BuildViewProvider buildViewProvider,
- RuleClassProvider ruleClassProvider) {
+ ConfiguredTargetFunction(
+ BuildViewProvider buildViewProvider,
+ RuleClassProvider ruleClassProvider,
+ Semaphore cpuBoundSemaphore) {
this.buildViewProvider = buildViewProvider;
this.ruleClassProvider = ruleClassProvider;
+ this.cpuBoundSemaphore = cpuBoundSemaphore;
}
private static boolean useDynamicConfigurations(BuildConfiguration config) {
@@ -195,6 +200,12 @@
TargetAndConfiguration ctgValue = new TargetAndConfiguration(target, configuration);
SkyframeDependencyResolver resolver = view.createDependencyResolver(env);
+
+ // TODO(janakr): this acquire() call may tie up this thread indefinitely, reducing the
+ // parallelism of Skyframe. This is a strict improvement over the prior state of the code, in
+ // which we ran with #processors threads, but ideally we would call #tryAcquire here, and if we
+ // failed, would exit this SkyFunction and restart it when permits were available.
+ cpuBoundSemaphore.acquire();
try {
// Get the configuration targets that trigger this rule's configurable attributes.
ImmutableMap<Label, ConfigMatchingProvider> configConditions = getConfigConditions(
@@ -256,6 +267,8 @@
}
throw new ConfiguredTargetFunctionException(
new ConfiguredValueCreationException(e.getMessage(), analysisRootCause));
+ } finally {
+ cpuBoundSemaphore.release();
}
}
