Optimize GC churn of parameter bindings performed before each user defined function call.
RELNOTES: None
PiperOrigin-RevId: 188199514
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Environment.java b/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
index d4e6403..fa6f7e8 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
@@ -16,6 +16,7 @@
import com.google.common.base.Joiner;
import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Sets;
import com.google.devtools.build.lib.cmdline.Label;
@@ -142,6 +143,21 @@
? ImmutableEmptyLexicalFrame.INSTANCE
: new MutableLexicalFrame(mutability);
}
+
+ static LexicalFrame createForUserDefinedFunctionCall(
+ ImmutableList<String> argumentNames, Object[] argumentValues, Environment env)
+ throws EvalException {
+ Preconditions.checkState(!env.mutability().isFrozen());
+ MutableLexicalFrame frame = new MutableLexicalFrame(
+ env.mutability(), /*initialCapacity=*/ argumentNames.size());
+ for (int i = 0; i < argumentNames.size(); i++) {
+ String argumentName = argumentNames.get(i);
+ Object argumentValue = argumentValues[i];
+ env.sanityCheckBindingUpdate(argumentName, argumentValue);
+ frame.putUnsafe(argumentName, argumentValue);
+ }
+ return frame;
+ }
}
private static final class ImmutableEmptyLexicalFrame implements LexicalFrame {
@@ -184,10 +200,16 @@
private static final class MutableLexicalFrame implements LexicalFrame {
private final Mutability mutability;
/** Bindings are maintained in order of creation. */
- private final LinkedHashMap<String, Object> bindings = new LinkedHashMap<>();
+ private final LinkedHashMap<String, Object> bindings;
- public MutableLexicalFrame(Mutability mutability) {
+ private MutableLexicalFrame(Mutability mutability, int initialCapacity) {
this.mutability = mutability;
+ this.bindings = new LinkedHashMap<>(initialCapacity);
+ }
+
+ private MutableLexicalFrame(Mutability mutability) {
+ this.mutability = mutability;
+ this.bindings = new LinkedHashMap<>();
}
@Override
@@ -204,6 +226,10 @@
@Override
public void put(Environment env, String varname, Object value) throws MutabilityException {
Mutability.checkMutable(this, env.mutability());
+ putUnsafe(varname, value);
+ }
+
+ private void putUnsafe(String varname, Object value) {
bindings.put(varname, value);
}
@@ -950,16 +976,7 @@
}
}
- /**
- * Modifies a binding in the current Frame of this Environment, as would an
- * {@link AssignmentStatement}. Does not try to modify an inherited binding.
- * This will shadow any inherited binding, which may be an error
- * that you want to guard against before calling this function.
- * @param varname the name of the variable to be bound
- * @param value the value to bind to the variable
- * @return this Environment, in fluid style
- */
- public Environment update(String varname, Object value) throws EvalException {
+ private void sanityCheckBindingUpdate(String varname, Object value) throws EvalException {
Preconditions.checkNotNull(value, "update(value == null)");
// prevents clashes between static and dynamic variables.
if (dynamicFrame.get(varname) != null) {
@@ -970,6 +987,19 @@
throw new EvalException(
null, String.format("Trying to update read-only global variable '%s'", varname));
}
+ }
+
+ /**
+ * Modifies a binding in the current Frame of this Environment, as would an
+ * {@link AssignmentStatement}. Does not try to modify an inherited binding.
+ * This will shadow any inherited binding, which may be an error
+ * that you want to guard against before calling this function.
+ * @param varname the name of the variable to be bound
+ * @param value the value to bind to the variable
+ * @return this Environment, in fluid style
+ */
+ public Environment update(String varname, Object value) throws EvalException {
+ sanityCheckBindingUpdate(varname, value);
try {
currentFrame().put(this, varname, Preconditions.checkNotNull(value));
} catch (MutabilityException e) {
