Add extra comment for implementation.

Add a comment noting that the check to throw the exception is
intentionally second so that it's out of the critical path.

Bug: 118339123
Test: N/A
Change-Id: I36c5ea67579bcd7906f711530392110d9987ffb4

1 files changed, 3 insertions, 0 deletions

diff --git a/core/java/android/util/SparseBooleanArray.java b/core/java/android/util/SparseBooleanArray.java
index 557404764aed..d6e0e53a210d 100644
--- a/core/java/android/util/SparseBooleanArray.java
+++ b/core/java/android/util/SparseBooleanArray.java
@@ -175,6 +175,7 @@ public class SparseBooleanArray implements Cloneable {
     public int keyAt(int index) {
         if (index >= mSize && UtilConfig.sThrowExceptionForUpperArrayOutOfBounds) {
             // The array might be slightly bigger than mSize, in which case, indexing won't fail.
+            // Check if exception should be thrown outside of the critical path.
             throw new ArrayIndexOutOfBoundsException(index);
         }
         return mKeys[index];
@@ -199,6 +200,7 @@ public class SparseBooleanArray implements Cloneable {
     public boolean valueAt(int index) {
         if (index >= mSize && UtilConfig.sThrowExceptionForUpperArrayOutOfBounds) {
             // The array might be slightly bigger than mSize, in which case, indexing won't fail.
+            // Check if exception should be thrown outside of the critical path.
             throw new ArrayIndexOutOfBoundsException(index);
         }
         return mValues[index];
@@ -215,6 +217,7 @@ public class SparseBooleanArray implements Cloneable {
     public void setValueAt(int index, boolean value) {
         if (index >= mSize && UtilConfig.sThrowExceptionForUpperArrayOutOfBounds) {
             // The array might be slightly bigger than mSize, in which case, indexing won't fail.
+            // Check if exception should be thrown outside of the critical path.
             throw new ArrayIndexOutOfBoundsException(index);
         }
         mValues[index] = value;