From 13e010a47627d47bdc44147436a79d33e811e0d9 Mon Sep 17 00:00:00 2001
From: Eric Anderson <ejona@google.com>
Date: Thu, 10 Jul 2025 11:02:48 -0700
Subject: [PATCH] core: Don't pre-compute DEADLINE_EXCEEDED message for delayed
 calls

The main reason I made a change here was to fix the tense from the
deadline "will be exceeded in" to "was exceeded after". But we really
don't want to be doing the string formatting unless the deadline is
actually exceeded. There were a few more changes to make some variables
effectively final.
---
 .../io/grpc/internal/DelayedClientCall.java   | 46 +++++++++----------
 .../java/io/grpc/xds/XdsNameResolverTest.java |  2 +-
 2 files changed, 23 insertions(+), 25 deletions(-)

diff --git a/core/src/main/java/io/grpc/internal/DelayedClientCall.java b/core/src/main/java/io/grpc/internal/DelayedClientCall.java
index f2b0c9a3f06..253237c3c7d 100644
--- a/core/src/main/java/io/grpc/internal/DelayedClientCall.java
+++ b/core/src/main/java/io/grpc/internal/DelayedClientCall.java
@@ -96,15 +96,13 @@ private boolean isAbeforeB(@Nullable Deadline a, @Nullable Deadline b) {
   private ScheduledFuture<?> scheduleDeadlineIfNeeded(
       ScheduledExecutorService scheduler, @Nullable Deadline deadline) {
     Deadline contextDeadline = context.getDeadline();
-    if (deadline == null && contextDeadline == null) {
-      return null;
-    }
-    long remainingNanos = Long.MAX_VALUE;
-    if (deadline != null) {
+    String deadlineName;
+    long remainingNanos;
+    if (deadline != null && isAbeforeB(deadline, contextDeadline)) {
+      deadlineName = "CallOptions";
       remainingNanos = deadline.timeRemaining(NANOSECONDS);
-    }
-
-    if (contextDeadline != null && contextDeadline.timeRemaining(NANOSECONDS) < remainingNanos) {
+    } else if (contextDeadline != null) {
+      deadlineName = "Context";
       remainingNanos = contextDeadline.timeRemaining(NANOSECONDS);
       if (logger.isLoggable(Level.FINE)) {
         StringBuilder builder =
@@ -121,29 +119,29 @@ private ScheduledFuture<?> scheduleDeadlineIfNeeded(
         }
         logger.fine(builder.toString());
       }
-    }
-
-    long seconds = Math.abs(remainingNanos) / TimeUnit.SECONDS.toNanos(1);
-    long nanos = Math.abs(remainingNanos) % TimeUnit.SECONDS.toNanos(1);
-    final StringBuilder buf = new StringBuilder();
-    String deadlineName = isAbeforeB(contextDeadline, deadline) ? "Context" : "CallOptions";
-    if (remainingNanos < 0) {
-      buf.append("ClientCall started after ");
-      buf.append(deadlineName);
-      buf.append(" deadline was exceeded. Deadline has been exceeded for ");
     } else {
-      buf.append("Deadline ");
-      buf.append(deadlineName);
-      buf.append(" will be exceeded in ");
+      return null;
     }
-    buf.append(seconds);
-    buf.append(String.format(Locale.US, ".%09d", nanos));
-    buf.append("s. ");
 
     /* Cancels the call if deadline exceeded prior to the real call being set. */
     class DeadlineExceededRunnable implements Runnable {
       @Override
       public void run() {
+        long seconds = Math.abs(remainingNanos) / TimeUnit.SECONDS.toNanos(1);
+        long nanos = Math.abs(remainingNanos) % TimeUnit.SECONDS.toNanos(1);
+        StringBuilder buf = new StringBuilder();
+        if (remainingNanos < 0) {
+          buf.append("ClientCall started after ");
+          buf.append(deadlineName);
+          buf.append(" deadline was exceeded. Deadline has been exceeded for ");
+        } else {
+          buf.append("Deadline ");
+          buf.append(deadlineName);
+          buf.append(" was exceeded after ");
+        }
+        buf.append(seconds);
+        buf.append(String.format(Locale.US, ".%09d", nanos));
+        buf.append("s");
         cancel(
             Status.DEADLINE_EXCEEDED.withDescription(buf.toString()),
             // We should not cancel the call if the realCall is set because there could be a
diff --git a/xds/src/test/java/io/grpc/xds/XdsNameResolverTest.java b/xds/src/test/java/io/grpc/xds/XdsNameResolverTest.java
index 7015a43f6ed..3fa31aedf6a 100644
--- a/xds/src/test/java/io/grpc/xds/XdsNameResolverTest.java
+++ b/xds/src/test/java/io/grpc/xds/XdsNameResolverTest.java
@@ -2239,7 +2239,7 @@ public long nanoTime() {
     assertThat(testCall).isNull();
     verifyRpcDelayedThenAborted(observer, 4000L, Status.DEADLINE_EXCEEDED.withDescription(
         "Deadline exceeded after up to 5000 ns of fault-injected delay:"
-            + " Deadline CallOptions will be exceeded in 0.000004000s. "));
+            + " Deadline CallOptions was exceeded after 0.000004000s"));
   }
 
   @Test