From fae934c4b181d403625a08831eec291f4329253f Mon Sep 17 00:00:00 2001
From: Martin Kustermann <kustermann@google.com>
Date: Fri, 10 Feb 2023 20:25:59 +0000
Subject: [PATCH] Revert part of "[vm] Allow sharing of deeply immutable lists
 across isolates"

It did have noticable xx% performance regression on

  ListCopy.List.int.unmodifiable.100

TEST=ci

Issue https://github.com/dart-lang/sdk/issues/51334

Change-Id: I160d7cc98aee2e064b1767519f4b5033656ee115
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/282400
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
---
 runtime/lib/growable_array.cc                 | 11 -------
 .../dart/isolates/fast_object_copy2_test.dart | 30 -------------------
 .../isolates/fast_object_copy2_test.dart      | 30 -------------------
 3 files changed, 71 deletions(-)

diff --git a/runtime/lib/growable_array.cc b/runtime/lib/growable_array.cc
index ff511312a79..02e40cbdf83 100644
--- a/runtime/lib/growable_array.cc
+++ b/runtime/lib/growable_array.cc
@@ -90,17 +90,6 @@ DEFINE_NATIVE_ENTRY(Internal_makeListFixedLength, 0, 1) {
 DEFINE_NATIVE_ENTRY(Internal_makeFixedListUnmodifiable, 0, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(Array, array, arguments->NativeArgAt(0));
   array.MakeImmutable();
-  const intptr_t len = array.Length();
-  bool is_deeply_immutable = true;
-  for (intptr_t i = 0; i < len; ++i) {
-    if (!CanShareObjectAcrossIsolates(array.At(i))) {
-      is_deeply_immutable = false;
-      break;
-    }
-  }
-  if (is_deeply_immutable) {
-    array.SetImmutable();
-  }
   return array.ptr();
 }
 
diff --git a/runtime/tests/vm/dart/isolates/fast_object_copy2_test.dart b/runtime/tests/vm/dart/isolates/fast_object_copy2_test.dart
index adc2661a659..9a3f1b714d3 100644
--- a/runtime/tests/vm/dart/isolates/fast_object_copy2_test.dart
+++ b/runtime/tests/vm/dart/isolates/fast_object_copy2_test.dart
@@ -111,7 +111,6 @@ class SendReceiveTest extends SendReceiveTestBase {
     await testSharable2();
     await testCopyableClosures();
     await testSharableTypedData();
-    await testUnmodifiableList();
   }
 
   Future testSharable() async {
@@ -177,35 +176,6 @@ class SendReceiveTest extends SendReceiveTestBase {
 
     malloc.free(bytes);
   }
-
-  Future testUnmodifiableList() async {
-    print('testUnmodifiableList');
-
-    // Sharable.
-    for (final sharable in [
-      1,
-      const Object(),
-      'foo',
-      List.unmodifiable([const Object()])
-    ]) {
-      final list = List.unmodifiable([sharable]);
-      final listCopy = await sendReceive(list);
-      Expect.identical(list, listCopy);
-    }
-
-    // Non-Sharable.
-    for (final nonSharable in [
-      Object(),
-      [],
-      {},
-      List.unmodifiable([Object()])
-    ]) {
-      final list = List.unmodifiable([nonSharable]);
-      final listCopy = await sendReceive(list);
-      Expect.notIdentical(list, listCopy);
-      Expect.notIdentical(list[0], listCopy[0]);
-    }
-  }
 }
 
 main() async {
diff --git a/runtime/tests/vm/dart_2/isolates/fast_object_copy2_test.dart b/runtime/tests/vm/dart_2/isolates/fast_object_copy2_test.dart
index 6d41f1a2b7d..b26863d22b8 100644
--- a/runtime/tests/vm/dart_2/isolates/fast_object_copy2_test.dart
+++ b/runtime/tests/vm/dart_2/isolates/fast_object_copy2_test.dart
@@ -111,7 +111,6 @@ class SendReceiveTest extends SendReceiveTestBase {
     await testSharable();
     await testSharable2();
     await testCopyableClosures();
-    await testUnmodifiableList();
   }
 
   Future testSharable() async {
@@ -159,35 +158,6 @@ class SendReceiveTest extends SendReceiveTestBase {
       Expect.equals(copyableClosures[i].runtimeType, copy2[i].runtimeType);
     }
   }
-
-  Future testUnmodifiableList() async {
-    print('testUnmodifiableList');
-
-    // Sharable.
-    for (final sharable in [
-      1,
-      const Object(),
-      'foo',
-      List.unmodifiable([const Object()])
-    ]) {
-      final list = List.unmodifiable([sharable]);
-      final listCopy = await sendReceive(list);
-      Expect.identical(list, listCopy);
-    }
-
-    // Non-Sharable.
-    for (final nonSharable in [
-      Object(),
-      [],
-      {},
-      List.unmodifiable([Object()])
-    ]) {
-      final list = List.unmodifiable([nonSharable]);
-      final listCopy = await sendReceive(list);
-      Expect.notIdentical(list, listCopy);
-      Expect.notIdentical(list[0], listCopy[0]);
-    }
-  }
 }
 
 main() async {