From 8029e7d0b5271823672c9189fee8ccd80bdc11b0 Mon Sep 17 00:00:00 2001
From: shade <unknown>
Date: Thu, 29 Oct 2015 14:08:19 +0300
Subject: [PATCH] 8140483: Atomic*FieldUpdaters final fields should be trusted
 Summary: Add exceptions for A*FU subclasses that do the actual work.
 Reviewed-by: jrose, vlivanov

---
 src/share/vm/ci/ciField.cpp          | 8 ++++++++
 src/share/vm/classfile/vmSymbols.hpp | 6 +++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/share/vm/ci/ciField.cpp b/src/share/vm/ci/ciField.cpp
index 58c191710..7dd09a98e 100644
--- a/src/share/vm/ci/ciField.cpp
+++ b/src/share/vm/ci/ciField.cpp
@@ -187,6 +187,14 @@ static bool trust_final_non_static_fields(ciInstanceKlass* holder) {
   // Even if general trusting is disabled, trust system-built closures in these packages.
   if (holder->is_in_package("java/lang/invoke") || holder->is_in_package("sun/invoke"))
     return true;
+  // Trust Atomic*FieldUpdaters: they are very important for performance, and make up one
+  // more reason not to use Unsafe, if their final fields are trusted. See more in JDK-8140483.
+  if (holder->name() == ciSymbol::java_util_concurrent_atomic_AtomicIntegerFieldUpdater_Impl() ||
+      holder->name() == ciSymbol::java_util_concurrent_atomic_AtomicLongFieldUpdater_CASUpdater() ||
+      holder->name() == ciSymbol::java_util_concurrent_atomic_AtomicLongFieldUpdater_LockedUpdater() ||
+      holder->name() == ciSymbol::java_util_concurrent_atomic_AtomicReferenceFieldUpdater_Impl()) {
+    return true;
+  }
   return TrustFinalNonStaticFields;
 }
 
diff --git a/src/share/vm/classfile/vmSymbols.hpp b/src/share/vm/classfile/vmSymbols.hpp
index 0a84cb074..222d2b067 100644
--- a/src/share/vm/classfile/vmSymbols.hpp
+++ b/src/share/vm/classfile/vmSymbols.hpp
@@ -203,7 +203,11 @@
   template(java_lang_StackTraceElement,               "java/lang/StackTraceElement")              \
                                                                                                   \
   /* Concurrency support */                                                                       \
-  template(java_util_concurrent_locks_AbstractOwnableSynchronizer,   "java/util/concurrent/locks/AbstractOwnableSynchronizer") \
+  template(java_util_concurrent_locks_AbstractOwnableSynchronizer,           "java/util/concurrent/locks/AbstractOwnableSynchronizer") \
+  template(java_util_concurrent_atomic_AtomicIntegerFieldUpdater_Impl,       "java/util/concurrent/atomic/AtomicIntegerFieldUpdater$AtomicIntegerFieldUpdaterImpl") \
+  template(java_util_concurrent_atomic_AtomicLongFieldUpdater_CASUpdater,    "java/util/concurrent/atomic/AtomicLongFieldUpdater$CASUpdater") \
+  template(java_util_concurrent_atomic_AtomicLongFieldUpdater_LockedUpdater, "java/util/concurrent/atomic/AtomicLongFieldUpdater$LockedUpdater") \
+  template(java_util_concurrent_atomic_AtomicReferenceFieldUpdater_Impl,     "java/util/concurrent/atomic/AtomicReferenceFieldUpdater$AtomicReferenceFieldUpdaterImpl") \
   template(sun_misc_Contended_signature,              "Lsun/misc/Contended;")                     \
                                                                                                   \
   /* class symbols needed by intrinsics */                                                        \
-- 
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