ART: Slightly change InitializeClass flow
Since 884f3b83ed6b2a378535ac6b2be57d6b2e22de09, verification isn't
run completely under a class' lock. This means it is possible to
race from unverified to initialized in InitializeClass. So check
the class state after VerifyClass, and handle new success and
failure cases.
Bug: 28254258
Change-Id: I22a6121477e409987281bc81c28b6c942f1bd319
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index 504d860..6fc1a5a 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -4451,7 +4451,20 @@
// We failed to verify, expect either the klass to be erroneous or verification failed at
// compile time.
if (klass->IsErroneous()) {
- CHECK(self->IsExceptionPending());
+ // The class is erroneous. This may be a verifier error, or another thread attempted
+ // verification and/or initialization and failed. We can distinguish those cases by
+ // whether an exception is already pending.
+ if (self->IsExceptionPending()) {
+ // Check that it's a VerifyError.
+ DCHECK_EQ("java.lang.Class<java.lang.VerifyError>",
+ PrettyClass(self->GetException()->GetClass()));
+ } else {
+ // Check that another thread attempted initialization.
+ DCHECK_NE(0, klass->GetClinitThreadId());
+ DCHECK_NE(self->GetTid(), klass->GetClinitThreadId());
+ // Need to rethrow the previous failure now.
+ ThrowEarlierClassFailure(klass.Get(), true);
+ }
VlogClassInitializationFailure(klass);
} else {
CHECK(Runtime::Current()->IsAotCompiler());
@@ -4461,6 +4474,14 @@
} else {
self->AssertNoPendingException();
}
+
+ // A separate thread could have moved us all the way to initialized. A "simple" example
+ // involves a subclass of the current class being initialized at the same time (which
+ // will implicitly initialize the superclass, if scheduled that way). b/28254258
+ DCHECK_NE(mirror::Class::kStatusError, klass->GetStatus());
+ if (klass->IsInitialized()) {
+ return true;
+ }
}
// If the class is kStatusInitializing, either this thread is
