ART: Add entries_ lock for race condition

GCDaemon thread would visit incorrect RegType content when there is
another thread initializing classes.
Add a lock to protect entries_.

https://code.google.com/p/android/issues/detail?id=159849

Change-Id: Iabaa1c7f5cc5106b60a6e3856152e0797e8a5d6d

2 files changed, 9 insertions, 1 deletions

diff --git a/runtime/base/mutex.cc b/runtime/base/mutex.cc
index 13dcb8c..2ec2b0c 100644
--- a/runtime/base/mutex.cc
+++ b/runtime/base/mutex.cc
@@ -46,6 +46,7 @@ Mutex* Locks::intern_table_lock_ = nullptr;
 Mutex* Locks::jni_libraries_lock_ = nullptr;
 Mutex* Locks::logging_lock_ = nullptr;
 Mutex* Locks::mem_maps_lock_ = nullptr;
+Mutex* Locks::method_verifiers_lock_ = nullptr;
 Mutex* Locks::modify_ldt_lock_ = nullptr;
 ReaderWriterMutex* Locks::mutator_lock_ = nullptr;
 Mutex* Locks::profiler_lock_ = nullptr;
@@ -1001,6 +1002,10 @@ void Locks::Init() {
     classlinker_classes_lock_ = new ReaderWriterMutex("ClassLinker classes lock",
                                                       current_lock_level);
 
+    UPDATE_CURRENT_LOCK_LEVEL(kMethodVerifiersLock);
+    DCHECK(method_verifiers_lock_ == nullptr);
+    method_verifiers_lock_ = new Mutex("Method verifiers lock", current_lock_level);
+
     UPDATE_CURRENT_LOCK_LEVEL(kMonitorPoolLock);
     DCHECK(allocated_monitor_ids_lock_ == nullptr);
     allocated_monitor_ids_lock_ =  new Mutex("allocated monitor ids lock", current_lock_level);
diff --git a/runtime/base/mutex.h b/runtime/base/mutex.h
index 3b052c0..f9e1e62 100644
--- a/runtime/base/mutex.h
+++ b/runtime/base/mutex.h
@@ -86,6 +86,7 @@ enum LockLevel {
   kModifyLdtLock,
   kAllocatedThreadIdsLock,
   kMonitorPoolLock,
+  kMethodVerifiersLock,
   kClassLinkerClassesLock,
   kBreakpointLock,
   kMonitorLock,
@@ -587,9 +588,11 @@ class Locks {
   // Guards lists of classes within the class linker.
   static ReaderWriterMutex* classlinker_classes_lock_ ACQUIRED_AFTER(breakpoint_lock_);
 
+  static Mutex* method_verifiers_lock_ ACQUIRED_AFTER(classlinker_classes_lock_);
+
   // When declaring any Mutex add DEFAULT_MUTEX_ACQUIRED_AFTER to use annotalysis to check the code
   // doesn't try to hold a higher level Mutex.
-  #define DEFAULT_MUTEX_ACQUIRED_AFTER ACQUIRED_AFTER(Locks::classlinker_classes_lock_)
+  #define DEFAULT_MUTEX_ACQUIRED_AFTER ACQUIRED_AFTER(Locks::method_verifiers_lock_)
 
   static Mutex* allocated_monitor_ids_lock_ ACQUIRED_AFTER(classlinker_classes_lock_);