commit d678802609ad07ec2f307caecce5fe5a16fedd46
author Sebastien Hertz <shertz@google.com> Mon Aug 05 17:47:40 2013 +0200
committer Ian Rogers <irogers@google.com> Mon Aug 12 06:37:43 2013 +0000
tree 6c34fc5b6e1eec5fd180065322ca20855963fb44
parent 00ae676e307c8e3c3b19852f41ad0547c4c523b8

Use reader writer mutex for safe checkcast map.

Use a ReaderWriterMutex to protect MethodVerifier::safecast_map_ like
what's done for MethodVerifier::dex_gc_maps_ and MethodVerifier::devirt_maps_.

Change-Id: Id2ac9c290cc524eb992ea7cabe63766e88753747
(cherry picked from commit b9c37fb5746cc240e86677e56cb0d74d829e3504)

runtime/verifier/method_verifier.cc

diff --git a/runtime/verifier/method_verifier.cc b/runtime/verifier/method_verifier.cc
index d10dc73..139f7ee 100644
--- a/runtime/verifier/method_verifier.cc
+++ b/runtime/verifier/method_verifier.cc
@@ -4061,20 +4061,19 @@
 
 void  MethodVerifier::SetSafeCastMap(MethodReference ref, const MethodSafeCastSet* cast_set) {
   DCHECK(Runtime::Current()->IsCompiler());
-  MutexLock mu(Thread::Current(), *safecast_map_lock_);
+  WriterMutexLock mu(Thread::Current(), *safecast_map_lock_);
   SafeCastMap::iterator it = safecast_map_->find(ref);
   if (it != safecast_map_->end()) {
     delete it->second;
     safecast_map_->erase(it);
   }
-
   safecast_map_->Put(ref, cast_set);
   DCHECK(safecast_map_->find(ref) != safecast_map_->end());
 }
 
 bool MethodVerifier::IsSafeCast(MethodReference ref, uint32_t pc) {
   DCHECK(Runtime::Current()->IsCompiler());
-  MutexLock mu(Thread::Current(), *safecast_map_lock_);
+  ReaderMutexLock mu(Thread::Current(), *safecast_map_lock_);
   SafeCastMap::const_iterator it = safecast_map_->find(ref);
   if (it == safecast_map_->end()) {
     return false;
@@ -4186,7 +4185,7 @@
 ReaderWriterMutex* MethodVerifier::dex_gc_maps_lock_ = NULL;
 MethodVerifier::DexGcMapTable* MethodVerifier::dex_gc_maps_ = NULL;
 
-Mutex* MethodVerifier::safecast_map_lock_ = NULL;
+ReaderWriterMutex* MethodVerifier::safecast_map_lock_ = NULL;
 MethodVerifier::SafeCastMap* MethodVerifier::safecast_map_ = NULL;
 
 ReaderWriterMutex* MethodVerifier::devirt_maps_lock_ = NULL;
@@ -4204,9 +4203,9 @@
       dex_gc_maps_ = new MethodVerifier::DexGcMapTable;
     }
 
-    safecast_map_lock_ = new Mutex("verifier Cast Elision lock");
+    safecast_map_lock_ = new ReaderWriterMutex("verifier Cast Elision lock");
     {
-      MutexLock mu(self, *safecast_map_lock_);
+      WriterMutexLock mu(self, *safecast_map_lock_);
       safecast_map_ = new MethodVerifier::SafeCastMap();
     }
 
@@ -4239,7 +4238,7 @@
     dex_gc_maps_lock_ = NULL;
 
     {
-      MutexLock mu(self, *safecast_map_lock_);
+      WriterMutexLock mu(self, *safecast_map_lock_);
       STLDeleteValues(safecast_map_);
       delete safecast_map_;
       safecast_map_ = NULL;

runtime/verifier/method_verifier.h

diff --git a/runtime/verifier/method_verifier.h b/runtime/verifier/method_verifier.h
index 3f98a00..5c06cd5 100644
--- a/runtime/verifier/method_verifier.h
+++ b/runtime/verifier/method_verifier.h
@@ -640,7 +640,7 @@
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
   static void SetSafeCastMap(MethodReference ref, const MethodSafeCastSet* mscs);
       LOCKS_EXCLUDED(safecast_map_lock_);
-  static Mutex* safecast_map_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
+  static ReaderWriterMutex* safecast_map_lock_ DEFAULT_MUTEX_ACQUIRED_AFTER;
   static SafeCastMap* safecast_map_ GUARDED_BY(safecast_map_lock_);
 
   // Devirtualization map.