commit b9c37fb5746cc240e86677e56cb0d74d829e3504
author Sebastien Hertz <shertz@google.com> Mon Aug 05 17:47:40 2013 +0200
committer Sebastien Hertz <shertz@google.com> Mon Aug 05 17:47:40 2013 +0200
tree f10bf94f63ad30aed84826db9a2dd73743152ee8
parent 99b1c14fc9f517f4882a596958ad2a0977d92daa

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

runtime/verifier/method_verifier.cc

diff --git a/runtime/verifier/method_verifier.cc b/runtime/verifier/method_verifier.cc
index 95fda9d..c420ea6 100644
--- a/runtime/verifier/method_verifier.cc
+++ b/runtime/verifier/method_verifier.cc
@@ -4063,20 +4063,19 @@
 
 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;
@@ -4197,7 +4196,7 @@
 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;
@@ -4215,9 +4214,9 @@
       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();
     }
 
@@ -4250,7 +4249,7 @@
     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 c7b8a74..e01f2c0 100644
--- a/runtime/verifier/method_verifier.h
+++ b/runtime/verifier/method_verifier.h
@@ -648,7 +648,7 @@
       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.