Change dex caches to be weak roots
Changed dex caches to be weak roots. This is necessary for class
unloading since the resolved types arrays would keep classes live
when they should be unloaded. Currently the dex caches still don't
get freed due to the class loader roots.
Also deleted some unused functionality in image writer.
Bug: 22720414
Change-Id: If22cb3cad7e3baabc8158a77d7f20799faf4c341
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index dc273d8..667dae2 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -273,7 +273,6 @@
array_iftable_(nullptr),
find_array_class_cache_next_victim_(0),
init_done_(false),
- log_new_dex_caches_roots_(false),
log_new_class_table_roots_(false),
intern_table_(intern_table),
quick_resolution_trampoline_(nullptr),
@@ -332,6 +331,12 @@
java_lang_Class->SetSuperClass(java_lang_Object.Get());
mirror::Class::SetStatus(java_lang_Object, mirror::Class::kStatusLoaded, self);
+ java_lang_Object->SetObjectSize(sizeof(mirror::Object));
+ runtime->SetSentinel(heap->AllocObject<true>(self,
+ java_lang_Object.Get(),
+ java_lang_Object->GetObjectSize(),
+ VoidFunctor()));
+
// Object[] next to hold class roots.
Handle<mirror::Class> object_array_class(hs.NewHandle(
AllocClass(self, java_lang_Class.Get(),
@@ -1139,11 +1144,11 @@
quick_imt_conflict_trampoline_ = oat_file.GetOatHeader().GetQuickImtConflictTrampoline();
quick_generic_jni_trampoline_ = oat_file.GetOatHeader().GetQuickGenericJniTrampoline();
quick_to_interpreter_bridge_trampoline_ = oat_file.GetOatHeader().GetQuickToInterpreterBridge();
+ StackHandleScope<2> hs(self);
mirror::Object* dex_caches_object = space->GetImageHeader().GetImageRoot(ImageHeader::kDexCaches);
- mirror::ObjectArray<mirror::DexCache>* dex_caches =
- dex_caches_object->AsObjectArray<mirror::DexCache>();
+ Handle<mirror::ObjectArray<mirror::DexCache>> dex_caches(
+ hs.NewHandle(dex_caches_object->AsObjectArray<mirror::DexCache>()));
- StackHandleScope<1> hs(self);
Handle<mirror::ObjectArray<mirror::Class>> class_roots(hs.NewHandle(
space->GetImageHeader().GetImageRoot(ImageHeader::kClassRoots)->
AsObjectArray<mirror::Class>()));
@@ -1153,6 +1158,13 @@
// as being Strings or not
mirror::String::SetClass(GetClassRoot(kJavaLangString));
+ mirror::Class* java_lang_Object = GetClassRoot(kJavaLangObject);
+ java_lang_Object->SetObjectSize(sizeof(mirror::Object));
+ Runtime::Current()->SetSentinel(Runtime::Current()->GetHeap()->AllocObject<true>(self,
+ java_lang_Object,
+ java_lang_Object->GetObjectSize(),
+ VoidFunctor()));
+
CHECK_EQ(oat_file.GetOatHeader().GetDexFileCount(),
static_cast<uint32_t>(dex_caches->GetLength()));
for (int32_t i = 0; i < dex_caches->GetLength(); i++) {
@@ -1246,7 +1258,6 @@
}
bool ClassLinker::ClassInClassTable(mirror::Class* klass) {
- ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_);
ClassTable* const class_table = ClassTableForClassLoader(klass->GetClassLoader());
return class_table != nullptr && class_table->Contains(klass);
}
@@ -1303,27 +1314,6 @@
// mapped image.
void ClassLinker::VisitRoots(RootVisitor* visitor, VisitRootFlags flags) {
class_roots_.VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal));
- Thread* const self = Thread::Current();
- {
- ReaderMutexLock mu(self, dex_lock_);
- if ((flags & kVisitRootFlagAllRoots) != 0) {
- for (GcRoot<mirror::DexCache>& dex_cache : dex_caches_) {
- dex_cache.VisitRoot(visitor, RootInfo(kRootVMInternal));
- }
- } else if ((flags & kVisitRootFlagNewRoots) != 0) {
- for (size_t index : new_dex_cache_roots_) {
- dex_caches_[index].VisitRoot(visitor, RootInfo(kRootVMInternal));
- }
- }
- if ((flags & kVisitRootFlagClearRootLog) != 0) {
- new_dex_cache_roots_.clear();
- }
- if ((flags & kVisitRootFlagStartLoggingNewRoots) != 0) {
- log_new_dex_caches_roots_ = true;
- } else if ((flags & kVisitRootFlagStopLoggingNewRoots) != 0) {
- log_new_dex_caches_roots_ = false;
- }
- }
VisitClassRoots(visitor, flags);
array_iftable_.VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal));
for (GcRoot<mirror::Class>& root : find_array_class_cache_) {
@@ -1698,7 +1688,6 @@
long_array->GetWithoutChecks(j)));
const DexFile::ClassDef* dex_class_def = cp_dex_file->FindClassDef(descriptor, hash);
if (dex_class_def != nullptr) {
- RegisterDexFile(*cp_dex_file);
mirror::Class* klass = DefineClass(self, descriptor, hash, class_loader,
*cp_dex_file, *dex_class_def);
if (klass == nullptr) {
@@ -1844,7 +1833,7 @@
CHECK(self->IsExceptionPending()); // Expect an OOME.
return nullptr;
}
- klass->SetDexCache(FindDexCache(dex_file));
+ klass->SetDexCache(RegisterDexFile(dex_file));
SetupClass(dex_file, dex_class_def, klass, class_loader.Get());
@@ -2478,58 +2467,52 @@
RegisterDexFile(dex_file, dex_cache);
}
-bool ClassLinker::IsDexFileRegisteredLocked(const DexFile& dex_file) {
- dex_lock_.AssertSharedHeld(Thread::Current());
- for (GcRoot<mirror::DexCache>& root : dex_caches_) {
- mirror::DexCache* dex_cache = root.Read();
- if (dex_cache->GetDexFile() == &dex_file) {
- return true;
- }
- }
- return false;
-}
-
-bool ClassLinker::IsDexFileRegistered(const DexFile& dex_file) {
- ReaderMutexLock mu(Thread::Current(), dex_lock_);
- return IsDexFileRegisteredLocked(dex_file);
-}
-
void ClassLinker::RegisterDexFileLocked(const DexFile& dex_file,
Handle<mirror::DexCache> dex_cache) {
- dex_lock_.AssertExclusiveHeld(Thread::Current());
+ Thread* const self = Thread::Current();
+ dex_lock_.AssertExclusiveHeld(self);
CHECK(dex_cache.Get() != nullptr) << dex_file.GetLocation();
CHECK(dex_cache->GetLocation()->Equals(dex_file.GetLocation()))
<< dex_cache->GetLocation()->ToModifiedUtf8() << " " << dex_file.GetLocation();
- dex_caches_.push_back(GcRoot<mirror::DexCache>(dex_cache.Get()));
- dex_cache->SetDexFile(&dex_file);
- if (log_new_dex_caches_roots_) {
- // TODO: This is not safe if we can remove dex caches.
- new_dex_cache_roots_.push_back(dex_caches_.size() - 1);
+ // Clean up pass to remove null dex caches.
+ // Null dex caches can occur due to class unloading and we are lazily removing null entries.
+ JavaVMExt* const vm = self->GetJniEnv()->vm;
+ for (auto it = dex_caches_.begin(); it != dex_caches_.end();) {
+ mirror::Object* dex_cache_root = self->DecodeJObject(*it);
+ if (dex_cache_root == nullptr) {
+ vm->DeleteWeakGlobalRef(self, *it);
+ it = dex_caches_.erase(it);
+ } else {
+ ++it;
+ }
}
+ dex_caches_.push_back(vm->AddWeakGlobalRef(self, dex_cache.Get()));
+ dex_cache->SetDexFile(&dex_file);
}
-void ClassLinker::RegisterDexFile(const DexFile& dex_file) {
+mirror::DexCache* ClassLinker::RegisterDexFile(const DexFile& dex_file) {
Thread* self = Thread::Current();
{
ReaderMutexLock mu(self, dex_lock_);
- if (IsDexFileRegisteredLocked(dex_file)) {
- return;
+ mirror::DexCache* dex_cache = FindDexCacheLocked(dex_file, true);
+ if (dex_cache != nullptr) {
+ return dex_cache;
}
}
// Don't alloc while holding the lock, since allocation may need to
// suspend all threads and another thread may need the dex_lock_ to
// get to a suspend point.
StackHandleScope<1> hs(self);
- Handle<mirror::DexCache> dex_cache(hs.NewHandle(AllocDexCache(self, dex_file)));
- CHECK(dex_cache.Get() != nullptr) << "Failed to allocate dex cache for "
- << dex_file.GetLocation();
- {
- WriterMutexLock mu(self, dex_lock_);
- if (IsDexFileRegisteredLocked(dex_file)) {
- return;
- }
- RegisterDexFileLocked(dex_file, dex_cache);
+ Handle<mirror::DexCache> h_dex_cache(hs.NewHandle(AllocDexCache(self, dex_file)));
+ CHECK(h_dex_cache.Get() != nullptr) << "Failed to allocate dex cache for "
+ << dex_file.GetLocation();
+ WriterMutexLock mu(self, dex_lock_);
+ mirror::DexCache* dex_cache = FindDexCacheLocked(dex_file, true);
+ if (dex_cache != nullptr) {
+ return dex_cache;
}
+ RegisterDexFileLocked(dex_file, h_dex_cache);
+ return h_dex_cache.Get();
}
void ClassLinker::RegisterDexFile(const DexFile& dex_file,
@@ -2538,36 +2521,44 @@
RegisterDexFileLocked(dex_file, dex_cache);
}
-mirror::DexCache* ClassLinker::FindDexCache(const DexFile& dex_file) {
- ReaderMutexLock mu(Thread::Current(), dex_lock_);
+mirror::DexCache* ClassLinker::FindDexCache(const DexFile& dex_file, bool allow_failure) {
+ Thread* const self = Thread::Current();
+ ReaderMutexLock mu(self, dex_lock_);
+ return FindDexCacheLocked(dex_file, allow_failure);
+}
+
+mirror::DexCache* ClassLinker::FindDexCacheLocked(const DexFile& dex_file, bool allow_failure) {
+ Thread* const self = Thread::Current();
// Search assuming unique-ness of dex file.
- for (size_t i = 0; i != dex_caches_.size(); ++i) {
- mirror::DexCache* dex_cache = GetDexCache(i);
- if (dex_cache->GetDexFile() == &dex_file) {
+ for (jobject weak_root : dex_caches_) {
+ mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>(self->DecodeJObject(weak_root));
+ if (dex_cache != nullptr && dex_cache->GetDexFile() == &dex_file) {
return dex_cache;
}
}
- // Search matching by location name.
+ if (allow_failure) {
+ return nullptr;
+ }
std::string location(dex_file.GetLocation());
- for (size_t i = 0; i != dex_caches_.size(); ++i) {
- mirror::DexCache* dex_cache = GetDexCache(i);
- if (dex_cache->GetDexFile()->GetLocation() == location) {
- return dex_cache;
- }
- }
// Failure, dump diagnostic and abort.
- for (size_t i = 0; i != dex_caches_.size(); ++i) {
- mirror::DexCache* dex_cache = GetDexCache(i);
- LOG(ERROR) << "Registered dex file " << i << " = " << dex_cache->GetDexFile()->GetLocation();
+ for (jobject weak_root : dex_caches_) {
+ mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>(self->DecodeJObject(weak_root));
+ if (dex_cache != nullptr) {
+ LOG(ERROR) << "Registered dex file " << dex_cache->GetDexFile()->GetLocation();
+ }
}
LOG(FATAL) << "Failed to find DexCache for DexFile " << location;
UNREACHABLE();
}
void ClassLinker::FixupDexCaches(ArtMethod* resolution_method) {
- ReaderMutexLock mu(Thread::Current(), dex_lock_);
- for (auto& dex_cache : dex_caches_) {
- dex_cache.Read()->Fixup(resolution_method, image_pointer_size_);
+ Thread* const self = Thread::Current();
+ ReaderMutexLock mu(self, dex_lock_);
+ for (jobject weak_root : dex_caches_) {
+ mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>(self->DecodeJObject(weak_root));
+ if (dex_cache != nullptr) {
+ dex_cache->Fixup(resolution_method, image_pointer_size_);
+ }
}
}
@@ -3403,11 +3394,13 @@
DCHECK(proxy_class->IsProxyClass());
DCHECK(proxy_method->IsProxyMethod());
{
- ReaderMutexLock mu(Thread::Current(), dex_lock_);
+ Thread* const self = Thread::Current();
+ ReaderMutexLock mu(self, dex_lock_);
// Locate the dex cache of the original interface/Object
- for (const GcRoot<mirror::DexCache>& root : dex_caches_) {
- auto* dex_cache = root.Read();
- if (proxy_method->HasSameDexCacheResolvedTypes(dex_cache->GetResolvedTypes())) {
+ for (jobject weak_root : dex_caches_) {
+ mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>(self->DecodeJObject(weak_root));
+ if (dex_cache != nullptr &&
+ proxy_method->HasSameDexCacheResolvedTypes(dex_cache->GetResolvedTypes())) {
ArtMethod* resolved_method = dex_cache->GetResolvedMethod(
proxy_method->GetDexMethodIndex(), image_pointer_size_);
CHECK(resolved_method != nullptr);
@@ -5864,11 +5857,6 @@
// We could move the jobject to the callers, but all call-sites do this...
ScopedObjectAccessUnchecked soa(self);
- // Register the dex files.
- for (const DexFile* dex_file : dex_files) {
- RegisterDexFile(*dex_file);
- }
-
// For now, create a libcore-level DexFile for each ART DexFile. This "explodes" multidex.
StackHandleScope<10> hs(self);