Hold dex caches live in class table
Prevents temporary dex caches being unloaded for the same dex file.
Usually this is OK, but if someone resolved a string in that dex
cache, it could leave stale pointers in BSS. Also it can use extra
memory in linear alloc if we allocate dex cache arrays multiple
times.
Bug: 29083330
Change-Id: Ia44668f013ceef1f5eb80f653a48d0f8004548c9
diff --git a/compiler/driver/compiler_driver-inl.h b/compiler/driver/compiler_driver-inl.h
index 3cb63e7..94f5acc 100644
--- a/compiler/driver/compiler_driver-inl.h
+++ b/compiler/driver/compiler_driver-inl.h
@@ -390,9 +390,8 @@
*devirt_target->dex_file, devirt_target->dex_method_index, dex_cache, class_loader,
nullptr, kVirtual);
} else {
- auto target_dex_cache(hs.NewHandle(class_linker->RegisterDexFile(
- *devirt_target->dex_file,
- class_linker->GetOrCreateAllocatorForClassLoader(class_loader.Get()))));
+ auto target_dex_cache(hs.NewHandle(class_linker->RegisterDexFile(*devirt_target->dex_file,
+ class_loader.Get())));
called_method = class_linker->ResolveMethod<ClassLinker::kNoICCECheckForCache>(
*devirt_target->dex_file, devirt_target->dex_method_index, target_dex_cache,
class_loader, nullptr, kVirtual);
diff --git a/compiler/driver/compiler_driver.cc b/compiler/driver/compiler_driver.cc
index d20f510..0387bcd 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -1057,9 +1057,8 @@
uint16_t exception_type_idx = exception_type.first;
const DexFile* dex_file = exception_type.second;
StackHandleScope<2> hs2(self);
- Handle<mirror::DexCache> dex_cache(hs2.NewHandle(class_linker->RegisterDexFile(
- *dex_file,
- Runtime::Current()->GetLinearAlloc())));
+ Handle<mirror::DexCache> dex_cache(hs2.NewHandle(class_linker->RegisterDexFile(*dex_file,
+ nullptr)));
Handle<mirror::Class> klass(hs2.NewHandle(
class_linker->ResolveType(*dex_file,
exception_type_idx,
@@ -2089,7 +2088,7 @@
hs.NewHandle(soa.Decode<mirror::ClassLoader*>(manager_->GetClassLoader())));
Handle<mirror::DexCache> dex_cache(hs.NewHandle(class_linker->RegisterDexFile(
dex_file,
- class_linker->GetOrCreateAllocatorForClassLoader(class_loader.Get()))));
+ class_loader.Get())));
mirror::Class* klass = class_linker->ResolveType(dex_file, type_idx, dex_cache, class_loader);
if (klass == nullptr) {
diff --git a/compiler/oat_test.cc b/compiler/oat_test.cc
index 21e198c..6d1f944 100644
--- a/compiler/oat_test.cc
+++ b/compiler/oat_test.cc
@@ -199,7 +199,7 @@
for (const std::unique_ptr<const DexFile>& dex_file : opened_dex_files) {
dex_files.push_back(dex_file.get());
ScopedObjectAccess soa(Thread::Current());
- class_linker->RegisterDexFile(*dex_file, runtime->GetLinearAlloc());
+ class_linker->RegisterDexFile(*dex_file, nullptr);
}
linker::MultiOatRelativePatcher patcher(compiler_driver_->GetInstructionSet(),
instruction_set_features_.get());
@@ -491,10 +491,7 @@
ClassLinker* const class_linker = Runtime::Current()->GetClassLinker();
for (const DexFile* dex_file : dex_files) {
ScopedObjectAccess soa(Thread::Current());
- class_linker->RegisterDexFile(
- *dex_file,
- class_linker->GetOrCreateAllocatorForClassLoader(
- soa.Decode<mirror::ClassLoader*>(class_loader)));
+ class_linker->RegisterDexFile(*dex_file, soa.Decode<mirror::ClassLoader*>(class_loader));
}
compiler_driver_->SetDexFilesForOatFile(dex_files);
compiler_driver_->CompileAll(class_loader, dex_files, &timings);
diff --git a/dex2oat/dex2oat.cc b/dex2oat/dex2oat.cc
index cce83f3..c4754ce 100644
--- a/dex2oat/dex2oat.cc
+++ b/dex2oat/dex2oat.cc
@@ -1462,7 +1462,8 @@
for (const auto& dex_file : dex_files_) {
ScopedObjectAccess soa(self);
dex_caches_.push_back(soa.AddLocalReference<jobject>(
- class_linker->RegisterDexFile(*dex_file, Runtime::Current()->GetLinearAlloc())));
+ class_linker->RegisterDexFile(*dex_file,
+ soa.Decode<mirror::ClassLoader*>(class_loader_))));
}
return true;
diff --git a/oatdump/oatdump.cc b/oatdump/oatdump.cc
index f5458c0..aa4635d 100644
--- a/oatdump/oatdump.cc
+++ b/oatdump/oatdump.cc
@@ -1118,8 +1118,7 @@
ScopedObjectAccess soa(Thread::Current());
Runtime* const runtime = Runtime::Current();
Handle<mirror::DexCache> dex_cache(
- hs->NewHandle(runtime->GetClassLinker()->RegisterDexFile(*dex_file,
- runtime->GetLinearAlloc())));
+ hs->NewHandle(runtime->GetClassLinker()->RegisterDexFile(*dex_file, nullptr)));
DCHECK(options_.class_loader_ != nullptr);
return verifier::MethodVerifier::VerifyMethodAndDump(
soa.Self(), vios, dex_method_idx, dex_file, dex_cache, *options_.class_loader_,
@@ -2283,7 +2282,7 @@
std::string error_msg;
const DexFile* const dex_file = OpenDexFile(odf, &error_msg);
CHECK(dex_file != nullptr) << error_msg;
- class_linker->RegisterDexFile(*dex_file, runtime->GetLinearAlloc());
+ class_linker->RegisterDexFile(*dex_file, nullptr);
class_path.push_back(dex_file);
}
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index 9e144dd..e789db6 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -2469,9 +2469,7 @@
self->AssertPendingOOMException();
return nullptr;
}
- mirror::DexCache* dex_cache = RegisterDexFile(
- dex_file,
- GetOrCreateAllocatorForClassLoader(class_loader.Get()));
+ mirror::DexCache* dex_cache = RegisterDexFile(dex_file, class_loader.Get());
if (dex_cache == nullptr) {
self->AssertPendingOOMException();
return nullptr;
@@ -3230,7 +3228,8 @@
dex_caches_.push_back(data);
}
-mirror::DexCache* ClassLinker::RegisterDexFile(const DexFile& dex_file, LinearAlloc* linear_alloc) {
+mirror::DexCache* ClassLinker::RegisterDexFile(const DexFile& dex_file,
+ mirror::ClassLoader* class_loader) {
Thread* self = Thread::Current();
{
ReaderMutexLock mu(self, dex_lock_);
@@ -3239,21 +3238,31 @@
return dex_cache;
}
}
+ LinearAlloc* const linear_alloc = GetOrCreateAllocatorForClassLoader(class_loader);
+ DCHECK(linear_alloc != nullptr);
+ ClassTable* table;
+ {
+ WriterMutexLock mu(self, *Locks::classlinker_classes_lock_);
+ table = InsertClassTableForClassLoader(class_loader);
+ }
// 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> h_dex_cache(hs.NewHandle(AllocDexCache(self, dex_file, linear_alloc)));
- WriterMutexLock mu(self, dex_lock_);
- mirror::DexCache* dex_cache = FindDexCacheLocked(self, dex_file, true);
- if (dex_cache != nullptr) {
- return dex_cache;
+ {
+ WriterMutexLock mu(self, dex_lock_);
+ mirror::DexCache* dex_cache = FindDexCacheLocked(self, dex_file, true);
+ if (dex_cache != nullptr) {
+ return dex_cache;
+ }
+ if (h_dex_cache.Get() == nullptr) {
+ self->AssertPendingOOMException();
+ return nullptr;
+ }
+ RegisterDexFileLocked(dex_file, h_dex_cache);
}
- if (h_dex_cache.Get() == nullptr) {
- self->AssertPendingOOMException();
- return nullptr;
- }
- RegisterDexFileLocked(dex_file, h_dex_cache);
+ table->InsertStrongRoot(h_dex_cache.Get());
return h_dex_cache.Get();
}
@@ -7991,7 +8000,7 @@
WriterMutexLock mu(self, *Locks::classlinker_classes_lock_);
ClassTable* const table = ClassTableForClassLoader(class_loader);
DCHECK(table != nullptr);
- if (table->InsertDexFile(dex_file) && class_loader != nullptr) {
+ if (table->InsertStrongRoot(dex_file) && class_loader != nullptr) {
// It was not already inserted, perform the write barrier to let the GC know the class loader's
// class table was modified.
Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(class_loader);
diff --git a/runtime/class_linker.h b/runtime/class_linker.h
index f6ce545..17b87cd 100644
--- a/runtime/class_linker.h
+++ b/runtime/class_linker.h
@@ -377,7 +377,8 @@
SHARED_REQUIRES(Locks::mutator_lock_)
REQUIRES(!dex_lock_, !Roles::uninterruptible_);
- mirror::DexCache* RegisterDexFile(const DexFile& dex_file, LinearAlloc* linear_alloc)
+ mirror::DexCache* RegisterDexFile(const DexFile& dex_file,
+ mirror::ClassLoader* class_loader)
REQUIRES(!dex_lock_)
SHARED_REQUIRES(Locks::mutator_lock_);
void RegisterDexFile(const DexFile& dex_file, Handle<mirror::DexCache> dex_cache)
diff --git a/runtime/class_table-inl.h b/runtime/class_table-inl.h
index 42e320a..d52365d 100644
--- a/runtime/class_table-inl.h
+++ b/runtime/class_table-inl.h
@@ -29,7 +29,7 @@
visitor.VisitRoot(root.AddressWithoutBarrier());
}
}
- for (GcRoot<mirror::Object>& root : dex_files_) {
+ for (GcRoot<mirror::Object>& root : strong_roots_) {
visitor.VisitRoot(root.AddressWithoutBarrier());
}
}
@@ -42,7 +42,7 @@
visitor.VisitRoot(root.AddressWithoutBarrier());
}
}
- for (GcRoot<mirror::Object>& root : dex_files_) {
+ for (GcRoot<mirror::Object>& root : strong_roots_) {
visitor.VisitRoot(root.AddressWithoutBarrier());
}
}
diff --git a/runtime/class_table.cc b/runtime/class_table.cc
index 8267c68..f5ebcc5 100644
--- a/runtime/class_table.cc
+++ b/runtime/class_table.cc
@@ -146,15 +146,15 @@
return ComputeModifiedUtf8Hash(descriptor);
}
-bool ClassTable::InsertDexFile(mirror::Object* dex_file) {
+bool ClassTable::InsertStrongRoot(mirror::Object* obj) {
WriterMutexLock mu(Thread::Current(), lock_);
- DCHECK(dex_file != nullptr);
- for (GcRoot<mirror::Object>& root : dex_files_) {
- if (root.Read() == dex_file) {
+ DCHECK(obj != nullptr);
+ for (GcRoot<mirror::Object>& root : strong_roots_) {
+ if (root.Read() == obj) {
return false;
}
}
- dex_files_.push_back(GcRoot<mirror::Object>(dex_file));
+ strong_roots_.push_back(GcRoot<mirror::Object>(obj));
return true;
}
diff --git a/runtime/class_table.h b/runtime/class_table.h
index 686381d..854a85e 100644
--- a/runtime/class_table.h
+++ b/runtime/class_table.h
@@ -133,8 +133,8 @@
REQUIRES(!lock_)
SHARED_REQUIRES(Locks::mutator_lock_);
- // Return true if we inserted the dex file, false if it already exists.
- bool InsertDexFile(mirror::Object* dex_file)
+ // Return true if we inserted the strong root, false if it already exists.
+ bool InsertStrongRoot(mirror::Object* obj)
REQUIRES(!lock_)
SHARED_REQUIRES(Locks::mutator_lock_);
@@ -162,9 +162,10 @@
mutable ReaderWriterMutex lock_;
// We have a vector to help prevent dirty pages after the zygote forks by calling FreezeSnapshot.
std::vector<ClassSet> classes_ GUARDED_BY(lock_);
- // Dex files used by the class loader which may not be owned by the class loader. We keep these
- // live so that we do not have issues closing any of the dex files.
- std::vector<GcRoot<mirror::Object>> dex_files_ GUARDED_BY(lock_);
+ // Extra strong roots that can be either dex files or dex caches. Dex files used by the class
+ // loader which may not be owned by the class loader must be held strongly live. Also dex caches
+ // are held live to prevent them being unloading once they have classes in them.
+ std::vector<GcRoot<mirror::Object>> strong_roots_ GUARDED_BY(lock_);
};
} // namespace art
diff --git a/runtime/native/dalvik_system_DexFile.cc b/runtime/native/dalvik_system_DexFile.cc
index f30f7a6..8c7c966 100644
--- a/runtime/native/dalvik_system_DexFile.cc
+++ b/runtime/native/dalvik_system_DexFile.cc
@@ -278,9 +278,7 @@
StackHandleScope<1> hs(soa.Self());
Handle<mirror::ClassLoader> class_loader(
hs.NewHandle(soa.Decode<mirror::ClassLoader*>(javaLoader)));
- class_linker->RegisterDexFile(
- *dex_file,
- class_linker->GetOrCreateAllocatorForClassLoader(class_loader.Get()));
+ class_linker->RegisterDexFile(*dex_file, class_loader.Get());
mirror::Class* result = class_linker->DefineClass(soa.Self(),
descriptor.c_str(),
hash,
diff --git a/runtime/native/dalvik_system_VMRuntime.cc b/runtime/native/dalvik_system_VMRuntime.cc
index 6c943dc..79b18aa 100644
--- a/runtime/native/dalvik_system_VMRuntime.cc
+++ b/runtime/native/dalvik_system_VMRuntime.cc
@@ -504,8 +504,7 @@
const DexFile* dex_file = boot_class_path[i];
CHECK(dex_file != nullptr);
StackHandleScope<1> hs(soa.Self());
- Handle<mirror::DexCache> dex_cache(
- hs.NewHandle(linker->RegisterDexFile(*dex_file, runtime->GetLinearAlloc())));
+ Handle<mirror::DexCache> dex_cache(hs.NewHandle(linker->RegisterDexFile(*dex_file, nullptr)));
if (kPreloadDexCachesStrings) {
for (size_t j = 0; j < dex_cache->NumStrings(); j++) {