Revert "Hold dex caches live in class table"

This reverts commit d6d49e56c2b7b11f474acb80cb02bb1fe9b7861e.

Bug: 29083330

(cherry picked from commit f102faf1bcbdb2149e3e7bf27b1819f621b7894b)

Change-Id: Id0c921bd6fe422159f8daa598dc8e7c9ed6eca47
diff --git a/compiler/driver/compiler_driver-inl.h b/compiler/driver/compiler_driver-inl.h
index 94f5acc..3cb63e7 100644
--- a/compiler/driver/compiler_driver-inl.h
+++ b/compiler/driver/compiler_driver-inl.h
@@ -390,8 +390,9 @@
           *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_loader.Get())));
+      auto target_dex_cache(hs.NewHandle(class_linker->RegisterDexFile(
+          *devirt_target->dex_file,
+          class_linker->GetOrCreateAllocatorForClassLoader(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 a4b4889..7708b97 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -1113,8 +1113,9 @@
       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,
-                                                                                     nullptr)));
+      Handle<mirror::DexCache> dex_cache(hs2.NewHandle(class_linker->RegisterDexFile(
+          *dex_file,
+          Runtime::Current()->GetLinearAlloc())));
       Handle<mirror::Class> klass(hs2.NewHandle(
           class_linker->ResolveType(*dex_file,
                                     exception_type_idx,
@@ -2155,7 +2156,7 @@
         hs.NewHandle(soa.Decode<mirror::ClassLoader*>(manager_->GetClassLoader())));
     Handle<mirror::DexCache> dex_cache(hs.NewHandle(class_linker->RegisterDexFile(
         dex_file,
-        class_loader.Get())));
+        class_linker->GetOrCreateAllocatorForClassLoader(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 6d1f944..21e198c 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, nullptr);
+      class_linker->RegisterDexFile(*dex_file, runtime->GetLinearAlloc());
     }
     linker::MultiOatRelativePatcher patcher(compiler_driver_->GetInstructionSet(),
                                             instruction_set_features_.get());
@@ -491,7 +491,10 @@
   ClassLinker* const class_linker = Runtime::Current()->GetClassLinker();
   for (const DexFile* dex_file : dex_files) {
     ScopedObjectAccess soa(Thread::Current());
-    class_linker->RegisterDexFile(*dex_file, soa.Decode<mirror::ClassLoader*>(class_loader));
+    class_linker->RegisterDexFile(
+        *dex_file,
+        class_linker->GetOrCreateAllocatorForClassLoader(
+            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 3db85c1..db26799 100644
--- a/dex2oat/dex2oat.cc
+++ b/dex2oat/dex2oat.cc
@@ -1456,8 +1456,7 @@
     for (const auto& dex_file : dex_files_) {
       ScopedObjectAccess soa(self);
       dex_caches_.push_back(soa.AddLocalReference<jobject>(
-          class_linker->RegisterDexFile(*dex_file,
-                                        soa.Decode<mirror::ClassLoader*>(class_loader_))));
+          class_linker->RegisterDexFile(*dex_file, Runtime::Current()->GetLinearAlloc())));
     }
 
     return true;
diff --git a/oatdump/oatdump.cc b/oatdump/oatdump.cc
index aa4635d..f5458c0 100644
--- a/oatdump/oatdump.cc
+++ b/oatdump/oatdump.cc
@@ -1118,7 +1118,8 @@
       ScopedObjectAccess soa(Thread::Current());
       Runtime* const runtime = Runtime::Current();
       Handle<mirror::DexCache> dex_cache(
-          hs->NewHandle(runtime->GetClassLinker()->RegisterDexFile(*dex_file, nullptr)));
+          hs->NewHandle(runtime->GetClassLinker()->RegisterDexFile(*dex_file,
+                                                                   runtime->GetLinearAlloc())));
       DCHECK(options_.class_loader_ != nullptr);
       return verifier::MethodVerifier::VerifyMethodAndDump(
           soa.Self(), vios, dex_method_idx, dex_file, dex_cache, *options_.class_loader_,
@@ -2282,7 +2283,7 @@
     std::string error_msg;
     const DexFile* const dex_file = OpenDexFile(odf, &error_msg);
     CHECK(dex_file != nullptr) << error_msg;
-    class_linker->RegisterDexFile(*dex_file, nullptr);
+    class_linker->RegisterDexFile(*dex_file, runtime->GetLinearAlloc());
     class_path.push_back(dex_file);
   }
 
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index e789db6..9e144dd 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -2469,7 +2469,9 @@
     self->AssertPendingOOMException();
     return nullptr;
   }
-  mirror::DexCache* dex_cache = RegisterDexFile(dex_file, class_loader.Get());
+  mirror::DexCache* dex_cache = RegisterDexFile(
+      dex_file,
+      GetOrCreateAllocatorForClassLoader(class_loader.Get()));
   if (dex_cache == nullptr) {
     self->AssertPendingOOMException();
     return nullptr;
@@ -3228,8 +3230,7 @@
   dex_caches_.push_back(data);
 }
 
-mirror::DexCache* ClassLinker::RegisterDexFile(const DexFile& dex_file,
-                                               mirror::ClassLoader* class_loader) {
+mirror::DexCache* ClassLinker::RegisterDexFile(const DexFile& dex_file, LinearAlloc* linear_alloc) {
   Thread* self = Thread::Current();
   {
     ReaderMutexLock mu(self, dex_lock_);
@@ -3238,31 +3239,21 @@
       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;
-    }
-    if (h_dex_cache.Get() == nullptr) {
-      self->AssertPendingOOMException();
-      return nullptr;
-    }
-    RegisterDexFileLocked(dex_file, h_dex_cache);
+  WriterMutexLock mu(self, dex_lock_);
+  mirror::DexCache* dex_cache = FindDexCacheLocked(self, dex_file, true);
+  if (dex_cache != nullptr) {
+    return dex_cache;
   }
-  table->InsertStrongRoot(h_dex_cache.Get());
+  if (h_dex_cache.Get() == nullptr) {
+    self->AssertPendingOOMException();
+    return nullptr;
+  }
+  RegisterDexFileLocked(dex_file, h_dex_cache);
   return h_dex_cache.Get();
 }
 
@@ -8000,7 +7991,7 @@
   WriterMutexLock mu(self, *Locks::classlinker_classes_lock_);
   ClassTable* const table = ClassTableForClassLoader(class_loader);
   DCHECK(table != nullptr);
-  if (table->InsertStrongRoot(dex_file) && class_loader != nullptr) {
+  if (table->InsertDexFile(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 17b87cd..f6ce545 100644
--- a/runtime/class_linker.h
+++ b/runtime/class_linker.h
@@ -377,8 +377,7 @@
       SHARED_REQUIRES(Locks::mutator_lock_)
       REQUIRES(!dex_lock_, !Roles::uninterruptible_);
 
-  mirror::DexCache* RegisterDexFile(const DexFile& dex_file,
-                                    mirror::ClassLoader* class_loader)
+  mirror::DexCache* RegisterDexFile(const DexFile& dex_file, LinearAlloc* linear_alloc)
       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 d52365d..42e320a 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 : strong_roots_) {
+  for (GcRoot<mirror::Object>& root : dex_files_) {
     visitor.VisitRoot(root.AddressWithoutBarrier());
   }
 }
@@ -42,7 +42,7 @@
       visitor.VisitRoot(root.AddressWithoutBarrier());
     }
   }
-  for (GcRoot<mirror::Object>& root : strong_roots_) {
+  for (GcRoot<mirror::Object>& root : dex_files_) {
     visitor.VisitRoot(root.AddressWithoutBarrier());
   }
 }
diff --git a/runtime/class_table.cc b/runtime/class_table.cc
index f5ebcc51..8267c68 100644
--- a/runtime/class_table.cc
+++ b/runtime/class_table.cc
@@ -146,15 +146,15 @@
   return ComputeModifiedUtf8Hash(descriptor);
 }
 
-bool ClassTable::InsertStrongRoot(mirror::Object* obj) {
+bool ClassTable::InsertDexFile(mirror::Object* dex_file) {
   WriterMutexLock mu(Thread::Current(), lock_);
-  DCHECK(obj != nullptr);
-  for (GcRoot<mirror::Object>& root : strong_roots_) {
-    if (root.Read() == obj) {
+  DCHECK(dex_file != nullptr);
+  for (GcRoot<mirror::Object>& root : dex_files_) {
+    if (root.Read() == dex_file) {
       return false;
     }
   }
-  strong_roots_.push_back(GcRoot<mirror::Object>(obj));
+  dex_files_.push_back(GcRoot<mirror::Object>(dex_file));
   return true;
 }
 
diff --git a/runtime/class_table.h b/runtime/class_table.h
index 854a85e..686381d 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 strong root, false if it already exists.
-  bool InsertStrongRoot(mirror::Object* obj)
+  // Return true if we inserted the dex file, false if it already exists.
+  bool InsertDexFile(mirror::Object* dex_file)
       REQUIRES(!lock_)
       SHARED_REQUIRES(Locks::mutator_lock_);
 
@@ -162,10 +162,9 @@
   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_);
-  // 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_);
+  // 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_);
 };
 
 }  // namespace art
diff --git a/runtime/native/dalvik_system_DexFile.cc b/runtime/native/dalvik_system_DexFile.cc
index 8c7c966..f30f7a6 100644
--- a/runtime/native/dalvik_system_DexFile.cc
+++ b/runtime/native/dalvik_system_DexFile.cc
@@ -278,7 +278,9 @@
       StackHandleScope<1> hs(soa.Self());
       Handle<mirror::ClassLoader> class_loader(
           hs.NewHandle(soa.Decode<mirror::ClassLoader*>(javaLoader)));
-      class_linker->RegisterDexFile(*dex_file, class_loader.Get());
+      class_linker->RegisterDexFile(
+          *dex_file,
+          class_linker->GetOrCreateAllocatorForClassLoader(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 79b18aa..6c943dc 100644
--- a/runtime/native/dalvik_system_VMRuntime.cc
+++ b/runtime/native/dalvik_system_VMRuntime.cc
@@ -504,7 +504,8 @@
     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, nullptr)));
+    Handle<mirror::DexCache> dex_cache(
+        hs.NewHandle(linker->RegisterDexFile(*dex_file, runtime->GetLinearAlloc())));
 
     if (kPreloadDexCachesStrings) {
       for (size_t j = 0; j < dex_cache->NumStrings(); j++) {