Allocate dex cache arrays in their class loader's linear alloc

Fixes memory leak for class unloading where the dex cache arrays
used to be in the runtime linear alloc which never got freed.

TODO: Some of the callers like the compiler just use the runtime
linear alloc. We could clean this up if we want to have class
unloading during compilation for some reason.

Added regression test.

Bug: 22720414

Change-Id: Ia50333a06a339efbdaedb5ad94b7a1ae841124ec

1 files changed, 10 insertions, 2 deletions

diff --git a/runtime/class_linker.h b/runtime/class_linker.h
index 93161f7bb7..a70967d49b 100644
--- a/runtime/class_linker.h
+++ b/runtime/class_linker.h
@@ -319,7 +319,7 @@ class ClassLinker {
       SHARED_REQUIRES(Locks::mutator_lock_)
       REQUIRES(!dex_lock_, !Roles::uninterruptible_);
 
-  mirror::DexCache* RegisterDexFile(const DexFile& dex_file)
+  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)
@@ -532,6 +532,12 @@ class ClassLinker {
   static LinearAlloc* GetAllocatorForClassLoader(mirror::ClassLoader* class_loader)
       SHARED_REQUIRES(Locks::mutator_lock_);
 
+  // Return the linear alloc for a class loader if it is already allocated, otherwise allocate and
+  // set it. TODO: Consider using a lock other than classlinker_classes_lock_.
+  static LinearAlloc* GetOrCreateAllocatorForClassLoader(mirror::ClassLoader* class_loader)
+      SHARED_REQUIRES(Locks::mutator_lock_)
+      REQUIRES(!Locks::classlinker_classes_lock_);
+
  private:
   struct ClassLoaderData {
     jweak weak_root;  // Weak root to enable class unloading.
@@ -570,7 +576,9 @@ class ClassLinker {
   mirror::Class* AllocClass(Thread* self, uint32_t class_size)
       SHARED_REQUIRES(Locks::mutator_lock_)
       REQUIRES(!Roles::uninterruptible_);
-  mirror::DexCache* AllocDexCache(Thread* self, const DexFile& dex_file)
+  mirror::DexCache* AllocDexCache(Thread* self,
+                                  const DexFile& dex_file,
+                                  LinearAlloc* linear_alloc)
       SHARED_REQUIRES(Locks::mutator_lock_)
       REQUIRES(!Roles::uninterruptible_);