ART: Add function to retrieve all tagged objects

Add functionality to retrieve all tagged objects. Add an allocator
that uses Allocate and Deallocate to optimize.

Amend test 903.

Bug: 31385027
Test: m test-art-host
Change-Id: Ibce79ddea33da0bb1354c41852e1d8cb63fff958
diff --git a/runtime/openjdkjvmti/jvmti_allocator.h b/runtime/openjdkjvmti/jvmti_allocator.h
new file mode 100644
index 0000000..1225c14
--- /dev/null
+++ b/runtime/openjdkjvmti/jvmti_allocator.h
@@ -0,0 +1,170 @@
+/* Copyright (C) 2016 The Android Open Source Project
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This file implements interfaces from the file jvmti.h. This implementation
+ * is licensed under the same terms as the file jvmti.h.  The
+ * copyright and license information for the file jvmti.h follows.
+ *
+ * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+#ifndef ART_RUNTIME_OPENJDKJVMTI_JVMTI_ALLOCATOR_H_
+#define ART_RUNTIME_OPENJDKJVMTI_JVMTI_ALLOCATOR_H_
+
+#include "base/logging.h"
+#include "base/macros.h"
+#include "jvmti.h"
+
+namespace openjdkjvmti {
+
+template <typename T> class JvmtiAllocator;
+
+template <>
+class JvmtiAllocator<void> {
+ public:
+  typedef void value_type;
+  typedef void* pointer;
+  typedef const void* const_pointer;
+
+  template <typename U>
+  struct rebind {
+    typedef JvmtiAllocator<U> other;
+  };
+
+  explicit JvmtiAllocator(jvmtiEnv* env) : env_(env) {}
+
+  template <typename U>
+  JvmtiAllocator(const JvmtiAllocator<U>& other)  // NOLINT, implicit
+      : env_(other.env_) {}
+
+  JvmtiAllocator(const JvmtiAllocator& other) = default;
+  JvmtiAllocator& operator=(const JvmtiAllocator& other) = default;
+  ~JvmtiAllocator() = default;
+
+ private:
+  jvmtiEnv* env_;
+
+  template <typename U>
+  friend class JvmtiAllocator;
+
+  template <typename U>
+  friend bool operator==(const JvmtiAllocator<U>& lhs, const JvmtiAllocator<U>& rhs);
+};
+
+template <typename T>
+class JvmtiAllocator {
+ public:
+  typedef T value_type;
+  typedef T* pointer;
+  typedef T& reference;
+  typedef const T* const_pointer;
+  typedef const T& const_reference;
+  typedef size_t size_type;
+  typedef ptrdiff_t difference_type;
+
+  template <typename U>
+  struct rebind {
+    typedef JvmtiAllocator<U> other;
+  };
+
+  explicit JvmtiAllocator(jvmtiEnv* env) : env_(env) {}
+
+  template <typename U>
+  JvmtiAllocator(const JvmtiAllocator<U>& other)  // NOLINT, implicit
+      : env_(other.env_) {}
+
+  JvmtiAllocator(const JvmtiAllocator& other) = default;
+  JvmtiAllocator& operator=(const JvmtiAllocator& other) = default;
+  ~JvmtiAllocator() = default;
+
+  size_type max_size() const {
+    return static_cast<size_type>(-1) / sizeof(T);
+  }
+
+  pointer address(reference x) const { return &x; }
+  const_pointer address(const_reference x) const { return &x; }
+
+  pointer allocate(size_type n, JvmtiAllocator<void>::pointer hint ATTRIBUTE_UNUSED = nullptr) {
+    DCHECK_LE(n, max_size());
+    if (env_ == nullptr) {
+      T* result = reinterpret_cast<T*>(malloc(n * sizeof(T)));
+      CHECK(result != nullptr || n == 0u);  // Abort if malloc() fails.
+      return result;
+    } else {
+      unsigned char* result;
+      jvmtiError alloc_error = env_->Allocate(n * sizeof(T), &result);
+      CHECK(alloc_error == JVMTI_ERROR_NONE);
+      return reinterpret_cast<T*>(result);
+    }
+  }
+  void deallocate(pointer p, size_type n ATTRIBUTE_UNUSED) {
+    if (env_ == nullptr) {
+      free(p);
+    } else {
+      jvmtiError dealloc_error = env_->Deallocate(reinterpret_cast<unsigned char*>(p));
+      CHECK(dealloc_error == JVMTI_ERROR_NONE);
+    }
+  }
+
+  void construct(pointer p, const_reference val) {
+    new (static_cast<void*>(p)) value_type(val);
+  }
+  template <class U, class... Args>
+  void construct(U* p, Args&&... args) {
+    ::new (static_cast<void*>(p)) U(std::forward<Args>(args)...);
+  }
+  void destroy(pointer p) {
+    p->~value_type();
+  }
+
+  inline bool operator==(JvmtiAllocator const& other) {
+    return env_ == other.env_;
+  }
+  inline bool operator!=(JvmtiAllocator const& other) {
+    return !operator==(other);
+  }
+
+ private:
+  jvmtiEnv* env_;
+
+  template <typename U>
+  friend class JvmtiAllocator;
+
+  template <typename U>
+  friend bool operator==(const JvmtiAllocator<U>& lhs, const JvmtiAllocator<U>& rhs);
+};
+
+template <typename T>
+inline bool operator==(const JvmtiAllocator<T>& lhs, const JvmtiAllocator<T>& rhs) {
+  return lhs.env_ == rhs.env_;
+}
+
+template <typename T>
+inline bool operator!=(const JvmtiAllocator<T>& lhs, const JvmtiAllocator<T>& rhs) {
+  return !(lhs == rhs);
+}
+
+}  // namespace openjdkjvmti
+
+#endif  // ART_RUNTIME_OPENJDKJVMTI_JVMTI_ALLOCATOR_H_