scoped_fast_native_object_access.h revision c645f1ddb7c40bea6a38eda4b3f83f6b6dec405b 
1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ART_RUNTIME_NATIVE_SCOPED_FAST_NATIVE_OBJECT_ACCESS_H_
18#define ART_RUNTIME_NATIVE_SCOPED_FAST_NATIVE_OBJECT_ACCESS_H_
19
20#include "base/casts.h"
21#include "jni_internal.h"
22#include "thread-inl.h"
23#include "mirror/art_method.h"
24#include "verify_object.h"
25
26namespace art {
27
28// Variant of ScopedObjectAccess that does no runnable transitions. Should only be used by "fast"
29// JNI methods.
30class ScopedFastNativeObjectAccess {
31 public:
32  explicit ScopedFastNativeObjectAccess(JNIEnv* env)
33    LOCKS_EXCLUDED(Locks::thread_suspend_count_lock_)
34    SHARED_LOCK_FUNCTION(Locks::mutator_lock_) ALWAYS_INLINE
35     : env_(down_cast<JNIEnvExt*>(env)), self_(ThreadForEnv(env)) {
36    Locks::mutator_lock_->AssertSharedHeld(Self());
37    DCHECK((*Self()->GetManagedStack()->GetTopQuickFrame())->IsFastNative());
38    // Don't work with raw objects in non-runnable states.
39    DCHECK_EQ(Self()->GetState(), kRunnable);
40  }
41
42  ~ScopedFastNativeObjectAccess() UNLOCK_FUNCTION(Locks::mutator_lock_) ALWAYS_INLINE {
43  }
44
45  Thread* Self() const {
46    return self_;
47  }
48
49  JNIEnvExt* Env() const {
50    return env_;
51  }
52
53  template<typename T>
54  T Decode(jobject obj) const
55      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
56    Locks::mutator_lock_->AssertSharedHeld(Self());
57    // Don't work with raw objects in non-runnable states.
58    DCHECK_EQ(Self()->GetState(), kRunnable);
59    return down_cast<T>(Self()->DecodeJObject(obj));
60  }
61
62  mirror::ArtField* DecodeField(jfieldID fid) const
63      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
64    Locks::mutator_lock_->AssertSharedHeld(Self());
65    // Don't work with raw objects in non-runnable states.
66    DCHECK_EQ(Self()->GetState(), kRunnable);
67    return reinterpret_cast<mirror::ArtField*>(fid);
68  }
69
70  /*
71   * Variant of ScopedObjectAccessUnched::AddLocalReference that without JNI work arounds
72   * or check JNI that should be being used by fast native methods.
73   */
74  template<typename T>
75  T AddLocalReference(mirror::Object* obj) const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
76    Locks::mutator_lock_->AssertSharedHeld(Self());
77    // Don't work with raw objects in non-runnable states.
78    DCHECK_EQ(Self()->GetState(), kRunnable);
79    if (obj == NULL) {
80      return NULL;
81    }
82
83    DCHECK_NE((reinterpret_cast<uintptr_t>(obj) & 0xffff0000), 0xebad0000);
84
85    IndirectReferenceTable& locals = Env()->locals;
86
87    uint32_t cookie = Env()->local_ref_cookie;
88    IndirectRef ref = locals.Add(cookie, obj);
89
90    return reinterpret_cast<T>(ref);
91  }
92
93 private:
94  JNIEnvExt* const env_;
95  Thread* const self_;
96};
97
98}  // namespace art
99
100#endif  // ART_RUNTIME_NATIVE_SCOPED_FAST_NATIVE_OBJECT_ACCESS_H_
101