1 /*
2 * Copyright (C) 2011 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 #include "jni_env_ext.h"
18
19 #include "check_jni.h"
20 #include "indirect_reference_table.h"
21 #include "java_vm_ext.h"
22 #include "jni_internal.h"
23
24 namespace art {
25
26 static constexpr size_t kMonitorsInitial = 32; // Arbitrary.
27 static constexpr size_t kMonitorsMax = 4096; // Arbitrary sanity check.
28
29 static constexpr size_t kLocalsInitial = 64; // Arbitrary.
30
31 // Checking "locals" requires the mutator lock, but at creation time we're really only interested
32 // in validity, which isn't changing. To avoid grabbing the mutator lock, factored out and tagged
33 // with NO_THREAD_SAFETY_ANALYSIS.
CheckLocalsValid(JNIEnvExt * in)34 static bool CheckLocalsValid(JNIEnvExt* in) NO_THREAD_SAFETY_ANALYSIS {
35 if (in == nullptr) {
36 return false;
37 }
38 return in->locals.IsValid();
39 }
40
Create(Thread * self_in,JavaVMExt * vm_in)41 JNIEnvExt* JNIEnvExt::Create(Thread* self_in, JavaVMExt* vm_in) {
42 std::unique_ptr<JNIEnvExt> ret(new JNIEnvExt(self_in, vm_in));
43 if (CheckLocalsValid(ret.get())) {
44 return ret.release();
45 }
46 return nullptr;
47 }
48
JNIEnvExt(Thread * self_in,JavaVMExt * vm_in)49 JNIEnvExt::JNIEnvExt(Thread* self_in, JavaVMExt* vm_in)
50 : self(self_in),
51 vm(vm_in),
52 local_ref_cookie(IRT_FIRST_SEGMENT),
53 locals(kLocalsInitial, kLocalsMax, kLocal, false),
54 check_jni(false),
55 critical(0),
56 monitors("monitors", kMonitorsInitial, kMonitorsMax) {
57 functions = unchecked_functions = GetJniNativeInterface();
58 if (vm->IsCheckJniEnabled()) {
59 SetCheckJniEnabled(true);
60 }
61 }
62
~JNIEnvExt()63 JNIEnvExt::~JNIEnvExt() {
64 }
65
NewLocalRef(mirror::Object * obj)66 jobject JNIEnvExt::NewLocalRef(mirror::Object* obj) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
67 if (obj == nullptr) {
68 return nullptr;
69 }
70 return reinterpret_cast<jobject>(locals.Add(local_ref_cookie, obj));
71 }
72
DeleteLocalRef(jobject obj)73 void JNIEnvExt::DeleteLocalRef(jobject obj) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
74 if (obj != nullptr) {
75 locals.Remove(local_ref_cookie, reinterpret_cast<IndirectRef>(obj));
76 }
77 }
78
SetCheckJniEnabled(bool enabled)79 void JNIEnvExt::SetCheckJniEnabled(bool enabled) {
80 check_jni = enabled;
81 functions = enabled ? GetCheckJniNativeInterface() : GetJniNativeInterface();
82 }
83
DumpReferenceTables(std::ostream & os)84 void JNIEnvExt::DumpReferenceTables(std::ostream& os) {
85 locals.Dump(os);
86 monitors.Dump(os);
87 }
88
PushFrame(int capacity)89 void JNIEnvExt::PushFrame(int capacity) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
90 UNUSED(capacity); // cpplint gets confused with (int) and thinks its a cast.
91 // TODO: take 'capacity' into account.
92 stacked_local_ref_cookies.push_back(local_ref_cookie);
93 local_ref_cookie = locals.GetSegmentState();
94 }
95
PopFrame()96 void JNIEnvExt::PopFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
97 locals.SetSegmentState(local_ref_cookie);
98 local_ref_cookie = stacked_local_ref_cookies.back();
99 stacked_local_ref_cookies.pop_back();
100 }
101
SegmentStateOffset()102 Offset JNIEnvExt::SegmentStateOffset() {
103 return Offset(OFFSETOF_MEMBER(JNIEnvExt, locals) +
104 IndirectReferenceTable::SegmentStateOffset().Int32Value());
105 }
106
107 } // namespace art
108