1 /*
2 * Copyright (C) 2012 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 "art_method-inl.h"
18 #include "entrypoints/entrypoint_utils-inl.h"
19 #include "mirror/object-inl.h"
20 #include "thread-inl.h"
21 #include "verify_object-inl.h"
22
23 namespace art {
24
ReadBarrierJni(mirror::CompressedReference<mirror::Object> * handle_on_stack,Thread * self ATTRIBUTE_UNUSED)25 extern void ReadBarrierJni(mirror::CompressedReference<mirror::Object>* handle_on_stack,
26 Thread* self ATTRIBUTE_UNUSED) {
27 // Call the read barrier and update the handle.
28 mirror::Object* to_ref = ReadBarrier::BarrierForRoot(handle_on_stack);
29 handle_on_stack->Assign(to_ref);
30 }
31
32 // Called on entry to JNI, transition out of Runnable and release share of mutator_lock_.
JniMethodStart(Thread * self)33 extern uint32_t JniMethodStart(Thread* self) {
34 JNIEnvExt* env = self->GetJniEnv();
35 DCHECK(env != nullptr);
36 uint32_t saved_local_ref_cookie = env->local_ref_cookie;
37 env->local_ref_cookie = env->locals.GetSegmentState();
38 ArtMethod* native_method = *self->GetManagedStack()->GetTopQuickFrame();
39 if (!native_method->IsFastNative()) {
40 // When not fast JNI we transition out of runnable.
41 self->TransitionFromRunnableToSuspended(kNative);
42 }
43 return saved_local_ref_cookie;
44 }
45
JniMethodStartSynchronized(jobject to_lock,Thread * self)46 extern uint32_t JniMethodStartSynchronized(jobject to_lock, Thread* self) {
47 self->DecodeJObject(to_lock)->MonitorEnter(self);
48 return JniMethodStart(self);
49 }
50
51 // TODO: NO_THREAD_SAFETY_ANALYSIS due to different control paths depending on fast JNI.
GoToRunnable(Thread * self)52 static void GoToRunnable(Thread* self) NO_THREAD_SAFETY_ANALYSIS {
53 ArtMethod* native_method = *self->GetManagedStack()->GetTopQuickFrame();
54 bool is_fast = native_method->IsFastNative();
55 if (!is_fast) {
56 self->TransitionFromSuspendedToRunnable();
57 } else if (UNLIKELY(self->TestAllFlags())) {
58 // In fast JNI mode we never transitioned out of runnable. Perform a suspend check if there
59 // is a flag raised.
60 DCHECK(Locks::mutator_lock_->IsSharedHeld(self));
61 self->CheckSuspend();
62 }
63 }
64
PopLocalReferences(uint32_t saved_local_ref_cookie,Thread * self)65 static void PopLocalReferences(uint32_t saved_local_ref_cookie, Thread* self)
66 SHARED_REQUIRES(Locks::mutator_lock_) {
67 JNIEnvExt* env = self->GetJniEnv();
68 if (UNLIKELY(env->check_jni)) {
69 env->CheckNoHeldMonitors();
70 }
71 env->locals.SetSegmentState(env->local_ref_cookie);
72 env->local_ref_cookie = saved_local_ref_cookie;
73 self->PopHandleScope();
74 }
75
JniMethodEnd(uint32_t saved_local_ref_cookie,Thread * self)76 extern void JniMethodEnd(uint32_t saved_local_ref_cookie, Thread* self) {
77 GoToRunnable(self);
78 PopLocalReferences(saved_local_ref_cookie, self);
79 }
80
JniMethodEndSynchronized(uint32_t saved_local_ref_cookie,jobject locked,Thread * self)81 extern void JniMethodEndSynchronized(uint32_t saved_local_ref_cookie, jobject locked,
82 Thread* self) {
83 GoToRunnable(self);
84 UnlockJniSynchronizedMethod(locked, self); // Must decode before pop.
85 PopLocalReferences(saved_local_ref_cookie, self);
86 }
87
88 // Common result handling for EndWithReference.
JniMethodEndWithReferenceHandleResult(jobject result,uint32_t saved_local_ref_cookie,Thread * self)89 static mirror::Object* JniMethodEndWithReferenceHandleResult(jobject result,
90 uint32_t saved_local_ref_cookie,
91 Thread* self)
92 NO_THREAD_SAFETY_ANALYSIS {
93 // Must decode before pop. The 'result' may not be valid in case of an exception, though.
94 mirror::Object* o = self->IsExceptionPending() ? nullptr : self->DecodeJObject(result);
95 PopLocalReferences(saved_local_ref_cookie, self);
96 // Process result.
97 if (UNLIKELY(self->GetJniEnv()->check_jni)) {
98 CheckReferenceResult(o, self);
99 }
100 VerifyObject(o);
101 return o;
102 }
103
JniMethodEndWithReference(jobject result,uint32_t saved_local_ref_cookie,Thread * self)104 extern mirror::Object* JniMethodEndWithReference(jobject result, uint32_t saved_local_ref_cookie,
105 Thread* self) {
106 GoToRunnable(self);
107 return JniMethodEndWithReferenceHandleResult(result, saved_local_ref_cookie, self);
108 }
109
JniMethodEndWithReferenceSynchronized(jobject result,uint32_t saved_local_ref_cookie,jobject locked,Thread * self)110 extern mirror::Object* JniMethodEndWithReferenceSynchronized(jobject result,
111 uint32_t saved_local_ref_cookie,
112 jobject locked, Thread* self) {
113 GoToRunnable(self);
114 UnlockJniSynchronizedMethod(locked, self);
115 return JniMethodEndWithReferenceHandleResult(result, saved_local_ref_cookie, self);
116 }
117
GenericJniMethodEnd(Thread * self,uint32_t saved_local_ref_cookie,jvalue result,uint64_t result_f,ArtMethod * called,HandleScope * handle_scope)118 extern uint64_t GenericJniMethodEnd(Thread* self,
119 uint32_t saved_local_ref_cookie,
120 jvalue result,
121 uint64_t result_f,
122 ArtMethod* called,
123 HandleScope* handle_scope)
124 // TODO: NO_THREAD_SAFETY_ANALYSIS as GoToRunnable() is NO_THREAD_SAFETY_ANALYSIS
125 NO_THREAD_SAFETY_ANALYSIS {
126 GoToRunnable(self);
127 // We need the mutator lock (i.e., calling GoToRunnable()) before accessing the shorty or the
128 // locked object.
129 jobject locked = called->IsSynchronized() ? handle_scope->GetHandle(0).ToJObject() : nullptr;
130 char return_shorty_char = called->GetShorty()[0];
131 if (return_shorty_char == 'L') {
132 if (locked != nullptr) {
133 UnlockJniSynchronizedMethod(locked, self);
134 }
135 return reinterpret_cast<uint64_t>(JniMethodEndWithReferenceHandleResult(
136 result.l, saved_local_ref_cookie, self));
137 } else {
138 if (locked != nullptr) {
139 UnlockJniSynchronizedMethod(locked, self); // Must decode before pop.
140 }
141 PopLocalReferences(saved_local_ref_cookie, self);
142 switch (return_shorty_char) {
143 case 'F': {
144 if (kRuntimeISA == kX86) {
145 // Convert back the result to float.
146 double d = bit_cast<double, uint64_t>(result_f);
147 return bit_cast<uint32_t, float>(static_cast<float>(d));
148 } else {
149 return result_f;
150 }
151 }
152 case 'D':
153 return result_f;
154 case 'Z':
155 return result.z;
156 case 'B':
157 return result.b;
158 case 'C':
159 return result.c;
160 case 'S':
161 return result.s;
162 case 'I':
163 return result.i;
164 case 'J':
165 return result.j;
166 case 'V':
167 return 0;
168 default:
169 LOG(FATAL) << "Unexpected return shorty character " << return_shorty_char;
170 return 0;
171 }
172 }
173 }
174
175 } // namespace art
176