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 "dex_file-inl.h"
18 #include "entrypoints/entrypoint_utils-inl.h"
19 #include "mirror/art_method-inl.h"
20 #include "mirror/class-inl.h"
21 #include "mirror/object.h"
22 #include "mirror/object-inl.h"
23 #include "mirror/object_array-inl.h"
24 #include "scoped_thread_state_change.h"
25 #include "thread.h"
26 #include "verify_object-inl.h"
27 
28 namespace art {
29 
30 // Called on entry to JNI, transition out of Runnable and release share of mutator_lock_.
JniMethodStart(Thread * self)31 extern uint32_t JniMethodStart(Thread* self) {
32   JNIEnvExt* env = self->GetJniEnv();
33   DCHECK(env != nullptr);
34   uint32_t saved_local_ref_cookie = env->local_ref_cookie;
35   env->local_ref_cookie = env->locals.GetSegmentState();
36   mirror::ArtMethod* native_method = self->GetManagedStack()->GetTopQuickFrame()->AsMirrorPtr();
37   if (!native_method->IsFastNative()) {
38     // When not fast JNI we transition out of runnable.
39     self->TransitionFromRunnableToSuspended(kNative);
40   }
41   return saved_local_ref_cookie;
42 }
43 
JniMethodStartSynchronized(jobject to_lock,Thread * self)44 extern uint32_t JniMethodStartSynchronized(jobject to_lock, Thread* self) {
45   self->DecodeJObject(to_lock)->MonitorEnter(self);
46   return JniMethodStart(self);
47 }
48 
49 // TODO: NO_THREAD_SAFETY_ANALYSIS due to different control paths depending on fast JNI.
GoToRunnable(Thread * self)50 static void GoToRunnable(Thread* self) NO_THREAD_SAFETY_ANALYSIS {
51   mirror::ArtMethod* native_method = self->GetManagedStack()->GetTopQuickFrame()->AsMirrorPtr();
52   bool is_fast = native_method->IsFastNative();
53   if (!is_fast) {
54     self->TransitionFromSuspendedToRunnable();
55   } else if (UNLIKELY(self->TestAllFlags())) {
56     // In fast JNI mode we never transitioned out of runnable. Perform a suspend check if there
57     // is a flag raised.
58     DCHECK(Locks::mutator_lock_->IsSharedHeld(self));
59     CheckSuspend(self);
60   }
61 }
62 
PopLocalReferences(uint32_t saved_local_ref_cookie,Thread * self)63 static void PopLocalReferences(uint32_t saved_local_ref_cookie, Thread* self)
64     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
65   JNIEnvExt* env = self->GetJniEnv();
66   env->locals.SetSegmentState(env->local_ref_cookie);
67   env->local_ref_cookie = saved_local_ref_cookie;
68   self->PopHandleScope();
69 }
70 
JniMethodEnd(uint32_t saved_local_ref_cookie,Thread * self)71 extern void JniMethodEnd(uint32_t saved_local_ref_cookie, Thread* self) {
72   GoToRunnable(self);
73   PopLocalReferences(saved_local_ref_cookie, self);
74 }
75 
76 
JniMethodEndSynchronized(uint32_t saved_local_ref_cookie,jobject locked,Thread * self)77 extern void JniMethodEndSynchronized(uint32_t saved_local_ref_cookie, jobject locked,
78                                      Thread* self) {
79   GoToRunnable(self);
80   UnlockJniSynchronizedMethod(locked, self);  // Must decode before pop.
81   PopLocalReferences(saved_local_ref_cookie, self);
82 }
83 
JniMethodEndWithReference(jobject result,uint32_t saved_local_ref_cookie,Thread * self)84 extern mirror::Object* JniMethodEndWithReference(jobject result, uint32_t saved_local_ref_cookie,
85                                                  Thread* self) {
86   GoToRunnable(self);
87   mirror::Object* o = self->DecodeJObject(result);  // Must decode before pop.
88   PopLocalReferences(saved_local_ref_cookie, self);
89   // Process result.
90   if (UNLIKELY(self->GetJniEnv()->check_jni)) {
91     if (self->IsExceptionPending()) {
92       return NULL;
93     }
94     CheckReferenceResult(o, self);
95   }
96   VerifyObject(o);
97   return o;
98 }
99 
JniMethodEndWithReferenceSynchronized(jobject result,uint32_t saved_local_ref_cookie,jobject locked,Thread * self)100 extern mirror::Object* JniMethodEndWithReferenceSynchronized(jobject result,
101                                                              uint32_t saved_local_ref_cookie,
102                                                              jobject locked, Thread* self) {
103   GoToRunnable(self);
104   UnlockJniSynchronizedMethod(locked, self);  // Must decode before pop.
105   mirror::Object* o = self->DecodeJObject(result);
106   PopLocalReferences(saved_local_ref_cookie, self);
107   // Process result.
108   if (UNLIKELY(self->GetJniEnv()->check_jni)) {
109     if (self->IsExceptionPending()) {
110       return NULL;
111     }
112     CheckReferenceResult(o, self);
113   }
114   VerifyObject(o);
115   return o;
116 }
117 
118 }  // namespace art
119