1 /*
2 * Copyright 2020 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 <atomic>
18 #include <string_view>
19
20 #include "arch/context.h"
21 #include "art_method-inl.h"
22 #include "instrumentation.h"
23 #include "jni.h"
24 #include "scoped_thread_state_change.h"
25 #include "stack.h"
26 #include "thread.h"
27
28 namespace art {
29 namespace StackWalkConcurrentInstrument {
30
31 std::atomic<bool> instrument_waiting = false;
32 std::atomic<bool> instrumented = false;
33
34 // Spin lock.
WaitForInstrument()35 static void WaitForInstrument() REQUIRES_SHARED(Locks::mutator_lock_) {
36 ScopedThreadSuspension sts(Thread::Current(), ThreadState::kWaitingForDeoptimization);
37 instrument_waiting = true;
38 while (!instrumented) {
39 }
40 }
41
42 class SelfStackWalkVisitor : public StackVisitor {
43 public:
REQUIRES_SHARED(Locks::mutator_lock_)44 explicit SelfStackWalkVisitor(Thread* thread) REQUIRES_SHARED(Locks::mutator_lock_)
45 : StackVisitor(thread, Context::Create(), StackWalkKind::kIncludeInlinedFrames) {}
46
VisitFrame()47 bool VisitFrame() override REQUIRES_SHARED(Locks::mutator_lock_) {
48 if (GetMethod()->GetNameView() == "$noinline$f") {
49 CHECK(!found_f_);
50 found_f_ = true;
51 } else if (GetMethod()->GetNameView() == "$noinline$g") {
52 CHECK(!found_g_);
53 found_g_ = true;
54 WaitForInstrument();
55 } else if (GetMethod()->GetNameView() == "$noinline$h") {
56 CHECK(!found_h_);
57 found_h_ = true;
58 }
59 return true;
60 }
61
62 bool found_f_ = false;
63 bool found_g_ = false;
64 bool found_h_ = false;
65 };
66
Java_Main_resetTest(JNIEnv *,jobject)67 extern "C" JNIEXPORT void JNICALL Java_Main_resetTest(JNIEnv*, jobject) {
68 instrument_waiting = false;
69 instrumented = false;
70 }
71
Java_Main_doSelfStackWalk(JNIEnv *,jobject)72 extern "C" JNIEXPORT void JNICALL Java_Main_doSelfStackWalk(JNIEnv*, jobject) {
73 ScopedObjectAccess soa(Thread::Current());
74 SelfStackWalkVisitor sswv(Thread::Current());
75 sswv.WalkStack();
76 CHECK(sswv.found_f_);
77 CHECK(sswv.found_g_);
78 CHECK(sswv.found_h_);
79 }
Java_Main_waitAndInstrumentStack(JNIEnv *,jobject,jobject target)80 extern "C" JNIEXPORT void JNICALL Java_Main_waitAndInstrumentStack(JNIEnv*,
81 jobject,
82 jobject target) {
83 while (!instrument_waiting) {
84 }
85 Thread* other = Runtime::Current()->GetThreadList()->SuspendThreadByPeer(
86 target, SuspendReason::kInternal);
87 CHECK(other != nullptr);
88 ScopedSuspendAll ssa(__FUNCTION__);
89 Runtime::Current()->GetInstrumentation()->InstrumentThreadStack(other,
90 /* force_deopt= */ false);
91 bool resumed = art::Runtime::Current()->GetThreadList()->Resume(other, SuspendReason::kInternal);
92 CHECK(resumed);
93 instrumented = true;
94 return;
95 }
96
97 } // namespace StackWalkConcurrentInstrument
98 } // namespace art
99