Merge "Keep internal stack trace methods declaring classes live"
diff --git a/runtime/thread.cc b/runtime/thread.cc
index 82e6fb0..65f71ef 100644
--- a/runtime/thread.cc
+++ b/runtime/thread.cc
@@ -1966,15 +1966,32 @@
pointer_size_(Runtime::Current()->GetClassLinker()->GetImagePointerSize()) {}
bool Init(int depth) SHARED_REQUIRES(Locks::mutator_lock_) ACQUIRE(Roles::uninterruptible_) {
- // Allocate method trace with format [method pointers][pcs].
- auto* cl = Runtime::Current()->GetClassLinker();
- trace_ = cl->AllocPointerArray(self_, depth * 2);
- const char* last_no_suspend_cause =
- self_->StartAssertNoThreadSuspension("Building internal stack trace");
- if (trace_ == nullptr) {
+ // Allocate method trace as an object array where the first element is a pointer array that
+ // contains the ArtMethod pointers and dex PCs. The rest of the elements are the declaring
+ // class of the ArtMethod pointers.
+ ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
+ StackHandleScope<1> hs(self_);
+ mirror::Class* array_class = class_linker->GetClassRoot(ClassLinker::kObjectArrayClass);
+ // The first element is the methods and dex pc array, the other elements are declaring classes
+ // for the methods to ensure classes in the stack trace don't get unloaded.
+ Handle<mirror::ObjectArray<mirror::Object>> trace(
+ hs.NewHandle(
+ mirror::ObjectArray<mirror::Object>::Alloc(hs.Self(), array_class, depth + 1)));
+ if (trace.Get() == nullptr) {
+ // Acquire uninterruptible_ in all paths.
+ self_->StartAssertNoThreadSuspension("Building internal stack trace");
self_->AssertPendingOOMException();
return false;
}
+ mirror::PointerArray* methods_and_pcs = class_linker->AllocPointerArray(self_, depth * 2);
+ const char* last_no_suspend_cause =
+ self_->StartAssertNoThreadSuspension("Building internal stack trace");
+ if (methods_and_pcs == nullptr) {
+ self_->AssertPendingOOMException();
+ return false;
+ }
+ trace->Set(0, methods_and_pcs);
+ trace_ = trace.Get();
// If We are called from native, use non-transactional mode.
CHECK(last_no_suspend_cause == nullptr) << last_no_suspend_cause;
return true;
@@ -1996,16 +2013,24 @@
if (m->IsRuntimeMethod()) {
return true; // Ignore runtime frames (in particular callee save).
}
- trace_->SetElementPtrSize<kTransactionActive>(
- count_, m, pointer_size_);
- trace_->SetElementPtrSize<kTransactionActive>(
- trace_->GetLength() / 2 + count_, m->IsProxyMethod() ? DexFile::kDexNoIndex : GetDexPc(),
- pointer_size_);
+ mirror::PointerArray* trace_methods_and_pcs = GetTraceMethodsAndPCs();
+ trace_methods_and_pcs->SetElementPtrSize<kTransactionActive>(count_, m, pointer_size_);
+ trace_methods_and_pcs->SetElementPtrSize<kTransactionActive>(
+ trace_methods_and_pcs->GetLength() / 2 + count_,
+ m->IsProxyMethod() ? DexFile::kDexNoIndex : GetDexPc(),
+ pointer_size_);
+ // Save the declaring class of the method to ensure that the declaring classes of the methods
+ // do not get unloaded while the stack trace is live.
+ trace_->Set(count_ + 1, m->GetDeclaringClass());
++count_;
return true;
}
- mirror::PointerArray* GetInternalStackTrace() const {
+ mirror::PointerArray* GetTraceMethodsAndPCs() const SHARED_REQUIRES(Locks::mutator_lock_) {
+ return down_cast<mirror::PointerArray*>(trace_->Get(0));
+ }
+
+ mirror::ObjectArray<mirror::Object>* GetInternalStackTrace() const {
return trace_;
}
@@ -2015,8 +2040,11 @@
int32_t skip_depth_;
// Current position down stack trace.
uint32_t count_;
- // An array of the methods on the stack, the last entries are the dex PCs.
- mirror::PointerArray* trace_;
+ // An object array where the first element is a pointer array that contains the ArtMethod
+ // pointers on the stack and dex PCs. The rest of the elements are the declaring
+ // class of the ArtMethod pointers. trace_[i+1] contains the declaring class of the ArtMethod of
+ // the i'th frame.
+ mirror::ObjectArray<mirror::Object>* trace_;
// For cross compilation.
const size_t pointer_size_;
@@ -2039,11 +2067,12 @@
return nullptr; // Allocation failed.
}
build_trace_visitor.WalkStack();
- mirror::PointerArray* trace = build_trace_visitor.GetInternalStackTrace();
+ mirror::ObjectArray<mirror::Object>* trace = build_trace_visitor.GetInternalStackTrace();
if (kIsDebugBuild) {
- // Second half is dex PCs.
- for (uint32_t i = 0; i < static_cast<uint32_t>(trace->GetLength() / 2); ++i) {
- auto* method = trace->GetElementPtrSize<ArtMethod*>(
+ mirror::PointerArray* trace_methods = build_trace_visitor.GetTraceMethodsAndPCs();
+ // Second half of trace_methods is dex PCs.
+ for (uint32_t i = 0; i < static_cast<uint32_t>(trace_methods->GetLength() / 2); ++i) {
+ auto* method = trace_methods->GetElementPtrSize<ArtMethod*>(
i, Runtime::Current()->GetClassLinker()->GetImagePointerSize());
CHECK(method != nullptr);
}
@@ -2062,12 +2091,16 @@
}
jobjectArray Thread::InternalStackTraceToStackTraceElementArray(
- const ScopedObjectAccessAlreadyRunnable& soa, jobject internal, jobjectArray output_array,
+ const ScopedObjectAccessAlreadyRunnable& soa,
+ jobject internal,
+ jobjectArray output_array,
int* stack_depth) {
- // Decode the internal stack trace into the depth, method trace and PC trace
- int32_t depth = soa.Decode<mirror::PointerArray*>(internal)->GetLength() / 2;
+ // Decode the internal stack trace into the depth, method trace and PC trace.
+ // Subtract one for the methods and PC trace.
+ int32_t depth = soa.Decode<mirror::Array*>(internal)->GetLength() - 1;
+ DCHECK_GE(depth, 0);
- auto* cl = Runtime::Current()->GetClassLinker();
+ ClassLinker* const class_linker = Runtime::Current()->GetClassLinker();
jobjectArray result;
@@ -2081,7 +2114,7 @@
} else {
// Create java_trace array and place in local reference table
mirror::ObjectArray<mirror::StackTraceElement>* java_traces =
- cl->AllocStackTraceElementArray(soa.Self(), depth);
+ class_linker->AllocStackTraceElementArray(soa.Self(), depth);
if (java_traces == nullptr) {
return nullptr;
}
@@ -2093,7 +2126,12 @@
}
for (int32_t i = 0; i < depth; ++i) {
- auto* method_trace = soa.Decode<mirror::PointerArray*>(internal);
+ mirror::ObjectArray<mirror::Object>* decoded_traces =
+ soa.Decode<mirror::Object*>(internal)->AsObjectArray<mirror::Object>();
+ // Methods and dex PC trace is element 0.
+ DCHECK(decoded_traces->Get(0)->IsIntArray() || decoded_traces->Get(0)->IsLongArray());
+ mirror::PointerArray* const method_trace =
+ down_cast<mirror::PointerArray*>(decoded_traces->Get(0));
// Prepare parameters for StackTraceElement(String cls, String method, String file, int line)
ArtMethod* method = method_trace->GetElementPtrSize<ArtMethod*>(i, sizeof(void*));
uint32_t dex_pc = method_trace->GetElementPtrSize<uint32_t>(
diff --git a/test/141-class-unload/expected.txt b/test/141-class-unload/expected.txt
index ff65a70..53d7abe 100644
--- a/test/141-class-unload/expected.txt
+++ b/test/141-class-unload/expected.txt
@@ -16,3 +16,8 @@
JNI_OnLoad called
JNI_OnUnload called
null
+1
+2
+JNI_OnLoad called
+class null false test
+JNI_OnUnload called
diff --git a/test/141-class-unload/src-ex/IntHolder.java b/test/141-class-unload/src-ex/IntHolder.java
index e4aa6b8..feff0d2 100644
--- a/test/141-class-unload/src-ex/IntHolder.java
+++ b/test/141-class-unload/src-ex/IntHolder.java
@@ -36,4 +36,8 @@
}
public static native void waitForCompilation();
+
+ public static Throwable generateStackTrace() {
+ return new Exception("test");
+ }
}
diff --git a/test/141-class-unload/src/Main.java b/test/141-class-unload/src/Main.java
index 105a2b9..3cc43ac 100644
--- a/test/141-class-unload/src/Main.java
+++ b/test/141-class-unload/src/Main.java
@@ -39,6 +39,8 @@
testNoUnloadInstance(constructor);
// Test JNI_OnLoad and JNI_OnUnload.
testLoadAndUnloadLibrary(constructor);
+ // Test that stack traces keep the classes live.
+ testStackTrace(constructor);
// Stress test to make sure we dont leak memory.
stressTest(constructor);
} catch (Exception e) {
@@ -75,6 +77,16 @@
System.out.println(loader.get());
}
+ private static void testStackTrace(Constructor constructor) throws Exception {
+ WeakReference<Class> klass = setUpUnloadClass(constructor);
+ Method stackTraceMethod = klass.get().getDeclaredMethod("generateStackTrace");
+ Throwable throwable = (Throwable) stackTraceMethod.invoke(klass.get());
+ stackTraceMethod = null;
+ Runtime.getRuntime().gc();
+ boolean isNull = klass.get() == null;
+ System.out.println("class null " + isNull + " " + throwable.getMessage());
+ }
+
private static void testLoadAndUnloadLibrary(Constructor constructor) throws Exception {
WeakReference<ClassLoader> loader = setUpLoadLibrary(constructor);
// No strong refernces to class loader, should get unloaded.
