/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <android-base/logging.h>
#include "art_method-inl.h"
#include "base/casts.h"
#include "entrypoints/entrypoint_utils-inl.h"
#include "indirect_reference_table.h"
#include "mirror/object-inl.h"
#include "thread-inl.h"
#include "verify_object.h"
namespace art {
static_assert(sizeof(IRTSegmentState) == sizeof(uint32_t), "IRTSegmentState size unexpected");
static_assert(std::is_trivial<IRTSegmentState>::value, "IRTSegmentState not trivial");
static inline void GoToRunnableFast(Thread* self) REQUIRES_SHARED(Locks::mutator_lock_);
extern void ReadBarrierJni(mirror::CompressedReference<mirror::Object>* handle_on_stack,
Thread* self ATTRIBUTE_UNUSED) {
DCHECK(kUseReadBarrier);
if (kUseBakerReadBarrier) {
DCHECK(handle_on_stack->AsMirrorPtr() != nullptr)
<< "The class of a static jni call must not be null";
// Check the mark bit and return early if it's already marked.
if (LIKELY(handle_on_stack->AsMirrorPtr()->GetMarkBit() != 0)) {
return;
}
}
// Call the read barrier and update the handle.
mirror::Object* to_ref = ReadBarrier::BarrierForRoot(handle_on_stack);
handle_on_stack->Assign(to_ref);
}
// Called on entry to fast JNI, push a new local reference table only.
extern uint32_t JniMethodFastStart(Thread* self) {
JNIEnvExt* env = self->GetJniEnv();
DCHECK(env != nullptr);
uint32_t saved_local_ref_cookie = bit_cast<uint32_t>(env->GetLocalRefCookie());
env->SetLocalRefCookie(env->GetLocalsSegmentState());
if (kIsDebugBuild) {
ArtMethod* native_method = *self->GetManagedStack()->GetTopQuickFrame();
CHECK(native_method->IsFastNative()) << native_method->PrettyMethod();
}
return saved_local_ref_cookie;
}
// Called on entry to JNI, transition out of Runnable and release share of mutator_lock_.
extern uint32_t JniMethodStart(Thread* self) {
JNIEnvExt* env = self->GetJniEnv();
DCHECK(env != nullptr);
uint32_t saved_local_ref_cookie = bit_cast<uint32_t>(env->GetLocalRefCookie());
env->SetLocalRefCookie(env->GetLocalsSegmentState());
ArtMethod* native_method = *self->GetManagedStack()->GetTopQuickFrame();
// TODO: Introduce special entrypoint for synchronized @FastNative methods?
// Or ban synchronized @FastNative outright to avoid the extra check here?
DCHECK(!native_method->IsFastNative() || native_method->IsSynchronized());
if (!native_method->IsFastNative()) {
// When not fast JNI we transition out of runnable.
self->TransitionFromRunnableToSuspended(kNative);
}
return saved_local_ref_cookie;
}
extern uint32_t JniMethodStartSynchronized(jobject to_lock, Thread* self) {
self->DecodeJObject(to_lock)->MonitorEnter(self);
return JniMethodStart(self);
}
// TODO: NO_THREAD_SAFETY_ANALYSIS due to different control paths depending on fast JNI.
static void GoToRunnable(Thread* self) NO_THREAD_SAFETY_ANALYSIS {
ArtMethod* native_method = *self->GetManagedStack()->GetTopQuickFrame();
bool is_fast = native_method->IsFastNative();
if (!is_fast) {
self->TransitionFromSuspendedToRunnable();
} else {
GoToRunnableFast(self);
}
}
ALWAYS_INLINE static inline void GoToRunnableFast(Thread* self) {
if (kIsDebugBuild) {
// Should only enter here if the method is @FastNative.
ArtMethod* native_method = *self->GetManagedStack()->GetTopQuickFrame();
CHECK(native_method->IsFastNative()) << native_method->PrettyMethod();
}
// When we are in @FastNative, we are already Runnable.
// Only do a suspend check on the way out of JNI.
if (UNLIKELY(self->TestAllFlags())) {
// In fast JNI mode we never transitioned out of runnable. Perform a suspend check if there
// is a flag raised.
DCHECK(Locks::mutator_lock_->IsSharedHeld(self));
self->CheckSuspend();
}
}
static void PopLocalReferences(uint32_t saved_local_ref_cookie, Thread* self)
REQUIRES_SHARED(Locks::mutator_lock_) {
JNIEnvExt* env = self->GetJniEnv();
if (UNLIKELY(env->IsCheckJniEnabled())) {
env->CheckNoHeldMonitors();
}
env->SetLocalSegmentState(env->GetLocalRefCookie());
env->SetLocalRefCookie(bit_cast<IRTSegmentState>(saved_local_ref_cookie));
self->PopHandleScope();
}
// TODO: These should probably be templatized or macro-ized.
// Otherwise there's just too much repetitive boilerplate.
extern void JniMethodEnd(uint32_t saved_local_ref_cookie, Thread* self) {
GoToRunnable(self);
PopLocalReferences(saved_local_ref_cookie, self);
}
extern void JniMethodFastEnd(uint32_t saved_local_ref_cookie, Thread* self) {
GoToRunnableFast(self);
PopLocalReferences(saved_local_ref_cookie, self);
}
extern void JniMethodEndSynchronized(uint32_t saved_local_ref_cookie,
jobject locked,
Thread* self) {
GoToRunnable(self);
UnlockJniSynchronizedMethod(locked, self); // Must decode before pop.
PopLocalReferences(saved_local_ref_cookie, self);
}
// Common result handling for EndWithReference.
static mirror::Object* JniMethodEndWithReferenceHandleResult(jobject result,
uint32_t saved_local_ref_cookie,
Thread* self)
NO_THREAD_SAFETY_ANALYSIS {
// Must decode before pop. The 'result' may not be valid in case of an exception, though.
ObjPtr<mirror::Object> o;
if (!self->IsExceptionPending()) {
o = self->DecodeJObject(result);
}
PopLocalReferences(saved_local_ref_cookie, self);
// Process result.
if (UNLIKELY(self->GetJniEnv()->IsCheckJniEnabled())) {
// CheckReferenceResult can resolve types.
StackHandleScope<1> hs(self);
HandleWrapperObjPtr<mirror::Object> h_obj(hs.NewHandleWrapper(&o));
CheckReferenceResult(h_obj, self);
}
VerifyObject(o);
return o.Ptr();
}
extern mirror::Object* JniMethodFastEndWithReference(jobject result,
uint32_t saved_local_ref_cookie,
Thread* self) {
GoToRunnableFast(self);
return JniMethodEndWithReferenceHandleResult(result, saved_local_ref_cookie, self);
}
extern mirror::Object* JniMethodEndWithReference(jobject result,
uint32_t saved_local_ref_cookie,
Thread* self) {
GoToRunnable(self);
return JniMethodEndWithReferenceHandleResult(result, saved_local_ref_cookie, self);
}
extern mirror::Object* JniMethodEndWithReferenceSynchronized(jobject result,
uint32_t saved_local_ref_cookie,
jobject locked,
Thread* self) {
GoToRunnable(self);
UnlockJniSynchronizedMethod(locked, self);
return JniMethodEndWithReferenceHandleResult(result, saved_local_ref_cookie, self);
}
extern uint64_t GenericJniMethodEnd(Thread* self,
uint32_t saved_local_ref_cookie,
jvalue result,
uint64_t result_f,
ArtMethod* called,
HandleScope* handle_scope)
// TODO: NO_THREAD_SAFETY_ANALYSIS as GoToRunnable() is NO_THREAD_SAFETY_ANALYSIS
NO_THREAD_SAFETY_ANALYSIS {
bool critical_native = called->IsCriticalNative();
bool fast_native = called->IsFastNative();
bool normal_native = !critical_native && !fast_native;
// @Fast and @CriticalNative do not do a state transition.
if (LIKELY(normal_native)) {
GoToRunnable(self);
}
// We need the mutator lock (i.e., calling GoToRunnable()) before accessing the shorty or the
// locked object.
jobject locked = called->IsSynchronized() ? handle_scope->GetHandle(0).ToJObject() : nullptr;
char return_shorty_char = called->GetShorty()[0];
if (return_shorty_char == 'L') {
if (locked != nullptr) {
DCHECK(normal_native) << " @FastNative and synchronize is not supported";
UnlockJniSynchronizedMethod(locked, self);
}
return reinterpret_cast<uint64_t>(JniMethodEndWithReferenceHandleResult(
result.l, saved_local_ref_cookie, self));
} else {
if (locked != nullptr) {
DCHECK(normal_native) << " @FastNative and synchronize is not supported";
UnlockJniSynchronizedMethod(locked, self); // Must decode before pop.
}
if (LIKELY(!critical_native)) {
PopLocalReferences(saved_local_ref_cookie, self);
}
switch (return_shorty_char) {
case 'F': {
if (kRuntimeISA == InstructionSet::kX86) {
// Convert back the result to float.
double d = bit_cast<double, uint64_t>(result_f);
return bit_cast<uint32_t, float>(static_cast<float>(d));
} else {
return result_f;
}
}
case 'D':
return result_f;
case 'Z':
return result.z;
case 'B':
return result.b;
case 'C':
return result.c;
case 'S':
return result.s;
case 'I':
return result.i;
case 'J':
return result.j;
case 'V':
return 0;
default:
LOG(FATAL) << "Unexpected return shorty character " << return_shorty_char;
return 0;
}
}
}
} // namespace art