runtime/entrypoints/quick/quick_jni_entrypoints.cc - platform/art - Git at Google

 /*
  * 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 "palette/palette.h"
 #include "thread-inl.h"
 #include "verify_object.h"

 // For methods that monitor JNI invocations and report their begin/end to
 // palette hooks.
 #define MONITOR_JNI(kind)                                \
   {                                                      \
     bool should_report = false;                          \
     PaletteShouldReportJniInvocations(&should_report);   \
     if (should_report) {                                 \
       kind(self->GetJniEnv());                           \
     }                                                    \
   }

 namespace art {

 static_assert(sizeof(IRTSegmentState) == sizeof(uint32_t), "IRTSegmentState size unexpected");
 static_assert(std::is_trivial<IRTSegmentState>::value, "IRTSegmentState not trivial");

 extern "C" void artJniReadBarrier(ArtMethod* method) {
   DCHECK(kUseReadBarrier);
   mirror::CompressedReference<mirror::Object>* declaring_class =
       method->GetDeclaringClassAddressWithoutBarrier();
   if (kUseBakerReadBarrier) {
     DCHECK(declaring_class->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(declaring_class->AsMirrorPtr()->GetMarkBit() != 0)) {
       return;
     }
   }
   // Call the read barrier and update the handle.
   mirror::Object* to_ref = ReadBarrier::BarrierForRoot(declaring_class);
   declaring_class->Assign(to_ref);
 }

 // Called on entry to JNI, transition out of Runnable and release share of mutator_lock_.
 extern "C" void artJniMethodStart(Thread* self) {
   if (kIsDebugBuild) {
     ArtMethod* native_method = *self->GetManagedStack()->GetTopQuickFrame();
     CHECK(!native_method->IsFastNative()) << native_method->PrettyMethod();
     CHECK(!native_method->IsCriticalNative()) << native_method->PrettyMethod();
   }

   // Transition out of runnable.
   self->TransitionFromRunnableToSuspended(ThreadState::kNative);
 }

 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));
 }

 // TODO: annotalysis disabled as monitor semantics are maintained in Java code.
 extern "C" void artJniUnlockObject(mirror::Object* locked, Thread* self)
     NO_THREAD_SAFETY_ANALYSIS REQUIRES(!Roles::uninterruptible_) {
   // Note: No thread suspension is allowed for successful unlocking, otherwise plain
   // `mirror::Object*` return value saved by the assembly stub would need to be updated.
   uintptr_t old_poison_object_cookie = kIsDebugBuild ? self->GetPoisonObjectCookie() : 0u;
   // Save any pending exception over monitor exit call.
   ObjPtr<mirror::Throwable> saved_exception = nullptr;
   if (UNLIKELY(self->IsExceptionPending())) {
     saved_exception = self->GetException();
     self->ClearException();
   }
   // Decode locked object and unlock, before popping local references.
   locked->MonitorExit(self);
   if (UNLIKELY(self->IsExceptionPending())) {
     LOG(FATAL) << "Exception during implicit MonitorExit for synchronized native method:\n"
         << self->GetException()->Dump()
         << (saved_exception != nullptr
                ? "\nAn exception was already pending:\n" + saved_exception->Dump()
                : "");
     UNREACHABLE();
   }
   // Restore pending exception.
   if (saved_exception != nullptr) {
     self->SetException(saved_exception);
   }
   if (kIsDebugBuild) {
     DCHECK_EQ(old_poison_object_cookie, self->GetPoisonObjectCookie());
   }
 }

 // TODO: These should probably be templatized or macro-ized.
 // Otherwise there's just too much repetitive boilerplate.

 extern "C" void artJniMethodEnd(Thread* self) {
   self->TransitionFromSuspendedToRunnable();

   if (kIsDebugBuild) {
     ArtMethod* native_method = *self->GetManagedStack()->GetTopQuickFrame();
     CHECK(!native_method->IsFastNative()) << native_method->PrettyMethod();
     CHECK(!native_method->IsCriticalNative()) << native_method->PrettyMethod();
   }
 }

 extern mirror::Object* JniDecodeReferenceResult(jobject result, Thread* self)
     REQUIRES_SHARED(Locks::mutator_lock_) {
   DCHECK(!self->IsExceptionPending());
   ObjPtr<mirror::Object> o = self->DecodeJObject(result);
   // 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 uint64_t GenericJniMethodEnd(Thread* self,
                                     uint32_t saved_local_ref_cookie,
                                     jvalue result,
                                     uint64_t result_f,
                                     ArtMethod* called)
     // NO_THREAD_SAFETY_ANALYSIS because we can enter this function with the mutator lock
     // unlocked for normal JNI, or locked for @FastNative and @CriticalNative.
     NO_THREAD_SAFETY_ANALYSIS {
   bool critical_native = called->IsCriticalNative();
   bool fast_native = called->IsFastNative();
   bool normal_native = !critical_native && !fast_native;

   // @CriticalNative does not do a state transition. @FastNative usually does not do a state
   // transition either but it performs a suspend check that may do state transitions.
   if (LIKELY(normal_native)) {
     if (UNLIKELY(self->ReadFlag(ThreadFlag::kMonitorJniEntryExit))) {
       artJniMonitoredMethodEnd(self);
     } else {
       artJniMethodEnd(self);
     }
   } else if (fast_native) {
     // When we are in @FastNative, we are already Runnable.
     DCHECK(Locks::mutator_lock_->IsSharedHeld(self));
     // Only do a suspend check on the way out of JNI just like compiled stubs.
     self->CheckSuspend();
   }
   // We need the mutator lock (i.e., calling `artJniMethodEnd()`) before accessing
   // the shorty or the locked object.
   if (called->IsSynchronized()) {
     DCHECK(normal_native) << "@FastNative/@CriticalNative and synchronize is not supported";
     ObjPtr<mirror::Object> lock = GetGenericJniSynchronizationObject(self, called);
     DCHECK(lock != nullptr);
     artJniUnlockObject(lock.Ptr(), self);
   }
   char return_shorty_char = called->GetShorty()[0];
   if (return_shorty_char == 'L') {
     uint64_t ret = reinterpret_cast<uint64_t>(
         UNLIKELY(self->IsExceptionPending()) ? nullptr : JniDecodeReferenceResult(result.l, self));
     PopLocalReferences(saved_local_ref_cookie, self);
     return ret;
   } else {
     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;
         UNREACHABLE();
     }
   }
 }

 extern "C" void artJniMonitoredMethodStart(Thread* self) {
   artJniMethodStart(self);
   MONITOR_JNI(PaletteNotifyBeginJniInvocation);
 }

 extern "C" void artJniMonitoredMethodEnd(Thread* self) {
   MONITOR_JNI(PaletteNotifyEndJniInvocation);
   artJniMethodEnd(self);
 }

 }  // namespace art
	/*
	* 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 "palette/palette.h"
	#include "thread-inl.h"
	#include "verify_object.h"

	// For methods that monitor JNI invocations and report their begin/end to
	// palette hooks.
	#define MONITOR_JNI(kind) \
	{ \
	bool should_report = false; \
	PaletteShouldReportJniInvocations(&should_report); \
	if (should_report) { \
	kind(self->GetJniEnv()); \
	} \
	}

	namespace art {

	static_assert(sizeof(IRTSegmentState) == sizeof(uint32_t), "IRTSegmentState size unexpected");
	static_assert(std::is_trivial<IRTSegmentState>::value, "IRTSegmentState not trivial");

	extern "C" void artJniReadBarrier(ArtMethod* method) {
	DCHECK(kUseReadBarrier);
	mirror::CompressedReference<mirror::Object>* declaring_class =
	method->GetDeclaringClassAddressWithoutBarrier();
	if (kUseBakerReadBarrier) {
	DCHECK(declaring_class->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(declaring_class->AsMirrorPtr()->GetMarkBit() != 0)) {
	return;
	}
	}
	// Call the read barrier and update the handle.
	mirror::Object* to_ref = ReadBarrier::BarrierForRoot(declaring_class);
	declaring_class->Assign(to_ref);
	}

	// Called on entry to JNI, transition out of Runnable and release share of mutator_lock_.
	extern "C" void artJniMethodStart(Thread* self) {
	if (kIsDebugBuild) {
	ArtMethod* native_method = *self->GetManagedStack()->GetTopQuickFrame();
	CHECK(!native_method->IsFastNative()) << native_method->PrettyMethod();
	CHECK(!native_method->IsCriticalNative()) << native_method->PrettyMethod();
	}

	// Transition out of runnable.
	self->TransitionFromRunnableToSuspended(ThreadState::kNative);
	}

	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));
	}

	// TODO: annotalysis disabled as monitor semantics are maintained in Java code.
	extern "C" void artJniUnlockObject(mirror::Object* locked, Thread* self)
	NO_THREAD_SAFETY_ANALYSIS REQUIRES(!Roles::uninterruptible_) {
	// Note: No thread suspension is allowed for successful unlocking, otherwise plain
	// `mirror::Object*` return value saved by the assembly stub would need to be updated.
	uintptr_t old_poison_object_cookie = kIsDebugBuild ? self->GetPoisonObjectCookie() : 0u;
	// Save any pending exception over monitor exit call.
	ObjPtr<mirror::Throwable> saved_exception = nullptr;
	if (UNLIKELY(self->IsExceptionPending())) {
	saved_exception = self->GetException();
	self->ClearException();
	}
	// Decode locked object and unlock, before popping local references.
	locked->MonitorExit(self);
	if (UNLIKELY(self->IsExceptionPending())) {
	LOG(FATAL) << "Exception during implicit MonitorExit for synchronized native method:\n"
	<< self->GetException()->Dump()
	<< (saved_exception != nullptr
	? "\nAn exception was already pending:\n" + saved_exception->Dump()
	: "");
	UNREACHABLE();
	}
	// Restore pending exception.
	if (saved_exception != nullptr) {
	self->SetException(saved_exception);
	}
	if (kIsDebugBuild) {
	DCHECK_EQ(old_poison_object_cookie, self->GetPoisonObjectCookie());
	}
	}

	// TODO: These should probably be templatized or macro-ized.
	// Otherwise there's just too much repetitive boilerplate.

	extern "C" void artJniMethodEnd(Thread* self) {
	self->TransitionFromSuspendedToRunnable();

	if (kIsDebugBuild) {
	ArtMethod* native_method = *self->GetManagedStack()->GetTopQuickFrame();
	CHECK(!native_method->IsFastNative()) << native_method->PrettyMethod();
	CHECK(!native_method->IsCriticalNative()) << native_method->PrettyMethod();
	}
	}

	extern mirror::Object* JniDecodeReferenceResult(jobject result, Thread* self)
	REQUIRES_SHARED(Locks::mutator_lock_) {
	DCHECK(!self->IsExceptionPending());
	ObjPtr<mirror::Object> o = self->DecodeJObject(result);
	// 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 uint64_t GenericJniMethodEnd(Thread* self,
	uint32_t saved_local_ref_cookie,
	jvalue result,
	uint64_t result_f,
	ArtMethod* called)
	// NO_THREAD_SAFETY_ANALYSIS because we can enter this function with the mutator lock
	// unlocked for normal JNI, or locked for @FastNative and @CriticalNative.
	NO_THREAD_SAFETY_ANALYSIS {
	bool critical_native = called->IsCriticalNative();
	bool fast_native = called->IsFastNative();
	bool normal_native = !critical_native && !fast_native;

	// @CriticalNative does not do a state transition. @FastNative usually does not do a state
	// transition either but it performs a suspend check that may do state transitions.
	if (LIKELY(normal_native)) {
	if (UNLIKELY(self->ReadFlag(ThreadFlag::kMonitorJniEntryExit))) {
	artJniMonitoredMethodEnd(self);
	} else {
	artJniMethodEnd(self);
	}
	} else if (fast_native) {
	// When we are in @FastNative, we are already Runnable.
	DCHECK(Locks::mutator_lock_->IsSharedHeld(self));
	// Only do a suspend check on the way out of JNI just like compiled stubs.
	self->CheckSuspend();
	}
	// We need the mutator lock (i.e., calling `artJniMethodEnd()`) before accessing
	// the shorty or the locked object.
	if (called->IsSynchronized()) {
	DCHECK(normal_native) << "@FastNative/@CriticalNative and synchronize is not supported";
	ObjPtr<mirror::Object> lock = GetGenericJniSynchronizationObject(self, called);
	DCHECK(lock != nullptr);
	artJniUnlockObject(lock.Ptr(), self);
	}
	char return_shorty_char = called->GetShorty()[0];
	if (return_shorty_char == 'L') {
	uint64_t ret = reinterpret_cast<uint64_t>(
	UNLIKELY(self->IsExceptionPending()) ? nullptr : JniDecodeReferenceResult(result.l, self));
	PopLocalReferences(saved_local_ref_cookie, self);
	return ret;
	} else {
	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;
	UNREACHABLE();
	}
	}
	}

	extern "C" void artJniMonitoredMethodStart(Thread* self) {
	artJniMethodStart(self);
	MONITOR_JNI(PaletteNotifyBeginJniInvocation);
	}

	extern "C" void artJniMonitoredMethodEnd(Thread* self) {
	MONITOR_JNI(PaletteNotifyEndJniInvocation);
	artJniMethodEnd(self);
	}

	} // namespace art