| // Copyright 2011 Google Inc. All Rights Reserved. |
| // Author: irogers@google.com (Ian Rogers) |
| #include "src/jni_compiler.h" |
| #include <sys/mman.h> |
| #include "src/assembler.h" |
| #include "src/calling_convention.h" |
| #include "src/macros.h" |
| #include "src/managed_register.h" |
| #include "src/logging.h" |
| #include "src/thread.h" |
| |
| namespace art { |
| |
| // Generate the JNI bridge for the given method, general contract: |
| // - Arguments are in the managed runtime format, either on stack or in |
| // registers, a reference to the method object is supplied as part of this |
| // convention. |
| // |
| void JniCompiler::Compile(Assembler* jni_asm, Method* native_method) { |
| CHECK(native_method->IsNative()); |
| JniCallingConvention jni_conv(native_method); |
| ManagedRuntimeCallingConvention mr_conv(native_method); |
| const bool is_static = native_method->IsStatic(); |
| |
| // 1. Build the frame |
| const size_t frame_size(jni_conv.FrameSize()); |
| jni_asm->BuildFrame(frame_size, mr_conv.MethodRegister()); |
| |
| // 2. Save callee save registers that aren't callee save in the native code |
| // TODO: implement computing the difference of the callee saves |
| // and saving |
| |
| // 3. Set up the StackHandleBlock |
| mr_conv.ResetIterator(FrameOffset(frame_size)); |
| jni_conv.ResetIterator(FrameOffset(0)); |
| jni_asm->StoreImmediateToFrame(jni_conv.ShbNumRefsOffset(), |
| jni_conv.HandleCount(), |
| mr_conv.InterproceduralScratchRegister()); |
| jni_asm->CopyRawPtrFromThread(jni_conv.ShbLinkOffset(), |
| Thread::TopShbOffset(), |
| mr_conv.InterproceduralScratchRegister()); |
| jni_asm->StoreStackOffsetToThread(Thread::TopShbOffset(), |
| jni_conv.ShbOffset(), |
| mr_conv.InterproceduralScratchRegister()); |
| |
| // 4. Place incoming reference arguments into handle block |
| jni_conv.Next(); // Skip JNIEnv* |
| // 4.5. Create Class argument for static methods out of passed method |
| if (is_static) { |
| FrameOffset handle_offset = jni_conv.CurrentParamHandleOffset(); |
| // Check handle offset is within frame |
| CHECK_LT(handle_offset.Uint32Value(), frame_size); |
| jni_asm->LoadRef(jni_conv.InterproceduralScratchRegister(), |
| mr_conv.MethodRegister(), Method::ClassOffset()); |
| jni_asm->ValidateRef(jni_conv.InterproceduralScratchRegister(), false); |
| jni_asm->StoreRef(handle_offset, jni_conv.InterproceduralScratchRegister()); |
| jni_conv.Next(); // handlerized so move to next argument |
| } |
| while (mr_conv.HasNext()) { |
| CHECK(jni_conv.HasNext()); |
| bool ref_param = jni_conv.IsCurrentParamAReference(); |
| CHECK(!ref_param || mr_conv.IsCurrentParamAReference()); |
| // References need handlerization and the handle address passing |
| if (ref_param) { |
| // Compute handle offset, note null is handlerized but its boxed value |
| // must be NULL |
| FrameOffset handle_offset = jni_conv.CurrentParamHandleOffset(); |
| // Check handle offset is within frame |
| CHECK_LT(handle_offset.Uint32Value(), frame_size); |
| bool input_in_reg = mr_conv.IsCurrentParamInRegister(); |
| CHECK(input_in_reg || mr_conv.IsCurrentParamOnStack()); |
| if (input_in_reg) { |
| LOG(FATAL) << "UNTESTED"; |
| ManagedRegister in_reg = mr_conv.CurrentParamRegister(); |
| jni_asm->ValidateRef(in_reg, mr_conv.IsCurrentParamPossiblyNull()); |
| jni_asm->StoreRef(handle_offset, in_reg); |
| } else { |
| FrameOffset in_off = mr_conv.CurrentParamStackOffset(); |
| jni_asm->ValidateRef(in_off, mr_conv.IsCurrentParamPossiblyNull()); |
| jni_asm->CopyRef(handle_offset, in_off, |
| mr_conv.InterproceduralScratchRegister()); |
| } |
| } |
| mr_conv.Next(); |
| jni_conv.Next(); |
| } |
| |
| // 5. Acquire lock for synchronized methods. Done here as references are held |
| // live in handle block but we're in managed code and can work on |
| // references |
| if (native_method->IsSynchronized()) { |
| jni_conv.ResetIterator(FrameOffset(0)); |
| jni_conv.Next(); // skip JNI environment |
| jni_asm->LockReferenceOnStack(jni_conv.CurrentParamHandleOffset()); |
| } |
| |
| // 6. Transition from being in managed to native code |
| // TODO: write out anchor, ensure the transition to native follow a store |
| // fence. |
| jni_asm->StoreImmediateToThread(Thread::StateOffset(), Thread::kNative, |
| mr_conv.InterproceduralScratchRegister()); |
| |
| // 7. Move frame down to allow space for out going args. Do for as short a |
| // time as possible to aid profiling.. |
| const size_t out_arg_size = jni_conv.OutArgSize(); |
| jni_asm->IncreaseFrameSize(out_arg_size); |
| |
| // 8. Iterate over arguments placing values from managed calling convention in |
| // to the convention required for a native call (shuffling). For references |
| // place an index/pointer to the reference after checking whether it is |
| // NULL (which must be encoded as NULL). |
| // NB. we do this prior to materializing the JNIEnv* and static's jclass to |
| // give as many free registers for the shuffle as possible |
| mr_conv.ResetIterator(FrameOffset(frame_size+out_arg_size)); |
| jni_conv.ResetIterator(FrameOffset(out_arg_size)); |
| jni_conv.Next(); // Skip JNIEnv* |
| if (is_static) { |
| FrameOffset handle_offset = jni_conv.CurrentParamHandleOffset(); |
| if (jni_conv.IsCurrentParamOnStack()) { |
| FrameOffset out_off = jni_conv.CurrentParamStackOffset(); |
| jni_asm->CreateStackHandle(out_off, handle_offset, |
| mr_conv.InterproceduralScratchRegister(), |
| false); |
| } else { |
| ManagedRegister out_reg = jni_conv.CurrentParamRegister(); |
| jni_asm->CreateStackHandle(out_reg, handle_offset, |
| ManagedRegister::NoRegister(), false); |
| } |
| jni_conv.Next(); |
| } |
| while (mr_conv.HasNext()) { |
| CHECK(jni_conv.HasNext()); |
| bool input_in_reg = mr_conv.IsCurrentParamInRegister(); |
| bool output_in_reg = jni_conv.IsCurrentParamInRegister(); |
| FrameOffset handle_offset(0); |
| bool null_allowed = false; |
| bool ref_param = jni_conv.IsCurrentParamAReference(); |
| CHECK(!ref_param || mr_conv.IsCurrentParamAReference()); |
| CHECK(input_in_reg || mr_conv.IsCurrentParamOnStack()); |
| CHECK(output_in_reg || jni_conv.IsCurrentParamOnStack()); |
| // References need handlerization and the handle address passing |
| if (ref_param) { |
| null_allowed = mr_conv.IsCurrentParamPossiblyNull(); |
| // Compute handle offset. Note null is placed in the SHB but the jobject |
| // passed to the native code must be null (not a pointer into the SHB |
| // as with regular references). |
| handle_offset = jni_conv.CurrentParamHandleOffset(); |
| // Check handle offset is within frame. |
| CHECK_LT(handle_offset.Uint32Value(), (frame_size+out_arg_size)); |
| } |
| if (input_in_reg && output_in_reg) { |
| LOG(FATAL) << "UNTESTED"; |
| ManagedRegister in_reg = mr_conv.CurrentParamRegister(); |
| ManagedRegister out_reg = jni_conv.CurrentParamRegister(); |
| if (ref_param) { |
| jni_asm->CreateStackHandle(out_reg, handle_offset, in_reg, |
| null_allowed); |
| } else { |
| jni_asm->Move(out_reg, in_reg); |
| } |
| } else if (!input_in_reg && !output_in_reg) { |
| FrameOffset out_off = jni_conv.CurrentParamStackOffset(); |
| if (ref_param) { |
| jni_asm->CreateStackHandle(out_off, handle_offset, |
| mr_conv.InterproceduralScratchRegister(), |
| null_allowed); |
| } else { |
| FrameOffset in_off = mr_conv.CurrentParamStackOffset(); |
| size_t param_size = mr_conv.CurrentParamSizeInBytes(); |
| CHECK_EQ(param_size, jni_conv.CurrentParamSizeInBytes()); |
| jni_asm->Copy(out_off, in_off, mr_conv.InterproceduralScratchRegister(), |
| param_size); |
| } |
| } else if (!input_in_reg && output_in_reg) { |
| LOG(FATAL) << "UNTESTED"; |
| FrameOffset in_off = mr_conv.CurrentParamStackOffset(); |
| ManagedRegister out_reg = jni_conv.CurrentParamRegister(); |
| // Check that incoming stack arguments are above the current stack frame. |
| CHECK_GT(in_off.Uint32Value(), frame_size); |
| if (ref_param) { |
| jni_asm->CreateStackHandle(out_reg, handle_offset, |
| ManagedRegister::NoRegister(), null_allowed); |
| } else { |
| unsigned int param_size = mr_conv.CurrentParamSizeInBytes(); |
| CHECK_EQ(param_size, jni_conv.CurrentParamSizeInBytes()); |
| jni_asm->Load(out_reg, in_off, param_size); |
| } |
| } else { |
| LOG(FATAL) << "UNTESTED"; |
| CHECK(input_in_reg && !output_in_reg); |
| ManagedRegister in_reg = mr_conv.CurrentParamRegister(); |
| FrameOffset out_off = jni_conv.CurrentParamStackOffset(); |
| // Check outgoing argument is within frame |
| CHECK_LT(out_off.Uint32Value(), frame_size); |
| if (ref_param) { |
| // TODO: recycle value in in_reg rather than reload from handle |
| jni_asm->CreateStackHandle(out_off, handle_offset, |
| mr_conv.InterproceduralScratchRegister(), |
| null_allowed); |
| } else { |
| size_t param_size = mr_conv.CurrentParamSizeInBytes(); |
| CHECK_EQ(param_size, jni_conv.CurrentParamSizeInBytes()); |
| jni_asm->Store(out_off, in_reg, param_size); |
| } |
| } |
| mr_conv.Next(); |
| jni_conv.Next(); |
| } |
| // 9. Create 1st argument, the JNI environment ptr |
| jni_conv.ResetIterator(FrameOffset(out_arg_size)); |
| if (jni_conv.IsCurrentParamInRegister()) { |
| jni_asm->LoadRawPtrFromThread(jni_conv.CurrentParamRegister(), |
| Thread::JniEnvOffset()); |
| } else { |
| jni_asm->CopyRawPtrFromThread(jni_conv.CurrentParamStackOffset(), |
| Thread::JniEnvOffset(), |
| jni_conv.InterproceduralScratchRegister()); |
| } |
| |
| // 10. Plant call to native code associated with method |
| jni_asm->Call(mr_conv.MethodRegister(), Method::NativeMethodOffset(), |
| mr_conv.InterproceduralScratchRegister()); |
| |
| // 11. Release outgoing argument area |
| jni_asm->DecreaseFrameSize(out_arg_size); |
| |
| // 12. Transition from being in native to managed code, possibly entering a |
| // safepoint |
| jni_asm->StoreImmediateToThread(Thread::StateOffset(), Thread::kRunnable, |
| mr_conv.InterproceduralScratchRegister()); |
| // TODO: check for safepoint transition |
| |
| // 13. Move to first handle offset |
| jni_conv.ResetIterator(FrameOffset(0)); |
| jni_conv.Next(); // skip JNI environment |
| |
| // 14. Release lock for synchronized methods (done in the managed state so |
| // references can be touched) |
| if (native_method->IsSynchronized()) { |
| jni_asm->UnLockReferenceOnStack(jni_conv.CurrentParamHandleOffset()); |
| } |
| |
| // 15. Place result in correct register possibly dehandlerizing |
| if (jni_conv.IsReturnAReference()) { |
| jni_asm->LoadReferenceFromStackHandle(mr_conv.ReturnRegister(), |
| jni_conv.ReturnRegister(), |
| jni_conv.CurrentParamHandleOffset()); |
| } else { |
| jni_asm->Move(mr_conv.ReturnRegister(), jni_conv.ReturnRegister()); |
| } |
| |
| // 16. Remove stack handle block from thread |
| jni_asm->CopyRawPtrToThread(Thread::TopShbOffset(), jni_conv.ShbLinkOffset(), |
| jni_conv.InterproceduralScratchRegister()); |
| |
| // 17. Remove activation |
| jni_asm->RemoveFrame(frame_size); |
| |
| // 18. Finalize code generation |
| size_t cs = jni_asm->CodeSize(); |
| MemoryRegion code(AllocateCode(cs), cs); |
| jni_asm->FinalizeInstructions(code); |
| native_method->SetCode(code.pointer()); |
| } |
| |
| void* JniCompiler::AllocateCode(size_t size) { |
| CHECK_LT(((jni_code_top_ - jni_code_) + size), jni_code_size_); |
| void *result = jni_code_top_; |
| jni_code_top_ += size; |
| return result; |
| } |
| |
| JniCompiler::JniCompiler() { |
| // TODO: this shouldn't be managed by the JniCompiler, we should have a |
| // code cache. |
| jni_code_size_ = 4096; |
| jni_code_ = static_cast<byte*>(mmap(NULL, jni_code_size_, |
| PROT_READ | PROT_WRITE | PROT_EXEC, |
| MAP_ANONYMOUS | MAP_PRIVATE, -1, 0)); |
| CHECK_NE(MAP_FAILED, jni_code_); |
| jni_code_top_ = jni_code_; |
| } |
| |
| JniCompiler::~JniCompiler() { |
| // TODO: this shouldn't be managed by the JniCompiler, we should have a |
| // code cache. |
| CHECK_EQ(0, munmap(jni_code_, jni_code_size_)); |
| } |
| |
| } // namespace art |