coroutines/src/generators/loadtime/future/FutureSMBuilder.java
2025-05-04 11:40:59 -04:00

335 lines
14 KiB
Java

package generators.loadtime.future;
import future.Future;
import future.Waker;
import generators.loadtime.*;
import java.lang.classfile.*;
import java.lang.classfile.instruction.SwitchCase;
import java.lang.constant.*;
import java.lang.reflect.Method;
import java.util.*;
import java.util.function.Consumer;
public class FutureSMBuilder extends StateMachineBuilder<FutureSMBuilder> {
public final static ClassDesc CD_Future = ClassDesc.ofDescriptor(Future.class.descriptorString());
public final static ClassDesc CD_Waker = ClassDesc.ofDescriptor(Waker.class.descriptorString());
public final static ClassDesc CD_Pending = ClassDesc.ofDescriptor(Future.Pending.class.descriptorString());
public final static MethodTypeDesc MTD_Future_Obj = MethodTypeDesc.of(CD_Future, ConstantDescs.CD_Object);
public final static MethodTypeDesc MTD_Future = MethodTypeDesc.of(CD_Future);
public final static MethodTypeDesc MTD_Object_Waker = MethodTypeDesc.of(ConstantDescs.CD_Object, CD_Waker);
public final static MethodTypeDesc MTD_Obj = MethodTypeDesc.of(ConstantDescs.CD_Object);
public final static String AWAITING_FIELD_NAME = "awaiting";
private final HashMap<Integer, Consumer<CodeBuilder>> cancellation_behavior = new HashMap<>();
static class AwaitHandler implements SpecialMethodHandler<FutureSMBuilder>{
final StateBuilder.State awaiting;
final Label save_label;
final Label resume_inline;
public AwaitHandler(FutureSMBuilder smb, CodeBuilder cob, Frame frame, StateBuilder sb) {
awaiting = sb.create(cob);
save_label = cob.newLabel();
resume_inline = cob.newLabel();
}
public ReplacementKind replacementKind(){return ReplacementKind.Immediate;}
@Override
public void build_prelude(FutureSMBuilder smb, CodeBuilder cob, Frame frame) {
cob.labelBinding(save_label);
var sst = new SavedStateTracker();
frame.save_locals(smb, cob, sst,2);
cob.storeLocal(TypeKind.REFERENCE, 2);
frame.save_stack(smb, cob, sst,1);
cob.loadLocal(TypeKind.REFERENCE, 2);
smb.yielding_state(awaiting, frame, sst);
smb.resumable_return(cob, awaiting, TypeKind.REFERENCE);
sst.restore_all(smb, cob);
cob.goto_(resume_inline);
}
@Override
public void build_inline(FutureSMBuilder smb, CodeBuilder cob, Frame frame) {
// [... Future]
var start = cob.newBoundLabel();
cob.dup().aload(1).invokeinterface(CD_Future, "poll", MTD_Object_Waker).dup().instanceOf(CD_Pending);
// [... Future Polled is_pending]
cob.ifThenElse(bcb -> {
awaiting.setState(smb, cob);
// [... Future Polled]
bcb.swap().aload(0).swap().putfield(smb.CD_this, AWAITING_FIELD_NAME, CD_Future);
// [... Polled]
cob.goto_(save_label).labelBinding(resume_inline);
bcb.aload(0).getfield(smb.CD_this, AWAITING_FIELD_NAME, CD_Future);
bcb.aload(0).aconst_null().putfield(smb.CD_this, AWAITING_FIELD_NAME, CD_Future);
bcb.goto_(start);
}, bcb -> {
bcb.swap().pop();
});
// [... Polled]
}
}
static class YieldHandler implements SpecialMethodHandler<FutureSMBuilder> {
final StateBuilder.State resume;
final Label save_ret;
final Label end;
public YieldHandler(FutureSMBuilder smb, CodeBuilder cob, Frame frame, StateBuilder sb) {
resume = sb.create(cob);
save_ret = cob.newLabel();
end = cob.newLabel();
}
public ReplacementKind replacementKind(){return ReplacementKind.Immediate;}
@Override
public void build_prelude(FutureSMBuilder smb, CodeBuilder cob, Frame frame) {
cob.labelBinding(save_ret);
var sst = frame.save(smb, cob, 2, 0);
resume.setState(smb, cob);
cob.getstatic(CD_Pending, "INSTANCE", CD_Pending);
smb.yielding_state(resume, frame, sst);
smb.resumable_return(cob, resume, TypeKind.REFERENCE);
sst.restore_all(smb, cob);
cob.goto_(end);
}
@Override
public void build_inline(FutureSMBuilder smb, CodeBuilder cob, Frame frame) {
cob.goto_(save_ret);
cob.labelBinding(end);
}
}
static class WakerHandler implements SpecialMethodHandler<FutureSMBuilder>{
protected WakerHandler(FutureSMBuilder smb, CodeBuilder cob, Frame frame, StateBuilder sb) {}
@Override
public void build_prelude(FutureSMBuilder smb, CodeBuilder cob, Frame frame) {}
@Override
public void build_inline(FutureSMBuilder smb, CodeBuilder cob, Frame frame) {
cob.aload(1);
}
@Override
public ReplacementKind replacementKind() {
return ReplacementKind.Immediate;
}
}
static class RetHandler implements SpecialMethodHandler<FutureSMBuilder>{
protected RetHandler(FutureSMBuilder smb, CodeBuilder cob, Frame frame, StateBuilder sb) {}
public ReplacementKind replacementKind(){return ReplacementKind.ReplacingNextReturn;}
@Override
public void build_prelude(FutureSMBuilder smb, CodeBuilder cob, Frame frame) {}
@Override
public void build_inline(FutureSMBuilder smb, CodeBuilder cob, Frame frame) {
cob.aload(0).loadConstant(-1).putfield(smb.CD_this, STATE_NAME, TypeKind.INT.upperBound());
smb.nonresumable_return(cob, TypeKind.REFERENCE);
}
}
static class RetVoidHandler implements SpecialMethodHandler<FutureSMBuilder>{
protected RetVoidHandler(FutureSMBuilder smb, CodeBuilder cob, Frame frame, StateBuilder sb) {}
public ReplacementKind replacementKind(){return ReplacementKind.ReplacingNextReturn;}
@Override
public void build_prelude(FutureSMBuilder smb, CodeBuilder cob, Frame frame) {
}
@Override
public void build_inline(FutureSMBuilder smb, CodeBuilder cob, Frame frame) {
cob.aload(0).loadConstant(-1).putfield(smb.CD_this, STATE_NAME, TypeKind.INT.upperBound()).aconst_null();
smb.nonresumable_return(cob, TypeKind.REFERENCE);
}
}
private String annotationStringValue(AnnotationValue value){
if (value instanceof AnnotationValue.OfString ofString) {
return ofString.stringValue();
}
throw new RuntimeException();
}
private ClassDesc annotationClassValue(AnnotationValue value){
if (value instanceof AnnotationValue.OfClass ofConstant) {
return ofConstant.classSymbol();
}
throw new RuntimeException();
}
private void yielding_state(StateBuilder.State state, Frame frame, SavedStateTracker sst){
if(frame.local_annotations().length==0)return;
ArrayList<Consumer<CodeBuilder>> field_cancellation_behavior = new ArrayList<>();
for(var ann : frame.local_annotations()){
if(ann.annotation().classSymbol().descriptorString().equals(Cancellation.class.descriptorString())){
var param = sst.load_param(ann.slot()-paramSlotOff+2);
ClassDesc owner = frame.locals()[ann.slot()].sym();
String name = "cancel";
for(var el : ann.annotation().elements()){
switch(el.name().stringValue()){
case "value" -> name = annotationStringValue(el.value());
case "owner" -> owner = annotationClassValue(el.value());
}
}
if(!owner.isClassOrInterface()){
throw new RuntimeException("Owner " + owner + " is not a class/interface cannot be used here");
}
boolean is_interface;
TypeKind ret;
try{
Class<?> clazz = getClass().getClassLoader().loadClass(owner.descriptorString().replace("/", ".").replace(";", "").substring(1));
var method = findMethod(clazz, name);
if(method==null){
throw new RuntimeException("Cannot find method '"+name+"' for class " + clazz);
}
clazz = method.getDeclaringClass();
owner = ClassDesc.ofDescriptor(clazz.descriptorString());
is_interface = clazz.isInterface();
ret = TypeKind.from(ClassDesc.ofDescriptor(method.getReturnType().descriptorString()));
}catch (Exception e){
throw new RuntimeException(e);
}
String final_name = name;
ClassDesc final_owner = owner;
field_cancellation_behavior.add(cob -> {
cob.trying(tcob -> {
tcob.aload(0).getfield(CD_this, param.name(), param.desc());
if(is_interface){
tcob.invokeinterface(final_owner, final_name, MethodTypeDesc.of(ConstantDescs.CD_void));
}else{
tcob.invokevirtual(final_owner, final_name, MethodTypeDesc.of(ConstantDescs.CD_void));
}
if(ret.slotSize()==1)tcob.pop();
if(ret.slotSize()==2)tcob.pop2();
}, cb -> cb.catchingAll(ccob -> {
ccob.aload(2).ifThenElse(Opcode.IFNONNULL, bcob -> {
bcob.aload(2).swap();
addSuppressed(bcob);
}, bcob -> {
bcob.astore(2);
});
}));
});
}
}
cancellation_behavior.put(state.id(), cob -> {
for(var fcb : field_cancellation_behavior) fcb.accept(cob);
});
}
private static Method findMethod(Class<?> owner, String name){
try{
return owner.getDeclaredMethod(name);
}catch (Exception ignore){}
if(owner.equals(Object.class))return null;
for(var iface : owner.getInterfaces()){
var method = findMethod(iface, name);
if(method!=null)return method;
}
if(!owner.isInterface()){
Class<?> sup = owner.getSuperclass();
if(sup!=null){
return findMethod(sup, name);
}
}
return findMethod(Object.class, name);
}
@Override
protected void buildStateMachineMethod(ClassBuilder clb){
clb.withInterfaces(List.of(clb.constantPool().classEntry(CD_Future)));
clb.withMethod("poll", MTD_Object_Waker, ClassFile.ACC_PUBLIC, mb -> mb.withCode(cob -> {
cob.localVariable(1, "waker", CD_Waker, cob.startLabel(), cob.endLabel());
buildStateMachineMethodCode(clb, cob, 2);
}));
clb.withMethod("cancel", MethodTypeDesc.of(ConstantDescs.CD_void), ClassFile.ACC_PUBLIC, mb -> mb.withCode(cob -> {
this.synchronized_start(cob);
cob.aload(0).getfield(CD_this, STATE_NAME, ConstantDescs.CD_int).istore(1);// state
cob.aconst_null().astore(2);// exception
cob.aload(0).loadConstant(-1).putfield(CD_this, STATE_NAME, ConstantDescs.CD_int);
cob.aload(0).getfield(CD_this, AWAITING_FIELD_NAME, CD_Future).ifThen(Opcode.IFNONNULL, boc -> {
boc.trying(tcob -> {
tcob.aload(0).getfield(CD_this, AWAITING_FIELD_NAME, CD_Future)
.aload(0).aconst_null().putfield(CD_this, AWAITING_FIELD_NAME, CD_Future)
.invokeinterface(CD_Future, "cancel", MethodTypeDesc.of(ConstantDescs.CD_void));
}, cb -> {
cb.catchingAll(ccob -> {
ccob.aload(2).ifThenElse(Opcode.IFNONNULL, bcob -> {
bcob.aload(2).swap();
addSuppressed(bcob);
}, bcob -> {
bcob.astore(2);
});
});
});
});
if(!cancellation_behavior.isEmpty()){
var states = cancellation_behavior.entrySet().stream().toList();
var cases = states.stream().map(v -> SwitchCase.of(v.getKey(), cob.newLabel())).toList();
cob.iload(1);
var end = cob.newLabel();
cob.tableswitch(end, cases);
for(int i = 0; i < states.size(); i ++){
cob.labelBinding(cases.get(i).target());
states.get(i).getValue().accept(cob);
cob.goto_(end);
}
cob.labelBinding(end);
}
this.synchronized_exit(cob);
cob.aload(2).ifThen(Opcode.IFNONNULL, bcob -> {
bcob.aload(2).athrow();
});
cob.return_();
}));
clb.withField(AWAITING_FIELD_NAME, CD_Future, ClassFile.ACC_PRIVATE);
}
private void addSuppressed(CodeBuilder cob) {
cob.invokevirtual(ClassDesc.ofDescriptor(Throwable.class.descriptorString()), "addSuppressed", MethodTypeDesc.of(ConstantDescs.CD_void, ClassDesc.ofDescriptor(Throwable.class.descriptorString())));
}
public FutureSMBuilder(ClassModel src_clm, MethodModel src_mem, CodeModel src_com) {
super(src_clm, src_mem, src_com, "Fut");
smmap.put(new SpecialMethod(CD_Future, "await", MTD_Obj), AwaitHandler::new);
smmap.put(new SpecialMethod(CD_Future, "ret", MTD_Future_Obj), RetHandler::new);
smmap.put(new SpecialMethod(CD_Future, "ret", MTD_Future), RetVoidHandler::new);
smmap.put(new SpecialMethod(CD_Future, "yield", ConstantDescs.MTD_void), YieldHandler::new);
smmap.put(new SpecialMethod(CD_Waker, "waker", MethodTypeDesc.of(CD_Waker)), WakerHandler::new);
}
}