concept.txt

next frame with exception handler instead of != null?
localThread needed?

----

call -> normal
restore method handle
restore code only for interrupts
what about restore code for run()? helper method calls real run()?

generate method handles
remember method handles during serialize


  private void dynamicXXX(ClassNode clazz) {
    for (MethodNode method : clazz.methods) {
      AbstractInsnNode[] instructions = method.instructions.toArray();
      for (AbstractInsnNode instruction : instructions) {
        if (instruction instanceof InvokeDynamicInsnNode dynamic) {
          System.err.println(">>> " + methodName(clazz, method) + ": " + dynamic.bsm + " [" + dynamic.bsmArgs.length + "]");
//          dynamic.desc = changeDescXXX(dynamic.desc);
          for (int i = 0; i < dynamic.bsmArgs.length; i++) {
            Object bsmArg = dynamic.bsmArgs[i];
            System.err.println(">>>-   " + bsmArg);
          }

          for (int i = 0; i < dynamic.bsmArgs.length; i++) {
            Object bsmArg = dynamic.bsmArgs[i];
            if (bsmArg instanceof Handle handle) {
              if (classInfoCache.isInterruptible(handle)) {
                String desc = changeDescXXX(handle.getDesc());
                dynamic.bsmArgs[i - 1] = Type.getType(desc);
                dynamic.bsmArgs[i] = new Handle(handle.getTag(), handle.getOwner(), handle.getName(), desc);
                dynamic.bsmArgs[i + 1] = Type.getType(desc);
              }
            }
          }

          for (int i = 0; i < dynamic.bsmArgs.length; i++) {
            Object bsmArg = dynamic.bsmArgs[i];
            System.err.println(">>>+   " + bsmArg);
          }
        }
      }
    }
  }

  protected String changeDescXXX(String desc) {
    int index = desc.indexOf(")");
    return desc.substring(0, index) + THREAD_IMPL_DESC + FRAME_IMPL_DESC + desc.substring(index);
  }


test
-------------------------------------------------------------------------------

SFE new:
--------

run:
- restore code dispatcher just for run
- not run: store last frame in local, call method handle of last frame
- while not serializing: local last frame--, call method handle of last frame

copy:
- restore code dispatcher which just restores the frame and jumps after interrupt/method call
- static field with same name with (unbound) method handle

interrupt:
- set last frame

method:
- same as frequent3

-------------------------------------------------------------------------------

SFE:
----

run:
- normal start vs.
- method handle call of last interrupt
- returned: new call, if no capture
- capture code
- replace returns with exception

abstract:
- signature + thread & (previous) frame

abstract copy:
- signature + thread & (previous) frame, no return value, private

concrete:
- signature + thread & (previous) frame
- init code, calculate current frame
- no restore code
- interrupt, capture top most frame
- capture code

concrete copy:
- signature == thread & (previous) frame, no return value
- init code, calculate current frame
- restore code only for interrupt
- interrupt, capture top most frame
- capture code: end of capture (because directly called by run())
- capture return value into frame at original exit points

-------------------------------------------------------------------------------

Ideas:
------

@RestorePoint?

-------------------------------------------------------------------------------

entered method / no capture:
  remember level in local
  level++
  normal

entered method / capture:
  remember level in local
  level++
  dispatcher
    dummy args
    enter interrupted method (direct call)                 | avoids restore of complete stack
    jump after normal method call (to "leave method" code) |
    PROBLEM: stack mismatch: special restore code or restore frame before method call

interrupt:
  capture frame
  set level to have being captured
  set capture

interrupt end:
  reset capture
  set level to have not being captured
  restore frame

left method / no capture:
  level--,
  set level to have not being captured
  restore frame

left method / capture:
  level--
  if level not captured
    capture frame
    set level to have being captured
  return

catch block:
  reset context to remembered level
  restore frame
  normal