Home Research Papers Posters Manuals Talks Download People Help Internal

util/RTH.h

Go to the documentation of this file.

/* 
RTH runtime: Return-based "Threads" package,
for multiple flows-of-control *without* any 
crazy threading work.

I'll probably regret this, but if I make this a 
C++-based API I can make local variable access much easier.

Orion Sky Lawlor, olawlor@acm.org, 2003/07/23
*/
#ifndef __CHARM_RTH_H
#define __CHARM_RTH_H

#include "pup.h"
#include <new> /* for in-place operator new */

class RTH_Locals {
public:
        virtual ~RTH_Locals();
        virtual void pup(PUP::er &p);
};


class RTH_Runtime;

typedef void (*RTH_Routine)(RTH_Runtime *runtime,
        void *object,RTH_Locals *locals,int pc);


/************************************************
RTH library interface: used for writing libraries
that call RTH routines and/or are called by RTH routines.
*/

RTH_Runtime *RTH_Runtime_create(RTH_Routine fn,int localsSize,void *obj);

RTH_Runtime *RTH_Runtime_pup(RTH_Runtime *runtime,PUP::er &p,void *obj);

void RTH_Runtime_suspend(RTH_Runtime *runtime,int nextPC);

void RTH_Runtime_resume(RTH_Runtime *runtime);

int RTH_Runtime_call(RTH_Runtime *runtime,RTH_Routine fn,int localsSize,int nextPC);

void RTH_Runtime_done(RTH_Runtime *runtime);

void RTH_Runtime_destroy(RTH_Runtime *runtime);


/************************************************
RTH "translator":
  Instruments user's source code with calls to
  the RTH runtime.
*/

#define RTH_Routine_locals(object,name) \
class RTH_Routine_##object##_##name : public RTH_Locals { \
  typedef RTH_Locals super; \
  typedef RTH_Routine_##object##_##name locals_t; \
public:  /* user's local variables go here */

#define RTH_Routine_code(object,name) \
  inline void name(RTH_Runtime *RTH_impl_runtime,\
              object *c,int RTH_impl_pc) { \
    switch(RTH_impl_pc) { \
    case 0: /* Program counter at routine start (PC_START): */ \
      new ((void *)this) locals_t; /* Call our locals' constructor in-place */

#define RTH_Routine_end(object,name) \
    /* end-of-routine: check if we need to resume our calling routine */ \
      RTH_Runtime_done(RTH_impl_runtime); \
      return;  \
    default: \
      printf("Bad pc %d\n",RTH_impl_pc); exit(1);/* unrecognized program counter: */ \
    }; /* Switch end */ \
  } /* User routine end */ \
\
  /* C-style call-function for user routine-- applies appropriate typecasts. */ \
  static void RTH_Call_routine(RTH_Runtime *runtime,\
              void *c,RTH_Locals *locals,int pc) \
  {\
    ((locals_t *)locals)->name(runtime,(object *)c,pc);\
  }\
\
}; /* locals_t class end */ 

#define RTH_Suspend() do {\
        RTH_Runtime_suspend(RTH_impl_runtime,__LINE__);\
        return;\
case __LINE__: ; \
} while(0)

#define RTH_Call(object,name) do{ \
     if (!RTH_Runtime_call(RTH_impl_runtime,RTH_Routine_lookup(object,name),__LINE__)) \
        return;\
case __LINE__: ; \
} while(0)

#define RTH_Routine_lookup(object,name) \
   RTH_Routine_##object##_##name::RTH_Call_routine, sizeof(RTH_Routine_##object##_##name)

#endif

---