calling scheme from c++ and c++ from scheme

.gitignore

@@ -0,0 +1,3 @@
*.o
*~
src/.depend

src/Makefile

@@ -34,7 +34,7 @@ BINDIR = $(PREFIX)/bin
PGOBENCH = ./$(EXE) bench 16 1 1000 default time

### Object files
OBJS = benchmark.o bitbase.o bitboard.o endgame.o evaluate.o main.o \
OBJS = guile.o benchmark.o bitbase.o bitboard.o endgame.o evaluate.o main.o \
	material.o misc.o movegen.o movepick.o pawns.o position.o psqt.o \
	search.o thread.o timeman.o tt.o uci.o ucioption.o syzygy/tbprobe.o

@@ -140,7 +140,7 @@ endif

### 3.1 Selecting compiler (default = gcc)

CXXFLAGS += -Wall -Wcast-qual -fno-exceptions -fno-rtti -std=c++11 $(EXTRACXXFLAGS)
CXXFLAGS += -Wall -Wcast-qual -fno-exceptions -fno-rtti -std=c++11 `pkg-config --cflags guile-2.0` $(EXTRACXXFLAGS)
DEPENDFLAGS += -std=c++11
LDFLAGS += $(EXTRALDFLAGS)

@@ -478,7 +478,7 @@ config-sanity:
	@test "$(comp)" = "gcc" || test "$(comp)" = "icc" || test "$(comp)" = "mingw" || test "$(comp)" = "clang"

$(EXE): $(OBJS)
	$(CXX) -o $@ $(OBJS) $(LDFLAGS)
	$(CXX) -o $@ $(OBJS) `pkg-config --libs guile-2.0` $(LDFLAGS)

gcc-profile-prepare:
	$(MAKE) ARCH=$(ARCH) COMP=$(COMP) gcc-profile-clean

src/evaluate.cpp

@@ -27,6 +27,7 @@
#include "evaluate.h"
#include "material.h"
#include "pawns.h"
#include "guile.h"

namespace {

@@ -765,8 +766,10 @@ Value Eval::evaluate(const Position& pos) {

  // If we have a specialized evaluation function for the current material
  // configuration, call it and return.
  if (ei.me->specialized_eval_exists())
  if (ei.me->specialized_eval_exists()) {
    //    printf("specialized!\n");
      return ei.me->evaluate(pos);
  }

  // Probe the pawn hash table
  ei.pi = Pawns::probe(pos);
@@ -848,7 +851,15 @@ Value Eval::evaluate(const Position& pos) {
      Trace::add(TOTAL, score);
  }

  return (pos.side_to_move() == WHITE ? v : -v) + Eval::Tempo; // Side to move point of view
  Value r = (pos.side_to_move() == WHITE ? v : -v) + Eval::Tempo;

  //#if WITH_GUILE

  r = guile_evaluate(pos, r);
  
  //  #endif

  return r; // Side to move point of view
}

// Explicit template instantiations

src/guile.cpp

@@ -0,0 +1,66 @@

#include "guile.h"


SCM display;
SCM evaluate;


SCM get_side_to_move(SCM pos)
{
  Position *rpos = (Position*)scm_to_pointer(pos);

  return scm_from_int(rpos->side_to_move());
}

void* init_guile(void* data)
{
  scm_gc();
  
  scm_c_primitive_load("/home/user/Stockfish/src/userscripts.scm");

  display = scm_c_public_lookup("guile", "display");
  scm_call_1(scm_variable_ref(display), scm_from_stringn("from C\n", 7, NULL, SCM_FAILED_CONVERSION_ERROR));

  scm_c_define_gsubr("side-to-move", 1, 0, 0, (void*)&get_side_to_move);
  
  evaluate = scm_c_public_lookup("userscripts", "evaluate");
  //evaluate = scm_c_public_lookup("guile-user", "evaluate");
  
  scm_call_1(scm_variable_ref(display), scm_variable_ref(evaluate));
  
  scm_c_primitive_load("/home/user/Stockfish/src/main.scm");

  //  printf("thread: %d\n", std::thread::id());
  printf("init for thread: %d %d\n", std::thread::id(), std::this_thread::get_id());

  //scm_call_0(scm_variable_ref(evaluate));
  //scm_call_0(scm_variable_ref(evaluate));
  //scm_call_0(scm_variable_ref(evaluate));
    
  return NULL;
}

Value guile_evaluate(const Position& pos, Value v)
{
  
  assert(evaluate != NULL);
  
  //SCM str = scm_from_stringn("from C\n", 7, NULL, SCM_FAILED_CONVERSION_ERROR);
  //SCM display = scm_c_public_lookup("", "display"); // guile

  //printf("thread: %d %d\n", std::thread::id(), std::this_thread::get_id());

  //evaluate = scm_c_public_lookup("userscripts", "evaluate");
  //scm_call_1(scm_variable_ref(display), scm_variable_ref(evaluate));

  //  printf("was %d\n", v);
  
  SCM r = scm_call_2(scm_variable_ref(evaluate),
		     scm_from_pointer((void*)&pos, NULL),
		     scm_from_int(v));

  //  printf("now is %d\n", (Value)scm_to_int(r));
  
  return (Value)scm_to_int(r);
}

src/guile.h

@@ -0,0 +1,18 @@
#ifndef GUILE_H_INCLUDED
#define GUILE_H_INCLUDED

#define WITH_GUILE

#include <libguile.h>
#include <thread>

#include "types.h"
#include "position.h"

//extern "C" SCM get_side_to_move(SCM pos);

void* init_guile(void* data);

Value guile_evaluate(const Position& pos, Value v);

#endif

src/main.cpp

@@ -27,9 +27,11 @@
#include "tt.h"
#include "uci.h"
#include "syzygy/tbprobe.h"
#include "guile.h"

int main(int argc, char* argv[]) {

  scm_with_guile(&init_guile, NULL);
  
  std::cout << engine_info() << std::endl;

  UCI::init(Options);

src/main.scm

@@ -0,0 +1,3 @@
(use-modules (userscripts))

; other glue code ...

src/thread.cpp

@@ -24,6 +24,7 @@
#include "search.h"
#include "thread.h"
#include "uci.h"
#include "guile.h"

using namespace Search;

@@ -34,18 +35,27 @@ ThreadPool Threads; // Global object

Thread::Thread() {

  resetCalls = exit = false;
  resetCalls = exit = scm_inited = false;
  maxPly = callsCnt = 0;
  history.clear();
  counterMoves.clear();
  idx = Threads.size(); // Start from 0

  std::unique_lock<Mutex> lk(mutex);
  searching = true;
  nativeThread = std::thread(&Thread::idle_loop, this);
  nativeThread = std::thread(&Thread::init_and_idle, this);
  sleepCondition.wait(lk, [&]{ return !searching; });
}

void Thread::init_and_idle()
{
  if(scm_inited == false) {
    scm_inited = true;
    scm_with_guile(&init_guile, NULL);
  }
  idle_loop();
}


/// Thread destructor wait for thread termination before returning

@@ -93,7 +103,6 @@ void Thread::start_searching(bool resume) {
/// Thread::idle_loop() is where the thread is parked when it has no work to do

void Thread::idle_loop() {

  while (!exit)
  {
      std::unique_lock<Mutex> lk(mutex);
@@ -120,7 +129,6 @@ void Thread::idle_loop() {
/// allocation of Endgames in the Thread constructor.

void ThreadPool::init() {

  push_back(new MainThread);
  read_uci_options();
}

src/thread.h

@@ -45,12 +45,15 @@ class Thread {
  std::thread nativeThread;
  Mutex mutex;
  ConditionVariable sleepCondition;
  bool exit, searching;

  bool exit, searching, scm_inited;
  
  
public:
  Thread();
  virtual ~Thread();
  virtual void search();

  void init_and_idle();
  void idle_loop();
  void start_searching(bool resume = false);
  void wait_for_search_finished();

src/userscripts.scm

@@ -0,0 +1,15 @@
(define-module (userscripts)
  #:export (evaluate))


(define (__evaluate pos v)
  (+ (- (random 1000) 500) v))

(define (_evaluate pos v)
  v)

(define (evaluate pos v)
  (if (= (side-to-move pos) 0)
      v
      (* -1 v)))