Cfish: Function call problem (segmentation fault)

[Look]

Hello,

Considering Cfish project:

I try to call a function in benchmark.c file. The existing calls work well in search.c file. But my newer call causes segmentation fault. I suspect there can be some sort of initializing code. I tried various ideas, none worked. part of code:

benchmark.c:

Code: Select all

void benchmark(Position *current, char *str)
{
    [CODE BEFORE]

    strcpy(buf, "fen ");
    strncat(buf, fens[i], 127 - 4);
    buf[127] = 0;


    position(&pos, buf);
    //evaluate(&pos); // causes problems, from evaluate.h
    
    [CODE AFTER]
}

Can you help me correctly call this function ?

[Dann Corbit]

The is from the main() for CFish:

Code: Select all

#include <stdio.h>

#include "bitboard.h"
#include "endgame.h"
#include "pawns.h"
#include "polybook.h"
#include "position.h"
#include "search.h"
#include "thread.h"
#include "tt.h"
#include "uci.h"
#include "tbprobe.h"

int main(int argc, char **argv)
{
    print_engine_info(false); // Probably don't need to call this, but it does not hurt to do it.  You should, of course, give credit

    psqt_init();  // For sure you should call this
    bitboards_init(); // For sure you should call this
    zob_init(); // For sure you should call this
    bitbases_init(); // For sure you should call this
#ifndef NNUE_PURE
    endgames_init(); // You probably should call this
#endif
    threads_init(); // you may or may not need to call this
    options_init(); // you may or may not need to call this
    search_clear(); // you may or may not need to call this
    // Now you can call eval.  You could use Ronald's code as a library
    ...

[Look]

I tried this:

Code: Select all

void benchmark(Position *current, char *str)
{
  char *token;
  char **fens;
  int numFens;

	psqt_init();
  	bitboards_init();
  	zob_init();
  	bitbases_init();
#ifndef NNUE_PURE
  	endgames_init();
#endif
  //	threads_init();
  	//options_init();
//  	search_clear();
    

  Limits = (struct LimitsType){ 0 };

[...]

Output is:

Code: Select all

[root@localhost src]# ./cfish bench
Cfish-fork 240321 64 POPCNT by Syzygy based on Stockfish
^Z
[14]+  Stopped                 ./cfish bench

After some waiting nothing happens.

[Dann Corbit]

Do you have gdb handy?
You can use that to understand exactly what is happening.

[Look]

I have access to gdb. After running cfish in gdb , program stays idle at zob_init() function. Also another observation is that calling "pos_is_ok" function in benchmak.c (with debug=yes) causes this error:

Code: Select all

usr/bin/ld: benchmark.o: in function `benchmark':
/home/mehdi/Documents/Cfish-master/src/benchmark.c:143: undefined reference to `pos_is_ok'
collect2: error: ld returned 1 exit status
make: *** [Makefile:966: cfish] Error 1

Function "pos_is_ok" is defined in position.h . I guess this has something to do with the Makefile. I am not used to Makefiles , though.

[Look]

I added this line to Makefile , but still I get error as in previous code.

Code: Select all

[CODE BEFORE]

### Object files
OBJS = 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 tbprobe.o thread.o timeman.o tt.o uci.o ucioption.o \
        numa.o settings.o polybook.o 

$(OBJS) : position.h

[CODE AFTER]

Error:

Code: Select all

/usr/bin/ld: benchmark.o: in function `benchmark':
/home/mehdi/Documents/Cfish-master/src/benchmark.c:143: undefined reference to `pos_is_ok'
collect2: error: ld returned 1 exit status
make: *** [Makefile:969: cfish] Error 1

[Dann Corbit]

pos_is_ok is only defined in DEBUG mode, and not in release:

Code: Select all

#ifndef NDEBUG
static int pos_is_ok(Position *pos, int *failedStep);
static int check_pos(Position *pos);
#else
#define check_pos(p) do {} while (0)
#endif

What, exactly, are you trying to do?

[Look]

[...]

What, exactly, are you trying to do?

I am trying to produce a newer type of ANN. For this , I need to call "evaluate" from position.h to benchmark.c file. After that I may be able to train the network.

[Dann Corbit]

It's not as simple as I thought.

I tried a clone of the benchmark function that would do an evaluation instead of a search.

Code: Select all

/*
  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
  Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
  Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad

  Stockfish is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  Stockfish is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "evaluate.h"
#include "misc.h"
#ifdef NNUE
#include "nnue.h"
#endif
#include "position.h"
#include "search.h"
#include "settings.h"
#include "thread.h"
#include "tt.h"
#include "uci.h"

static char *Defaults[] = {
    "setoption name UCI_Chess960 value false",
    "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1",
    "r3k2r/p1ppqpb1/bn2pnp1/3PN3/1p2P3/2N2Q1p/PPPBBPPP/R3K2R w KQkq - 0 10",
    "8/2p5/3p4/KP5r/1R3p1k/8/4P1P1/8 w - - 0 11",
    "4rrk1/pp1n3p/3q2pQ/2p1pb2/2PP4/2P3N1/P2B2PP/4RRK1 b - - 7 19",
    "rq3rk1/ppp2ppp/1bnpb3/3N2B1/3NP3/7P/PPPQ1PP1/2KR3R w - - 7 14 moves d4e6",
    "r1bq1r1k/1pp1n1pp/1p1p4/4p2Q/4Pp2/1BNP4/PPP2PPP/3R1RK1 w - - 2 14 moves g2g4",
    "r3r1k1/2p2ppp/p1p1bn2/8/1q2P3/2NPQN2/PPP3PP/R4RK1 b - - 2 15",
    "r1bbk1nr/pp3p1p/2n5/1N4p1/2Np1B2/8/PPP2PPP/2KR1B1R w kq - 0 13",
    "r1bq1rk1/ppp1nppp/4n3/3p3Q/3P4/1BP1B3/PP1N2PP/R4RK1 w - - 1 16",
    "4r1k1/r1q2ppp/ppp2n2/4P3/5Rb1/1N1BQ3/PPP3PP/R5K1 w - - 1 17",
    "2rqkb1r/ppp2p2/2npb1p1/1N1Nn2p/2P1PP2/8/PP2B1PP/R1BQK2R b KQ - 0 11",
    "r1bq1r1k/b1p1npp1/p2p3p/1p6/3PP3/1B2NN2/PP3PPP/R2Q1RK1 w - - 1 16",
    "3r1rk1/p5pp/bpp1pp2/8/q1PP1P2/b3P3/P2NQRPP/1R2B1K1 b - - 6 22",
    "r1q2rk1/2p1bppp/2Pp4/p6b/Q1PNp3/4B3/PP1R1PPP/2K4R w - - 2 18",
    "4k2r/1pb2ppp/1p2p3/1R1p4/3P4/2r1PN2/P4PPP/1R4K1 b - - 3 22",
    "3q2k1/pb3p1p/4pbp1/2r5/PpN2N2/1P2P2P/5PP1/Q2R2K1 b - - 4 26",
    "6k1/6p1/6Pp/ppp5/3pn2P/1P3K2/1PP2P2/3N4 b - - 0 1",
    "3b4/5kp1/1p1p1p1p/pP1PpP1P/P1P1P3/3KN3/8/8 w - - 0 1",
    "2K5/p7/7P/5pR1/8/5k2/r7/8 w - - 0 1 moves g5g6 f3e3 g6g5 e3f3",
    "8/6pk/1p6/8/PP3p1p/5P2/4KP1q/3Q4 w - - 0 1",
    "7k/3p2pp/4q3/8/4Q3/5Kp1/P6b/8 w - - 0 1",
    "8/2p5/8/2kPKp1p/2p4P/2P5/3P4/8 w - - 0 1",
    "8/1p3pp1/7p/5P1P/2k3P1/8/2K2P2/8 w - - 0 1",
    "8/pp2r1k1/2p1p3/3pP2p/1P1P1P1P/P5KR/8/8 w - - 0 1",
    "8/3p4/p1bk3p/Pp6/1Kp1PpPp/2P2P1P/2P5/5B2 b - - 0 1",
    "5k2/7R/4P2p/5K2/p1r2P1p/8/8/8 b - - 0 1",
    "6k1/6p1/P6p/r1N5/5p2/7P/1b3PP1/4R1K1 w - - 0 1",
    "1r3k2/4q3/2Pp3b/3Bp3/2Q2p2/1p1P2P1/1P2KP2/3N4 w - - 0 1",
    "6k1/4pp1p/3p2p1/P1pPb3/R7/1r2P1PP/3B1P2/6K1 w - - 0 1",
    "8/3p3B/5p2/5P2/p7/PP5b/k7/6K1 w - - 0 1",
    "5rk1/q6p/2p3bR/1pPp1rP1/1P1Pp3/P3B1Q1/1K3P2/R7 w - - 93 90",
    "4rrk1/1p1nq3/p7/2p1P1pp/3P2bp/3Q1Bn1/PPPB4/1K2R1NR w - - 40 21",
    "r3k2r/3nnpbp/q2pp1p1/p7/Pp1PPPP1/4BNN1/1P5P/R2Q1RK1 w kq - 0 16",
    "3Qb1k1/1r2ppb1/pN1n2q1/Pp1Pp1Pr/4P2p/4BP2/4B1R1/1R5K b - - 11 40",
    "4k3/3q1r2/1N2r1b1/3ppN2/2nPP3/1B1R2n1/2R1Q3/3K4 w - - 5 1",

    // 5-man positions
    "8/8/8/8/5kp1/P7/8/1K1N4 w - - 0 1",     // Kc2 - mate
    "8/8/8/5N2/8/p7/8/2NK3k w - - 0 1",      // Na2 - mate
    "8/3k4/8/8/8/4B3/4KB2/2B5 w - - 0 1",    // draw

    // 6-man positions
    "8/8/1P6/5pr1/8/4R3/7k/2K5 w - - 0 1",   // Re5 - mate
    "8/2p4P/8/kr6/6R1/8/8/1K6 w - - 0 1",    // Ka2 - mate
    "8/8/3P3k/8/1p6/8/1P6/1K3n2 b - - 0 1",  // Nd2 - draw

    // 7-man positions
    "8/R7/2q5/8/6k1/8/1P5p/K6R w - - 0 124", // Draw

    // Mate and stalemate positions
    "6k1/3b3r/1p1p4/p1n2p2/1PPNpP1q/P3Q1p1/1R1RB1P1/5K2 b - - 0 1",
    "r2r1n2/pp2bk2/2p1p2p/3q4/3PN1QP/2P3R1/P4PP1/5RK1 w - - 0 1",
    "8/8/8/8/8/6k1/6p1/6K1 w - -",
    "7k/7P/6K1/8/3B4/8/8/8 b - -",

    // Chess 960
    "setoption name UCI_Chess960 value true",
    "bbqnnrkr/pppppppp/8/8/8/8/PPPPPPPP/BBQNNRKR w HFhf - 0 1 moves g2g3 d7d5 d2d4 c8h3 c1g5 e8d6 g5e7 f7f6",
    "setoption name UCI_Chess960 value false"
};

// benchmark() runs a simple benchmark by letting Stockfish analyze a set
// of positions for a given limit each. There are six optional parameters:
// - Transposition table size. Default is 16 MB.
// - Number of search threads to use. Default is 1 thread.
// - Limit value for each search. Default is (depth) 13.
// - File name with the positions to search in FEN format. The default
//   positions are listed above.
// - Type of the limit value: depth (default), time (in msecs), nodes.
// - Evaluation: classical, nnue (hybrid), pure (NNUE only), mixed (default).

void evaluation(Position *current, char *str)
{
    char *token;
    char **fens;
    int numFens;

    Limits = (struct LimitsType) {
        0
    };
    int threads     = 1;
    int ttSize      = (token = strtok(str, " ")) ? atoi(token)  : 16;
    char *fenFile   = (token = strtok(NULL, " ")) ? token        : "default";
#if defined(NNUE) && !defined(NNUE_PURE)
    char *evalType  = (token = strtok(NULL, " ")) ? token        : "nnue";
#endif

    delayedSettings.ttSize = ttSize;
    delayedSettings.numThreads = threads;
    process_delayed_settings();
    search_clear();
    threads_set_number(delayedSettings.numThreads);
    if (strcasecmp(fenFile, "default") == 0) {
        fens = Defaults;
        numFens = sizeof(Defaults) / sizeof(char *);
    }
    else if (strcasecmp(fenFile, "current") == 0) {
        fens = malloc(sizeof(*fens));
        fens[0] = malloc(128);
        pos_fen(current, fens[0]);
        numFens = 1;
    }
    else {
        int maxFens = 100;
        numFens = 0;
        FILE *F = fopen(fenFile, "r");
        if (!F) {
            fprintf(stderr, "Unable to open file %s\n", fenFile);
            return;
        }
        fens = malloc(maxFens * sizeof(*fens));
        fens[0] = NULL;
        size_t length = 0;
        while (getline(&fens[numFens], &length, F) > 0) {
            numFens++;
            if (numFens == maxFens) {
                maxFens += 100;
                fens = realloc(fens, maxFens * sizeof(*fens));
            }
            fens[numFens] = NULL;
            length = 0;
        }
        fclose(F);
    }

    uint64_t nodes = 0;
    Position pos;
    memset(&pos, 0, sizeof(pos));
    pos.stackAllocation = malloc(63 + 217 * sizeof(*pos.stack));
    pos.stack = (Stack *)(((uintptr_t)pos.stackAllocation + 0x3f) & ~0x3f);
    pos.st = pos.stack + 7;
    pos.moveList = malloc(10000 * sizeof(*pos.moveList));
    TimePoint elapsed = now();

    int numOpts = 0;
    for (int i = 0; i < numFens; i++)
        if (strncmp(fens[i], "setoption ", 9) == 0)
            numOpts++;

    for (int i = 0, j = 0; i < numFens; i++) {
        char buf[128];

        if (strncmp(fens[i], "setoption ", 9) == 0) {
            strncpy(buf, fens[i] + 10, 127 - 10);
            buf[127] = 0;
            setoption(buf);
            continue;
        }

        strcpy(buf, "fen ");
        strncat(buf, fens[i], 127 - 4);
        buf[127] = 0;

        position(&pos, buf);

        fprintf(stderr, "\nPosition: %d/%d\n", ++j, numFens - numOpts);

#if defined(NNUE) && !defined(NNUE_PURE)
        if (strcasecmp(evalType, "classical") == 0)
            useNNUE = EVAL_CLASSICAL;
        else if (strcasecmp(evalType, "nnue") == 0)
            useNNUE = EVAL_HYBRID;
        else if (strcasecmp(evalType, "pure") == 0)
            useNNUE = EVAL_PURE;
        else if (strcasecmp(evalType, "mixed") == 0)
            useNNUE = j & 1 ? EVAL_CLASSICAL : EVAL_HYBRID;
#endif

        Value eval = evaluate(&pos);
        printf("%s ce %d;\n", fens[i], (int) eval);
        nodes++;
    }

    elapsed = now() - elapsed + 1; // Ensure positivity to avoid a 'divide by zero'

    fprintf(stderr, "\n==========================="
            "\nTotal time (ms) : %" PRIu64
            "\nNodes evaluated : %" PRIu64
            "\nNodes/second    : %" PRIu64 "\n",
            elapsed, nodes, 1000 * nodes / elapsed);

    if (fens != Defaults) {
        for (int i = 0; i < numFens; i++)
            free(fens[i]);
        free(fens);
    }
    free(pos.stackAllocation);
    free(pos.moveList);
}

However...
When I called evaluate from the main thread, the material table for the position was not properly generated, so this crashed with an access violation during the lookup:

Code: Select all

INLINE MaterialEntry *material_probe(const Position *pos)
{
    Key key = material_key();
    MaterialEntry *e = &pos->materialTable[key >> (64-13)];

    if (unlikely(e->key != key))
        material_entry_fill(pos, e, key);

    return e;
}

[Look]

As a workaround , can one call this cloned benchmark somewhere that it works ? like search.c where inits are done right ? So I can try another function I want to accomplish.