/* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- */
// vim: ft=cpp:expandtab:ts=8:sw=4:softtabstop=4:
#ident "$Id$"
/*======
This file is part of PerconaFT.


Copyright (c) 2006, 2015, Percona and/or its affiliates. All rights reserved.

    PerconaFT is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License, version 2,
    as published by the Free Software Foundation.

    PerconaFT 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 PerconaFT.  If not, see <http://www.gnu.org/licenses/>.

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

    PerconaFT is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License, version 3,
    as published by the Free Software Foundation.

    PerconaFT 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 Affero General Public License for more details.

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

#ident "Copyright (c) 2006, 2015, Percona and/or its affiliates. All rights reserved."

// for all i: T(i) reads 0, gets a read lock on 0
// for all i: T(i) writes 0, enters a deadlock
// tokudb detects deadlock on the fly
// --poll runs the  deadlock detector until all the txns are resolved

#include "test.h"
#include "toku_pthread.h"
#include <portability/toku_atomic.h>

static void write_row(DB *db, DB_TXN *txn, int k, int v, int expect_r) {
    DBT key; dbt_init(&key, &k, sizeof k);
    DBT value; dbt_init(&value, &v, sizeof v);
    int r = db->put(db, txn, &key, &value, 0); assert(r == expect_r);
}

static void read_row(DB *db, DB_TXN *txn, int k, int expect_r) {
    DBT key; dbt_init(&key, &k, sizeof k);
    DBT value; dbt_init_malloc(&value);
    int r = db->get(db, txn, &key, &value, 0); assert(r == expect_r);
    toku_free(value.data);
}

static volatile int n_txns;

struct write_one_arg {
    DB_TXN *txn;
    DB *db;
    int k;
    int v;
};

static void *write_one_f(void *arg) {
    struct write_one_arg *f_arg = (struct write_one_arg *) arg;
    DB_TXN *txn = f_arg->txn;
    DB *db = f_arg->db;
    int k = f_arg->k;
    int v = f_arg->v;

    DBT key; dbt_init(&key, &k, sizeof k);
    DBT value; dbt_init(&value, &v, sizeof v);
    int r = db->put(db, txn, &key, &value, 0);
    if (verbose)
        printf("%s %p %d\n", __FUNCTION__, arg, r);
    assert(r == 0 || r == DB_LOCK_DEADLOCK);
    if (r == 0) {
        r = txn->commit(txn, 0); assert(r == 0);
    } else {
        r = txn->abort(txn); assert(r == 0);
    }
    (void) toku_sync_fetch_and_sub(&n_txns, 1);

    return arg;
}

static void update_deadlock(DB_ENV *db_env, DB *db, int do_txn, int nrows, int ntxns, int poll_deadlock UU()) {
    int r;

    // populate the initial tree
    DB_TXN *txn_init = NULL;
    if (do_txn) {
        r = db_env->txn_begin(db_env, NULL, &txn_init, 0); assert(r == 0);
    }
    for (int k = 0; k < nrows; k++) {
        write_row(db, txn_init, htonl(k), k, 0);
    }
    if (do_txn) {
        r = txn_init->commit(txn_init, 0); assert(r == 0);
    }

    // create the transactions
    n_txns = ntxns;
    DB_TXN *txns[ntxns];
    for (int i = 0; i < ntxns; i++) {
        txns[i] = NULL;
        if (do_txn) {
            r = db_env->txn_begin(db_env, NULL, &txns[i], 0); assert(r == 0);
        }
    }

#ifdef BLOCKING_ROW_LOCKS_READS_NOT_SHARED
    // spice this test up a bit when reads locks are not shared.
    // test that a dining philosopher's style deadlock is detected
    // by having each txn take a distinct read lock, and then request
    // a write lock on the value "next" to it (i + 1 mod ntxns)

    // get read locks
    for (int i = 0; i < ntxns; i++) {
        read_row(db, txns[i], htonl(i), 0);
    }

    // get write locks
    toku_pthread_t tids[ntxns];
    for (int i = 0 ; i < ntxns; i++) {
        struct write_one_arg *XMALLOC(arg);
        *arg = (struct write_one_arg) { txns[i], db, (int) htonl((i + 1) % ntxns), 0};
        r = toku_pthread_create(&tids[i], NULL, write_one_f, arg);
    }
#else
    // get read locks
    for (int i = 0; i < ntxns; i++) {
        read_row(db, txns[i], htonl(0), 0);
    }

    // get write locks
    toku_pthread_t tids[ntxns];
    for (int i = 0 ; i < ntxns; i++) {
        struct write_one_arg *XMALLOC(arg);
        *arg = (struct write_one_arg) { txns[i], db, (int) htonl(0), 0};
        r = toku_pthread_create(&tids[i], NULL, write_one_f, arg);
    }
#endif

    // cleanup
    for (int i = 0; i < ntxns; i++) {
        void *ret = NULL;
        r = toku_pthread_join(tids[i], &ret); assert(r == 0); toku_free(ret);
    }
}

int test_main(int argc, char * const argv[]) {
    uint64_t cachesize = 0;
    uint32_t pagesize = 0;
    int do_txn = 1;
    int nrows = 1000;
    int ntxns = 2;
    int poll_deadlock = 0;
    const char *db_env_dir = TOKU_TEST_FILENAME;
    const char *db_filename = "simple_deadlock";
    int db_env_open_flags = DB_CREATE | DB_PRIVATE | DB_INIT_MPOOL | DB_INIT_TXN | DB_INIT_LOCK | DB_INIT_LOG | DB_THREAD;

    // parse_args(argc, argv);
    for (int i = 1; i < argc; i++) {
        if (strcmp(argv[i], "-v") == 0 || strcmp(argv[i], "--verbose") == 0) {
            verbose++;
            continue;
        }
        if (strcmp(argv[i], "-q") == 0 || strcmp(argv[i], "--quiet") == 0) {
            if (verbose > 0)
                verbose--;
            continue;
        }
        if (strcmp(argv[i], "--nrows") == 0 && i+1 < argc) {
            nrows = atoi(argv[++i]);
            continue;
        }
        if (strcmp(argv[i], "--ntxns") == 0 && i+1 < argc) {
            ntxns = atoi(argv[++i]);
            continue;
        }
        if (strcmp(argv[i], "--poll") == 0) {
            poll_deadlock = 1;
            continue;
        }
        assert(0);
    }

    // setup env
    int r;
    char rm_cmd[strlen(db_env_dir) + strlen("rm -rf ") + 1];
    snprintf(rm_cmd, sizeof(rm_cmd), "rm -rf %s", db_env_dir);
    r = system(rm_cmd); assert(r == 0);

    r = toku_os_mkdir(db_env_dir, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH); assert(r == 0);

    DB_ENV *db_env = NULL;
    r = db_env_create(&db_env, 0); assert(r == 0);
    if (cachesize) {
        const uint64_t gig = 1 << 30;
        r = db_env->set_cachesize(db_env, cachesize / gig, cachesize % gig, 1); assert(r == 0);
    }
    if (!do_txn)
        db_env_open_flags &= ~(DB_INIT_TXN | DB_INIT_LOG);
    r = db_env->open(db_env, db_env_dir, db_env_open_flags, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); assert(r == 0);
    r = db_env->set_lock_timeout(db_env, 30 * 1000, nullptr); assert(r == 0);

    // create the db
    DB *db = NULL;
    r = db_create(&db, db_env, 0); assert(r == 0);
    DB_TXN *create_txn = NULL;
    if (do_txn) {
        r = db_env->txn_begin(db_env, NULL, &create_txn, 0); assert(r == 0);
    }
    if (pagesize) {
        r = db->set_pagesize(db, pagesize); assert(r == 0);
    }
    r = db->open(db, create_txn, db_filename, NULL, DB_BTREE, DB_CREATE, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); assert(r == 0);
    if (do_txn) {
        r = create_txn->commit(create_txn, 0); assert(r == 0);
    }

    // run test
    update_deadlock(db_env, db, do_txn, nrows, ntxns, poll_deadlock);

    // close env
    r = db->close(db, 0); assert(r == 0); db = NULL;
    r = db_env->close(db_env, 0); assert(r == 0); db_env = NULL;

    return 0;
}
