/* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- */
// vim: ft=cpp:expandtab:ts=8:sw=4:softtabstop=4:
#ident "$Id$"
#ident "Copyright (c) 2007-2012 Tokutek Inc.  All rights reserved."
#ident "The technology is licensed by the Massachusetts Institute of Technology, Rutgers State University of New Jersey, and the Research Foundation of State University of New York at Stony Brook under United States of America Serial No. 11/760379 and to the patents and/or patent applications resulting from it."
// this test demonstrates that the lock manager can detect a simple deadlock with 2 transactions on 2 threads
// the threads do:
// T(a) put 0, grabs write lock on 0
// T(b) put N-1, grabs write lock on N-1
// T(a) put N-1, try's to grab write lock on N-1, should return lock not granted
// T(b) put 0, try's to grab write lock on 0, should return deadlock
// T(b) abort
// T(a) gets lock W(N-1)
// T(A) commit

#include "test.h"
#include "toku_pthread.h"

struct test_seq {
    int state;
    toku_mutex_t lock;
    toku_cond_t cv;
};

static void test_seq_init(struct test_seq *seq) {
    seq->state = 0;
    toku_mutex_init(&seq->lock, NULL);
    toku_cond_init(&seq->cv, NULL);
}

static void test_seq_destroy(struct test_seq *seq) {
    toku_mutex_destroy(&seq->lock);
    toku_cond_destroy(&seq->cv);
}

static void test_seq_sleep(struct test_seq *seq, int new_state) {
    toku_mutex_lock(&seq->lock);
    while (seq->state != new_state) {
        toku_cond_wait(&seq->cv, &seq->lock);
    }
    toku_mutex_unlock(&seq->lock);
}

static void test_seq_next_state(struct test_seq *seq) {
    toku_mutex_lock(&seq->lock);
    seq->state++;
    toku_cond_broadcast(&seq->cv);
    toku_mutex_unlock(&seq->lock);
}

static void insert_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);
}

struct run_txn_b_arg {
    struct test_seq *test_seq;
    DB_TXN *txn_b;
    DB *db;
    int n;
};

static void *run_txn_b(void *arg) {
    struct run_txn_b_arg *b_arg = (struct run_txn_b_arg *) arg;
    struct test_seq *test_seq = b_arg->test_seq;
    DB_TXN *txn_b = b_arg->txn_b;
    DB *db = b_arg->db;
    int n = b_arg->n;

    test_seq_sleep(test_seq, 1);
    insert_row(db, txn_b, htonl(n-1), n-1, 0);
    test_seq_next_state(test_seq);

    test_seq_sleep(test_seq, 3);
    insert_row(db, txn_b, htonl(0), 0, DB_LOCK_NOTGRANTED);
    test_seq_next_state(test_seq);

    test_seq_sleep(test_seq, 5);
    int r = txn_b->abort(txn_b); assert(r == 0);    

    return arg;
}

static void simple_deadlock(DB_ENV *db_env, DB *db, int do_txn, int n) {
    int r;

    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 < n; k++) {
        insert_row(db, txn_init, htonl(k), k, 0);
    }

    if (do_txn) {
        r = txn_init->commit(txn_init, 0); assert(r == 0);
    }

    uint32_t txn_flags = 0;
#if USE_BDB
    txn_flags = DB_TXN_NOWAIT; // force no wait for BDB to avoid a bug described below
#endif

    DB_TXN *txn_a = NULL;
    if (do_txn) {
        r = db_env->txn_begin(db_env, NULL, &txn_a, txn_flags); assert(r == 0);
    }

    DB_TXN *txn_b = NULL;
    if (do_txn) {
        r = db_env->txn_begin(db_env, NULL, &txn_b, txn_flags); assert(r == 0);
    }

    struct test_seq test_seq; ZERO_STRUCT(test_seq); test_seq_init(&test_seq);

    toku_pthread_t tid;
    struct run_txn_b_arg arg = { &test_seq, txn_b, db, n};
    r = toku_pthread_create(&tid, NULL, run_txn_b, &arg);

    test_seq_sleep(&test_seq, 0);
    insert_row(db, txn_a, htonl(0), 0, 0);
    test_seq_next_state(&test_seq);

    test_seq_sleep(&test_seq, 2);
    // BDB does not time out this lock request, so the test hangs. it looks like a bug in bdb's __lock_get_internal.
    insert_row(db, txn_a, htonl(n-1), n-1, DB_LOCK_NOTGRANTED);
    test_seq_next_state(&test_seq);

    test_seq_sleep(&test_seq, 4);
    if (do_txn) {
        r = txn_a->abort(txn_a); assert(r == 0);
    }
    test_seq_next_state(&test_seq);

    void *ret = NULL;
    r = toku_pthread_join(tid, &ret); assert(r == 0);

    test_seq_destroy(&test_seq);
}

int test_main(int argc, char * const argv[]) {
    uint64_t cachesize = 0;
    uint32_t pagesize = 0;
    int do_txn = 1;
    int nrows = 1000;
    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], "-n") == 0 && i+1 < argc) {
            nrows = atoi(argv[++i]);
            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);
#if USE_BDB
    r = db_env->set_flags(db_env, DB_TIME_NOTGRANTED, 1); assert(r == 0); // force DB_LOCK_DEADLOCK to DB_LOCK_NOTGRANTED
#endif
    r = db_env->open(db_env, db_env_dir, db_env_open_flags, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); assert(r == 0);
#if defined(USE_TDB)
    r = db_env->set_lock_timeout(db_env, 0); assert(r == 0); // no wait
#elif defined(USE_BDB)
    r = db_env->set_lk_detect(db_env, DB_LOCK_YOUNGEST); assert(r == 0);
    r = db_env->set_timeout(db_env, 10000, DB_SET_LOCK_TIMEOUT); assert(r == 0);
#endif

    // 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
    simple_deadlock(db_env, db, do_txn, nrows);

    // 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;
}
