/* -*- 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."

#include "test.h"

#include <toku_portability.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <db.h>
#include <string.h>

#include <memory.h>

#include <portability/toku_atomic.h>
#include <portability/toku_pthread.h>
#include <portability/toku_random.h>

#include <util/omt.h>
#include <util/rwlock.h>

namespace toku {

namespace test {

static inline uint32_t fudge(const uint32_t x) { return x + 300; }
static inline uint32_t defudge(const uint32_t fx) { return fx - 300; }

int test_iterator(const uint32_t &v, const uint32_t idx, bool *const UU(unused));
int test_iterator(const uint32_t &v, const uint32_t idx, bool *const UU(unused)) {
    invariant(defudge(v) == idx);
    return 0;
}

int check_iterator_before(const uint32_t &v, const uint32_t idx, bool *const called);
int check_iterator_before(const uint32_t &v, const uint32_t idx, bool *const called) {
    invariant(defudge(v) == idx);
    invariant(idx % 10 < 5);
    called[idx] = true;
    return 0;
}

int check_iterator_after(const uint32_t &v, const uint32_t UU(idx), bool *const called);
int check_iterator_after(const uint32_t &v, const uint32_t UU(idx), bool *const called) {
    invariant(defudge(v) % 10 >= 5);
    called[defudge(v)] = true;
    return 0;
}

int die(const uint32_t &UU(v), const uint32_t UU(idx), void *const UU(unused));
int die(const uint32_t &UU(v), const uint32_t UU(idx), void *const UU(unused)) {
    abort();
    return 0; // hahaha
}

static void run_test(uint32_t nelts) {
    assert(nelts % 10 == 0);  // run_test depends on nelts being a multiple of 10

    omt<uint32_t, uint32_t, true> omt;
    omt.create();
    omt.verify_marks_consistent();
    for (uint32_t i = 0; i < nelts; ++i) {
        omt.insert_at(fudge(i), i);
    }
    omt.verify_marks_consistent();

    int r;
    for (uint32_t i = 0; i < nelts / 10; ++i) {
        r = omt.iterate_and_mark_range<bool, test_iterator>(i * 10, i * 10 + 5, nullptr);
        invariant_zero(r);
        omt.verify_marks_consistent();
    }

    bool called[nelts];
    ZERO_ARRAY(called);
    r = omt.iterate_over_marked<bool, check_iterator_before>(called);
    invariant_zero(r);
    for (uint32_t i = 0; i < nelts; ++i) {
        if (i % 10 < 5) {
            invariant(called[i]);
        } else {
            invariant(!called[i]);
        }
    }
    omt.verify_marks_consistent();

    invariant(omt.size() == nelts);

    omt.delete_all_marked();
    omt.verify_marks_consistent();

    invariant(omt.size() * 2 == nelts);

    r = omt.iterate_over_marked<void, die>(nullptr);
    invariant_zero(r);

    ZERO_ARRAY(called);
    r = omt.iterate<bool, check_iterator_after>(called);
    invariant_zero(r);
    omt.verify_marks_consistent();

    for (uint32_t i = 0; i < nelts; ++i) {
        if (i % 10 < 5) {
            invariant(!called[i]);
        } else {
            invariant(called[i]);
        }
    }

    omt.destroy();
}

typedef omt<uint32_t, uint32_t, true> stress_omt;

int int_heaviside(const uint32_t &v, const uint32_t &target);
int int_heaviside(const uint32_t &v, const uint32_t &target) {
    return (v > target) - (v < target);
}

struct stress_shared {
    stress_omt *omt;
    volatile bool running;
    struct rwlock lock;
    toku_mutex_t mutex;
    int num_marker_threads;
};

struct reader_extra {
    int tid;
    stress_shared *shared;
    uint64_t iterations;
    uint64_t last_iteration;
    char buf_read[8];
    char buf_write[8];
    struct random_data rand_read;
    struct random_data rand_write;
};

static void generate_range(struct random_data *rng, const struct stress_shared &shared, uint32_t *begin, uint32_t *limit) {
    const uint32_t nelts = shared.omt->size();
    double range_limit_d = nelts;
    range_limit_d /= 1000;
    range_limit_d /= shared.num_marker_threads;
    range_limit_d += 1;
    uint32_t range_limit = static_cast<uint32_t>(range_limit_d);
    if (range_limit < 5) {
        range_limit = 5;
    }
    if (range_limit > 1000) {
        range_limit = 1000;
    }
    *begin = rand_choices(rng, nelts - 1);
    if (*begin + range_limit > nelts) {
        range_limit = nelts - *begin;
    }
    *limit = *begin + rand_choices(rng, range_limit);
}

struct pair {
    uint32_t begin;
    uint32_t limit;
};

int mark_read_iterator(const uint32_t &UU(v), const uint32_t idx, struct pair * const pair);
int mark_read_iterator(const uint32_t &UU(v), const uint32_t idx, struct pair * const pair) {
    invariant(defudge(v) == idx);
    invariant(idx >= pair->begin);
    invariant(idx < pair->limit);
    return 0;
}

static void *stress_mark_worker(void *extrav) {
    struct reader_extra *CAST_FROM_VOIDP(extra, extrav);
    struct stress_shared &shared = *extra->shared;
    toku_mutex_t &mutex = shared.mutex;

    while (shared.running) {
        toku_mutex_lock(&mutex);
        rwlock_read_lock(&shared.lock, &mutex);
        toku_mutex_unlock(&mutex);

        struct pair range;
        generate_range(&extra->rand_read, shared, &range.begin, &range.limit);

        shared.omt->iterate_and_mark_range<pair, mark_read_iterator>(range.begin, range.limit, &range);

        ++extra->iterations;

        toku_mutex_lock(&mutex);
        rwlock_read_unlock(&shared.lock);
        toku_mutex_unlock(&mutex);

        usleep(1);
    }

    return nullptr;
}

template<typename T>
class array_ftor {
    int m_count;
    T *m_array;
public:
    array_ftor(int size) : m_count(0) {
        XMALLOC_N(size, m_array);
    }
    ~array_ftor() {
        toku_free(m_array);
    }
    void operator() (const T &x) { m_array[m_count++] = x; }
    template<class callback_t>
    void iterate(callback_t &cb) const {
        for (int i = 0; i < m_count; ++i) {
            cb(m_array[i]);
        }
    }
};

int use_array_ftor(const uint32_t &v, const uint32_t UU(idx), array_ftor<uint32_t> *const fp);
int use_array_ftor(const uint32_t &v, const uint32_t UU(idx), array_ftor<uint32_t> *const fp) {
    array_ftor<uint32_t> &f = *fp;
    f(v);
    return 0;
}

class inserter {
    stress_omt *m_omt;
public:
    inserter(stress_omt *omt) : m_omt(omt) {}
    void operator() (const uint32_t &x) {
        m_omt->insert<uint32_t, int_heaviside>(x, x, nullptr);
    }
};

/*
 * split the range evenly/not evenly between marker threads
 * context tells it the range
 * context also holds iteration number
 *
 * N threads
 * N 'contexts' holds iteration number, seed
 *
 * create rng based on seed
 * loop:
 *   generate random range.  Mark that range, increment iteration number
 *
 *
 * 
 *
 * for each context
     * create rng based on context->last_seed
     *   loop (iteration number times)
     *     mark (in array) random range
     * context->last_seed := context->seed
 * check the array and the omt
 *
 */

static void simulate_reader_marks_on_array(struct reader_extra *const reader, const struct stress_shared &shared, bool *const should_be_marked) {
    if (verbose) {
        fprintf(stderr, "thread %d ran %" PRIu64 " iterations\n", reader->tid, reader->iterations - reader->last_iteration);
    }
    for (; reader->last_iteration < reader->iterations; ++reader->last_iteration) {
        uint32_t begin;
        uint32_t limit;

        generate_range(&reader->rand_write, shared, &begin, &limit);

        for (uint32_t i = begin; i < limit; i++) {
            should_be_marked[i] = true;
        }
    }
}

int copy_marks(const uint32_t &v, const uint32_t idx, bool * const is_marked);
int copy_marks(const uint32_t &v, const uint32_t idx, bool * const is_marked) {
    invariant(defudge(v) == idx);
    is_marked[idx] = true;
    return 0;
}

static inline uint32_t count_true(const bool *const bools, uint32_t n) {
    uint32_t count = 0;
    for (uint32_t i = 0; i < n; ++i) {
        if (bools[i]) {
            ++count;
        }
    }
    return count;
}

static void stress_deleter(struct reader_extra *const readers, int num_marker_threads, stress_omt *omt) {
    // Verify (iterate_over_marked) agrees exactly with iterate_and_mark_range (multithreaded)
    stress_shared &shared = *readers[0].shared;
    bool should_be_marked[omt->size()];
    ZERO_ARRAY(should_be_marked);

    for (int i = 0; i < num_marker_threads; i++) {
        simulate_reader_marks_on_array(&readers[i], shared, should_be_marked);
    }

    bool is_marked_according_to_iterate[omt->size()];
    ZERO_ARRAY(is_marked_according_to_iterate);

    omt->verify_marks_consistent();
    omt->iterate_over_marked<bool, copy_marks>(&is_marked_according_to_iterate[0]);
    omt->verify_marks_consistent();

    invariant(!memcmp(should_be_marked, is_marked_according_to_iterate, sizeof(should_be_marked)));

    if (verbose) {
        double frac_marked = count_true(should_be_marked, omt->size());
        frac_marked /= omt->size();

        fprintf(stderr, "Marked: %0.4f\n", frac_marked);
        omt->verify_marks_consistent();
    }

    array_ftor<uint32_t> aftor(omt->size());
    omt->iterate_over_marked<array_ftor<uint32_t>, use_array_ftor>(&aftor);
    omt->delete_all_marked();
    omt->verify_marks_consistent();
    omt->iterate_over_marked<void, die>(nullptr);
    inserter ins(omt);
    aftor.iterate(ins);
    omt->verify_marks_consistent();
}

static void *stress_delete_worker(void *extrav) {
    reader_extra *CAST_FROM_VOIDP(readers, extrav);
    stress_shared &shared = *readers[0].shared;
    int num_marker_threads = shared.num_marker_threads;
    toku_mutex_t &mutex = shared.mutex;
    const double repetitions = 20;
    for (int i = 0; i < repetitions; ++i) {
        // sleep 0 - 0.15s
        // early iterations sleep for a short time
        // later iterations sleep longer
        int sleep_for = 1000 * 100 * (1.5 * (i+1) / repetitions);
        usleep(sleep_for);

        toku_mutex_lock(&mutex);
        rwlock_write_lock(&shared.lock, &mutex);
        toku_mutex_unlock(&mutex);

        stress_deleter(readers, num_marker_threads, shared.omt);

        toku_mutex_lock(&mutex);
        rwlock_write_unlock(&shared.lock);
        toku_mutex_unlock(&mutex);
    }
    toku_sync_bool_compare_and_swap(&shared.running, true, false);
    return nullptr;
}

static void stress_test(int nelts) {
    stress_omt omt;
    omt.create();
    for (int i = 0; i < nelts; ++i) {
        omt.insert_at(fudge(i), i);
    }

    const int num_marker_threads = 5;
    struct stress_shared extra;
    ZERO_STRUCT(extra);
    extra.omt = &omt;
    toku_mutex_init(&extra.mutex, NULL);
    rwlock_init(&extra.lock);
    extra.running = true;
    extra.num_marker_threads = num_marker_threads;

    struct reader_extra readers[num_marker_threads];
    ZERO_ARRAY(readers);

    srandom(time(NULL));
    toku_pthread_t marker_threads[num_marker_threads];
    for (int i = 0; i < num_marker_threads; ++i) {
        struct reader_extra &reader = readers[i];
        reader.tid = i;
        reader.shared = &extra;

        int r;
        int seed = random();
        r = myinitstate_r(seed, reader.buf_read, 8, &reader.rand_read);
        invariant_zero(r);
        r = myinitstate_r(seed, reader.buf_write, 8, &reader.rand_write);
        invariant_zero(r);

        toku_pthread_create(&marker_threads[i], NULL, stress_mark_worker, &reader);
    }

    toku_pthread_t deleter_thread;
    toku_pthread_create(&deleter_thread, NULL, stress_delete_worker, &readers[0]);
    toku_pthread_join(deleter_thread, NULL);

    for (int i = 0; i < num_marker_threads; ++i) {
        toku_pthread_join(marker_threads[i], NULL);
    }

    rwlock_destroy(&extra.lock);
    toku_mutex_destroy(&extra.mutex);

    omt.destroy();
}

} // end namespace test

} // end namespace toku

int test_main(int argc, const char *argv[]) {
    default_parse_args(argc, argv);

    for (int i = 10; i <= 80; i*=2) {
        toku::test::run_test(i);
    }

    toku::test::run_test(9000);

    toku::test::stress_test(1000 * 100);

    return 0;
}
