/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "namespace.h"
#include <sys/mman.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <pthread.h>
#include "un-namespace.h"
#include "libc_private.h"

#include "thr_private.h"

/* Used in symbol lookup of libthread_db */
struct pthread_key _thread_keytable[PTHREAD_KEYS_MAX];

__weak_reference(_thr_key_create, pthread_key_create);
__weak_reference(_thr_key_create, _pthread_key_create);
__weak_reference(_thr_key_delete, pthread_key_delete);
__weak_reference(_thr_key_delete, _pthread_key_delete);
__weak_reference(_thr_getspecific, pthread_getspecific);
__weak_reference(_thr_getspecific, _pthread_getspecific);
__weak_reference(_thr_setspecific, pthread_setspecific);
__weak_reference(_thr_setspecific, _pthread_setspecific);

int
_thr_key_create(pthread_key_t *key, void (*destructor)(void *))
{
        struct pthread *curthread;
        int i;

        _thr_check_init();

        curthread = _get_curthread();

        THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
        for (i = 0; i < PTHREAD_KEYS_MAX; i++) {

                if (_thread_keytable[i].allocated == 0) {
                        _thread_keytable[i].allocated = 1;
                        _thread_keytable[i].destructor = destructor;
                        _thread_keytable[i].seqno++;

                        THR_LOCK_RELEASE(curthread, &_keytable_lock);
                        *key = i + 1;
                        return (0);
                }

        }
        THR_LOCK_RELEASE(curthread, &_keytable_lock);
        return (EAGAIN);
}

int
_thr_key_delete(pthread_key_t userkey)
{
        struct pthread *curthread;
        int key, ret;

        key = userkey - 1;
        if ((unsigned int)key >= PTHREAD_KEYS_MAX)
                return (EINVAL);
        curthread = _get_curthread();
        THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
        if (_thread_keytable[key].allocated) {
                _thread_keytable[key].allocated = 0;
                ret = 0;
        } else {
                ret = EINVAL;
        }
        THR_LOCK_RELEASE(curthread, &_keytable_lock);
        return (ret);
}

void 
_thread_cleanupspecific(void)
{
        struct pthread *curthread;
        void (*destructor)(void *);
        const void *data;
        int i, key;

        curthread = _get_curthread();
        if (curthread->specific == NULL)
                return;
        THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
        for (i = 0; i < PTHREAD_DESTRUCTOR_ITERATIONS &&
            curthread->specific_data_count > 0; i++) {
                for (key = 0; key < PTHREAD_KEYS_MAX &&
                    curthread->specific_data_count > 0; key++) {
                        destructor = NULL;

                        if (_thread_keytable[key].allocated &&
                            (curthread->specific[key].data != NULL)) {
                                if (curthread->specific[key].seqno ==
                                    _thread_keytable[key].seqno) {
                                        data = curthread->specific[key].data;
                                        destructor = _thread_keytable[key].
                                            destructor;
                                }
                                curthread->specific[key].data = NULL;
                                curthread->specific_data_count--;
                        } else if (curthread->specific[key].data != NULL) {
                                /* 
                                 * This can happen if the key is
                                 * deleted via pthread_key_delete
                                 * without first setting the value to
                                 * NULL in all threads.  POSIX says
                                 * that the destructor is not invoked
                                 * in this case.
                                 */
                                curthread->specific[key].data = NULL;
                                curthread->specific_data_count--;
                        }

                        /*
                         * If there is a destructor, call it with the
                         * key table entry unlocked.
                         */
                        if (destructor != NULL) {
                                THR_LOCK_RELEASE(curthread, &_keytable_lock);
                                destructor(__DECONST(void *, data));
                                THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
                        }
                }
        }
        THR_LOCK_RELEASE(curthread, &_keytable_lock);
        __thr_free(curthread->specific);
        curthread->specific = NULL;
        if (curthread->specific_data_count > 0) {
                stderr_debug("Thread %p has exited with leftover "
                    "thread-specific data after %d destructor iterations\n",
                    curthread, PTHREAD_DESTRUCTOR_ITERATIONS);
        }
}

int 
_thr_setspecific(pthread_key_t userkey, const void *value)
{
        struct pthread *pthread;
        void *tmp;
        pthread_key_t key;

        key = userkey - 1;
        if ((unsigned int)key >= PTHREAD_KEYS_MAX ||
            !_thread_keytable[key].allocated)
                return (EINVAL);

        pthread = _get_curthread();
        if (pthread->specific == NULL) {
                tmp = __thr_calloc(PTHREAD_KEYS_MAX,
                    sizeof(struct pthread_specific_elem));
                if (tmp == NULL)
                        return (ENOMEM);
                pthread->specific = tmp;
        }
        if (pthread->specific[key].data == NULL) {
                if (value != NULL)
                        pthread->specific_data_count++;
        } else if (value == NULL)
                pthread->specific_data_count--;
        pthread->specific[key].data = value;
        pthread->specific[key].seqno = _thread_keytable[key].seqno;
        return (0);
}

void *
_thr_getspecific(pthread_key_t userkey)
{
        struct pthread *pthread;
        const void *data;
        pthread_key_t key;

        /* Check if there is specific data. */
        key = userkey - 1;
        if ((unsigned int)key >= PTHREAD_KEYS_MAX)
                return (NULL);

        pthread = _get_curthread();
        /* Check if this key has been used before. */
        if (_thread_keytable[key].allocated && pthread->specific != NULL &&
            pthread->specific[key].seqno == _thread_keytable[key].seqno) {
                /* Return the value: */
                data = pthread->specific[key].data;
        } else {
                /*
                 * This key has not been used before, so return NULL
                 * instead.
                 */
                data = NULL;
        }
        return (__DECONST(void *, data));
}

void
_thr_tsd_unload(struct dl_phdr_info *phdr_info)
{
        struct pthread *curthread;
        void (*destructor)(void *);
        int key;

        curthread = _get_curthread();
        THR_LOCK_ACQUIRE(curthread, &_keytable_lock);
        for (key = 0; key < PTHREAD_KEYS_MAX; key++) {
                if (!_thread_keytable[key].allocated)
                        continue;
                destructor = _thread_keytable[key].destructor;
                if (destructor == NULL)
                        continue;
                if (__elf_phdr_match_addr(phdr_info, destructor))
                        _thread_keytable[key].destructor = NULL;
        }
        THR_LOCK_RELEASE(curthread, &_keytable_lock);
}