/* Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include <ctype.h>

#include <stdio.h>

#include "apu_config.h"

#include "apu.h"

#include "apr_pools.h"

#include "apr_tables.h"

#include "apr_dso.h"

#include "apr_strings.h"

#include "apr_hash.h"

#include "apr_file_io.h"

#include "apr_env.h"

#include "apr_atomic.h"

#include "apu_internal.h"

#include "apu_version.h"

#if APU_DSO_BUILD

#if APR_HAS_THREADS

static apr_thread_mutex_t* mutex = NULL;

#endif

static apr_hash_t *dsos = NULL;

static apr_uint32_t initialised = 0, in_init = 1;

#if APR_HAS_THREADS

apr_status_t apu_dso_mutex_lock()

{

    return apr_thread_mutex_lock(mutex);

}

apr_status_t apu_dso_mutex_unlock()

{

    return apr_thread_mutex_unlock(mutex);

}

#else

apr_status_t apu_dso_mutex_lock() {

    return APR_SUCCESS;

}

apr_status_t apu_dso_mutex_unlock() {

    return APR_SUCCESS;

}

#endif

static apr_status_t apu_dso_term(void *ptr)

{

    /* set statics to NULL so init can work again */

    dsos = NULL;

#if APR_HAS_THREADS

    mutex = NULL;

#endif

    /* Everything else we need is handled by cleanups registered

     * when we created mutexes and loaded DSOs

     */

    return APR_SUCCESS;

}

apr_status_t apu_dso_init(apr_pool_t *pool)

{

    apr_status_t ret = APR_SUCCESS;

    apr_pool_t *parent;

    if (apr_atomic_inc32(&initialised)) {

        apr_atomic_set32(&initialised, 1); /* prevent wrap-around */

        while (apr_atomic_read32(&in_init)) /* wait until we get fully inited */

            ;

        return APR_SUCCESS;

    }

    /* Top level pool scope, need process-scope lifetime */

    for (parent = apr_pool_parent_get(pool);

         parent && parent != pool;

         parent = apr_pool_parent_get(pool))

        pool = parent;

    dsos = apr_hash_make(pool);

#if APR_HAS_THREADS

    ret = apr_thread_mutex_create(&mutex, APR_THREAD_MUTEX_DEFAULT, pool);

    /* This already registers a pool cleanup */

#endif

    apr_pool_cleanup_register(pool, NULL, apu_dso_term,

                              apr_pool_cleanup_null);

    apr_atomic_dec32(&in_init);

    return ret;

}

apr_status_t apu_dso_load(apr_dso_handle_t **dlhandleptr,

                          apr_dso_handle_sym_t *dsoptr,

                          const char *module,

                          const char *modsym,

                          apr_pool_t *pool)

{

    apr_dso_handle_t *dlhandle = NULL;

    char *pathlist;

    char path[APR_PATH_MAX + 1];

    apr_array_header_t *paths;

    apr_pool_t *global;

    apr_status_t rv = APR_EDSOOPEN;

    char *eos = NULL;

    int i;

    *dsoptr = apr_hash_get(dsos, module, APR_HASH_KEY_STRING);

    if (*dsoptr) {

        return APR_EINIT;

    }

    /* The driver DSO must have exactly the same lifetime as the

     * drivers hash table; ignore the passed-in pool */

    global = apr_hash_pool_get(dsos);

    /* Retrieve our path search list or prepare for a single search */

    if ((apr_env_get(&pathlist, APR_DSOPATH, pool) != APR_SUCCESS)

          || (apr_filepath_list_split(&paths, pathlist, pool) != APR_SUCCESS))

        paths = apr_array_make(pool, 1, sizeof(char*));

#if defined(APU_DSO_LIBDIR)

    /* Always search our prefix path, but on some platforms such as

     * win32 this may be left undefined

     */

    (*((char **)apr_array_push(paths))) = APU_DSO_LIBDIR;

#endif

    for (i = 0; i < paths->nelts; ++i)

    {

#if defined(WIN32)

        /* Use win32 dso search semantics and attempt to

         * load the relative lib on the first pass.

         */

        if (!eos) {

            eos = path;

            --i;

        }

        else

#endif

        {

            eos = apr_cpystrn(path, ((char**)paths->elts)[i], sizeof(path));

            if ((eos > path) && (eos - path < sizeof(path) - 1))

                *(eos++) = '/';

        }

        apr_cpystrn(eos, module, sizeof(path) - (eos - path));

        rv = apr_dso_load(&dlhandle, path, global);

        if (dlhandleptr) {

            *dlhandleptr = dlhandle;

        }

        if (rv == APR_SUCCESS) { /* APR_EDSOOPEN */

            break;

        }

#if defined(APU_DSO_LIBDIR)

        else if (i < paths->nelts - 1) {

#else

        else {   /* No APU_DSO_LIBDIR to skip */

#endif

             /* try with apr-util-APU_MAJOR_VERSION appended */

            eos = apr_cpystrn(eos,

                              "apr-util-" APU_STRINGIFY(APU_MAJOR_VERSION) "/",

                              sizeof(path) - (eos - path));

            apr_cpystrn(eos, module, sizeof(path) - (eos - path));

            rv = apr_dso_load(&dlhandle, path, global);

            if (dlhandleptr) {

                *dlhandleptr = dlhandle;

            }

            if (rv == APR_SUCCESS) { /* APR_EDSOOPEN */

                break;

            }

        }

    }

    if (rv != APR_SUCCESS) /* APR_ESYMNOTFOUND */

        return rv;

    rv = apr_dso_sym(dsoptr, dlhandle, modsym);

    if (rv != APR_SUCCESS) { /* APR_ESYMNOTFOUND */

        apr_dso_unload(dlhandle);

    }

    else {

        module = apr_pstrdup(global, module);

        apr_hash_set(dsos, module, APR_HASH_KEY_STRING, *dsoptr);

    }

    return rv;

}

#endif /* APU_DSO_BUILD */