/*
 * 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 "fcgid_proctbl.h"
#include "apr_shm.h"
#include "fcgid_global.h"

static apr_thread_mutex_t *g_sharelock = NULL;

static fcgid_procnode *g_proc_array = NULL; /* Contain all process slot */
static fcgid_procnode *g_free_list_header = NULL;   /* Attach to no process list */
static fcgid_procnode *g_busy_list_header = NULL;   /* Attach to a working process list */
static fcgid_procnode *g_idle_list_header = NULL;   /* Attach to an idle process list */
static fcgid_procnode *g_error_list_header = NULL;  /* Attach to an error process list */
static fcgid_share *_global_memory = NULL;
static fcgid_global_share *g_global_share = NULL;   /* global information */
static size_t g_table_size = FCGID_PROC_TABLE_SIZE;

apr_status_t proctable_pre_config(apr_pool_t *p, apr_pool_t *plog,
                                  apr_pool_t *ptemp)
{
    return APR_SUCCESS;
}

apr_status_t
proctable_post_config(server_rec * main_server, apr_pool_t * pconf)
{
    long shmem_size = sizeof(fcgid_share);
    fcgid_procnode *ptmpnode = NULL;
    int i;
    apr_status_t rv = APR_SUCCESS;

    if ((rv = apr_thread_mutex_create(&g_sharelock,
                                      APR_THREAD_MUTEX_DEFAULT,
                                      pconf)) != APR_SUCCESS) {
        /* Fatal error */
        ap_log_error(APLOG_MARK, APLOG_EMERG, rv, main_server,
                     "mod_fcgid: Can't create global mutex");
        exit(1);
    }

    /* There is only one process in WinNT mpm, share memory is not necessary */
    _global_memory = (fcgid_share *) apr_pcalloc(pconf, shmem_size);

    g_proc_array = _global_memory->procnode_array;
    g_global_share = &_global_memory->global;

    g_global_share->must_exit = 0;

    /* Init the array */
    g_idle_list_header = g_proc_array;
    g_busy_list_header = g_idle_list_header + 1;
    g_error_list_header = g_busy_list_header + 1;
    g_free_list_header = g_error_list_header + 1;
    ptmpnode = g_free_list_header;
    for (i = 0; i < FCGID_MAX_APPLICATION; i++) {
        ptmpnode->next_index = ptmpnode - g_proc_array + 1;
        ptmpnode++;
    }

    return APR_SUCCESS;
}

apr_status_t
proctable_child_init(server_rec * main_server, apr_pool_t * pchild)
{
    return APR_SUCCESS;
}

static apr_status_t proctable_lock_internal(void)
{
    return apr_thread_mutex_lock(g_sharelock);
}

static apr_status_t proctable_unlock_internal(void)
{
    return apr_thread_mutex_unlock(g_sharelock);
}

fcgid_procnode *proctable_get_free_list(void)
{
    return g_free_list_header;
}

fcgid_procnode *proctable_get_busy_list(void)
{
    return g_busy_list_header;
}

fcgid_procnode *proctable_get_idle_list(void)
{
    return g_idle_list_header;
}

fcgid_procnode *proctable_get_table_array(void)
{
    return g_proc_array;
}

fcgid_procnode *proctable_get_error_list(void)
{
    return g_error_list_header;
}

fcgid_global_share *proctable_get_globalshare(void)
{
    return g_global_share;
}

size_t proctable_get_table_size(void)
{
    return g_table_size;
}

void proctable_lock(request_rec *r)
{
    /* Lock error is a fatal error */
    apr_status_t rv;

    if ((rv = proctable_lock_internal()) != APR_SUCCESS) {
        ap_log_rerror(APLOG_MARK, APLOG_EMERG, rv, r,
                      "mod_fcgid: can't lock process table");
        exit(1);
    }
}

void proctable_unlock(request_rec *r)
{
    /* Lock error is a fatal error */
    apr_status_t rv;

    if ((rv = proctable_unlock_internal()) != APR_SUCCESS) {
        ap_log_rerror(APLOG_MARK, APLOG_EMERG, rv, r,
                      "mod_fcgid: can't unlock process table");
        exit(1);
    }
}

void proctable_pm_lock(server_rec * s)
{
    /* Lock error is a fatal error */
    apr_status_t rv;

    if ((rv = proctable_lock_internal()) != APR_SUCCESS) {
        ap_log_error(APLOG_MARK, APLOG_EMERG, rv, s,
                     "mod_fcgid: can't lock process table in PM");
        exit(1);
    }
}

void proctable_pm_unlock(server_rec * s)
{
    /* Lock error is a fatal error */
    apr_status_t rv;

    if ((rv = proctable_unlock_internal()) != APR_SUCCESS) {
        ap_log_error(APLOG_MARK, APLOG_EMERG, rv, s,
                     "mod_fcgid: can't unlock process table in PM");
        exit(1);
    }
}

void proctable_print_debug_info(server_rec * main_server)
{
    int freecount = 0;
    fcgid_procnode *current_node;

    for (current_node = &g_proc_array[g_free_list_header->next_index];
         current_node != g_proc_array;
         current_node = &g_proc_array[current_node->next_index])
        freecount++;

    ap_log_error(APLOG_MARK, APLOG_WARNING, 0, main_server,
                 "mod_fcgid: total node count: %d, free node count: %d",
                 FCGID_MAX_APPLICATION, freecount);

    for (current_node = &g_proc_array[g_idle_list_header->next_index];
         current_node != g_proc_array;
         current_node = &g_proc_array[current_node->next_index]) {
        ap_log_error(APLOG_MARK, APLOG_WARNING, 0, main_server,
                     "mod_fcgid: idle node index: %d",
                     current_node - g_proc_array);
    }

    for (current_node = &g_proc_array[g_busy_list_header->next_index];
         current_node != g_proc_array;
         current_node = &g_proc_array[current_node->next_index]) {
        ap_log_error(APLOG_MARK, APLOG_WARNING, 0, main_server,
                     "mod_fcgid: busy node index: %d",
                     current_node - g_proc_array);
    }

    for (current_node = &g_proc_array[g_error_list_header->next_index];
         current_node != g_proc_array;
         current_node = &g_proc_array[current_node->next_index]) {
        ap_log_error(APLOG_MARK, APLOG_WARNING, 0, main_server,
                     "mod_fcgid: error node index: %d",
                     current_node - g_proc_array);
    }
}