[paraslash.git] / audiod.c

/*
 * Copyright (C) 2005-2006 Andre Noll <noll@mathematik.tu-darmstadt.de>
 *
 *     This program is free software; you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation; either version 2 of the License, or
 *     (at your option) any later version.
 *
 *     This program 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 this program; if not, write to the Free Software
 *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 */

/** \file audiod.c the paraslash's audio daemon */

#include "para.h"

#include "audiod.cmdline.h"
#include "list.h"
#include "close_on_fork.h"
#include "sched.h"
#include "recv.h"
#include "filter.h"
#include "grab_client.cmdline.h"
#include "grab_client.h"

#include "error.h"
#include "audiod.h"
#include "net.h"
#include "daemon.h"
#include "string.h"
#include "fd.h"
#include "write.h"
#include "write_common.h"

/** define the array of error lists needed by para_audiod */
INIT_AUDIOD_ERRLISTS;
/** define the array containing all supported audio formats */
DEFINE_AUDIO_FORMAT_ARRAY;

/** defines how to handle one supported audio format */
struct audio_format_info {
        /** pointer to the receiver for this audio format */
        struct receiver *receiver;
        /** the receiver configuration */
        void *receiver_conf;
        /** the number of filters that should be activated for this audio format */
        unsigned int num_filters;
        /** pointer to the array of filters to be activated */
        struct filter **filters;
        /** pointer to the array of filter configurations */
        void **filter_conf;
        /** the number of filters that should be activated for this audio format */
        unsigned int num_writers;
        /** pointer to the array of writers to be activated */
        struct writer **writers;
        /** pointer to the array of writer configurations */
        void **writer_conf;
        /** do not start receiver/filters/writer before this time */
        struct timeval restart_barrier;
};

struct slot_info slot[MAX_STREAM_SLOTS];


int audiod_status = AUDIOD_ON;

struct gengetopt_args_info conf;
static char *socket_name;
static FILE *logfile;
static struct audio_format_info afi[NUM_AUDIO_FORMATS];

static struct signal_task signal_task_struct, *sig_task = &signal_task_struct;

static struct status_task status_task_struct;
struct status_task *stat_task = &status_task_struct;

/**
 * the task for handling audiod commands
 *
 * \sa struct task, struct sched
 */
struct command_task {
        /** the local listening socket */
        int fd;
        /** the associated task structure */
        struct task task;
};

struct signal_task {
        int fd;
        int signum;
        struct task task;
};

/** iterate over all supported audio formats */
#define FOR_EACH_AUDIO_FORMAT(af) for (af = 0; af < NUM_AUDIO_FORMATS; af++)

/**
 * get the audio format number
 * \param name the name of the audio format
 *
 * \return The audio format number on success, -E_UNSUPPORTED_AUDIO_FORMAT if
 * \a name is not a supported audio format.
 */
int get_audio_format_num(char *name)
{
        int i;
        FOR_EACH_AUDIO_FORMAT(i)
                if (!strcmp(name, audio_formats[i]))
                        return i;
        return -E_UNSUPPORTED_AUDIO_FORMAT;
}

/*
 * log function. first argument is loglevel.
 */
void para_log(int ll, const char* fmt,...)
{
        va_list argp;
        FILE *outfd;
        struct tm *tm;
        time_t t1;
        char str[MAXLINE] = "";
        static char *hostname;

        if (ll < conf.loglevel_arg)
                return;
        if (!hostname)
                hostname = para_hostname();
        outfd = logfile? logfile : stderr;
        time(&t1);
        tm = localtime(&t1);
        strftime(str, MAXLINE, "%b %d %H:%M:%S", tm);
        fprintf(outfd, "%s %s ", str, hostname);
        if (conf.loglevel_arg <= INFO)
                fprintf(outfd, "%i ", ll);
        va_start(argp, fmt);
        vfprintf(outfd, fmt, argp);
        va_end(argp);
}

static char *configfile_exists(void)
{
        static char *config_file;

        if (!config_file) {
                char *home = para_homedir();
                config_file = make_message("%s/.paraslash/audiod.conf", home);
                free(home);
        }
        return file_exists(config_file)? config_file : NULL;
}

static void setup_signal_handling(void)
{
        sig_task->fd = para_signal_init();
        PARA_INFO_LOG("signal pipe: fd %d\n", sig_task->fd);
        para_install_sighandler(SIGINT);
        para_install_sighandler(SIGTERM);
        para_install_sighandler(SIGCHLD);
        para_install_sighandler(SIGHUP);
        para_install_sighandler(SIGPIPE);
//      signal(SIGPIPE, SIG_IGN);
}

static void clear_slot(int slot_num)
{
        struct slot_info *s = &slot[slot_num];

        PARA_INFO_LOG("clearing slot %d\n", slot_num);
        memset(s, 0, sizeof(struct slot_info));
        s->format = -1;
}

static void close_receiver(int slot_num)
{
        struct slot_info *s = &slot[slot_num];
        struct audio_format_info *a;
        const struct timeval restart_delay = {0, 200 * 1000};

        if (s->format < 0 || !s->receiver_node)
                return;
        a = &afi[s->format];
        PARA_NOTICE_LOG("closing %s receiver in slot %d (eof = %d)\n",
                audio_formats[s->format] , slot_num, s->receiver_node->eof);
//      if (!s->receiver_node->eof)
//              unregister_task(&s->receiver_node->task);
        a->receiver->close(s->receiver_node);
        free(s->receiver_node);
        s->receiver_node = NULL;
        /* set restart barrier */
        tv_add(now, &restart_delay, &afi[s->format].restart_barrier);
}

static void kill_all_decoders(void)
{
        int i;

        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
                if (s->wng && !s->wng->eof) {
                        PARA_INFO_LOG("unregistering writer node group in slot %d\n",
                                i);
                        wng_unregister(s->wng);
                        s->wng->eof = 1;
                }
                if (s->fc && !s->fc->eof) {
                        PARA_INFO_LOG("unregistering filter chain in slot %d\n", i);
                        unregister_task(&s->fc->task);
                        s->fc->eof = 1;
                }
                if (s->receiver_node && !s->receiver_node->eof) {
                        PARA_INFO_LOG("unregistering receiver_node in slot %d\n", i);
                        unregister_task(&s->receiver_node->task);
                        s->receiver_node->eof = 1;
                }
        }
}

static int get_empty_slot(void)
{
        int i;
        struct slot_info *s;

        FOR_EACH_SLOT(i) {
                s = &slot[i];
                if (s->format < 0) {
                        clear_slot(i);
                        return i;
                }
                if (s->wng || s->receiver_node || s->fc)
                        continue;
                clear_slot(i);
                return i;
        }
        return -E_NO_MORE_SLOTS;
}

static int decoder_running(int format)
{
        int i, ret = 0;
        struct slot_info *s;

        FOR_EACH_SLOT(i) {
                s = &slot[i];
                if (s->format == format && s->receiver_node)
                        ret |= 1;
                if (s->format == format && s->wng)
                        ret |= 2;
        }
        return ret;
}

static void close_stat_pipe(void)
{
        int i;

        if (stat_task->fd < 0)
                return;
        PARA_NOTICE_LOG("%s", "closing status pipe\n");
        close(stat_task->fd);
        del_close_on_fork_list(stat_task->fd);
        stat_task->fd = -1;
//      kill_all_decoders();
        for (i = 0; i < NUM_STAT_ITEMS; i++) {
                free(stat_task->stat_item_values[i]);
                stat_task->stat_item_values[i] = NULL;
        }
        dump_empty_status();
        stat_task->length_seconds = 0;
        stat_task->offset_seconds = 0;
        audiod_status_dump();
        stat_task->playing = 0;
        stat_task->stat_item_values[SI_STATUS_BAR] = make_message(
                "%s:no connection to para_server\n",
                status_item_list[SI_STATUS_BAR]);
        stat_client_write(stat_task->stat_item_values[SI_STATUS_BAR], SI_STATUS_BAR);
}

void __noreturn clean_exit(int status, const char *msg)
{
        PARA_EMERG_LOG("%s\n", msg);
        if (socket_name)
                unlink(socket_name);
        if (stat_task->fd >= 0)
                close_stat_pipe();
        exit(status);
}

/**
 * get the number of filters
 *
 * \param audio_format_num the number identifying the audio format
 *
 * \return the number of filters for the given audio format
 *
 * \sa struct filter;
 */
int num_filters(int audio_format_num)
{
        return afi[audio_format_num].num_filters;
}

static void filter_event_handler(struct task *t)
{
        PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-t->ret));
        struct filter_chain *fc = t->private_data;
        fc->eof = 1;
        unregister_task(t);
}

static void open_filters(int slot_num)
{
        struct slot_info *s = &slot[slot_num];
        struct audio_format_info *a = &afi[s->format];
        int nf = a->num_filters;
        int i;

        s->fc = NULL;
        if (!nf)
                return;
        PARA_INFO_LOG("opening %s filters\n", audio_formats[s->format]);
        s->fc = para_calloc(sizeof(struct filter_chain));
        INIT_LIST_HEAD(&s->fc->filters);
        s->fc->inbuf = s->receiver_node->buf;
        s->fc->in_loaded = &s->receiver_node->loaded;
        s->fc->input_eof = &s->receiver_node->eof;
        s->fc->task.pre_select = filter_pre_select;
        s->fc->task.event_handler = filter_event_handler;
        s->fc->task.private_data = s->fc;
        s->fc->eof = 0;

        s->receiver_node->output_eof = &s->fc->eof;
        sprintf(s->fc->task.status, "filter chain");
        for (i = 0; i < nf; i++) {
                struct filter_node *fn = para_calloc(sizeof(struct filter_node));
                fn->conf = a->filter_conf[i];
                fn->fc = s->fc;
                fn->filter = a->filters[i];
                INIT_LIST_HEAD(&fn->callbacks);
                list_add_tail(&fn->node, &s->fc->filters);
                fn->filter->open(fn);
                PARA_NOTICE_LOG("%s filter %d/%d (%s) started in slot %d\n",
                        audio_formats[s->format], i + 1,  nf,
                        fn->filter->name, slot_num);
                s->fc->outbuf = fn->buf;
                s->fc->out_loaded = &fn->loaded;
        }
        register_task(&s->fc->task);
}

static void wng_event_handler(struct task *t)
{
        struct writer_node_group *wng = t->private_data;

        PARA_INFO_LOG("%s\n", PARA_STRERROR(-t->ret));
        wng->eof = 1;
        wng_unregister(wng);
}

static void open_writers(int slot_num)
{
        int ret, i;
        struct slot_info *s = &slot[slot_num];
        struct audio_format_info *a = &afi[s->format];

        PARA_INFO_LOG("opening %s writers\n", audio_formats[s->format]);
        if (!a->num_writers)
                s->wng = setup_default_wng();
        else
                s->wng = wng_new(a->num_writers);
        if (s->fc) {
                s->wng->buf = s->fc->outbuf;
                s->wng->loaded = s->fc->out_loaded;
                s->wng->input_eof = &s->fc->eof;
                s->wng->channels = &s->fc->channels;
                s->wng->samplerate = &s->fc->samplerate;
                s->fc->output_eof = &s->wng->eof;
                PARA_INFO_LOG("samplerate: %d\n", *s->wng->samplerate);
        } else {
                s->wng->buf = s->receiver_node->buf;
                s->wng->loaded = &s->receiver_node->loaded;
                s->wng->input_eof = &s->receiver_node->eof;
        }
        s->wng->task.event_handler = wng_event_handler;
        for (i = 0; i < a->num_writers; i++) {
                s->wng->writer_nodes[i].conf = a->writer_conf[i];
                s->wng->writer_nodes[i].writer = a->writers[i];
        }
        ret = wng_open(s->wng);
        if (ret < 0) {
                PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
                return;
        }
        s->wstime = *now;
        activate_inactive_grab_clients(slot_num, s->format, &s->fc->filters);
}

static void rn_event_handler(struct task *t)
{
        struct receiver_node *rn = t->private_data;

        PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-t->ret));
        unregister_task(t);
        rn->eof = 1;
}

static void open_receiver(int format)
{
        struct audio_format_info *a = &afi[format];
        struct slot_info *s;
        int ret, slot_num;
        struct receiver_node *rn;

        slot_num = get_empty_slot();
        if (slot_num < 0)
                clean_exit(EXIT_FAILURE, PARA_STRERROR(-slot_num));
        s = &slot[slot_num];
        s->format = format;
        s->receiver_node = para_calloc(sizeof(struct receiver_node));
        rn = s->receiver_node;
        rn->receiver = a->receiver;
        rn->conf = a->receiver_conf;
        ret = a->receiver->open(s->receiver_node);
        if (ret < 0) {
                PARA_ERROR_LOG("failed to open receiver (%s)\n",
                        PARA_STRERROR(-ret));
                free(s->receiver_node);
                s->receiver_node = NULL;
                return;
        }
        PARA_NOTICE_LOG("started %s: %s receiver in slot %d\n",
                audio_formats[s->format], a->receiver->name, slot_num);
        rn->task.private_data = s->receiver_node;
        rn->task.pre_select = a->receiver->pre_select;
        rn->task.post_select = a->receiver->post_select;
        rn->task.event_handler = rn_event_handler;
        sprintf(rn->task.status, "%s receiver node", rn->receiver->name);
        register_task(&rn->task);
}

static int open_current_receiver(struct sched *s)
{
        int i;
        struct timeval diff;

        if (!stat_task->af_status)
                return 0;
        i = get_audio_format_num(stat_task->af_status);
        if (i < 0)
                return 0;
        if (decoder_running(i))
                return 0;
        if (tv_diff(now, &afi[i].restart_barrier, &diff) < 0) {
                s->timeout = diff;
                return 0;
        }
        open_receiver(i);
        return 1;
}

static void compute_time_diff(const struct timeval *status_time)
{
        struct timeval tmp, diff;
        static int count;
        int sign, sa_time_diff_sign = stat_task->sa_time_diff_sign;
        const struct timeval max_deviation = {0, 500 * 1000};
        const int time_smooth = 5;

        sign = tv_diff(status_time, now, &diff);
//              PARA_NOTICE_LOG("%s: sign = %i, sa_time_diff_sign = %i\n", __func__,
//                      sign, sa_time_diff_sign);
        if (!count) {
                sa_time_diff_sign = sign;
                stat_task->sa_time_diff = diff;
                count++;
                return;
        }
        if (count > 5) {
                int s = tv_diff(&diff, &stat_task->sa_time_diff, &tmp);
                if (tv_diff(&max_deviation, &tmp, NULL) < 0)
                        PARA_WARNING_LOG("time diff jump: %lims\n",
                                s * tv2ms(&tmp));
        }
        count++;
        sa_time_diff_sign = tv_convex_combination(
                sa_time_diff_sign * time_smooth, &stat_task->sa_time_diff,
                count > 10? sign : sign * time_smooth, &diff,
                &tmp);
        stat_task->sa_time_diff = tmp;
        PARA_DEBUG_LOG("time diff (cur/avg): %s%lums/%s%lums\n",
                sign > 0? "+" : "-",
                tv2ms(&diff),
                sa_time_diff_sign ? "+" : "-",
                tv2ms(&stat_task->sa_time_diff)
        );
}

static void check_stat_line(char *line)
{
        int itemnum;
        size_t ilen = 0;
        long unsigned sec, usec;
        char *tmp;

//      PARA_INFO_LOG("line: %s\n", line);
        if (!line)
                return;
        itemnum = stat_line_valid(line);
        if (itemnum < 0) {
                PARA_WARNING_LOG("invalid status line: %s\n", line);
                return;
        }
        tmp = make_message("%s\n", line);
        stat_client_write(tmp, itemnum);
        free(tmp);
        free(stat_task->stat_item_values[itemnum]);
        stat_task->stat_item_values[itemnum] = para_strdup(line);
        ilen = strlen(status_item_list[itemnum]);
        switch (itemnum) {
        case SI_STATUS:
                stat_task->playing = strstr(line, "playing")? 1 : 0;
                break;
        case SI_FORMAT:
                free(stat_task->af_status);
                stat_task->af_status = para_strdup(line + ilen + 1);
                break;
        case SI_OFFSET:
                stat_task->offset_seconds = atoi(line + ilen + 1);
                break;
        case SI_LENGTH:
                stat_task->length_seconds = atoi(line + ilen + 1);
                break;
        case SI_STREAM_START:
                if (sscanf(line + ilen + 1, "%lu.%lu", &sec, &usec) == 2) {
                        stat_task->server_stream_start.tv_sec = sec;
                        stat_task->server_stream_start.tv_usec = usec;
                }
                break;
        case SI_CURRENT_TIME:
                if (sscanf(line + ilen + 1, "%lu.%lu", &sec, &usec) == 2) {
                        struct timeval tv = {sec, usec};
                        compute_time_diff(&tv);
                }
                break;
        }
}

static void handle_signal(int sig)
{
        switch (sig) {
        case SIGCHLD:
                for (;;) {
                        pid_t pid = para_reap_child();
                        if (pid <= 0)
                                return;
                        PARA_CRIT_LOG("para_client died (pid %d)\n", pid);
                }
        case SIGINT:
        case SIGTERM:
        case SIGHUP:
                PARA_EMERG_LOG("terminating on signal %d\n", sig);
                clean_exit(EXIT_FAILURE, "caught deadly signal");
                return;
        }
}

static void try_to_close_slot(int slot_num)
{
        struct slot_info *s = &slot[slot_num];

        if (s->format < 0)
                return;
        if (s->receiver_node && !s->receiver_node->eof)
                return;
        if (s->fc && !s->fc->eof)
                return;
        if (s->wng && !s->wng->eof)
                return;
        PARA_INFO_LOG("closing slot %d \n", slot_num);
        wng_close(s->wng);
        close_filters(s->fc);
        free(s->fc);
        close_receiver(slot_num);
        clear_slot(slot_num);
}

/*
 * Check if any receivers/filters/writers need to be started and do so if
 * neccessary.  Since the pre_select function didn't have a chance yet to put
 * file descriptors into the fd sets given by s, make the upcoming select()
 * return immediately to avoid a long timeout in case we started something.
 */
static void audiod_pre_select(struct sched *s, __a_unused struct task *t)
{
        int i;
        struct timeval min_delay = {0, 1};

        t->ret = 1;
        if (audiod_status != AUDIOD_ON || !stat_task->playing)
                return kill_all_decoders();
        if (open_current_receiver(s))
                s->timeout = min_delay;
        FOR_EACH_SLOT(i) {
                struct slot_info *sl = &slot[i];
                struct audio_format_info *a;

                if (sl->format < 0)
                        continue;
                a = &afi[sl->format];
                if (!sl->receiver_node)
                        continue;
                if (!a->num_filters) {
                        if (sl->receiver_node->loaded && !sl->wng) {
                                open_writers(i);
                                s->timeout = min_delay;
                        }
                        continue;
                }
                if (sl->receiver_node->loaded && !sl->fc) {
                        open_filters(i);
                        s->timeout = min_delay;
                        continue;
                }
                if (sl->fc && *sl->fc->out_loaded && !sl->wng) {
                        open_writers(i);
                        s->timeout = min_delay;
                }
        }
}

static void audiod_post_select(__a_unused struct sched *s,
        __a_unused struct task *t)
{
        int i;

        /* save away the current time for other users */
        t->ret = 1;
        FOR_EACH_SLOT(i)
                try_to_close_slot(i);
}

static void init_audiod_task(struct task *t)
{
        t->pre_select = audiod_pre_select;
        t->post_select = audiod_post_select;
        t->event_handler = NULL;
        t->private_data = t;
        sprintf(t->status, "audiod task");
}

static int parse_stream_command(const char *txt, char **cmd)
{
        char *p = strchr(txt, ':');
        int i;

        if (!p)
                return -E_MISSING_COLON;
        p++;
        FOR_EACH_AUDIO_FORMAT(i) {
                if (strncmp(txt, audio_formats[i], strlen(audio_formats[i])))
                        continue;
                *cmd = p;
                return i;
        }
        return -E_UNSUPPORTED_AUDIO_FORMAT;
}

static int add_filter(int format, char *cmdline)
{
        struct audio_format_info *a = &afi[format];
        int filter_num, nf = a->num_filters;

        filter_num = check_filter_arg(cmdline, &a->filter_conf[nf]);
        if (filter_num < 0)
                return filter_num;
        a->filters[nf] = &filters[filter_num];
        a->num_filters++;
        PARA_INFO_LOG("%s filter %d: %s\n", audio_formats[format], nf + 1,
                a->filters[nf]->name);
        return filter_num;
}

static int init_writers(void)
{
        int i, ret, nw;
        char *cmd;
        struct audio_format_info *a;

        init_supported_writers();
        nw = PARA_MAX(1, conf.writer_given);
        PARA_INFO_LOG("maximal number of writers: %d\n", nw);
        FOR_EACH_AUDIO_FORMAT(i) {
                a = &afi[i];
                a->writer_conf = para_malloc(nw * sizeof(void *));
                a->writers = para_malloc(nw * sizeof(struct writer *));
                a->num_writers = 0;
        }
        for (i = 0; i < conf.writer_given; i++) {
                void *wconf;
                int writer_num;
                ret = parse_stream_command(conf.writer_arg[i], &cmd);
                if (ret < 0)
                        goto out;
                a = &afi[ret];
                nw = a->num_writers;
                wconf = check_writer_arg(cmd, &writer_num);
                if (!wconf) {
                        ret = writer_num;
                        goto out;
                }
                a->writers[nw] = &writers[writer_num];
                a->writer_conf[nw] = wconf;
                PARA_INFO_LOG("%s writer #%d: %s\n", audio_formats[ret],
                        nw, writer_names[writer_num]);
                a->num_writers++;
        }
        ret = 1;
out:
        return ret;
}

static int init_receivers(void)
{
        int i, ret, receiver_num;
        char *cmd = NULL;
        struct audio_format_info *a;

        for (i = 0; receivers[i].name; i++) {
                PARA_INFO_LOG("initializing %s receiver\n", receivers[i].name);
                receivers[i].init(&receivers[i]);
        }
        for (i = 0; i < conf.receiver_given; i++) {
                char *arg = conf.receiver_arg[i];
                char *recv = strchr(arg, ':');
                ret = -E_MISSING_COLON;
                if (!recv)
                        goto out;
                *recv = '\0';
                recv++;
                ret = get_audio_format_num(arg);
                if (ret < 0)
                        goto out;
                afi[ret].receiver_conf = check_receiver_arg(recv, &receiver_num);
                if (!afi[ret].receiver_conf) {
                        ret = -E_RECV_SYNTAX;
                        goto out;
                }
                afi[ret].receiver = &receivers[receiver_num];
        }
        /* use the first available receiver with no arguments
         * for those audio formats for which no receiver
         * was specified
         */
        cmd = para_strdup(receivers[0].name);
        FOR_EACH_AUDIO_FORMAT(i) {
                a = &afi[i];
                if (a->receiver_conf)
                        continue;
                a->receiver_conf = check_receiver_arg(cmd, &receiver_num);
                if (!a->receiver_conf)
                        return -E_RECV_SYNTAX;
                a->receiver = &receivers[receiver_num];
        }
        ret = 1;
out:
        free(cmd);
        return ret;
}

static int init_default_filters(void)
{
        int i, ret = 1;

        FOR_EACH_AUDIO_FORMAT(i) {
                struct audio_format_info *a = &afi[i];
                char *tmp;
                int j;

                if (a->num_filters)
                        continue; /* no default -- nothing to to */
                /* add "dec" to audio format name */
                tmp = make_message("%sdec", audio_formats[i]);
                for (j = 0; filters[j].name; j++)
                        if (!strcmp(tmp, filters[j].name))
                                break;
                free(tmp);
                ret = -E_UNSUPPORTED_FILTER;
                if (!filters[j].name)
                        goto out;
                tmp = para_strdup(filters[j].name);
                ret = add_filter(i, tmp);
                free(tmp);
                if (ret < 0)
                        goto out;
                PARA_INFO_LOG("%s -> default filter: %s\n", audio_formats[i],
                        filters[j].name);
        }
out:
        return ret;
}

static int init_filters(void)
{
        int i, ret, nf;

        filter_init(filters);
        nf = PARA_MAX(1,  conf.filter_given);
        PARA_INFO_LOG("maximal number of filters: %d\n", nf);
        FOR_EACH_AUDIO_FORMAT(i) {
                afi[i].filter_conf = para_malloc(nf * sizeof(void *));
                afi[i].filters = para_malloc(nf * sizeof(struct filter *));
        }
        if (!conf.no_default_filters_given)
                return init_default_filters();
        for (i = 0; i < conf.filter_given; i++) {
                char *arg = conf.filter_arg[i];
                char *filter_name = strchr(arg, ':');
                ret = -E_MISSING_COLON;
                if (!filter_name)
                        goto out;
                *filter_name = '\0';
                filter_name++;
                ret = get_audio_format_num(arg);
                if (ret < 0)
                        goto out;
                ret = add_filter(ret, filter_name);
                if (ret < 0)
                        goto out;
        }
        ret = init_default_filters(); /* use default values for the rest */
out:
        return ret;
}

static int init_stream_io(void)
{
        int ret;

        ret = init_writers();
        if (ret < 0)
                return ret;
        ret = init_receivers();
        if (ret < 0)
                return ret;
        ret = init_filters();
        if (ret < 0)
                return ret;
        return 1;
}

static int audiod_get_socket(void)
{
        struct sockaddr_un unix_addr;
        int fd;

        if (conf.socket_given)
                socket_name = para_strdup(conf.socket_arg);
        else {
                char *hn = para_hostname();
                socket_name = make_message("/var/paraslash/audiod_socket.%s",
                        hn);
                free(hn);
        }
        PARA_NOTICE_LOG("local socket: %s\n", socket_name);
        if (conf.force_given)
                unlink(socket_name);
        fd = create_pf_socket(socket_name, &unix_addr,
                        S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
        if (fd < 0) {
                PARA_EMERG_LOG("%s", "can not connect to socket\n");
                exit(EXIT_FAILURE); /* do not unlink socket */
        }
        if (listen(fd , 5) < 0) {
                PARA_EMERG_LOG("%s", "can not listen on socket\n");
                exit(EXIT_FAILURE); /* do not unlink socket */
        }
        add_close_on_fork_list(fd);
        return fd;
}

static int open_stat_pipe(void)
{
        int ret, fd[3] = {-1, 1, 0};
        pid_t pid;
        ret = para_exec_cmdline_pid(&pid, BINDIR "/para_client stat", fd);
        if (ret >= 0) {
                ret = fd[1];
                PARA_NOTICE_LOG("stat pipe opened, fd %d\n", ret);
                add_close_on_fork_list(ret);
        } else
                clean_exit(EXIT_FAILURE, "failed to open status pipe");
        return ret;
}

void signal_event_handler(struct task *t)
{
        struct signal_task *st = t->private_data;

        if (t->ret != -E_SIGNAL_CAUGHT)
                PARA_ERROR_LOG("%s (ignored)\n", PARA_STRERROR(-t->ret));
        else
                handle_signal(st->signum);
}

void signal_pre_select(struct sched *s, struct task *t)
{
        struct signal_task *st = t->private_data;
        t->ret = 1;
        para_fd_set(st->fd, &s->rfds, &s->max_fileno);
}

void signal_post_select(struct sched *s, struct task *t)
{
        struct signal_task *st = t->private_data;
        t->ret = 1;
        if (!FD_ISSET(st->fd, &s->rfds))
                return;
        t->ret = -E_SIGNAL_CAUGHT;
        st->signum = para_next_signal();
}

void signal_setup_default(struct signal_task *st)
{
        st->task.pre_select = signal_pre_select;
        st->task.post_select = signal_post_select;
        st->task.private_data = st;
        sprintf(st->task.status, "signal task");
}

static void command_pre_select(struct sched *s, struct task *t)
{
        struct command_task *ct = t->private_data;
        t->ret = 1;
        para_fd_set(ct->fd, &s->rfds, &s->max_fileno);

}

static void command_post_select(struct sched *s, struct task *t)
{
        int ret;
        struct command_task *ct = t->private_data;

        t->ret = 1; /* always successful */
        if (audiod_status != AUDIOD_OFF)
                audiod_status_dump();
        if (!FD_ISSET(ct->fd, &s->rfds))
                return;
        ret = handle_connect(ct->fd);
        if (ret < 0)
                PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
}

static void init_command_task(struct command_task *ct)
{
        ct->task.pre_select = command_pre_select;
        ct->task.post_select = command_post_select;
        ct->task.event_handler = NULL;
        ct->task.private_data = ct;
        ct->fd = audiod_get_socket(); /* doesn't return on errors */
        sprintf(ct->task.status, "command task");
}

static void status_event_handler(__a_unused struct task *t)
{
        struct timeval delay = {1, 0};
        int i;
        struct status_task *st = t->private_data;

        PARA_ERROR_LOG("%s\n", PARA_STRERROR(-t->ret));
        close_stat_pipe();
        /* avoid busy loop if server is down */
        tv_add(now, &delay, &st->restart_barrier);
        FOR_EACH_AUDIO_FORMAT(i)
                afi[i].restart_barrier = st->restart_barrier;
}

static void status_pre_select(struct sched *s, struct task *t)
{
        struct status_task *st = t->private_data;
        t->ret = 1;
        if (st->fd >= 0 && audiod_status == AUDIOD_OFF)
                close_stat_pipe();
        if (st->fd < 0 && audiod_status != AUDIOD_OFF
                && tv_diff(now, &st->restart_barrier, NULL) > 0) {
                st->fd = open_stat_pipe();
                st->loaded = 0;
                st->buf[0] = '\0';
        }
        if (st->fd >= 0 && audiod_status != AUDIOD_OFF)
                para_fd_set(st->fd, &s->rfds, &s->max_fileno);
}

static void status_post_select(struct sched *s, struct task *t)
{
        struct status_task *st = t->private_data;

        t->ret = 1;
        if (st->fd < 0 || !FD_ISSET(st->fd, &s->rfds))
                return;
        t->ret = read(st->fd, st->buf + st->loaded, STRINGSIZE - 1 - st->loaded);
        if (t->ret <= 0) {
                if (!t->ret)
                        t->ret = -E_STATUS_EOF;
                return;
        }
        st->buf[t->ret + st->loaded] = '\0';
        st->loaded = for_each_line(st->buf, t->ret + st->loaded,
                &check_stat_line);
}

static void init_status_task(struct status_task *st)
{
        memset(st, 0, sizeof(struct status_task));
        st->task.pre_select = status_pre_select;
        st->task.post_select = status_post_select;
        st->task.event_handler = status_event_handler;
        st->task.private_data = st;
        st->fd = -1;
        st->sa_time_diff_sign = 1;
        sprintf(st->task.status, "status task");
}

static void set_initial_status(void)
{
        audiod_status = AUDIOD_ON;
        if (!conf.mode_given)
                return;
        if (!strcmp(conf.mode_arg, "sb")) {
                audiod_status = AUDIOD_STANDBY;
                return;
        }
        if (!strcmp(conf.mode_arg, "off")) {
                audiod_status = AUDIOD_OFF;
                return;
        }
        if (strcmp(conf.mode_arg, "on"))
                PARA_WARNING_LOG("%s", "invalid mode\n");
}

int main(int argc, char *argv[])
{
        char *cf;
        int ret, i;
        struct sched s;
        struct command_task command_task_struct, *cmd_task = &command_task_struct;
        struct task audiod_task_struct, *audiod_task = &audiod_task_struct;

        init_sched();

        valid_fd_012();
        cmdline_parser(argc, argv, &conf);
        para_drop_privileges(conf.user_arg, conf.group_arg);
        cf = configfile_exists();
        if (cf) {
                if (cmdline_parser_configfile(cf, &conf, 0, 0, 0)) {
                        PARA_EMERG_LOG("%s", "parse error in config file\n");
                        exit(EXIT_FAILURE);
                }
        }
        if (conf.logfile_given)
                logfile = open_log(conf.logfile_arg);
        log_welcome("para_audiod", conf.loglevel_arg);
        i = init_stream_io();
        if (i < 0) {
                PARA_EMERG_LOG("init stream io error: %s\n", PARA_STRERROR(-i));
                exit(EXIT_FAILURE);
        }
        server_uptime(UPTIME_SET);
        set_initial_status();
        FOR_EACH_SLOT(i)
                clear_slot(i);
        init_grabbing();
        setup_signal_handling();
        signal_setup_default(sig_task);
        sig_task->task.event_handler = signal_event_handler;

        init_status_task(stat_task);
        init_command_task(cmd_task);
        init_audiod_task(audiod_task);

        if (conf.daemon_given)
                daemon_init();

        register_task(&sig_task->task);
        register_task(&cmd_task->task);
        register_task(&stat_task->task);
        register_task(audiod_task);
        s.default_timeout.tv_sec = 3;
        s.default_timeout.tv_usec = 99 * 1000;
        ret = sched(&s);

        PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
        return EXIT_FAILURE;
}