Fix wng_open error handling.
[paraslash.git] / audiod.c
index fcce8ae9dd1d87e7480412524b77cb5f5b97cbdf..68c84fb4df31bf54266643e709b40918bce53fb7 100644 (file)
--- a/audiod.c
+++ b/audiod.c
@@ -18,7 +18,6 @@
 
 /** \file audiod.c the paraslash's audio daemon */
 
-#include <sys/time.h> /* gettimeofday */
 #include "para.h"
 
 #include "audiod.cmdline.h"
@@ -36,6 +35,8 @@
 #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;
@@ -53,48 +54,43 @@ enum {AUDIOD_OFF, AUDIOD_ON, AUDIOD_STANDBY};
 
 /** defines how to handle one supported audio format */
 struct audio_format_info {
-/** pointer to the receiver for this audio format */
+       /** pointer to the receiver for this audio format */
        struct receiver *receiver;
-/** the receiver configuration */
+       /** the receiver configuration */
        void *receiver_conf;
-/** the number of filters that should be activated for this audio format */
+       /** 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 */
+       /** pointer to the array of filters to be activated */
        struct filter **filters;
-/** pointer to the array of filter configurations */
+       /** pointer to the array of filter configurations */
        void **filter_conf;
-/** output of the last filter is written to stdin of this command */
-       char *write_cmd;
-/** do not start receiver/filters/writer before this time */
+       /** 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;
 };
 
 /**
  * describes one instance of a receiver-filter-writer chain
  *
- * \sa receier_node, receiver, filter, filter_node, filter_chain_info
+ * \sa receier_node, receiver, filter, filter_node, filter_chain, writer,
+ * writer_node, writer_node_group.
   */
 struct slot_info {
        /** number of the audio format in this slot */
        int format;
-       /** the file descriptor of the writer */
-       int write_fd;
-       /** the process id of the writer */
-       pid_t wpid;
-       /** time of the last successful read from the receiver */
-       struct timeval rtime;
-       /** time the last write to the write fd happend */
-       struct timeval wtime;
        /** writer start time */
        struct timeval wstime;
-       /** did we include \a write_fd in the fdset */
-       int  wcheck;
-       /** set to one if we have sent the TERM signal to \a wpid */
-       int wkilled;
        /** the receiver info associated with this slot */
        struct receiver_node *receiver_node;
        /** the active filter chain */
        struct filter_chain *fc;
+       /** the active writer node group */
+       struct writer_node_group *wng;
 };
 static struct slot_info slot[MAX_STREAM_SLOTS];
 
@@ -109,30 +105,40 @@ static char *af_status, /* the audio format announced in server status */
        *socket_name, *hostname;
 static char *stat_item_values[NUM_STAT_ITEMS];
 static FILE *logfile;
-static const struct timeval restart_delay = {0, 300 * 1000};
-
+static const struct timeval restart_delay = {0, 200 * 1000};
 static struct audio_format_info afi[NUM_AUDIO_FORMATS];
+static struct timeval *now;
 
 static struct signal_task signal_task_struct, *sig_task = &signal_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;
 };
-static struct command_task command_task_struct, *cmd_task = &command_task_struct;
 
+/**
+ * the task for audiod's child (para_client stat)
+ *
+ * \sa struct task, struct sched
+ */
 struct status_task {
+       /** the output of the stat command is read from this fd */
        int fd;
-       struct task task;
+       /** stat data is stored here */
        char buf[STRINGSIZE];
+       /** number of bytes loaded in \a buf */
        unsigned loaded;
-};
-static struct status_task status_task_struct, *stat_task = &status_task_struct;
-
-struct audiod_task {
+       /** the associated task structure */
        struct task task;
 };
-static struct audiod_task audiod_task_struct, *at = &audiod_task_struct;
+static struct status_task status_task_struct, *stat_task = &status_task_struct;
 
 struct signal_task {
        int fd;
@@ -140,13 +146,17 @@ struct signal_task {
        struct task task;
 };
 
-
 /** defines one command of para_audiod */
 struct audiod_command {
        /** the name of the command */
        const char *name;
        /** pointer to the function that handles the command */
        int (*handler)(int, int, char**);
+       /**
+        * if the command prefers to handle the full line (rather than the usual
+        * argv[] array), it stores a pointer to the corresponding line handling
+        * function here. In this case, the above \a handler pointer must be NULL.
+        */
        int (*line_handler)(int, char*);
        /** one-line description of the command */
        const char *description;
@@ -314,7 +324,7 @@ static int client_write(int fd, const char *buf)
 
 static char *get_time_string(struct timeval *newest_stime)
 {
-       struct timeval now, diff, adj_stream_start, tmp;
+       struct timeval diff, adj_stream_start, tmp;
        int total = 0, use_server_time = 1;
 
        if (!playing) {
@@ -338,8 +348,7 @@ static char *get_time_string(struct timeval *newest_stime)
                        use_server_time = 0;
                }
        }
-       gettimeofday(&now, NULL);
-       tv_diff(&now, &tmp, &diff);
+       tv_diff(now, &tmp, &diff);
        total = diff.tv_sec + offset_seconds;
        if (total > length_seconds)
                total = length_seconds;
@@ -374,7 +383,7 @@ static struct timeval *wstime(void)
        struct timeval *max = NULL;
        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
-               if (s->wpid <= 0)
+               if (!s->wng)
                        continue;
                if (max && tv_diff(&s->wstime, max, NULL) <= 0)
                        continue;
@@ -392,7 +401,7 @@ __malloc static char *decoder_flags(void)
                char flag = '0';
                if (s->receiver_node)
                        flag += 1;
-               if (s->wpid > 0)
+               if (s->wng)
                        flag += 2;
                decoder_flags[i] = flag;
        }
@@ -465,29 +474,6 @@ static void clear_slot(int slot_num)
        s->format = -1;
 }
 
-static void kill_stream_writer(int slot_num)
-{
-       struct slot_info *s = &slot[slot_num];
-
-       if (s->format < 0 || s->wkilled || s->wpid <= 0)
-               return;
-       PARA_DEBUG_LOG("kill -TERM %d (%s stream writer in slot %d)\n",
-               s->wpid, audio_formats[s->format], slot_num);
-       kill(s->wpid, SIGTERM);
-       s->wkilled = 1;
-}
-
-static void set_restart_barrier(int format, struct timeval *now)
-{
-       struct timeval tmp;
-
-       if (now)
-               tmp = *now;
-       else
-               gettimeofday(&tmp, NULL);
-       tv_add(&tmp, &restart_delay, &afi[format].restart_barrier);
-}
-
 static void close_receiver(int slot_num)
 {
        struct slot_info *s = &slot[slot_num];
@@ -496,55 +482,40 @@ static void close_receiver(int slot_num)
        if (s->format < 0 || !s->receiver_node)
                return;
        a = &afi[s->format];
-       PARA_NOTICE_LOG("closing %s recevier in slot %d (eof = %d)\n",
+       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(s->format, 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)
-               if (slot[i].format >= 0) {
-                       PARA_INFO_LOG("stopping decoder in slot %d\n", i);
-                       kill_stream_writer(i);
-               }
-}
-
-static void check_sigchld(void)
-{
-       pid_t pid;
-       int i;
-       struct timeval now;
-       gettimeofday(&now, NULL);
-
-reap_next_child:
-       pid = para_reap_child();
-       if (pid <= 0)
-               return;
        FOR_EACH_SLOT(i) {
                struct slot_info *s = &slot[i];
-               long lifetime;
-               if (s->format < 0)
-                       continue;
-               if (pid == s->wpid) {
-                       s->wpid = -1;
-                       lifetime = now.tv_sec - s->wstime.tv_sec;
-                       PARA_INFO_LOG("%s stream writer in slot %d died "
-                               "after %li secs\n",
-                               audio_formats[s->format], i, lifetime);
-                       set_restart_barrier(s->format, &now);
-                       goto reap_next_child;
+               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;
                }
        }
-       PARA_CRIT_LOG("para_client died (pid %d)\n", pid);
-       goto reap_next_child;
 }
 
 static int get_empty_slot(void)
@@ -558,11 +529,7 @@ static int get_empty_slot(void)
                        clear_slot(i);
                        return i;
                }
-               if (s->write_fd > 0 || s->wpid > 0)
-                       continue;
-               if (s->receiver_node)
-                       continue;
-               if (s->fc)
+               if (s->wng || s->receiver_node || s->fc)
                        continue;
                clear_slot(i);
                return i;
@@ -579,7 +546,7 @@ static int decoder_running(int format)
                s = &slot[i];
                if (s->format == format && s->receiver_node)
                        ret |= 1;
-               if (s->format == format && s->wpid > 0)
+               if (s->format == format && s->wng)
                        ret |= 2;
        }
        return ret;
@@ -605,7 +572,8 @@ static void close_stat_pipe(void)
        offset_seconds = 0;
        audiod_status_dump();
        playing = 0;
-       stat_item_values[SI_STATUS_BAR] = make_message("%s:no connection to para_server\n",
+       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_item_values[SI_STATUS_BAR], SI_STATUS_BAR);
 }
@@ -613,7 +581,6 @@ static void close_stat_pipe(void)
 static void __noreturn clean_exit(int status, const char *msg)
 {
        PARA_EMERG_LOG("%s\n", msg);
-       kill_all_decoders();
        if (socket_name)
                unlink(socket_name);
        if (stat_task->fd >= 0)
@@ -621,38 +588,21 @@ static void __noreturn clean_exit(int status, const char *msg)
        exit(status);
 }
 
-__malloc static char *glob_cmd(char *cmd)
-{
-       char *ret, *replacement;
-       struct timeval tmp, delay, rss; /* real stream start */
-
-       delay.tv_sec = conf.stream_delay_arg / 1000;
-       delay.tv_usec = (conf.stream_delay_arg % 1000) * 1000;
-//     PARA_INFO_LOG("delay: %lu:%lu\n", delay.tv_sec, delay.tv_usec);
-       if (sa_time_diff_sign < 0)
-               tv_add(&server_stream_start, &sa_time_diff, &rss);
-       else
-               tv_diff(&server_stream_start, &sa_time_diff, &rss);
-       tv_add(&rss, &delay, &tmp);
-       replacement = make_message("%lu:%lu",
-               (long unsigned)tmp.tv_sec,
-               (long unsigned)tmp.tv_usec);
-       ret = s_a_r(cmd, "STREAM_START", replacement);
-       free(replacement);
-       if (!ret)
-               goto out;
-       PARA_INFO_LOG("cmd: %s, repl: %s\n", cmd, ret);
-out:
-       return ret;
-}
-
-/** get the number of filters for the given audio format */
+/**
+ * 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;
 }
 
-void filter_event_handler(struct task *t)
+static void filter_event_handler(struct task *t)
 {
        PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-t->ret));
        unregister_task(t);
@@ -664,23 +614,23 @@ static void open_filters(int slot_num)
        struct audio_format_info *a = &afi[s->format];
        int nf = a->num_filters;
        int i;
-       static int output_eof; /* FIXME */
 
-       s->fc = para_calloc(sizeof(struct filter_chain));
-       INIT_LIST_HEAD(&s->fc->filters);
+       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->output_eof = &output_eof;
-       output_eof = 0;
-
        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->task.flags = 0;
        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));
@@ -697,8 +647,6 @@ static void open_filters(int slot_num)
                s->fc->out_loaded = &fn->loaded;
        }
        register_task(&s->fc->task);
-//     PARA_DEBUG_LOG("output loaded for filter chain %p: %p\n", s->fc,
-//             s->fc->out_loaded);
 }
 
 static struct filter_node *find_filter_node(int slot_num, int format, int filternum)
@@ -726,40 +674,67 @@ static struct filter_node *find_filter_node(int slot_num, int format, int filter
        return NULL;
 }
 
-static void start_stream_writer(int slot_num)
+static void wng_event_handler(struct task *t)
 {
-       int ret, fds[3] = {1, -1, -1};
+       struct writer_node_group *wng = t->private_data;
+       int i;
+
+       wng_unregister(wng);
+       FOR_EACH_SLOT(i) {
+               struct slot_info *s = &slot[i];
+               if (s->wng != wng)
+                       continue;
+               PARA_INFO_LOG("slot %d: %s\n", i, PARA_STRERROR(-t->ret));
+       }
+}
+
+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];
-       char *glob = NULL;
-
-       if (a->write_cmd)
-               glob = glob_cmd(a->write_cmd);
-       if (!glob)
-               glob = para_strdup("para_write -w alsa");
-       PARA_INFO_LOG("starting stream writer: %s\n", glob);
-       open_filters(slot_num);
-       ret = para_exec_cmdline_pid(&s->wpid, glob, fds);
-       free(glob);
+
+       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];
+               sprintf(s->wng->writer_nodes[i].task.status, "writer_node");
+       }
+       ret = wng_open(s->wng);
        if (ret < 0) {
-               PARA_ERROR_LOG("exec failed (%d)\n", ret);
+               PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
                return;
        }
-       s->write_fd = fds[0];
-       add_close_on_fork_list(s->write_fd);
-       /* we write to this fd in do_select, so we need non-blocking */
-       mark_fd_nonblock(s->write_fd);
-       gettimeofday(&s->wstime, NULL);
+       s->wstime = *now;
        current_decoder = slot_num;
        activate_inactive_grab_clients(slot_num, s->format, &s->fc->filters);
 }
 
-void rn_event_handler(struct task *t)
+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);
 }
+
 static void open_receiver(int format)
 {
        struct audio_format_info *a = &afi[format];
@@ -772,8 +747,6 @@ static void open_receiver(int format)
                clean_exit(EXIT_FAILURE, PARA_STRERROR(-slot_num));
        s = &slot[slot_num];
        s->format = format;
-       gettimeofday(&s->rtime, NULL);
-       s->wtime = s->rtime;
        s->receiver_node = para_calloc(sizeof(struct receiver_node));
        rn = s->receiver_node;
        rn->receiver = a->receiver;
@@ -789,7 +762,6 @@ static void open_receiver(int format)
        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;
-       PARA_NOTICE_LOG("rn = %p\n", rn->task.private_data);
        rn->task.pre_select = a->receiver->pre_select;
        rn->task.post_select = a->receiver->post_select;
        rn->task.event_handler = rn_event_handler;
@@ -800,14 +772,12 @@ static void open_receiver(int format)
 
 static int is_frozen(int format)
 {
-       struct timeval now;
        struct audio_format_info *a = &afi[format];
 
-       gettimeofday(&now, NULL);
-       return (tv_diff(&now, &a->restart_barrier, NULL) > 0)? 0 : 1;
+       return (tv_diff(now, &a->restart_barrier, NULL) > 0)? 0 : 1;
 }
 
-static void start_current_receiver(void)
+static void open_current_receiver(void)
 {
        int i;
 
@@ -816,21 +786,20 @@ static void start_current_receiver(void)
        i = get_audio_format_num(af_status);
        if (i < 0)
                return;
-       if ((decoder_running(i) & 1) || is_frozen(i))
+       if (decoder_running(i) || is_frozen(i))
                return;
        open_receiver(i);
 }
 
 static void compute_time_diff(const struct timeval *status_time)
 {
-       struct timeval now, tmp, diff;
+       struct timeval tmp, diff;
        static int count;
        int sign;
        const struct timeval max_deviation = {0, 500 * 1000};
        const int time_smooth = 5;
 
-       gettimeofday(&now, NULL);
-       sign = tv_diff(status_time, &now, &diff);
+       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) {
@@ -851,7 +820,7 @@ static void compute_time_diff(const struct timeval *status_time)
                count > 10? sign : sign * time_smooth, &diff,
                &tmp);
        sa_time_diff = tmp;
-       PARA_INFO_LOG("time diff (cur/avg): %s%lums/%s%lums\n",
+       PARA_DEBUG_LOG("time diff (cur/avg): %s%lums/%s%lums\n",
                sign > 0? "+" : "-",
                tv2ms(&diff),
                sa_time_diff_sign ? "+" : "-",
@@ -913,7 +882,12 @@ static void handle_signal(int sig)
 {
        switch (sig) {
        case SIGCHLD:
-               return check_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:
@@ -923,184 +897,75 @@ static void handle_signal(int sig)
        }
 }
 
-static void check_timeouts(void)
-{
-       struct timeval now;
-       int slot_num, timeout = conf.stream_timeout_arg;
-
-       gettimeofday(&now, NULL);
-       FOR_EACH_SLOT(slot_num) {
-               struct slot_info *s = &slot[slot_num];
-               if (s->format < 0)
-                       continue;
-               /* check read time */
-               if (s->receiver_node &&
-                       now.tv_sec > s->rtime.tv_sec + timeout) {
-                       PARA_INFO_LOG("%s input buffer (slot %d) not ready\n",
-                               audio_formats[s->format], slot_num);
-                       s->receiver_node->eof = 1;
-               }
-               /* check write time */
-               if (s->wpid > 0 && !s->wkilled &&
-                       now.tv_sec > s->wtime.tv_sec + timeout) {
-                       PARA_INFO_LOG("%s output buffer (slot %d) not ready\n",
-                               audio_formats[s->format], slot_num);
-                       kill_stream_writer(slot_num);
-               }
-       }
-}
-
-static size_t get_loaded_bytes(int slot_num)
-{
-       size_t loaded = 0;
-       struct slot_info *s = &slot[slot_num];
-       struct receiver_node *rn = s->receiver_node;
-
-       if (s->format < 0)
-               goto out;
-
-       if (afi[s->format].num_filters) {
-               if (s->fc)
-                       loaded = *s->fc->out_loaded;
-       } else {
-               if (rn)
-                       loaded = rn->loaded;
-       }
-out:
-       return loaded;
-}
-
-static void close_writer(int slot_num)
-{
-       struct slot_info *s = &slot[slot_num];
-       if (s->write_fd > 0) {
-               PARA_INFO_LOG("slot %d: closing write fd %d\n", slot_num,
-                       s->write_fd);
-               close(s->write_fd);
-               del_close_on_fork_list(s->write_fd);
-               s->write_fd = -1;
-       }
-       if (s->fc)
-               *s->fc->output_eof = 1; /* FIXME */
-}
-
-
-static void close_decoder_if_idle(int slot_num)
+static void try_to_close_slot(int slot_num)
 {
        struct slot_info *s = &slot[slot_num];
-       struct receiver_node *rn = s->receiver_node;
 
        if (s->format < 0)
                return;
-       if (!s->fc)
+       if (s->receiver_node && !s->receiver_node->eof)
                return;
-       if (!rn->eof && !s->fc->eof && s->wpid > 0)
+       if (s->fc && !s->fc->eof)
                return;
-       if (!s->fc->eof && s->wpid > 0 && get_loaded_bytes(slot_num))
+       if (s->wng && !s->wng->eof)
                return;
-       close_writer(slot_num);
-       if (s->wpid > 0)
-               return; /* wait until writer dies before closing filters */
-       PARA_INFO_LOG("closing all filters in slot %d (filter_chain %p)\n",
-               slot_num, s->fc);
+       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);
 }
 
-static void audiod_pre_select(struct sched *s, struct task *t)
+static void audiod_pre_select(struct sched *s, __a_unused struct task *t)
 {
        int i;
 
+       t->ret = 1;
+       now = &s->now;
        if (audiod_status != AUDIOD_ON)
                kill_all_decoders();
        else if (playing)
-               start_current_receiver();
-       check_timeouts();
+               open_current_receiver();
        FOR_EACH_SLOT(i) {
+               struct slot_info *s = &slot[i];
                struct audio_format_info *a;
-               struct receiver_node *rn;
 
-               close_decoder_if_idle(i);
-               slot[i].wcheck = 0;
-               if (slot[i].format < 0)
+               try_to_close_slot(i);
+               if (s->format < 0)
                        continue;
-               a = &afi[slot[i].format];
-               rn = slot[i].receiver_node;
-               if (rn && rn->loaded && !slot[i].wpid) {
-                       PARA_INFO_LOG("no writer in slot %d\n", i);
-                       start_stream_writer(i);
-               }
-               if (slot[i].write_fd <= 0)
+               a = &afi[s->format];
+               if (!s->receiver_node)
                        continue;
-               if (!get_loaded_bytes(i))
+               if (!a->num_filters) {
+                       if (s->receiver_node->loaded && !s->wng)
+                               open_writers(i);
                        continue;
-               para_fd_set(slot[i].write_fd, &s->wfds, &s->max_fileno);
-               slot[i].wcheck = 1;
-       }
-}
-
-static int write_audio_data(int slot_num)
-{
-       struct slot_info *s = &slot[slot_num];
-       struct audio_format_info *a = &afi[s->format];
-       struct receiver_node *rn = s->receiver_node;
-       int ret;
-       char **buf;
-       size_t *len;
-
-       if (a->num_filters) {
-               buf = &s->fc->outbuf;
-               len = s->fc->out_loaded;
-       } else {
-               buf = &rn->buf;
-               len = &rn->loaded;
+               }
+               if (s->receiver_node->loaded && !s->fc) {
+                       open_filters(i);
+                       continue;
+               }
+               if (s->fc && *s->fc->out_loaded && !s->wng)
+                       open_writers(i);
        }
-       PARA_DEBUG_LOG("writing %p (%zd bytes)\n", *buf, *len);
-       ret = write(s->write_fd, *buf, *len);
-       PARA_DEBUG_LOG("wrote %d/%zd\n", ret, *len);
-       if (ret < 0) {
-               PARA_WARNING_LOG("write error in slot %d (fd %d): %s\n",
-                       slot_num, s->write_fd, strerror(errno));
-               *len = 0;
-               close_writer(slot_num);
-//             s->fc->error = E_WRITE_AUDIO_DATA;
-       } else if (ret != *len) {
-               PARA_DEBUG_LOG("partial %s write (%i/%zd) for slot %d\n",
-                       audio_formats[s->format], ret, *len, slot_num);
-               *len -= ret;
-               memmove(*buf, *buf + ret, *len);
-       } else
-               *len = 0;
-       if (ret > 0)
-               gettimeofday(&s->wtime, NULL);
-       return ret;
 }
 
-static void audiod_post_select(struct sched *s, struct task *t)
+static void audiod_post_select(struct sched *s, __a_unused struct task *t)
 {
-       int ret, i;
-
-       FOR_EACH_SLOT(i) {
-               struct receiver_node *rn = slot[i].receiver_node;
-
-               if (rn && rn->loaded)
-                       slot[i].rtime = s->now;
-               if (slot[i].write_fd <= 0 || !slot[i].wcheck
-                       || !FD_ISSET(slot[i].write_fd, &s->wfds))
-                       continue;
-               ret = write_audio_data(i);
-       }
+       /* only save away the current time for other users */
+       now = &s->now;
+       t->ret = 1;
 }
 
-static void init_audiod_task(struct audiod_task *at)
+static void init_audiod_task(struct task *t)
 {
-       at->task.pre_select = audiod_pre_select;
-       at->task.post_select = audiod_post_select;
-       at->task.private_data = at;
-       at->task.flags = 0;
-       sprintf(at->task.status, "audiod task");
+       t->pre_select = audiod_pre_select;
+       t->post_select = audiod_post_select;
+       t->event_handler = NULL;
+       t->private_data = t;
+       t->flags = 0;
+       sprintf(t->status, "audiod task");
 }
 
 static int parse_stream_command(const char *txt, char **cmd)
@@ -1135,53 +1000,51 @@ static int add_filter(int format, char *cmdline)
        return filter_num;
 }
 
-static int setup_default_filters(void)
+static int init_writers(void)
 {
-       int i, ret = 1;
+       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) {
-               struct audio_format_info *a = &afi[i];
-               char *tmp;
-               int j;
-               if (a->num_filters)
-                       continue;
-               /* 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);
+               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;
-               PARA_INFO_LOG("%s -> default filter: %s\n", audio_formats[i],
-                       filters[j].name);
-               ret = add_filter(i, "wav");
-               if (ret < 0)
+               a = &afi[ret];
+               nw = a->num_writers;
+               wconf = check_writer_arg(cmd, &writer_num);
+               if (!wconf) {
+                       ret = writer_num;
                        goto out;
-               PARA_INFO_LOG("%s -> default filter: wav\n", audio_formats[i]);
+               }
+               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_stream_io(void)
+static int init_receivers(void)
 {
-       int i, ret, receiver_num, nf;
-       char *cmd;
+       int i, ret, receiver_num;
+       char *cmd = NULL;
+       struct audio_format_info *a;
 
-       for (i = 0; i < conf.stream_write_cmd_given; i++) {
-               ret = parse_stream_command(conf.stream_write_cmd_arg[i], &cmd);
-               if (ret < 0)
-                       goto out;
-               afi[ret].write_cmd = para_strdup(cmd);
-               PARA_INFO_LOG("%s write command: %s\n", audio_formats[ret], afi[ret].write_cmd);
-       }
        for (i = 0; receivers[i].name; i++) {
                PARA_INFO_LOG("initializing %s receiver\n", receivers[i].name);
                receivers[i].init(&receivers[i]);
@@ -1210,7 +1073,7 @@ static int init_stream_io(void)
         */
        cmd = para_strdup(receivers[0].name);
        FOR_EACH_AUDIO_FORMAT(i) {
-               struct audio_format_info *a = &afi[i];
+               a = &afi[i];
                if (a->receiver_conf)
                        continue;
                a->receiver_conf = check_receiver_arg(cmd, &receiver_num);
@@ -1218,17 +1081,57 @@ static int init_stream_io(void)
                        return -E_RECV_SYNTAX;
                a->receiver = &receivers[receiver_num];
        }
+       ret = 1;
+out:
        free(cmd);
-       /* filters */
+       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(2,  conf.filter_given) + 1;
-       PARA_INFO_LOG("allocating space for %d filters\n", nf);
+       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(char *));
+               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 setup_default_filters();
+               return init_default_filters();
        for (i = 0; i < conf.filter_given; i++) {
                char *arg = conf.filter_arg[i];
                char *filter_name = strchr(arg, ':');
@@ -1244,11 +1147,27 @@ static int init_stream_io(void)
                if (ret < 0)
                        goto out;
        }
-       ret = 1;
+       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 dump_commands(int fd)
 {
        char *buf = para_strdup(""), *tmp = NULL;
@@ -1376,29 +1295,6 @@ out:
        return ret;
 }
 
-#if 0
-static char *list_filters(void)
-{
-       int i, j;
-       char *tmp, *msg = make_message("format\tnum\tcmd\n");
-
-       FOR_EACH_AUDIO_FORMAT(i) {
-               for (j = 0; j < afi[i].num_filters; j++) {
-                       tmp = make_message("%s\t%i\t%s\n",
-                               afi[i].name, j, afi[i].filter_cmds[j]);
-                       msg = para_strcat(msg, tmp);
-                       free(tmp);
-               }
-               tmp = make_message("%s\t%i\t%s\n", afi[i].name,
-                       j, afi[i].write_cmd);
-               msg = para_strcat(msg, tmp);
-               free(tmp);
-       }
-       return msg;
-}
-#endif
-
-
 static int com_grab(int fd, char *cmdline)
 {
        struct grab_client *gc;
@@ -1492,13 +1388,13 @@ static int check_perms(uid_t uid)
        return -E_UCRED_PERM;
 }
 
-static int handle_connect(void)
+static int handle_connect(int accept_fd)
 {
        int i, argc, ret, clifd = -1;
        char *cmd = NULL, *p, *buf = para_calloc(MAXLINE), **argv = NULL;
        struct sockaddr_un unix_addr;
 
-       ret = para_accept(cmd_task->fd, &unix_addr, sizeof(struct sockaddr_un));
+       ret = para_accept(accept_fd, &unix_addr, sizeof(struct sockaddr_un));
        if (ret < 0)
                goto out;
        clifd = ret;
@@ -1549,9 +1445,10 @@ out:
        return ret;
 }
 
-static void audiod_get_socket(void)
+static int audiod_get_socket(void)
 {
        struct sockaddr_un unix_addr;
+       int fd;
 
        if (conf.socket_given)
                socket_name = para_strdup(conf.socket_arg);
@@ -1561,20 +1458,21 @@ static void audiod_get_socket(void)
                        hn);
                free(hn);
        }
-       PARA_NOTICE_LOG("connecting to local socket %s\n", socket_name);
+       PARA_NOTICE_LOG("local socket: %s\n", socket_name);
        if (conf.force_given)
                unlink(socket_name);
-       cmd_task->fd = create_pf_socket(socket_name, &unix_addr,
+       fd = create_pf_socket(socket_name, &unix_addr,
                        S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IWOTH);
-       if (cmd_task->fd < 0) {
+       if (fd < 0) {
                PARA_EMERG_LOG("%s", "can not connect to socket\n");
                exit(EXIT_FAILURE); /* do not unlink socket */
        }
-       if (listen(cmd_task->fd , 5) < 0) {
+       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(cmd_task->fd);
+       add_close_on_fork_list(fd);
+       return fd;
 }
 
 static int open_stat_pipe(void)
@@ -1626,6 +1524,7 @@ void signal_setup_default(struct signal_task *st)
 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);
 
 }
@@ -1635,22 +1534,24 @@ 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();
-       t->ret = 1; /* always successful */
        if (!FD_ISSET(ct->fd, &s->rfds))
                return;
-       ret = handle_connect();
+       ret = handle_connect(ct->fd);
        if (ret < 0)
                PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
 }
 
-void init_command_task(struct command_task *ct)
+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->task.flags = 0;
+       ct->fd = audiod_get_socket(); /* doesn't return on errors */
        sprintf(ct->task.status, "command task");
 }
 
@@ -1682,7 +1583,7 @@ static void status_post_select(struct sched *s, struct task *t)
        if (ret <= 0) {
                close_stat_pipe();
                /* avoid busy loop if server is down */
-               while (sleep(1) > 0)
+               while (sleep(1) > 0) /* FIXME */
                        ; /* try again*/
        } else {
                st->buf[ret + st->loaded] = '\0';
@@ -1703,84 +1604,6 @@ static void init_status_task(struct status_task *st)
        sprintf(st->task.status, "status task");
 }
 
-
-
-#if 0
-/* TODO: move everything before the select call to pre_select() */
-static void __noreturn audiod_mainloop(void)
-{
-       fd_set rfds, wfds;
-       int ret, max_fileno, sbo = 0;
-       char status_buf[STRINGSIZE] = "";
-       struct timeval tv;
-
-
-
-repeat:
-       FD_ZERO(&wfds);
-       FD_ZERO(&rfds);
-       max_fileno = -1;
-       /* always check signal pipe and the local socket */
-       para_fd_set(signal_pipe, &rfds, &max_fileno);
-       para_fd_set(audiod_socket, &rfds, &max_fileno);
-
-       if (audiod_status != AUDIOD_ON)
-               kill_all_decoders();
-       else if (playing)
-               start_current_receiver();
-
-       set_stream_fds(&wfds, &max_fileno);
-       /* status pipe */
-       if (stat_pipe >= 0 && audiod_status == AUDIOD_OFF)
-               close_stat_pipe();
-       if (stat_pipe < 0 && audiod_status != AUDIOD_OFF) {
-               stat_pipe = open_stat_pipe();
-               sbo = 0;
-               status_buf[0] = '\0';
-       }
-       if (stat_pipe >= 0 && audiod_status != AUDIOD_OFF)
-               para_fd_set(stat_pipe, &rfds, &max_fileno);
-       /* local socket */
-       tv.tv_sec = 0;
-       tv.tv_usec = 200 * 1000;
-       audiod_pre_select(&rfds, &wfds, &tv, &max_fileno);
-       ret = para_select(max_fileno + 1, &rfds, &wfds, &tv);
-       if (ret < 0)
-               goto repeat;
-       if (audiod_status != AUDIOD_OFF)
-               audiod_status_dump();
-       audiod_post_select(ret, &rfds, &wfds);
-       /* read status pipe */
-       if (stat_pipe >=0 && FD_ISSET(stat_pipe, &rfds)) {
-               ret = read(stat_pipe, status_buf + sbo, STRINGSIZE - 1 - sbo);
-               if (ret <= 0) {
-                       close_stat_pipe();
-                       /* avoid busy loop if server is down */
-                       while (sleep(1) > 0)
-                               ; /* try again*/
-               } else {
-                       status_buf[ret + sbo] = '\0';
-                       sbo = for_each_line(status_buf, ret + sbo,
-                               &check_stat_line);
-               }
-       }
-       slot_io(&wfds);
-       if (FD_ISSET(audiod_socket, &rfds)) {
-               ret = handle_connect();
-               if (ret < 0) {
-                       PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
-               }
-       }
-       /* signals */
-       if (FD_ISSET(signal_pipe, &rfds)) {
-               int sig_nr = para_next_signal();
-               if (sig_nr > 0)
-                       handle_signal(sig_nr);
-       }
-       goto repeat;
-}
-#endif
-
 static void set_initial_status(void)
 {
        audiod_status = AUDIOD_ON;
@@ -1803,6 +1626,8 @@ 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();
 
@@ -1831,23 +1656,22 @@ int main(int argc, char *argv[])
                clear_slot(i);
        init_grabbing();
        setup_signal_handling();
-       if (conf.daemon_given)
-               daemon_init();
-       audiod_get_socket(); /* doesn't return on errors */
-
        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(at);
+       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(&at->task);
+       register_task(audiod_task);
        s.default_timeout.tv_sec = 0;
-       s.default_timeout.tv_usec = 999 * 1000;
+       s.default_timeout.tv_usec = 99 * 1000;
        ret = sched(&s);
 
        PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));