Merge branch 'refs/heads/t/kill_usleep'

[paraslash.git] / oss_write.c

diff --git a/oss_write.c b/oss_write.c
index 8ca3c525a664b3faf307d5c5d66c6886e7a3c8eb..35f7b6280115ec53bf88d5f2e303e34f8cc45d98 100644 (file)
--- a/oss_write.c
+++ b/oss_write.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009-2012 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2009-2014 Andre Noll <maan@tuebingen.mpg.de>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -31,6 +31,29 @@ struct private_oss_write_data {
        int bytes_per_frame;
 };
 
+/*
+ * We keep one bit of static storage to make sure only one instance of the oss
+ * writer is running at any given time.
+ */
+static bool sound_device_busy;
+
+static bool sound_device_is_busy(void)
+{
+       return sound_device_busy;
+}
+
+static void set_sound_device_busy(void)
+{
+       assert(!sound_device_busy);
+       sound_device_busy = true;
+}
+
+static void set_sound_device_idle(void)
+{
+       assert(sound_device_busy);
+       sound_device_busy = false;
+}
+
 static int get_oss_format(enum sample_format sf)
 {
        switch (sf) {
@@ -44,13 +67,13 @@ static int get_oss_format(enum sample_format sf)
        }
 }
 
-static void oss_pre_select(struct sched *s, struct task *t)
+static void oss_pre_select(struct sched *s, void *context)
 {
-       struct writer_node *wn = container_of(t, struct writer_node, task);
+       struct writer_node *wn = context;
        struct private_oss_write_data *powd = wn->private_data;
        int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
 
-       if (ret == 0)
+       if (ret == 0 || (sound_device_is_busy() && !powd))
                return;
        if (ret < 0 || !powd)
                return sched_min_delay(s);
@@ -65,6 +88,7 @@ static void oss_close(struct writer_node *wn)
                return;
        close(powd->fd);
        free(powd);
+       set_sound_device_idle();
 }
 
 /*
@@ -157,17 +181,17 @@ err_free:
        return ret;
 }
 
-static void oss_post_select(__a_unused struct sched *s,
-               struct task *t)
+static int oss_post_select(__a_unused struct sched *s, void *context)
 {
-       struct writer_node *wn = container_of(t, struct writer_node, task);
+       struct writer_node *wn = context;
        struct private_oss_write_data *powd = wn->private_data;
        struct btr_node *btrn = wn->btrn;
        size_t frames, bytes;
        int ret;
        char *data;
+       audio_buf_info abi;
 
-       ret = task_get_notification(t);
+       ret = task_get_notification(wn->task);
        if (ret < 0)
                goto out;
        ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
@@ -175,13 +199,17 @@ static void oss_post_select(__a_unused struct sched *s,
                goto out;
        if (!powd) {
                int32_t rate, ch, format;
+
+               if (sound_device_is_busy())
+                       return 0;
                get_btr_sample_rate(btrn, &rate);
                get_btr_channels(btrn, &ch);
                get_btr_sample_format(btrn, &format);
                ret = oss_init(wn, rate, ch, format);
                if (ret < 0)
                        goto out;
-               return;
+               set_sound_device_busy();
+               return 0;
        }
        btr_merge(btrn, wn->min_iqs);
        bytes = btr_next_buffer(btrn, &data);
@@ -193,15 +221,24 @@ static void oss_post_select(__a_unused struct sched *s,
        ret = 0;
        if (!FD_ISSET(powd->fd, &s->wfds))
                goto out;
+       /* get maximal number of bytes that can be written */
+       ret = ioctl(powd->fd, SNDCTL_DSP_GETOSPACE, &abi);
+       if (ret >= 0) {
+               size_t max_frames = abi.bytes / powd->bytes_per_frame;
+               if (max_frames == 0)
+                       goto out;
+               /* cap number of frames to avoid sound artefacts */
+               frames = PARA_MIN(frames, max_frames);
+       }
        ret = xwrite(powd->fd, data, frames * powd->bytes_per_frame);
        if (ret < 0)
                goto out;
        btr_consume(btrn, ret);
        ret = 0;
 out:
-       t->error = ret;
        if (ret < 0)
                btr_remove_node(&wn->btrn);
+       return ret;
 }
 
 __malloc static void *oss_parse_config_or_die(int argc, char **argv)
@@ -235,9 +272,6 @@ void oss_write_init(struct writer *w)
        w->post_select = oss_post_select;
        w->parse_config_or_die = oss_parse_config_or_die;
        w->free_config = oss_free_config;
-       w->help = (struct ggo_help) {
-               .short_help = oss_write_args_info_help,
-               .detailed_help = oss_write_args_info_detailed_help
-       };
+       w->help = (struct ggo_help)DEFINE_GGO_HELP(oss_write);
        oss_write_cmdline_parser_free(&dummy);
 }