Make local sockets world-readable.

[paraslash.git] / oss_write.c

diff --git a/oss_write.c b/oss_write.c
index d547acf7422e2437a2af0d74f706d477bea8c309..12cf8b69bef2a7a189425df8ed15604f5cf10220 100644 (file)
--- a/oss_write.c
+++ b/oss_write.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009-2014 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2009 Andre Noll <maan@tuebingen.mpg.de>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -8,7 +8,6 @@
 
 #include <regex.h>
 #include <sys/ioctl.h>
-#include <fcntl.h>
 #include <sys/soundcard.h>
 
 #include "para.h"
@@ -31,6 +30,29 @@ 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 +66,13 @@ 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 +87,7 @@ static void oss_close(struct writer_node *wn)
                return;
        close(powd->fd);
        free(powd);
+       set_sound_device_idle();
 }
 
 /*
@@ -123,7 +146,7 @@ static int oss_init(struct writer_node *wn, unsigned sample_rate,
         * Set sampling rate
         *
         * If we request a higher sampling rate than is supported by the
-        * device, the the highest possible speed is automatically used. The
+        * device, the highest possible speed is automatically used. The
         * value actually used is returned as the new value of the argument.
         */
        rate = sample_rate;
@@ -157,17 +180,17 @@ err_free:
        return ret;
 }
 
-static int 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);
@@ -175,12 +198,16 @@ static int 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;
+               set_sound_device_busy();
                return 0;
        }
        btr_merge(btrn, wn->min_iqs);
@@ -193,6 +220,15 @@ static int 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;