Quelle  thread.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
#include <linux/kthread.h>
#include <linux/wait.h>

#include "spk_types.h"
#include "speakup.h"
#include "spk_priv.h"

DECLARE_WAIT_QUEUE_HEAD(speakup_event);
EXPORT_SYMBOL_GPL(speakup_event);

int speakup_thread(void *data)
{
 unsigned long flags;
 int should_break;
 struct bleep our_sound;

 our_sound.active = 0;
 our_sound.freq = 0;
 our_sound.jiffies = 0;

 mutex_lock(&spk_mutex);
 while (1) {
  DEFINE_WAIT(wait);

  while (1) {
   spin_lock_irqsave(&speakup_info.spinlock, flags);
   our_sound = spk_unprocessed_sound;
   spk_unprocessed_sound.active = 0;
   prepare_to_wait(&speakup_event, &wait,
     TASK_INTERRUPTIBLE);
   should_break = kthread_should_stop() ||
    our_sound.active ||
    (synth && synth->catch_up && synth->alive &&
     (speakup_info.flushing ||
     !synth_buffer_empty()));
   spin_unlock_irqrestore(&speakup_info.spinlock, flags);
   if (should_break)
    break;
   mutex_unlock(&spk_mutex);
   schedule();
   mutex_lock(&spk_mutex);
  }
  finish_wait(&speakup_event, &wait);
  if (kthread_should_stop())
   break;

  if (our_sound.active)
   kd_mksound(our_sound.freq, our_sound.jiffies);
  if (synth && synth->catch_up && synth->alive) {
   /*
 * It is up to the callee to take the lock, so that it
 * can sleep whenever it likes
 */
   synth->catch_up(synth);
  }

  speakup_start_ttys();
 }
 mutex_unlock(&spk_mutex);
 return 0;
}