mpd/src/decoder_control.c
Max Kellermann 3888ef2f55 decoder_control: properly cancel an existing command in dc_stop()
When the decoder thread has a pending command, send the STOP command
to cancel this command.  Send STOP again if the decoder thread is
still running after that, just in case the decoder thread has executed
the previous command (which was overwritten).
2009-04-25 15:19:01 +02:00

125 lines
2.7 KiB
C

/*
* Copyright (C) 2003-2009 The Music Player Daemon Project
* http://www.musicpd.org
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "decoder_control.h"
#include <assert.h>
struct decoder_control dc;
void dc_init(void)
{
notify_init(&dc.notify);
dc.state = DECODE_STATE_STOP;
dc.command = DECODE_COMMAND_NONE;
}
void dc_deinit(void)
{
notify_deinit(&dc.notify);
}
void
dc_command_wait(struct notify *notify)
{
while (dc.command != DECODE_COMMAND_NONE) {
notify_signal(&dc.notify);
notify_wait(notify);
}
}
static void
dc_command(struct notify *notify, enum decoder_command cmd)
{
dc.command = cmd;
dc_command_wait(notify);
}
static void dc_command_async(enum decoder_command cmd)
{
dc.command = cmd;
notify_signal(&dc.notify);
}
void
dc_start(struct notify *notify, struct song *song)
{
assert(dc.pipe != NULL);
assert(song != NULL);
dc.next_song = song;
dc_command(notify, DECODE_COMMAND_START);
}
void
dc_start_async(struct song *song)
{
assert(dc.pipe != NULL);
assert(song != NULL);
dc.next_song = song;
dc_command_async(DECODE_COMMAND_START);
}
void
dc_stop(struct notify *notify)
{
if (dc.command != DECODE_COMMAND_NONE)
/* Attempt to cancel the current command. If it's too
late and the decoder thread is already executing
the old command, we'll call STOP again in this
function (see below). */
dc_command(notify, DECODE_COMMAND_STOP);
if (dc.state != DECODE_STATE_STOP && dc.state != DECODE_STATE_ERROR)
dc_command(notify, DECODE_COMMAND_STOP);
}
bool
dc_seek(struct notify *notify, double where)
{
assert(dc.state != DECODE_STATE_START);
assert(where >= 0.0);
if (dc.state == DECODE_STATE_STOP ||
dc.state == DECODE_STATE_ERROR || !dc.seekable)
return false;
dc.seek_where = where;
dc.seek_error = false;
dc_command(notify, DECODE_COMMAND_SEEK);
if (dc.seek_error)
return false;
return true;
}
void
dc_quit(void)
{
assert(dc.thread != NULL);
dc.quit = true;
dc_command_async(DECODE_COMMAND_STOP);
g_thread_join(dc.thread);
dc.thread = NULL;
}