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-rw-r--r--src/main_notify.c130
1 files changed, 130 insertions, 0 deletions
diff --git a/src/main_notify.c b/src/main_notify.c
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index 000000000..bb5db8259
--- /dev/null
+++ b/src/main_notify.c
@@ -0,0 +1,130 @@
+/* the Music Player Daemon (MPD)
+ * Copyright (C) 2003-2007 Warren Dukes <warren.dukes@gmail.com>
+ * Copyright (C) 2008 Eric Wong <normalperson@yhbt.net>
+ *
+ * This project's homepage is: 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "main_notify.h"
+#include "notify.h"
+#include "utils.h"
+#include "ioops.h"
+#include "gcc.h"
+#include "log.h"
+
+static struct ioOps main_notify_IO;
+static int main_pipe[2];
+static pthread_t main_task;
+static pthread_cond_t main_wakeup = PTHREAD_COND_INITIALIZER;
+static pthread_mutex_t main_wakeup_mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_mutex_t select_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+static int ioops_fdset(fd_set * rfds,
+ mpd_unused fd_set * wfds, mpd_unused fd_set * efds)
+{
+ FD_SET(main_pipe[0], rfds);
+ return main_pipe[0];
+}
+
+static void consume_pipe(void)
+{
+ char buffer[2];
+ ssize_t r = read(main_pipe[0], buffer, sizeof(buffer));
+
+ if (r < 0 && errno != EAGAIN && errno != EINTR)
+ FATAL("error reading from pipe: %s\n", strerror(errno));
+}
+
+static int ioops_consume(int fd_count, fd_set * rfds,
+ mpd_unused fd_set * wfds, mpd_unused fd_set * efds)
+{
+ if (FD_ISSET(main_pipe[0], rfds)) {
+ consume_pipe();
+ FD_CLR(main_pipe[0], rfds);
+ fd_count--;
+ }
+ return fd_count;
+}
+
+void init_main_notify(void)
+{
+ if (pipe(main_pipe) < 0)
+ FATAL("Couldn't open pipe: %s", strerror(errno));
+ if (set_nonblocking(main_pipe[0]) < 0)
+ FATAL("Couldn't set non-blocking on main_notify fd: %s",
+ strerror(errno));
+ if (set_nonblocking(main_pipe[1]) < 0)
+ FATAL("Couldn't set non-blocking on main_notify fd: %s",
+ strerror(errno));
+ main_notify_IO.fdset = ioops_fdset;
+ main_notify_IO.consume = ioops_consume;
+ registerIO(&main_notify_IO);
+ main_task = pthread_self();
+}
+
+static int wakeup_via_pipe(void)
+{
+ int ret = pthread_mutex_trylock(&select_mutex);
+ if (ret == EBUSY) {
+ ssize_t w = write(main_pipe[1], "", 1);
+ if (w < 0 && errno != EAGAIN && errno != EINTR)
+ FATAL("error writing to pipe: %s\n",
+ strerror(errno));
+ return 1;
+ } else {
+ pthread_mutex_unlock(&select_mutex);
+ return 0;
+ }
+}
+
+static void wakeup_via_cond(void)
+{
+ int ret = pthread_mutex_trylock(&main_wakeup_mutex);
+
+ if (ret == EBUSY)
+ return; /* nope, no need to wakeup at all */
+ pthread_cond_broadcast(&main_wakeup);
+ pthread_mutex_unlock(&main_wakeup_mutex);
+}
+
+void wakeup_main_task(void)
+{
+ assert(!pthread_equal(main_task, pthread_self()));
+
+ if (!wakeup_via_pipe())
+ wakeup_via_cond();
+}
+
+void main_notify_lock(void)
+{
+ assert(pthread_equal(main_task, pthread_self()));
+ pthread_mutex_lock(&select_mutex);
+}
+
+void main_notify_unlock(void)
+{
+ assert(pthread_equal(main_task, pthread_self()));
+ pthread_mutex_unlock(&select_mutex);
+}
+
+void wait_main_task(void)
+{
+ assert(pthread_equal(main_task, pthread_self()));
+
+ pthread_mutex_lock(&main_wakeup_mutex);
+ pthread_cond_wait(&main_wakeup, &main_wakeup_mutex);
+}
+