introduce struct condition as a more correct version of Notify

Start using it in the HTTP code

git-svn-id: https://svn.musicpd.org/mpd/trunk@7395 09075e82-0dd4-0310-85a5-a0d7c8717e4f

1 files changed, 76 insertions, 0 deletions

diff --git a/src/condition.h b/src/condition.h
new file mode 100644
index 000000000..576ff9dc3
--- /dev/null
+++ b/src/condition.h
@@ -0,0 +1,76 @@
+/* the Music Player Daemon (MPD)
+ * Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
+ * Copyright (C) 2008 Max Kellermann <max@duempel.org>
+ * 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
+ */
+
+#ifndef CONDITION_H
+#define CONDITION_H
+
+#include "os_compat.h"
+
+struct condition {
+	pthread_mutex_t mutex;
+	pthread_cond_t cond;
+};
+
+void cond_init(struct condition *cond);
+
+/**
+ * The thread which shall be notified by this object must call this
+ * function before any cond_wait() invocation.  It locks the mutex.
+ */
+void cond_enter(struct condition *cond);
+
+/**
+ * Neutralize cond_leave().
+ */
+void cond_leave(struct condition *cond);
+
+/**
+ * Wait for a conditio.  Return immediately if we have already
+ * been notified since we last returned from cond_wait().
+ */
+void cond_wait(struct condition *cond);
+
+/**
+ * Wait for a condition with timeout
+ *
+ * @param sec number of seconds to wait for (subject to change)
+ *
+ * @return ETIMEDOUT if timed out, 0 if notification was received
+ */
+int cond_timedwait(struct condition *cond, const long sec);
+
+/**
+ * Notify the thread there is a waiter.  This function never blocks.
+ *
+ * @return EBUSY if it was unable to lock the mutex, 0 on success
+ */
+int cond_signal_async(struct condition *cond);
+
+/**
+ * Notify the thread synchronously, i.e. wait until it can deliver
+ * the notification.
+ */
+void cond_signal_sync(struct condition *cond);
+
+/**
+ * cond_destroy - destroy the cond and internal structures
+ */
+void cond_destroy(struct condition *cond);
+
+#endif /* CONDITION_H */