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-rw-r--r--src/notify.h45
1 files changed, 29 insertions, 16 deletions
diff --git a/src/notify.h b/src/notify.h
index 9f1a1961b..f79518f8f 100644
--- a/src/notify.h
+++ b/src/notify.h
@@ -19,29 +19,42 @@
#ifndef NOTIFY_H
#define NOTIFY_H
-/*
- * This library implements inter-process signalling using blocking
- * read() on an anonymous pipe. As a side effect, the read() system
- * call has the same signal interruption behaviour as the old sleep
- * function.
- *
- * As soon as mpd uses threading instead of fork()/shm, we can replace
- * this library with a pthread_cond object.
- *
- * This code is experimental and carries a lot of overhead. Still, it
- * uses less resources than the old polling code with a fixed sleep
- * time.
- *
- */
+#include "os_compat.h"
typedef struct _Notify {
- int fds[2];
+ pthread_mutex_t mutex;
+ pthread_cond_t cond;
+ int pending;
} Notify;
-void notifyInit(Notify *notify);
+int notifyInit(Notify *notify);
+
+/**
+ * The thread which shall be notified by this object must call this
+ * function before any notifyWait() invocation. It locks the mutex.
+ */
+void notifyEnter(Notify *notify);
+
+/**
+ * Neutralize notifyLeave().
+ */
+void notifyLeave(Notify *notify);
+/**
+ * Wait for a notification. Return immediately if we have already
+ * been notified since we last returned from notifyWait().
+ */
void notifyWait(Notify *notify);
+/**
+ * Notify the thread. This function never blocks.
+ */
void notifySignal(Notify *notify);
+/**
+ * Notify the thread synchonously, i.e. wait until it has received the
+ * notification.
+ */
+void notifySignalSync(Notify *notify);
+
#endif