Initial support for a lightweight 'deferred callbacks'.

A 'deferred callback' is just a function that we've queued in the
event base.  This ability is needed for some mt stuff, and for complex
callback chains.  For internal use only.

svn:r1150

1 files changed, 56 insertions, 0 deletions

diff --git a/defer-internal.h b/defer-internal.h
new file mode 100644
index 00000000..1f451c13
--- /dev/null
+++ b/defer-internal.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2009 Niels Provos and Nick Mathewson
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef _DEFER_INTERNAL_H_
+#define _DEFER_INTERNAL_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "event-config.h"
+#include <sys/queue.h>
+
+struct deferred_cb;
+
+typedef void (*deferred_cb_fn)(struct deferred_cb *, void *);
+
+struct deferred_cb {
+	TAILQ_ENTRY (deferred_cb) (cb_next);
+	unsigned queued : 1;
+	deferred_cb_fn cb;
+	void *arg;
+};
+
+void event_deferred_cb_init(struct deferred_cb *, deferred_cb_fn, void *);
+void event_deferred_cb_cancel(struct event_base *, struct deferred_cb *);
+void event_deferred_cb_schedule(struct event_base *, struct deferred_cb *);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _EVENT_INTERNAL_H_ */
+