some infra

third_party/concord/concord-notifier.h

@@ -0,0 +1,50 @@
+/**
+ * @file concord-notifier.h
+ * @author Cogmasters
+ * @brief Notifier fds listening to pipe, this can be used to propagate events
+ */
+
+#ifndef CONCORD_NOTIFIER_H
+#define CONCORD_NOTIFIER_H
+
+#include "concord-error.h"
+
+/**
+ * @brief Open notifier pipe
+ *
+ * @param pipe The pipe to open for emitting notifications
+ * @return CCORDcode on success, CCORD_ERRNO on error
+ */
+CCORDcode ccord_notifier_open(int pipe[2]);
+
+/**
+ * @brief Close notifier pipe
+ *
+ * @param pipe The pipe to close
+ */
+void ccord_notifier_close(int pipe[2]);
+
+/**
+ * @brief Notify fds listening to pipe
+ *
+ * @param pipe The pipe to notify
+ */
+void ccord_notifier_notify(int pipe[2]);
+
+/**
+ * @brief Whether or not pipe is currently notifying fds
+ *
+ * @param pipe The pipe to check
+ * @return 1 if notifying, 0 if not
+ */
+_Bool ccord_notifier_is_notifying(int pipe[2]);
+
+/**
+ * @brief Receive a listener for pipe notifications
+ *
+ * @param pipe The pipe to listen to
+ * @return fd on success, -1 on error
+ */
+int ccord_notifier_listen(const int pipe[2]);
+
+#endif /* CONCORD_NOTIFIER_H */