Imported Upstream version 0.8.0~pre1upstream/0.8.0_pre1

1 files changed, 196 insertions, 0 deletions

diff --git a/src/common/fdset.h b/src/common/fdset.h
new file mode 100644
index 0000000..10196bf
--- /dev/null
+++ b/src/common/fdset.h
@@ -0,0 +1,196 @@
+/*  Copyright (C) 2011 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    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 3 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, see <http://www.gnu.org/licenses/>.
+ */
+/*!
+ * \file fdset.h
+ *
+ * \author Marek Vavrusa <marek.vavrusa@nic.cz>
+ *
+ * \brief Wrapper for native I/O multiplexing.
+ *
+ * Selects best implementation according to config.
+ * - select()
+ * - poll() \todo
+ * - epoll()
+ * - kqueue()
+ *
+ * \addtogroup common_lib
+ * @{
+ */
+
+#ifndef _KNOTD_FDSET_H_
+#define _KNOTD_FDSET_H_
+
+#include <stddef.h>
+
+/*! \brief Opaque pointer to implementation-specific fdset data. */
+typedef struct fdset_t fdset_t;
+
+/*! \brief Unified event types. */
+enum fdset_event_t {
+	OS_EV_READ  = 1 << 0, /*!< Readable event. */
+	OS_EV_WRITE = 1 << 1, /*!< Writeable event. */
+	OS_EV_ERROR = 1 << 2  /*!< Error event. */
+};
+
+/*! \brief File descriptor set iterator. */
+typedef struct fdset_it_t {
+	int fd;     /*!< Current file descriptor. */
+	int events; /*!< Returned events. */
+	size_t pos; /* Internal usage. */
+} fdset_it_t;
+
+/*!
+ * \brief File descriptor set implementation backend.
+ * \notice Functions documentation following.
+ * \internal
+ */
+struct fdset_backend_t
+{
+	fdset_t* (*fdset_new)();
+	int (*fdset_destroy)(fdset_t*);
+	int (*fdset_add)(fdset_t*, int, int);
+	int (*fdset_remove)(fdset_t*, int);
+	int (*fdset_wait)(fdset_t*);
+	int (*fdset_begin)(fdset_t*, fdset_it_t*);
+	int (*fdset_end)(fdset_t*, fdset_it_t*);
+	int (*fdset_next)(fdset_t*, fdset_it_t*);
+	const char* (*fdset_method)();
+};
+
+/*!
+ * \brief Selected backend.
+ * \internal
+ */
+extern struct fdset_backend_t _fdset_backend;
+
+/*!
+ * \brief Create new fdset.
+ *
+ * FDSET implementation depends on system.
+ *
+ * \retval Pointer to initialized FDSET structure if successful.
+ * \retval NULL on error.
+ */
+static inline fdset_t *fdset_new() {
+	return _fdset_backend.fdset_new();
+}
+
+/*!
+ * \brief Destroy FDSET.
+ *
+ * \retval 0 if successful.
+ * \retval -1 on error.
+ */
+static inline int fdset_destroy(fdset_t * fdset) {
+	return _fdset_backend.fdset_destroy(fdset);
+}
+
+/*!
+ * \brief Add file descriptor to watched set.
+ *
+ * \param fdset Target set.
+ * \param fd Added file descriptor.
+ * \param events Mask of watched events.
+ *
+ * \retval 0 if successful.
+ * \retval -1 on errors.
+ */
+static inline int fdset_add(fdset_t *fdset, int fd, int events) {
+	return _fdset_backend.fdset_add(fdset, fd, events);
+}
+
+
+/*!
+ * \brief Remove file descriptor from watched set.
+ *
+ * \param fdset Target set.
+ * \param fd File descriptor to be removed.
+ *
+ * \retval 0 if successful.
+ * \retval -1 on errors.
+ */
+static inline int fdset_remove(fdset_t *fdset, int fd) {
+	return _fdset_backend.fdset_remove(fdset, fd);
+}
+
+/*!
+ * \brief Poll set for new events.
+ *
+ * \param fdset Target set.
+ *
+ * \retval Number of events if successful.
+ * \retval -1 on errors.
+ *
+ * \todo Timeout.
+ */
+static inline int fdset_wait(fdset_t *fdset) {
+	return _fdset_backend.fdset_wait(fdset);
+}
+
+/*!
+ * \brief Set event iterator to the beginning of last polled events.
+ *
+ * \param fdset Target set.
+ * \param it Event iterator.
+ *
+ * \retval 0 if successful.
+ * \retval -1 on errors.
+ */
+static inline int fdset_begin(fdset_t *fdset, fdset_it_t *it) {
+	return _fdset_backend.fdset_begin(fdset, it);
+}
+
+/*!
+ * \brief Set event iterator to the end of last polled events.
+ *
+ * \param fdset Target set.
+ * \param it Event iterator.
+ *
+ * \retval 0 if successful.
+ * \retval -1 on errors.
+ */
+static inline int fdset_end(fdset_t *fdset, fdset_it_t *it) {
+	return _fdset_backend.fdset_end(fdset, it);
+}
+
+/*!
+ * \brief Set event iterator to the next event.
+ *
+ * Event iterator fd will be set to -1 if next event doesn't exist.
+ *
+ * \param fdset Target set.
+ * \param it Event iterator.
+ *
+ * \retval 0 if successful.
+ * \retval -1 on errors.
+ */
+static inline int fdset_next(fdset_t *fdset, fdset_it_t *it) {
+	return _fdset_backend.fdset_next(fdset, it);
+}
+
+/*!
+ * \brief Returned name of underlying poll method.
+ *
+ * \retval Name if successful.
+ * \retval NULL if no method was loaded (shouldn't happen).
+ */
+static inline const char* fdset_method() {
+	return _fdset_backend.fdset_method();
+}
+
+#endif /* _KNOTD_FDSET_H_ */
+
+/*! @} */