-/* Copyright (C) 2008 Board of Trustees, Leland Stanford Jr. University.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to
- * deal in the Software without restriction, including without limitation the
- * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
- * sell copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
+/* Copyright (c) 2008 The Board of Trustees of The Leland Stanford
+ * Junior University
+ *
+ * We are making the OpenFlow specification and associated documentation
+ * (Software) available for public use and benefit with the expectation
+ * that others will use, modify and enhance the Software and contribute
+ * those enhancements back to the community. However, since we would
+ * like to make the Software available for broadest use, with as few
+ * restrictions as possible permission is hereby granted, free of
+ * charge, to any person obtaining a copy of this Software to deal in
+ * the Software under the copyrights without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * The name and trademarks of copyright holder(s) may NOT be used in
+ * advertising or publicity pertaining to the Software or any
+ * derivatives without specific, written prior permission.
+ */
+
+/* High-level wrapper around the "poll" system call.
*
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
+ * Intended usage is for the program's main loop to go about its business
+ * servicing whatever events it needs to. Then, when it runs out of immediate
+ * tasks, it calls each subordinate module's "wait" function, which in turn
+ * calls one (or more) of the functions poll_fd_wait(), poll_immediate_wake(),
+ * and poll_timer_wait() to register to be awakened when the appropriate event
+ * occurs. Then the main loop calls poll_block(), which blocks until one of
+ * the registered events happens.
*
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
- * IN THE SOFTWARE.
- */
+ * There is also some support for autonomous subroutines that are executed by
+ * poll_block() when a file descriptor becomes ready. To prevent these
+ * routines from starving if events are continously ready, the application
+ * should bound the amount of work it does between poll_block() calls. */
#ifndef POLL_LOOP_H
#define POLL_LOOP_H 1
#include <poll.h>
-typedef void poll_fd_func(int fd, short int revents, void *aux);
+struct poll_waiter;
+
+/* Schedule events to wake up the following poll_block(). */
+struct poll_waiter *poll_fd_wait(int fd, short int events);
+void poll_timer_wait(int msec);
+void poll_immediate_wake(void);
+/* Wait until an event occurs. */
+void poll_block(void);
+
+/* Autonomous function callbacks. */
+typedef void poll_fd_func(int fd, short int revents, void *aux);
struct poll_waiter *poll_fd_callback(int fd, short int events,
poll_fd_func *, void *aux);
-struct poll_waiter *poll_fd_wait(int fd, short int events, short int *revents);
-void poll_cancel(struct poll_waiter *);
-void poll_immediate_wake(void);
-void poll_timer_wait(int msec);
-void poll_block(void);
+/* Cancel a file descriptor callback or event. */
+void poll_cancel(struct poll_waiter *);
#endif /* poll-loop.h */
git://git.onelab.eu / sliver-openvswitch.git / blobdiff