This file is part of GNUnet
Copyright (C) 2009-2016 GNUnet e.V.
- GNUnet 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, or (at your
- option) any later version.
+ GNUnet is free software: you can redistribute it and/or modify it
+ under the terms of the GNU Affero General Public License as published
+ by the Free Software Foundation, either version 3 of the License,
+ or (at your option) any later version.
GNUnet 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.
+ Affero General Public License for more details.
+
+ You should have received a copy of the GNU Affero General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
- You should have received a copy of the GNU General Public License
- along with GNUnet; see the file COPYING. If not, write to the
- Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA.
+ SPDX-License-Identifier: AGPL3.0-or-later
*/
/**
#include "gnunet_network_lib.h"
+/**
+ * Possible events on FDs, used as a bitmask.
+ * Modelled after GPollFD.
+ */
+enum GNUNET_SCHEDULER_EventType
+{
+
+ /**
+ * No event (useful for timeout).
+ */
+ GNUNET_SCHEDULER_ET_NONE = 0,
+
+ /**
+ * Data available for reading.
+ */
+ GNUNET_SCHEDULER_ET_IN = 1,
+
+ /**
+ * Buffer available for writing.
+ */
+ GNUNET_SCHEDULER_ET_OUT = 2,
+
+ /**
+ *
+ */
+ GNUNET_SCHEDULER_ET_HUP = 4,
+
+ /**
+ *
+ */
+ GNUNET_SCHEDULER_ET_ERR = 8,
+
+ /**
+ *
+ */
+ GNUNET_SCHEDULER_ET_PRI = 16,
+
+ /**
+ *
+ */
+ GNUNET_SCHEDULER_ET_NVAL = 32
+
+};
+
+
+/**
+ * Information about an event relating to a file descriptor/socket.
+ */
+struct GNUNET_SCHEDULER_FdInfo
+{
+
+ /**
+ * GNUnet network socket the event is about, matches @a sock,
+ * NULL if this is about a file handle or if no network
+ * handle was given to the scheduler originally.
+ */
+ const struct GNUNET_NETWORK_Handle *fd;
+
+ /**
+ * GNUnet file handle the event is about, matches @a sock,
+ * NULL if this is about a network socket or if no network
+ * handle was given to the scheduler originally.
+ */
+ const struct GNUNET_DISK_FileHandle *fh;
+
+ /**
+ * Type of the event that was generated related to @e sock.
+ */
+ enum GNUNET_SCHEDULER_EventType et;
+
+ /**
+ * Underlying OS handle the event was about.
+ */
+ int sock;
+
+};
+
+
/**
* Context information passed to each scheduler task.
*/
enum GNUNET_SCHEDULER_Reason reason;
/**
- * Set of file descriptors ready for reading;
- * note that additional bits may be set
- * that were not in the original request
+ * Length of the following array.
+ */
+ unsigned int fds_len;
+
+ /**
+ * Array of length @e fds_len with information about ready FDs.
+ * Note that we use the same format regardless of the internal
+ * event loop that was used. The given array should only contain
+ * information about file descriptors relevant to the current task.
+ */
+ const struct GNUNET_SCHEDULER_FdInfo *fds;
+
+ /**
+ * Set of file descriptors ready for reading; note that additional
+ * bits may be set that were not in the original request.
+ * @deprecated
*/
const struct GNUNET_NETWORK_FDSet *read_ready;
/**
- * Set of file descriptors ready for writing;
- * note that additional bits may be set
- * that were not in the original request.
+ * Set of file descriptors ready for writing; note that additional
+ * bits may be set that were not in the original request.
+ * @deprecated
*/
const struct GNUNET_NETWORK_FDSet *write_ready;
};
+/**
+ * Function used by event-loop implementations to signal the scheduler
+ * that a particular @a task is ready due to an event specified in the
+ * et field of @a fdi.
+ *
+ * This function will then queue the task to notify the application
+ * that the task is ready (with the respective priority).
+ *
+ * @param task the task that is ready
+ * @param fdi information about the related FD
+ */
+void
+GNUNET_SCHEDULER_task_ready (struct GNUNET_SCHEDULER_Task *task,
+ struct GNUNET_SCHEDULER_FdInfo *fdi);
+
+
+/**
+ * Handle to the scheduler's state to be used by the driver.
+ */
+struct GNUNET_SCHEDULER_Handle;
+
+
+/**
+ * Function called by external event loop implementations to tell the
+ * scheduler to run some of the tasks that are ready. Must be called
+ * only after #GNUNET_SCHEDULER_driver_init has been called and before
+ * #GNUNET_SCHEDULER_driver_done is called.
+ * This function may return even though there are tasks left to run
+ * just to give other tasks a chance as well. If we return #GNUNET_YES,
+ * the event loop implementation should call this function again as
+ * soon as possible, while if we return #GNUNET_NO it must block until
+ * either the operating system has more work (the scheduler has no more
+ * work to do right now) or the timeout set by the scheduler (using the
+ * set_wakeup callback) is reached.
+ *
+ * @param sh scheduler handle that was returned by
+ * #GNUNET_SCHEDULER_driver_init
+ * @return #GNUNET_YES if there are more tasks that are ready,
+ * and thus we would like to run more (yield to avoid
+ * blocking other activities for too long) #GNUNET_NO
+ * if we are done running tasks (yield to block)
+ */
+int
+GNUNET_SCHEDULER_do_work (struct GNUNET_SCHEDULER_Handle *sh);
+
+
+/**
+ * API an external event loop has to implement for
+ * #GNUNET_SCHEDULER_driver_init.
+ */
+struct GNUNET_SCHEDULER_Driver
+{
+
+ /**
+ * Closure to pass to the functions in this struct.
+ */
+ void *cls;
+
+ /**
+ * Add a @a task to be run if the conditions specified in the
+ * et field of the given @a fdi are satisfied. The et field will
+ * be cleared after this call and the driver is expected to set
+ * the type of the actual event before passing @a fdi to
+ * #GNUNET_SCHEDULER_task_ready.
+ *
+ * @param cls closure
+ * @param task task to add
+ * @param fdi conditions to watch for
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
+ * (i.e. @a fdi too high or invalid)
+ */
+ int
+ (*add)(void *cls,
+ struct GNUNET_SCHEDULER_Task *task,
+ struct GNUNET_SCHEDULER_FdInfo *fdi);
+
+ /**
+ * Delete a @a task from the set of tasks to be run. A task may
+ * comprise multiple FdInfo entries previously added with the add
+ * function. The driver is expected to delete them all.
+ *
+ * @param cls closure
+ * @param task task to delete
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
+ * (i.e. @a task does not match prior @e add call)
+ */
+ int
+ (*del)(void *cls,
+ struct GNUNET_SCHEDULER_Task *task);
+
+ /**
+ * Set time at which we definitively want to get a wakeup call.
+ *
+ * @param cls closure
+ * @param dt time when we want to wake up next
+ */
+ void
+ (*set_wakeup)(void *cls,
+ struct GNUNET_TIME_Absolute dt);
+
+};
+
+
/**
* Signature of the main function of a task.
*
* @param cls closure
- * @param tc context information (why was this task triggered now)
*/
typedef void
(*GNUNET_SCHEDULER_TaskCallback) (void *cls);
+/**
+ * Function called by external event loop implementations to initialize
+ * the scheduler. An external implementation has to provide @a driver
+ * which contains callbacks for the scheduler (see definition of struct
+ * #GNUNET_SCHEDULER_Driver). The callbacks are used to instruct the
+ * external implementation to watch for events. If it detects any of
+ * those events it is expected to call #GNUNET_SCHEDULER_do_work to let
+ * the scheduler handle it. If an event is related to a specific task
+ * (e.g. the scheduler gave instructions to watch a file descriptor),
+ * the external implementation is expected to mark that task ready
+ * before by calling #GNUNET_SCHEDULER_task_ready.
+ *
+ * This function has to be called before any tasks are scheduled and
+ * before GNUNET_SCHEDULER_do_work is called for the first time. It
+ * allocates resources that have to be freed again by calling
+ * #GNUNET_SCHEDULER_driver_done.
+ *
+ * This function installs the same signal handlers as
+ * #GNUNET_SCHEDULER_run. This means SIGTERM (and other similar signals)
+ * will induce a call to #GNUNET_SCHEDULER_shutdown during the next
+ * call to #GNUNET_SCHEDULER_do_work. As a result, SIGTERM causes all
+ * active tasks to be scheduled with reason
+ * #GNUNET_SCHEDULER_REASON_SHUTDOWN. (However, tasks added afterwards
+ * will execute normally!). Note that any particular signal will only
+ * shut down one scheduler; applications should always only create a
+ * single scheduler.
+ *
+ * @param driver to use for the event loop
+ * @return handle to be passed to #GNUNET_SCHEDULER_do_work and
+ * #GNUNET_SCHEDULER_driver_done
+ */
+struct GNUNET_SCHEDULER_Handle *
+GNUNET_SCHEDULER_driver_init (const struct GNUNET_SCHEDULER_Driver *driver);
+
+
+/**
+ * Counter-part of #GNUNET_SCHEDULER_driver_init. Has to be called
+ * by external event loop implementations after the scheduler has
+ * shut down. This is the case if both of the following conditions
+ * are met:
+ *
+ * - all tasks the scheduler has added through the driver's add
+ * callback have been removed again through the driver's del
+ * callback
+ * - the timeout the scheduler has set through the driver's
+ * add_wakeup callback is FOREVER
+ *
+ * @param sh the handle returned by #GNUNET_SCHEDULER_driver_init
+ */
+void
+GNUNET_SCHEDULER_driver_done (struct GNUNET_SCHEDULER_Handle *sh);
+
+
+/**
+ * Obtain the driver for using select() as the event loop.
+ *
+ * @return NULL on error
+ */
+struct GNUNET_SCHEDULER_Driver *
+GNUNET_SCHEDULER_driver_select (void);
+
+
/**
* Signature of the select function used by the scheduler.
* #GNUNET_NETWORK_socket_select matches it.
GNUNET_SCHEDULER_run (GNUNET_SCHEDULER_TaskCallback task,
void *task_cls);
+/**
+ * Initialize and run scheduler. This function will return when all
+ * tasks have completed. When @ install_signals is GNUNET_YES, then
+ * this function behaves in the same was as GNUNET_SCHEDULER_run does.
+ * If @ install_signals is GNUNET_NO then no signal handlers are
+ * installed.
+ *
+ * @param install_signals whether to install signals (GNUNET_YES/NO)
+ * @param task task to run first (and immediately)
+ * @param task_cls closure of @a task
+ */
+void
+GNUNET_SCHEDULER_run_with_optional_signals (int install_signals,
+ GNUNET_SCHEDULER_TaskCallback task,
+ void *task_cls);
+
/**
- * Request the shutdown of a scheduler. Marks all tasks
+ * Request the shutdown of a scheduler. Marks all tasks
* awaiting shutdown as ready. Note that tasks
* scheduled with #GNUNET_SCHEDULER_add_shutdown() AFTER this call
* will be delayed until the next shutdown signal.
/**
* Cancel the task with the specified identifier.
- * The task must not yet have run.
+ * The task must not yet have run. Only allowed to be called as long as the
+ * scheduler is running, that is one of the following conditions is met:
+ *
+ * - #GNUNET_SCHEDULER_run has been called and has not returned yet
+ * - #GNUNET_SCHEDULER_driver_init has been run and
+ * #GNUNET_SCHEDULER_driver_done has not been called yet
*
* @param task id of the task to cancel
- * @return the closure of the callback of the cancelled task
+ * @return original closure of the task
*/
void *
GNUNET_SCHEDULER_cancel (struct GNUNET_SCHEDULER_Task *task);
* will be scheduled for execution once the delay has expired. It
* will be run with the DEFAULT priority.
*
- * @param delay when should this operation time out?
+ * @param delay with which the operation should be run
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
void *task_cls);
+/**
+ * Schedule a new task to be run at the specified time. The task
+ * will be scheduled for execution once specified time has been
+ * reached. It will be run with the DEFAULT priority.
+ *
+ * @param at time at which this operation should run
+ * @param task main function of the task
+ * @param task_cls closure of @a task
+ * @return unique task identifier for the job
+ * only valid until @a task is started!
+ */
+struct GNUNET_SCHEDULER_Task *
+GNUNET_SCHEDULER_add_at (struct GNUNET_TIME_Absolute at,
+ GNUNET_SCHEDULER_TaskCallback task,
+ void *task_cls);
+
+
/**
* Schedule a new task to be run with a specified delay. The task
* will be scheduled for execution once the delay has expired.
*
- * @param delay when should this operation time out?
+ * @param delay when should this operation time out?
* @param priority priority to use for the task
* @param task main function of the task
* @param task_cls closure of @a task
void *task_cls);
+/**
+ * Schedule a new task to be run at the specified time. The task
+ * will be scheduled for execution at time @a at.
+ *
+ * @param at time when the operation should run
+ * @param priority priority to use for the task
+ * @param task main function of the task
+ * @param task_cls closure of @a task
+ * @return unique task identifier for the job
+ * only valid until @a task is started!
+ */
+struct GNUNET_SCHEDULER_Task *
+GNUNET_SCHEDULER_add_at_with_priority (struct GNUNET_TIME_Absolute at,
+ enum GNUNET_SCHEDULER_Priority priority,
+ GNUNET_SCHEDULER_TaskCallback task,
+ void *task_cls);
+
+
/**
* Schedule a new task to be run with a specified delay or when the
* specified file descriptor is ready for reading. The delay can be
* used as a timeout on the socket being ready. The task will be
* scheduled for execution once either the delay has expired or the
* socket operation is ready. It will be run with the DEFAULT priority.
+ * Only allowed to be called as long as the scheduler is running, that
+ * is one of the following conditions is met:
+ *
+ * - #GNUNET_SCHEDULER_run has been called and has not returned yet
+ * - #GNUNET_SCHEDULER_driver_init has been run and
+ * #GNUNET_SCHEDULER_driver_done has not been called yet
*
* @param delay when should this operation time out?
* @param rfd read file-descriptor
* socket being ready. The task will be scheduled for execution once
* either the delay has expired or the socket operation is ready. It
* will be run with the DEFAULT priority.
+ * Only allowed to be called as long as the scheduler is running, that
+ * is one of the following conditions is met:
+ *
+ * - #GNUNET_SCHEDULER_run has been called and has not returned yet
+ * - #GNUNET_SCHEDULER_driver_init has been run and
+ * #GNUNET_SCHEDULER_driver_done has not been called yet
*
* @param delay when should this operation time out?
* @param priority priority to use for the task
* specified file descriptor is ready for writing. The delay can be
* used as a timeout on the socket being ready. The task will be
* scheduled for execution once either the delay has expired or the
- * socket operation is ready. It will be run with the DEFAULT priority.
+ * socket operation is ready. It will be run with the priority of
+ * the calling task.
+ * Only allowed to be called as long as the scheduler is running, that
+ * is one of the following conditions is met:
*
- * * @param delay when should this operation time out?
+ * - #GNUNET_SCHEDULER_run has been called and has not returned yet
+ * - #GNUNET_SCHEDULER_driver_init has been run and
+ * #GNUNET_SCHEDULER_driver_done has not been called yet
+ *
+ * @param delay when should this operation time out?
* @param wfd write file-descriptor
* @param task main function of the task
* @param task_cls closure of @a task
* used as a timeout on the socket being ready. The task will be
* scheduled for execution once either the delay has expired or the
* socket operation is ready.
+ * Only allowed to be called as long as the scheduler is running, that
+ * is one of the following conditions is met:
+ *
+ * - #GNUNET_SCHEDULER_run has been called and has not returned yet
+ * - #GNUNET_SCHEDULER_driver_init has been run and
+ * #GNUNET_SCHEDULER_driver_done has not been called yet
*
* @param delay when should this operation time out?
* @param priority priority of the task
* @param on_read whether to poll the file-descriptor for readability
* @param on_write whether to poll the file-descriptor for writability
* @param task main function of the task
- * @param task_cls closure of @a task
+ * @param task_cls closure of task
* @return unique task identifier for the job
* only valid until "task" is started!
*/
GNUNET_SCHEDULER_TaskCallback task,
void *task_cls);
+
/**
* Schedule a new task to be run with a specified delay or when the
* specified file descriptor is ready for reading. The delay can be
* used as a timeout on the socket being ready. The task will be
* scheduled for execution once either the delay has expired or the
* socket operation is ready. It will be run with the DEFAULT priority.
+ * Only allowed to be called as long as the scheduler is running, that
+ * is one of the following conditions is met:
*
- * * @param delay when should this operation time out?
+ * - #GNUNET_SCHEDULER_run has been called and has not returned yet
+ * - #GNUNET_SCHEDULER_driver_init has been run and
+ * #GNUNET_SCHEDULER_driver_done has not been called yet
+ *
+ * @param delay when should this operation time out?
* @param rfd read file-descriptor
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
- * only valid until "task" is started!
+ * only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_read_file (struct GNUNET_TIME_Relative delay,
* used as a timeout on the socket being ready. The task will be
* scheduled for execution once either the delay has expired or the
* socket operation is ready. It will be run with the DEFAULT priority.
+ * Only allowed to be called as long as the scheduler is running, that
+ * is one of the following conditions is met:
+ *
+ * - #GNUNET_SCHEDULER_run has been called and has not returned yet
+ * - #GNUNET_SCHEDULER_driver_init has been run and
+ * #GNUNET_SCHEDULER_driver_done has not been called yet
*
- * * @param delay when should this operation time out?
+ * @param delay when should this operation time out?
* @param wfd write file-descriptor
* @param task main function of the task
* @param task_cls closure of @a task
* used as a timeout on the socket being ready. The task will be
* scheduled for execution once either the delay has expired or the
* socket operation is ready.
+ * Only allowed to be called as long as the scheduler is running, that
+ * is one of the following conditions is met:
+ *
+ * - #GNUNET_SCHEDULER_run has been called and has not returned yet
+ * - #GNUNET_SCHEDULER_driver_init has been run and
+ * #GNUNET_SCHEDULER_driver_done has not been called yet
*
- * @param delay when should this operation time out?
+ * @param delay when should this operation time out?
* @param priority priority of the task
* @param fd file-descriptor
* @param on_read whether to poll the file-descriptor for readability
* (prerequisite-run)
* && (delay-ready
* || any-rs-ready
- * || any-ws-ready)
+ * || any-ws-ready) )
* </code>
+ * Only allowed to be called as long as the scheduler is running, that
+ * is one of the following conditions is met:
+ *
+ * - #GNUNET_SCHEDULER_run has been called and has not returned yet
+ * - #GNUNET_SCHEDULER_driver_init has been run and
+ * #GNUNET_SCHEDULER_driver_done has not been called yet
*
* @param prio how important is this task?
- * @param delay how long should we wait?
+ * @param delay how long should we wait?
* @param rs set of file descriptors we want to read (can be NULL)
* @param ws set of file descriptors we want to write (can be NULL)
* @param task main function of the task
* @param task_cls closure of @a task
* @return unique task identifier for the job
- * only valid until "task" is started!
+ * only valid until @a task is started!
*/
struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_select (enum GNUNET_SCHEDULER_Priority prio,
* Sets the select function to use in the scheduler (scheduler_select).
*
* @param new_select new select function to use (NULL to reset to default)
- * @param new_select_cls closure for 'new_select'
+ * @param new_select_cls closure for @a new_select
*/
void
GNUNET_SCHEDULER_set_select (GNUNET_SCHEDULER_select new_select,
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