/*
This file is part of GNUnet
- (C) 2009 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2009-2013 Christian Grothoff (and other contributing authors)
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 2, or (at your
+ by the Free Software Foundation; either version 3, or (at your
option) any later version.
GNUnet is distributed in the hope that it will be useful, but
* @file include/gnunet_scheduler_lib.h
* @brief API to schedule computations using continuation passing style
* @author Christian Grothoff
+ * @defgroup scheduler Event loop (scheduler)
+ * @{
*/
#ifndef GNUNET_SCHEDULER_LIB_H
/**
* Opaque reference to a task.
*/
-typedef unsigned long long GNUNET_SCHEDULER_TaskIdentifier;
-
-
-/**
- * Constant used to indicate that the scheduled
- * task has no others as prerequisites.
- */
-#define GNUNET_SCHEDULER_NO_TASK ((GNUNET_SCHEDULER_TaskIdentifier) 0)
+struct GNUNET_SCHEDULER_Task;
/**
* Reasons why the schedule may have triggered
*/
enum GNUNET_SCHEDULER_Reason
{
+ /**
+ * This task is not ready.
+ */
+ GNUNET_SCHEDULER_REASON_NONE = 0,
+
/**
* This is the very first task run during startup.
*/
- GNUNET_SCHEDULER_REASON_STARTUP = 0,
+ GNUNET_SCHEDULER_REASON_STARTUP = 1,
/**
* We are shutting down and are running all shutdown-related tasks
* (regardless of timeout, etc.).
*/
- GNUNET_SCHEDULER_REASON_SHUTDOWN = 1,
+ GNUNET_SCHEDULER_REASON_SHUTDOWN = 2,
/**
* The specified timeout has expired.
* (also set if the delay given was 0).
*/
- GNUNET_SCHEDULER_REASON_TIMEOUT = 2,
+ GNUNET_SCHEDULER_REASON_TIMEOUT = 4,
/**
* The reading socket is ready.
*/
- GNUNET_SCHEDULER_REASON_READ_READY = 4,
+ GNUNET_SCHEDULER_REASON_READ_READY = 8,
/**
* The writing socket is ready.
*/
- GNUNET_SCHEDULER_REASON_WRITE_READY = 8,
+ GNUNET_SCHEDULER_REASON_WRITE_READY = 16,
/**
* The prerequisite task is done.
*/
- GNUNET_SCHEDULER_REASON_PREREQ_DONE = 16
+ GNUNET_SCHEDULER_REASON_PREREQ_DONE = 32
};
/**
* Run with the default priority (normal
- * P2P operations). Higher than BACKGROUND.
+ * P2P operations). Any task that is scheduled
+ * without an explicit priority being specified
+ * will run with this priority.
*/
GNUNET_SCHEDULER_PRIORITY_DEFAULT = 3,
* @param cls closure
* @param tc context information (why was this task triggered now)
*/
-typedef void (*GNUNET_SCHEDULER_Task) (void *cls,
- const struct
- GNUNET_SCHEDULER_TaskContext * tc);
+typedef void
+(*GNUNET_SCHEDULER_TaskCallback) (void *cls,
+ const struct GNUNET_SCHEDULER_TaskContext *tc);
+
+
+/**
+ * Signature of the select function used by the scheduler.
+ * #GNUNET_NETWORK_socket_select matches it.
+ *
+ * @param cls closure
+ * @param rfds set of sockets to be checked for readability
+ * @param wfds set of sockets to be checked for writability
+ * @param efds set of sockets to be checked for exceptions
+ * @param timeout relative value when to return
+ * @return number of selected sockets, #GNUNET_SYSERR on error
+ */
+typedef int
+(*GNUNET_SCHEDULER_select) (void *cls,
+ struct GNUNET_NETWORK_FDSet *rfds,
+ struct GNUNET_NETWORK_FDSet *wfds,
+ struct GNUNET_NETWORK_FDSet *efds,
+ struct GNUNET_TIME_Relative timeout);
/**
* Initialize and run scheduler. This function will return when all
* tasks have completed. On systems with signals, receiving a SIGTERM
- * (and other similar signals) will cause "GNUNET_SCHEDULER_shutdown"
+ * (and other similar signals) will cause #GNUNET_SCHEDULER_shutdown
* to be run after the active task is complete. As a result, SIGTERM
* causes all active tasks to be scheduled with reason
- * "GNUNET_SCHEDULER_REASON_SHUTDOWN". (However, tasks added
+ * #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 task task to run first (and immediately)
* @param task_cls closure of task
*/
-void GNUNET_SCHEDULER_run (GNUNET_SCHEDULER_Task task, void *task_cls);
+void
+GNUNET_SCHEDULER_run (GNUNET_SCHEDULER_TaskCallback task,
+ void *task_cls);
/**
- * Request the shutdown of a scheduler. Marks all currently
+ * Request the shutdown of the scheduler. Marks all currently
* pending tasks as ready because of shutdown. This will
* cause all tasks to run (as soon as possible, respecting
* priorities and prerequisite tasks). Note that tasks
* scheduled AFTER this call may still be delayed arbitrarily.
*/
-void GNUNET_SCHEDULER_shutdown ();
+void
+GNUNET_SCHEDULER_shutdown (void);
/**
* dropped (if the decision should be made based on the number of
* tasks ready to run).
*
- * * @param p priority-level to query, use KEEP to query the level
+ * @param p priority-level to query, use KEEP to query the level
* of the current task, use COUNT to get the sum over
* all priority levels
* @return number of tasks pending right now
*/
-unsigned int GNUNET_SCHEDULER_get_load (enum GNUNET_SCHEDULER_Priority p);
+unsigned int
+GNUNET_SCHEDULER_get_load (enum GNUNET_SCHEDULER_Priority p);
/**
* Obtain the reason code for why the current task was
- * started. Will return the same value as
+ * started. Will return the same value as
* the GNUNET_SCHEDULER_TaskContext's reason field.
*
- * * @return reason(s) why the current task is run
+ * @return reason(s) why the current task is run
*/
enum GNUNET_SCHEDULER_Reason
-GNUNET_SCHEDULER_get_reason ();
+GNUNET_SCHEDULER_get_reason (void);
/**
* Cancel the task with the specified identifier.
* The task must not yet have run.
*
- * * @param task id of the task to cancel
+ * @param task id of the task to cancel
* @return the closure of the callback of the cancelled task
*/
-void *GNUNET_SCHEDULER_cancel (GNUNET_SCHEDULER_TaskIdentifier task);
+void *
+GNUNET_SCHEDULER_cancel (struct GNUNET_SCHEDULER_Task *task);
/**
* similar to the other "add" functions except that there is no delay
* and the reason code can be specified.
*
- * * @param task main function of the task
+ * @param task main function of the task
* @param task_cls closure of task
* @param reason reason for task invocation
*/
void
-GNUNET_SCHEDULER_add_continuation (GNUNET_SCHEDULER_Task task,
+GNUNET_SCHEDULER_add_continuation (GNUNET_SCHEDULER_TaskCallback task,
void *task_cls,
enum GNUNET_SCHEDULER_Reason reason);
/**
- * Schedule a new task to be run after the specified prerequisite task
- * has completed. It will be run with the priority of the calling
- * task.
+ * Continue the current execution with the given function. This is
+ * similar to the other "add" functions except that there is no delay
+ * and the reason code can be specified.
*
- * * @param prerequisite_task run this task after the task with the given
- * task identifier completes (and any of our other
- * conditions, such as delay, read or write-readiness
- * are satisfied). Use GNUNET_SCHEDULER_NO_TASK to not have any dependency
- * on completion of other tasks (this will cause the task to run as
- * soon as possible).
* @param task main function of the task
- * @param task_cls closure of task
- * @return unique task identifier for the job
- * only valid until "task" is started!
+ * @param task_cls closure for @a task
+ * @param reason reason for task invocation
+ * @param priority priority to use for the task
*/
-GNUNET_SCHEDULER_TaskIdentifier
-GNUNET_SCHEDULER_add_after (GNUNET_SCHEDULER_TaskIdentifier prerequisite_task,
- GNUNET_SCHEDULER_Task task,
- void *task_cls);
+void
+GNUNET_SCHEDULER_add_continuation_with_priority (GNUNET_SCHEDULER_TaskCallback task,
+ void *task_cls,
+ enum GNUNET_SCHEDULER_Reason reason,
+ enum GNUNET_SCHEDULER_Priority priority);
/**
* Schedule a new task to be run with a specified priority.
*
- * * @param prio how important is the new task?
+ * @param prio how important is the new task?
* @param task main function of the task
- * @param task_cls closure of 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!
*/
-GNUNET_SCHEDULER_TaskIdentifier
+struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_with_priority (enum GNUNET_SCHEDULER_Priority prio,
- GNUNET_SCHEDULER_Task task,
- void *task_cls);
+ GNUNET_SCHEDULER_TaskCallback task,
+ void *task_cls);
/**
- * Schedule a new task to be run as soon as possible. The task
- * will be run with the priority of the calling task.
+ * Schedule a new task to be run as soon as possible. Note that this
+ * does not guarantee that this will be the next task that is being
+ * run, as other tasks with higher priority (or that are already ready
+ * to run) might get to run first. Just as with delays, clients must
+ * not rely on any particular order of execution between tasks
+ * scheduled concurrently.
*
- * * @param task main function of the task
- * @param task_cls closure of task
+ * The task will be run with the DEFAULT priority.
+ *
+ * @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_now (GNUNET_SCHEDULER_TaskCallback task,
+ void *task_cls);
+
+
+/**
+ * Schedule a new task to be run as soon as possible with the
+ * (transitive) ignore-shutdown flag either explicitly set or
+ * explicitly enabled. This task (and all tasks created from it,
+ * other than by another call to this function) will either count or
+ * not count for the 'lifeness' of the process. This API is only
+ * useful in a few special cases.
+ *
+ * @param lifeness #GNUNET_YES if the task counts for lifeness, #GNUNET_NO if not.
+ * @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!
*/
-GNUNET_SCHEDULER_TaskIdentifier
-GNUNET_SCHEDULER_add_now (GNUNET_SCHEDULER_Task task,
- void *task_cls);
+struct GNUNET_SCHEDULER_Task *
+GNUNET_SCHEDULER_add_now_with_lifeness (int lifeness,
+ 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. It
- * will be run with the priority of the calling task.
+ * will be run with the DEFAULT priority.
*
* * @param delay when should this operation time out? Use
- * GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
+ * #GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
* @param task main function of the task
- * @param task_cls closure of 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!
*/
-GNUNET_SCHEDULER_TaskIdentifier
+struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_delayed (struct GNUNET_TIME_Relative delay,
- GNUNET_SCHEDULER_Task task,
- void *task_cls);
+ 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? Use
+ * #GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
+ * @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_delayed_with_priority (struct GNUNET_TIME_Relative delay,
+ enum GNUNET_SCHEDULER_Priority priority,
+ GNUNET_SCHEDULER_TaskCallback task,
+ void *task_cls);
/**
* 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 priority of
- * the calling task.
+ * socket operation is ready. It will be run with the DEFAULT priority.
*
* * @param delay when should this operation time out? Use
- * GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
+ * #GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
* @param rfd read file-descriptor
* @param task main function of the task
- * @param task_cls closure of 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!
*/
-GNUNET_SCHEDULER_TaskIdentifier
+struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_read_net (struct GNUNET_TIME_Relative delay,
- struct GNUNET_NETWORK_Handle *rfd,
- GNUNET_SCHEDULER_Task task,
- void *task_cls);
+ struct GNUNET_NETWORK_Handle *rfd,
+ GNUNET_SCHEDULER_TaskCallback task,
+ void *task_cls);
+
+
+/**
+ * Schedule a new task to be run with a specified priority and to be
+ * run after the 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.
+ *
+ * @param delay when should this operation time out? Use
+ * #GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
+ * @param priority priority to use for the task
+ * @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 @a task is started!
+ */
+struct GNUNET_SCHEDULER_Task *
+GNUNET_SCHEDULER_add_read_net_with_priority (struct GNUNET_TIME_Relative delay,
+ enum GNUNET_SCHEDULER_Priority priority,
+ struct GNUNET_NETWORK_Handle *rfd,
+ GNUNET_SCHEDULER_TaskCallback task,
+ void *task_cls);
/**
* 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 priority of
- * the calling task.
+ * socket operation is ready. It will be run with the DEFAULT priority.
*
* * @param delay when should this operation time out? Use
- * GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
+ * #GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
* @param wfd write file-descriptor
* @param task main function of the task
- * @param task_cls closure of 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!
*/
-GNUNET_SCHEDULER_TaskIdentifier
+struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_write_net (struct GNUNET_TIME_Relative delay,
- struct GNUNET_NETWORK_Handle *wfd,
- GNUNET_SCHEDULER_Task task,
- void *task_cls);
+ struct GNUNET_NETWORK_Handle *wfd,
+ 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. 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.
+ *
+ * @param delay when should this operation time out? Use
+ * #GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
+ * @param priority priority of the task
+ * @param fd file-descriptor
+ * @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
+ * @return unique task identifier for the job
+ * only valid until "task" is started!
+ */
+struct GNUNET_SCHEDULER_Task *
+GNUNET_SCHEDULER_add_net_with_priority (struct GNUNET_TIME_Relative delay,
+ enum GNUNET_SCHEDULER_Priority priority,
+ struct GNUNET_NETWORK_Handle *fd,
+ int on_read,
+ int on_write,
+ 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 priority of
- * the calling task.
+ * socket operation is ready. It will be run with the DEFAULT priority.
*
* * @param delay when should this operation time out? Use
- * GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
+ * #GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
* @param rfd read file-descriptor
* @param task main function of the task
- * @param task_cls closure of task
+ * @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until "task" is started!
*/
-GNUNET_SCHEDULER_TaskIdentifier
+struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_read_file (struct GNUNET_TIME_Relative delay,
- const struct GNUNET_DISK_FileHandle *rfd,
- GNUNET_SCHEDULER_Task task,
- void *task_cls);
+ const struct GNUNET_DISK_FileHandle *rfd,
+ GNUNET_SCHEDULER_TaskCallback task,
+ void *task_cls);
/**
* 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 priority of
- * the calling task.
+ * socket operation is ready. It will be run with the DEFAULT priority.
*
* * @param delay when should this operation time out? Use
- * GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
+ * #GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
* @param wfd write file-descriptor
* @param task main function of the task
- * @param task_cls closure of 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!
*/
-GNUNET_SCHEDULER_TaskIdentifier
+struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_write_file (struct GNUNET_TIME_Relative delay,
- const struct GNUNET_DISK_FileHandle *wfd,
- GNUNET_SCHEDULER_Task task,
- void *task_cls);
+ const struct GNUNET_DISK_FileHandle *wfd,
+ 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. 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.
+ *
+ * @param delay when should this operation time out? Use
+ * #GNUNET_TIME_UNIT_FOREVER_REL for "on shutdown"
+ * @param priority priority of the task
+ * @param fd file-descriptor
+ * @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
+ * @return unique task identifier for the job
+ * only valid until @a task is started!
+ */
+struct GNUNET_SCHEDULER_Task *
+GNUNET_SCHEDULER_add_file_with_priority (struct GNUNET_TIME_Relative delay,
+ enum GNUNET_SCHEDULER_Priority priority,
+ const struct GNUNET_DISK_FileHandle *fd,
+ int on_read, int on_write,
+ GNUNET_SCHEDULER_TaskCallback task,
+ void *task_cls);
/**
* || shutdown-active)
* </code>
*
- * * @param prio how important is this task?
- * @param prerequisite_task run this task after the task with the given
- * task identifier completes (and any of our other
- * conditions, such as delay, read or write-readiness
- * are satisfied). Use GNUNET_SCHEDULER_NO_TASK to not have any dependency
- * on completion of other tasks.
- * @param delay how long should we wait? Use GNUNET_TIME_UNIT_FOREVER_REL for "forever",
+ * @param prio how important is this task?
+ * @param delay how long should we wait? Use #GNUNET_TIME_UNIT_FOREVER_REL for "forever",
* which means that the task will only be run after we receive SIGTERM
* @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 task
+ * @param task_cls closure of @a task
* @return unique task identifier for the job
* only valid until "task" is started!
*/
-GNUNET_SCHEDULER_TaskIdentifier
+struct GNUNET_SCHEDULER_Task *
GNUNET_SCHEDULER_add_select (enum GNUNET_SCHEDULER_Priority prio,
- GNUNET_SCHEDULER_TaskIdentifier
- prerequisite_task,
struct GNUNET_TIME_Relative delay,
- const struct GNUNET_NETWORK_FDSet * rs,
- const struct GNUNET_NETWORK_FDSet * ws,
- GNUNET_SCHEDULER_Task task,
- void *task_cls);
+ const struct GNUNET_NETWORK_FDSet *rs,
+ const struct GNUNET_NETWORK_FDSet *ws,
+ GNUNET_SCHEDULER_TaskCallback task,
+ void *task_cls);
+
+/**
+ * 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'
+ */
+void
+GNUNET_SCHEDULER_set_select (GNUNET_SCHEDULER_select new_select,
+ void *new_select_cls);
+
+
+/** @} */ /* end of group scheduler */
#if 0 /* keep Emacsens' auto-indent happy */
{
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