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finish conversion to standard .h commenting conventions

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Bob Halley 1999-05-18 19:23:53 +00:00
parent ff1a344725
commit 9b27701a8d
1 changed files with 342 additions and 27 deletions
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369
lib/isc/include/isc/task.h
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@ -25,7 +25,11 @@
/*
* Task System
*
* XXX <TBS> XXX
* The task system provides a lightweight execution context, which is
* basically an event queue. When a task's event queue is non-empty, the
* task is runnable. A small work crew of threads, typically one per CPU,
* execute runnable tasks by dispatching the events on the tasks' event
* queues. Context switching between tasks is fast.
*
* MP:
* The module ensures appropriate synchronization of data structures it
@ -68,31 +72,306 @@ ISC_LANG_BEGINDECLS
***** Tasks.
*****/
isc_result_t isc_task_create(isc_taskmgr_t *,
isc_mem_t *,
unsigned int,
isc_task_t **);
void isc_task_attach(isc_task_t *,
isc_task_t **);
void isc_task_detach(isc_task_t **);
isc_mem_t * isc_task_mem(isc_task_t *);
isc_result_t isc_task_send(isc_task_t *,
isc_event_t **);
unsigned int isc_task_purge(isc_task_t *, void *,
isc_eventtype_t);
unsigned int isc_task_purgerange(isc_task_t *,
void *,
isc_eventtype_t,
isc_eventtype_t);
isc_result_t isc_task_allowsend(isc_task_t *,
isc_boolean_t);
isc_result_t isc_task_allowdone(isc_task_t *,
isc_boolean_t);
isc_result_t isc_task_onshutdown(isc_task_t *,
isc_taskaction_t,
void *);
void isc_task_shutdown(isc_task_t *);
void isc_task_destroy(isc_task_t **);
isc_result_t
isc_task_create(isc_taskmgr_t *manager, isc_mem_t *mctx,
unsigned int quantum, isc_task_t **taskp);
/*
* Create a task running.
*
* Notes:
*
* If 'quantum' is non-zero, then only that many events can be dispatched
* before the task must yield to other tasks waiting to execute. If
* quantum is zero, then the default quantum of the task manager will
* be used.
*
* The 'quantum' option may be removed from isc_task_create() in the
* future. If this happens, isc_task_getquantum() and
* isc_task_setquantum() will be provided.
*
* Requires:
*
* 'manager' is a valid task manager.
*
* 'mctx' is a valid memory context.
*
* taskp != NULL && *taskp == NULL
*
* Ensures:
*
* On success, '*taskp' is bound to the new task.
*
* Returns:
*
* ISC_R_SUCCESS
* ISC_R_NOMEMORY
* ISC_R_UNEXPECTED
*/
void
isc_task_attach(isc_task_t *source, isc_task_t **targetp);
/*
* Attach *targetp to source.
*
* Requires:
*
* 'source' is a valid task.
*
* 'targetp' points to a NULL isc_task_t *.
*
* Ensures:
*
* *targetp is attached to source.
*/
void
isc_task_detach(isc_task_t **taskp);
/*
* Detach *taskp from its task.
*
* Requires:
*
* '*taskp' is a valid task.
*
* Ensures:
*
* *taskp is NULL.
*
* If '*taskp' is the last reference to the task and
* the task has been shutdown,
*
* All resources used by the task will be freed.
*/
isc_mem_t *
isc_task_mem(isc_task_t *task);
/*
* Get the task's memory context.
*
* Requires:
*
* 'task' is a valid task.
*
* Returns:
*
* The memory context specified when the task was created.
*/
isc_result_t
isc_task_send(isc_task_t *task, isc_event_t **eventp);
/*
* Send '*event' to 'task'.
*
* Requires:
*
* 'task' is a valid task.
*
* Ensures
*
* On success, *eventp == NULL
*
* Returns:
*
* ISC_R_SUCCESS
* ISC_R_TASKDONE The task is done.
* ISC_R_TASKNOSEND Sending events to the task is not
* currently allowed.
*/
unsigned int
isc_task_purgerange(isc_task_t *task, void *sender, isc_eventtype_t first,
isc_eventtype_t last);
/*
* Purge events from a task's event queue.
*
* Notes:
* Events whose sender is 'sender', and whose type is >= first and
* <= last will be purged. A sender of NULL will match any sender.
*
* Requires:
*
* 'task' is a valid task.
*
* last >= first
*
* Returns:
*
* The number of events purged.
*/
unsigned int
isc_task_purge(isc_task_t *task, void *sender, isc_eventtype_t type);
/*
* Purge events from a task's event queue.
*
* Notes:
* Events whose sender is 'sender', and whose type is 'type'
* will be purged. A sender of NULL will match any sender.
*
* This function is equivalent to
*
* isc_task_purgerange(task, sender, type, type);
*
* Requires:
*
* 'task' is a valid task.
*
* last >= first
*
* Returns:
*
* The number of events purged.
*/
isc_result_t
isc_task_allowsend(isc_task_t *task, isc_boolean_t allow);
/*
* Allow or disallow sending events to 'task'.
*
* Notes:
*
* Sending events is allowed when a task is created.
*
* This functionality will always be available, but the interface
* may change in the future. In particular, it may be unified with
* isc_task_allowdone() in an isc_task_getoptions()/isc_task_setoptions()
* block.
*
* Requires:
*
* 'task' is a valid task.
*
* Ensures:
*
* On success,
*
* If 'allow' is ISC_TRUE, then events may be send to the task.
* Otherwise, any attempt to send an event to the task will be
* disallowed and return ISC_R_TASKNOSEND.
*
* Returns:
*
* ISC_R_SUCCESS
* ISC_R_TASKDONE The task is done.
*/
isc_result_t
isc_task_allowdone(isc_task_t *task, isc_boolean_t allow);
/*
* Allow or disallow automatic termination of 'task'.
*
* Notes:
*
* Automatic task termination is allowed when a task is created.
*
* This functionality will always be available, but the interface
* may change in the future. In particular, it may be unified with
* isc_task_allowsend() in an isc_task_getoptions()/isc_task_setoptions()
* block.
*
* Requires:
*
* 'task' is a valid task.
*
* Ensures:
*
* On success,
*
* If 'allow' is ISC_TRUE, then when a task has been shutdown
* and its event queue becomes empty, the task will enter the
* done state. Otherwise, a task that is shutting down will not
* exit, even if its event queue becomes empty.
*
* Returns:
*
* ISC_R_SUCCESS
* ISC_R_TASKDONE The task is done.
*/
isc_result_t
isc_task_onshutdown(isc_task_t *task, isc_taskaction_t action, void *arg);
/*
* Send a shutdown event with action 'action' and argument 'arg' when
* 'task' is shutdown.
*
* Notes:
*
* Shutdown events are posted in LIFO order.
*
* Requires:
*
* 'task' is a valid task.
*
* 'action' is a valid task action.
*
* Ensures:
*
* When the task is shutdown, shutdown events requested with
* isc_task_onshutdown() will be appended to the task's event queue.
*
* Returns:
*
* ISC_R_SUCCESS
* ISC_R_NOMEMORY
* ISC_R_TASKSHUTTINGDOWN Task is shutting down.
* ISC_R_TASKSHUTDOWN Task is shut down.
*/
void
isc_task_shutdown(isc_task_t *task);
/*
* Shutdown 'task'.
*
* Notes:
*
* Shutting down a task causes any shutdown events requested with
* isc_task_onshutdown() to be posted (in LIFO order). The task
* moves into a "shutting down" mode which prevents further calls
* to isc_task_onshutdown(). If automatic task termination is allowed,
* the task will enter the done state (i.e. terminate) when the event
* queue becomes empty.
*
* Trying to shutdown a task that has already been shutdown has no
* effect.
*
* Requires:
*
* 'task' is a valid task.
*
* Ensures:
*
* Any shutdown events requested with isc_task_onshutdown() have been
* posted (in LIFO order).
*/
void
isc_task_destroy(isc_task_t **taskp);
/*
* Destroy '*taskp'.
*
* Notes:
*
* This call is equivalent to:
*
* isc_task_shutodown(*taskp);
* isc_task_detach(taskp);
*
* Requires:
*
* '*taskp' is a valid task.
*
* Ensures:
*
* Any shutdown events requested with isc_task_onshutdown() have been
* posted (in LIFO order).
*
* *taskp == NULL
*
* If '*taskp' is the last reference to the task,
*
* All resources used by the task will be freed.
*/
/*****
@ -113,6 +392,10 @@ isc_taskmgr_create(isc_mem_t *mctx, unsigned int workers,
* create 'workers' threads, but if at least one thread creation
* succeeds, isc_taskmgr_create() may return ISC_R_SUCCESS.
*
* If 'default_quantum' is non-zero, then it will be used as the default
* quantum value when tasks are created. If zero, then an implementation
* defined default quantum will be used.
*
* Requires:
*
* 'mctx' is a valid memory context.
@ -134,7 +417,39 @@ isc_taskmgr_create(isc_mem_t *mctx, unsigned int workers,
* ISC_R_UNEXPECTED An unexpected error occurred.
*/
void isc_taskmgr_destroy(isc_taskmgr_t **);
void
isc_taskmgr_destroy(isc_taskmgr_t **managerp);
/*
* Destroy '*managerp'.
*
* Notes:
*
* Calling isc_taskmgr_destroy() will shutdown all tasks managed by
* *managerp that haven't already been shutdown. The call will block
* until all tasks have entered the done state.
*
* isc_taskmgr_destroy() must not be called by a task event action,
* because it would block forever waiting for the event action to
* complete. An event action that wants to cause task manager shutdown
* should request some non-event action thread of execution to do the
* shutdown, e.g. by signalling a condition variable or using
* isc_app_shutdown().
*
* Task manager references are not reference counted, so the caller
* must ensure that no attempt will be made to use the manager after
* isc_taskmgr_destroy() returns.
*
* Requires:
*
* '*managerp' is a valid task manager.
*
* isc_taskmgr_destroy() has not be called previously on '*managerp'.
*
* Ensures:
*
* All resources used by the task manager, and any tasks it managed,
* have been freed.
*/
ISC_LANG_ENDDECLS