text: /*
   * Copyright (C) 2009-2012, 2014  Internet Systems Consortium, Inc. ("ISC")
   *
   * Permission to use, copy, modify, and/or distribute this software for any
   * purpose with or without fee is hereby granted, provided that the above
   * copyright notice and this permission notice appear in all copies.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
   * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
   * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
   * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
   * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
   * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
   * PERFORMANCE OF THIS SOFTWARE.
   */
  
  /* $Id$ */
  
  #include <config.h>
  
  #include <unistd.h>
  
  #include <isc/app.h>
  #include <isc/magic.h>
  #include <isc/mutex.h>
  #include <isc/once.h>
  #include <isc/task.h>
  #include <isc/util.h>
  
  static isc_mutex_t createlock;
  static isc_once_t once = ISC_ONCE_INIT;
  static isc_taskmgrcreatefunc_t taskmgr_createfunc = NULL;
  
  static void
  initialize(void) {
  	RUNTIME_CHECK(isc_mutex_init(&createlock) == ISC_R_SUCCESS);
  }
  
  isc_result_t
  isc_task_register(isc_taskmgrcreatefunc_t createfunc) {
  	isc_result_t result = ISC_R_SUCCESS;
  
  	RUNTIME_CHECK(isc_once_do(&once, initialize) == ISC_R_SUCCESS);
  
  	LOCK(&createlock);
  	if (taskmgr_createfunc == NULL)
  		taskmgr_createfunc = createfunc;
  	else
  		result = ISC_R_EXISTS;
  	UNLOCK(&createlock);
  
  	return (result);
  }
  
  isc_result_t
  isc_taskmgr_createinctx(isc_mem_t *mctx, isc_appctx_t *actx,
  			unsigned int workers, unsigned int default_quantum,
  			isc_taskmgr_t **managerp)
  {
  	isc_result_t result;
  
  	LOCK(&createlock);
  
  	REQUIRE(taskmgr_createfunc != NULL);
  	result = (*taskmgr_createfunc)(mctx, workers, default_quantum,
  				       managerp);
  
  	UNLOCK(&createlock);
  
  	if (result == ISC_R_SUCCESS)
  		isc_appctx_settaskmgr(actx, *managerp);
  
  	return (result);
  }
  
  isc_result_t
  isc_taskmgr_create(isc_mem_t *mctx, unsigned int workers,
  		   unsigned int default_quantum, isc_taskmgr_t **managerp)
  {
  	isc_result_t result;
  
  	LOCK(&createlock);
  
  	REQUIRE(taskmgr_createfunc != NULL);
  	result = (*taskmgr_createfunc)(mctx, workers, default_quantum,
  				       managerp);
  
  	UNLOCK(&createlock);
  
  	return (result);
  }
  
  void
  isc_taskmgr_destroy(isc_taskmgr_t **managerp) {
  	REQUIRE(managerp != NULL && ISCAPI_TASKMGR_VALID(*managerp));
  
  	(*managerp)->methods->destroy(managerp);
  
  	ENSURE(*managerp == NULL);
  }
  
  void
  isc_taskmgr_setmode(isc_taskmgr_t *manager, isc_taskmgrmode_t mode) {
  	REQUIRE(ISCAPI_TASKMGR_VALID(manager));
  
  	manager->methods->setmode(manager, mode);
  }
  
  isc_taskmgrmode_t
  isc_taskmgr_mode(isc_taskmgr_t *manager) {
  	REQUIRE(ISCAPI_TASKMGR_VALID(manager));
  
  	return (manager->methods->mode(manager));
  }
  
  isc_result_t
  isc_task_create(isc_taskmgr_t *manager, unsigned int quantum,
  		isc_task_t **taskp)
  {
  	REQUIRE(ISCAPI_TASKMGR_VALID(manager));
  	REQUIRE(taskp != NULL && *taskp == NULL);
  
  	return (manager->methods->taskcreate(manager, quantum, taskp));
  }
  
  void
  isc_task_attach(isc_task_t *source, isc_task_t **targetp) {
  	REQUIRE(ISCAPI_TASK_VALID(source));
  	REQUIRE(targetp != NULL && *targetp == NULL);
  
  	source->methods->attach(source, targetp);
  
  	ENSURE(*targetp == source);
  }
  
  void
  isc_task_detach(isc_task_t **taskp) {
  	REQUIRE(taskp != NULL && ISCAPI_TASK_VALID(*taskp));
  
  	(*taskp)->methods->detach(taskp);
  
  	ENSURE(*taskp == NULL);
  }
  
  void
  isc_task_send(isc_task_t *task, isc_event_t **eventp) {
  	REQUIRE(ISCAPI_TASK_VALID(task));
  	REQUIRE(eventp != NULL && *eventp != NULL);
  
  	task->methods->send(task, eventp);
  
  	ENSURE(*eventp == NULL);
  }
  
  void
  isc_task_sendanddetach(isc_task_t **taskp, isc_event_t **eventp) {
  	REQUIRE(taskp != NULL && ISCAPI_TASK_VALID(*taskp));
  	REQUIRE(eventp != NULL && *eventp != NULL);
  
  	(*taskp)->methods->sendanddetach(taskp, eventp);
  
  	ENSURE(*taskp == NULL && *eventp == NULL);
  }
  
  unsigned int
  isc_task_unsend(isc_task_t *task, void *sender, isc_eventtype_t type,
  		void *tag, isc_eventlist_t *events)
  {
  	REQUIRE(ISCAPI_TASK_VALID(task));
  
  	return (task->methods->unsend(task, sender, type, tag, events));
  }
  
  isc_result_t
  isc_task_onshutdown(isc_task_t *task, isc_taskaction_t action, void *arg)
  {
  	REQUIRE(ISCAPI_TASK_VALID(task));
  
  	return (task->methods->onshutdown(task, action, arg));
  }
  
  void
  isc_task_shutdown(isc_task_t *task) {
  	REQUIRE(ISCAPI_TASK_VALID(task));
  
  	task->methods->shutdown(task);
  }
  
  void
  isc_task_setname(isc_task_t *task, const char *name, void *tag) {
  	REQUIRE(ISCAPI_TASK_VALID(task));
  
  	task->methods->setname(task, name, tag);
  }
  
  unsigned int
  isc_task_purge(isc_task_t *task, void *sender, isc_eventtype_t type, void *tag)
  {
  	REQUIRE(ISCAPI_TASK_VALID(task));
  
  	return (task->methods->purgeevents(task, sender, type, tag));
  }
  
  void
  isc_taskmgr_setexcltask(isc_taskmgr_t *mgr, isc_task_t *task) {
  	REQUIRE(ISCAPI_TASK_VALID(task));
  	mgr->methods->setexcltask(mgr, task);
  }
  
  isc_result_t
  isc_taskmgr_excltask(isc_taskmgr_t *mgr, isc_task_t **taskp) {
  	return (mgr->methods->excltask(mgr, taskp));
  }
  
  isc_result_t
  isc_task_beginexclusive(isc_task_t *task) {
  	REQUIRE(ISCAPI_TASK_VALID(task));
  
  	return (task->methods->beginexclusive(task));
  }
  
  void
  isc_task_endexclusive(isc_task_t *task) {
  	REQUIRE(ISCAPI_TASK_VALID(task));
  
  	task->methods->endexclusive(task);
  }
  
  void
  isc_task_setprivilege(isc_task_t *task, isc_boolean_t priv) {
  	REQUIRE(ISCAPI_TASK_VALID(task));
  
  	task->methods->setprivilege(task, priv);
  }
  
  isc_boolean_t
  isc_task_privilege(isc_task_t *task) {
  	REQUIRE(ISCAPI_TASK_VALID(task));
  
  	return (task->methods->privilege(task));
  }
  
  
  /*%
   * This is necessary for libisc's internal timer implementation.  Other
   * implementation might skip implementing this.
   */
  unsigned int
  isc_task_purgerange(isc_task_t *task, void *sender, isc_eventtype_t first,
  		    isc_eventtype_t last, void *tag)
  {
  	REQUIRE(ISCAPI_TASK_VALID(task));
  
  	return (task->methods->purgerange(task, sender, first, last, tag));
  }
  