X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=sched.h;h=4d57c75f3e3bf9b3076e60012bd80fba7cb4567c;hp=ebd38a8ceb8dbf8cfbe7a6fe6982f8baeaa37845;hb=06372eab260c4d2cba43bfef0d668744aa6c1216;hpb=c075e867311c77dfb7171241597e613290d1f62b;ds=sidebyside diff --git a/sched.h b/sched.h index ebd38a8c..4d57c75f 100644 --- a/sched.h +++ b/sched.h @@ -1,85 +1,68 @@ /* - * Copyright (C) 2006 Andre Noll + * Copyright (C) 2006-2008 Andre Noll * - * This program 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 of the License, or - * (at your option) any later version. - * - * This program 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. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. + * Licensed under the GPL v2. For licencing details see COPYING. */ -/** \file sched.h sched and task structures and exported symbols from sched.c */ +/** \file sched.h Sched and task structures and exported symbols from sched.c. */ /** - * paraslash's scheduler + * Paraslash's scheduler. * - * desinged with KISS in mind. It maintains two lists: The pre_select list - * and the post_select list. Tasks add hokks to these lists by registering - * themselves to the scheduler. + * Designed with KISS in mind. It manages two lists of tasks. The pre_select + * list contains pointers to functions that are called before calling select() + * from the main loop. Similarly, \a post_select_list is a list of function + * pointers each of which is called after the select call. Tasks add hooks to + * these lists by registering themselves to the scheduler. */ struct sched { - /** initial value before any pre_select call */ + /** Initial value before any pre_select call. */ struct timeval default_timeout; - /** the current timeout for the upcoming select call */ + /** The current timeout for the upcoming select call. */ struct timeval timeout; - /** fds that should be watched for readability */ + /** fds that should be watched for readability. */ fd_set rfds; - /** fds that should be watched for writability */ + /** fds that should be watched for writability. */ fd_set wfds; - /** highest numbered file descriptor in any of the above fd sets */ + /** Highest numbered file descriptor in any of the above fd sets. */ int max_fileno; - /** the return value of the previous select call */ - int select_ret; + /** In non-NULL, use this function instead of para_select. */ + int (*select_function)(int, fd_set *, fd_set *, struct timeval *); }; /** - * paraslash's task structure + * Paraslash's task structure. * - * before registering a task to the scheduler, the task structure must be + * Before registering a task to the scheduler, the task structure must be * filled in properly by the caller. * - * If one of these functions return a negative value via \a t->ret the - * (optional) event_handler gets called (it may also be called in case another - * event happend). In many cases the only possible event is an error or an eof - * condition and the event handler simply unregisters the task from the - * scheduler. + * If one of these functions sets \a t->error to a negative value, the + * task gets unregistered automatically. * - * \sa struct sched + * \sa struct sched. */ struct task { - /** pointer to the struct this task is embedded in */ - void *private_data; /** - * the pre select hook of \a t + * The pre select hook of \a t. * * Its purpose is to add file descriptors to the fd sets of the - * scheduler and to decrease the select timeout if neccessary. + * scheduler and to decrease the select timeout if necessary. */ void (*pre_select)(struct sched *s, struct task *t); /** - * the postselect hook of \a t + * The postselect hook of \a t. * - * evaluate and act upon the results of the previous select call. + * Evaluate and act upon the results of the previous select call. */ void (*post_select)(struct sched *s, struct task *t); - /** gets called if pre_select or post_select returned an error */ - void (*event_handler)(struct task *t); - /** pre_select() and post_select store their return value here */ - int ret; - /** position of the task in the pre_select list of the scheduler */ + /** Whether this task is in error state. */ + int error; + /** Position of the task in the pre_select list of the scheduler. */ struct list_head pre_select_node; - /** position of the task in the post_select list of the scheduler */ + /** Position of the task in the post_select list of the scheduler. */ struct list_head post_select_node; - /** descriptive text and current status of the task */ + /** Descriptive text and current status of the task. */ char status[MAXLINE]; }; @@ -92,8 +75,7 @@ struct task { extern struct timeval *now; void register_task(struct task *t); -void unregister_task(struct task *t); -int sched(struct sched *s); -void init_sched(void); +int schedule(struct sched *s); char *get_task_list(void); int kill_task(char *id); +void sched_shutdown(void);