+++ /dev/null
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
- * Copyright (c) 2002 Cray Inc.
- * Copyright (c) 2002 Eric Hoffman
- *
- * This file is part of Lustre, http://www.lustre.org.
- *
- * Lustre is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * Lustre 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 Lustre; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-/* timer.c:
- * this file implements a simple priority-queue based timer system. when
- * combined with a file which implements now() and block(), it can
- * be used to provide course-grained time-based callbacks.
- */
-
-#include <pqtimer.h>
-#include <stdlib.h>
-#include <string.h>
-
-struct timer {
- void (*function)(void *);
- void *arg;
- when w;
- int interval;
- int disable;
-};
-
-typedef struct thunk *thunk;
-struct thunk {
- void (*f)(void *);
- void *a;
- thunk next;
-};
-
-extern when now(void);
-
-static thunk thunks;
-static int internal;
-static void (*block_function)(when);
-static int number_of_timers;
-static int size_of_pqueue;
-static timer *timers;
-
-
-static void heal(int where)
-{
- int left=(where<<1);
- int right=(where<<1)+1;
- int min=where;
- timer temp;
-
- if (left <= number_of_timers)
- if (timers[left]->w < timers[min]->w) min=left;
- if (right <= number_of_timers)
- if (timers[right]->w < timers[min]->w) min=right;
- if (min != where){
- temp=timers[where];
- timers[where]=timers[min];
- timers[min]=temp;
- heal(min);
- }
-}
-
-static void add_pqueue(int i)
-{
- timer temp;
- int parent=(i>>1);
- if ((i>1) && (timers[i]->w< timers[parent]->w)){
- temp=timers[i];
- timers[i]=timers[parent];
- timers[parent]=temp;
- add_pqueue(parent);
- }
-}
-
-static void add_timer(timer t)
-{
- if (size_of_pqueue<(number_of_timers+2)){
- int oldsize=size_of_pqueue;
- timer *new=(void *)malloc(sizeof(struct timer)*(size_of_pqueue+=10));
- memcpy(new,timers,sizeof(timer)*oldsize);
- timers=new;
- }
- timers[++number_of_timers]=t;
- add_pqueue(number_of_timers);
-}
-
-/* Function: register_timer
- * Arguments: interval: the time interval from the current time when
- * the timer function should be called
- * function: the function to call when the time has expired
- * argument: the argument to call it with.
- * Returns: a pointer to a timer structure
- */
-timer register_timer(when interval,
- void (*function)(void *),
- void *argument)
-{
- timer t=(timer)malloc(sizeof(struct timer));
-
- t->arg=argument;
- t->function=function;
- t->interval=interval;
- t->disable=0;
- t->w=now()+interval;
- add_timer(t);
- if (!internal && (number_of_timers==1))
- block_function(t->w);
- return(t);
-}
-
-/* Function: remove_timer
- * Arguments: t:
- * Returns: nothing
- *
- * remove_timer removes a timer from the system, insuring
- * that it will never be called. It does not actually
- * free the timer due to reentrancy issues.
- */
-
-void remove_timer(timer t)
-{
- t->disable=1;
-}
-
-
-
-void timer_fire()
-{
- timer current;
-
- current=timers[1];
- timers[1]=timers[number_of_timers--];
- heal(1);
- if (!current->disable) {
- (*current->function)(current->arg);
- }
- free(current);
-}
-
-when next_timer(void)
-{
- when here=now();
-
- while (number_of_timers && (timers[1]->w <= here)) timer_fire();
- if (number_of_timers) return(timers[1]->w);
- return(0);
-}
-
-/* Function: timer_loop
- * Arguments: none
- * Returns: never
- *
- * timer_loop() is the blocking dispatch function for the timer.
- * Is calls the block() function registered with init_timer,
- * and handles associated with timers that have been registered.
- */
-void timer_loop()
-{
- when here;
-
- while (1){
- thunk z;
- here=now();
-
- for (z=thunks;z;z=z->next) (*z->f)(z->a);
-
- if (number_of_timers){
- if (timers[1]->w > here){
- (*block_function)(timers[1]->w);
- } else {
- timer_fire();
- }
- } else {
- thunk z;
- for (z=thunks;z;z=z->next) (*z->f)(z->a);
- (*block_function)(0);
- }
- }
-}
-
-
-/* Function: register_thunk
- * Arguments: f: the function to call
- * a: the single argument to call it with
- *
- * Thunk functions get called at irregular intervals, they
- * should not assume when, or take a particularily long
- * amount of time. Thunks are for background cleanup tasks.
- */
-void register_thunk(void (*f)(void *),void *a)
-{
- thunk t=(void *)malloc(sizeof(struct thunk));
- t->f=f;
- t->a=a;
- t->next=thunks;
- thunks=t;
-}
-
-/* Function: initialize_timer
- * Arguments: block: the function to call to block for the specified interval
- *
- * initialize_timer() must be called before any other timer function,
- * including timer_loop.
- */
-void initialize_timer(void (*block)(when))
-{
- block_function=block;
- number_of_timers=0;
- size_of_pqueue=10;
- timers=(timer *)malloc(sizeof(timer)*size_of_pqueue);
- thunks=0;
-}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff