/* * The mrouted program is covered by the license in the accompanying file * named "LICENSE.mrouted". Use of the mrouted program represents acceptance * of the terms and conditions listed in that file. * * The mrouted program is COPYRIGHT 1989 by The Board of Trustees of * Leland Stanford Junior University. * * * callout.c,v 3.8.4.5 1997/05/16 20:18:25 fenner Exp * * $FreeBSD$ */ #include "defs.h" /* the code below implements a callout queue */ static int id = 0; static struct timeout_q *Q = 0; /* pointer to the beginning of timeout queue */ struct timeout_q { struct timeout_q *next; /* next event */ int id; cfunc_t func; /* function to call */ void *data; /* func's data */ int time; /* time offset to next event*/ }; #ifdef CALLOUT_DEBUG static void print_Q __P((void)); #else #define print_Q() #endif void callout_init() { if (Q) { log(LOG_ERR, 0, "timer used before callout_init()"); exit(1); } Q = (struct timeout_q *) 0; } void free_all_callouts() { struct timeout_q *p; while (Q) { p = Q; Q = Q->next; free(p); } } /* * elapsed_time seconds have passed; perform all the events that should * happen. */ void age_callout_queue(elapsed_time) int elapsed_time; { struct timeout_q *ptr, *expQ; #ifdef CALLOUT_DEBUG IF_DEBUG(DEBUG_TIMEOUT) log(LOG_DEBUG, 0, "aging queue (elapsed time %d):", elapsed_time); print_Q(); #endif expQ = Q; ptr = NULL; while (Q) { if (Q->time > elapsed_time) { Q->time -= elapsed_time; if (ptr) { ptr->next = NULL; break; } return; } else { elapsed_time -= Q->time; ptr = Q; Q = Q->next; } } /* handle queue of expired timers */ while (expQ) { ptr = expQ; if (ptr->func) ptr->func(ptr->data); expQ = expQ->next; free(ptr); } } /* * Return in how many seconds age_callout_queue() would like to be called. * Return -1 if there are no events pending. */ int timer_nextTimer() { if (Q) { if (Q->time < 0) { log(LOG_WARNING, 0, "timer_nextTimer top of queue says %d", Q->time); return 0; } return Q->time; } return -1; } /* * sets the timer */ int timer_setTimer(delay, action, data) int delay; /* number of units for timeout */ cfunc_t action; /* function to be called on timeout */ void *data; /* what to call the timeout function with */ { struct timeout_q *ptr, *node, *prev; #ifdef CALLOUT_DEBUG IF_DEBUG(DEBUG_TIMEOUT) log(LOG_DEBUG, 0, "setting timer:"); print_Q(); #endif /* create a node */ node = (struct timeout_q *)malloc(sizeof(struct timeout_q)); if (node == 0) { log(LOG_WARNING, 0, "Malloc Failed in timer_settimer\n"); return -1; } node->func = action; node->data = data; node->time = delay; node->next = 0; node->id = ++id; prev = ptr = Q; /* insert node in the queue */ /* if the queue is empty, insert the node and return */ if (!Q) Q = node; else { /* chase the pointer looking for the right place */ while (ptr) { if (delay < ptr->time) { /* right place */ node->next = ptr; if (ptr == Q) Q = node; else prev->next = node; ptr->time -= node->time; return node->id; } else { /* keep moving */ delay -= ptr->time; node->time = delay; prev = ptr; ptr = ptr->next; } } prev->next = node; } return node->id; } /* returns the time until the timer is scheduled */ int timer_leftTimer(timer_id) int timer_id; { struct timeout_q *ptr; int left = 0; if (!timer_id) return -1; for (ptr = Q; ptr; ptr = ptr->next) { left += ptr->time; if (ptr->id == timer_id) return left; } return -1; } /* clears the associated timer */ void timer_clearTimer(timer_id) int timer_id; { struct timeout_q *ptr, *prev; if (!timer_id) return; prev = ptr = Q; /* * find the right node, delete it. the subsequent node's time * gets bumped up */ while (ptr) { if (ptr->id == timer_id) { /* got the right node */ /* unlink it from the queue */ if (ptr == Q) Q = Q->next; else prev->next = ptr->next; /* increment next node if any */ if (ptr->next != 0) (ptr->next)->time += ptr->time; if (ptr->data) free(ptr->data); free(ptr); return; } prev = ptr; ptr = ptr->next; } } #ifdef CALLOUT_DEBUG /* * debugging utility */ static void print_Q() { struct timeout_q *ptr; IF_DEBUG(DEBUG_TIMEOUT) for (ptr = Q; ptr; ptr = ptr->next) log(LOG_DEBUG, 0, "(%d,%d) ", ptr->id, ptr->time); } #endif /* CALLOUT_DEBUG */