/* This file is part of the program psim. Copyright (C) 1994-1998, Andrew Cagney <cagney@highland.com.au> 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 02111-1307, USA. */ #ifndef _EVENTS_C_ #define _EVENTS_C_ #include "basics.h" #include "events.h" #include <signal.h> #if !defined (SIM_EVENTS_POLL_RATE) #define SIM_EVENTS_POLL_RATE 0x1000 #endif /* The event queue maintains a single absolute time using two variables. TIME_OF_EVENT: this holds the time at which the next event is ment to occure. If no next event it will hold the time of the last event. TIME_FROM_EVENT: The current distance from TIME_OF_EVENT. If an event is pending, this will be positive. If no future event is pending this will be negative. This variable is decremented once for each iteration of a clock cycle. Initially, the clock is started at time one (1) with TIME_OF_EVENT == 0 and TIME_FROM_EVENT == -1. Clearly there is a bug in that this code assumes that the absolute time counter will never become greater than 2^62. */ typedef struct _event_entry event_entry; struct _event_entry { void *data; event_handler *handler; signed64 time_of_event; event_entry *next; }; struct _event_queue { int processing; event_entry *queue; event_entry *volatile held; event_entry *volatile *volatile held_end; signed64 time_of_event; signed64 time_from_event; }; STATIC_INLINE_EVENTS\ (void) sim_events_poll (void *data) { event_queue *queue = data; /* just re-schedule in 1000 million ticks time */ event_queue_schedule (queue, SIM_EVENTS_POLL_RATE, sim_events_poll, queue); sim_io_poll_quit (); } INLINE_EVENTS\ (event_queue *) event_queue_create(void) { event_queue *new_event_queue = ZALLOC(event_queue); new_event_queue->processing = 0; new_event_queue->queue = NULL; new_event_queue->held = NULL; new_event_queue->held_end = &new_event_queue->held; /* both times are already zero */ return new_event_queue; } INLINE_EVENTS\ (void) event_queue_init(event_queue *queue) { event_entry *event; /* drain the interrupt queue */ { #if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK) sigset_t old_mask; sigset_t new_mask; sigfillset(&new_mask); /*-LOCK-*/ sigprocmask(SIG_SETMASK, &new_mask, &old_mask); #endif event = queue->held; while (event != NULL) { event_entry *dead = event; event = event->next; zfree(dead); } queue->held = NULL; queue->held_end = &queue->held; #if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK) /*-UNLOCK-*/ sigprocmask(SIG_SETMASK, &old_mask, NULL); #endif } /* drain the normal queue */ event = queue->queue; while (event != NULL) { event_entry *dead = event; event = event->next; zfree(dead); } queue->queue = NULL; /* wind time back to one */ queue->processing = 0; queue->time_of_event = 0; queue->time_from_event = -1; /* schedule our initial counter event */ event_queue_schedule (queue, 0, sim_events_poll, queue); } INLINE_EVENTS\ (signed64) event_queue_time(event_queue *queue) { return queue->time_of_event - queue->time_from_event; } STATIC_INLINE_EVENTS\ (void) update_time_from_event(event_queue *events) { signed64 current_time = event_queue_time(events); if (events->queue != NULL) { events->time_from_event = (events->queue->time_of_event - current_time); events->time_of_event = events->queue->time_of_event; } else { events->time_of_event = current_time - 1; events->time_from_event = -1; } if (WITH_TRACE && ppc_trace[trace_events]) { event_entry *event; int i; for (event = events->queue, i = 0; event != NULL; event = event->next, i++) { TRACE(trace_events, ("event time-from-event - time %ld, delta %ld - event %d, tag 0x%lx, time %ld, handler 0x%lx, data 0x%lx\n", (long)current_time, (long)events->time_from_event, i, (long)event, (long)event->time_of_event, (long)event->handler, (long)event->data)); } } ASSERT(current_time == event_queue_time(events)); } STATIC_INLINE_EVENTS\ (void) insert_event_entry(event_queue *events, event_entry *new_event, signed64 delta) { event_entry *curr; event_entry **prev; signed64 time_of_event; if (delta < 0) error("what is past is past!\n"); /* compute when the event should occure */ time_of_event = event_queue_time(events) + delta; /* find the queue insertion point - things are time ordered */ prev = &events->queue; curr = events->queue; while (curr != NULL && time_of_event >= curr->time_of_event) { ASSERT(curr->next == NULL || curr->time_of_event <= curr->next->time_of_event); prev = &curr->next; curr = curr->next; } ASSERT(curr == NULL || time_of_event < curr->time_of_event); /* insert it */ new_event->next = curr; *prev = new_event; new_event->time_of_event = time_of_event; /* adjust the time until the first event */ update_time_from_event(events); } INLINE_EVENTS\ (event_entry_tag) event_queue_schedule(event_queue *events, signed64 delta_time, event_handler *handler, void *data) { event_entry *new_event = ZALLOC(event_entry); new_event->data = data; new_event->handler = handler; insert_event_entry(events, new_event, delta_time); TRACE(trace_events, ("event scheduled at %ld - tag 0x%lx - time %ld, handler 0x%lx, data 0x%lx\n", (long)event_queue_time(events), (long)new_event, (long)new_event->time_of_event, (long)new_event->handler, (long)new_event->data)); return (event_entry_tag)new_event; } INLINE_EVENTS\ (event_entry_tag) event_queue_schedule_after_signal(event_queue *events, signed64 delta_time, event_handler *handler, void *data) { event_entry *new_event = ZALLOC(event_entry); new_event->data = data; new_event->handler = handler; new_event->time_of_event = delta_time; /* work it out later */ new_event->next = NULL; { #if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK) sigset_t old_mask; sigset_t new_mask; sigfillset(&new_mask); /*-LOCK-*/ sigprocmask(SIG_SETMASK, &new_mask, &old_mask); #endif if (events->held == NULL) { events->held = new_event; } else { *events->held_end = new_event; } events->held_end = &new_event->next; #if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK) /*-UNLOCK-*/ sigprocmask(SIG_SETMASK, &old_mask, NULL); #endif } TRACE(trace_events, ("event scheduled at %ld - tag 0x%lx - time %ld, handler 0x%lx, data 0x%lx\n", (long)event_queue_time(events), (long)new_event, (long)new_event->time_of_event, (long)new_event->handler, (long)new_event->data)); return (event_entry_tag)new_event; } INLINE_EVENTS\ (void) event_queue_deschedule(event_queue *events, event_entry_tag event_to_remove) { event_entry *to_remove = (event_entry*)event_to_remove; ASSERT((events->time_from_event >= 0) == (events->queue != NULL)); if (event_to_remove != NULL) { event_entry *current; event_entry **ptr_to_current; for (ptr_to_current = &events->queue, current = *ptr_to_current; current != NULL && current != to_remove; ptr_to_current = ¤t->next, current = *ptr_to_current); if (current == to_remove) { *ptr_to_current = current->next; TRACE(trace_events, ("event descheduled at %ld - tag 0x%lx - time %ld, handler 0x%lx, data 0x%lx\n", (long)event_queue_time(events), (long)event_to_remove, (long)current->time_of_event, (long)current->handler, (long)current->data)); zfree(current); update_time_from_event(events); } else { TRACE(trace_events, ("event descheduled at %ld - tag 0x%lx - not found\n", (long)event_queue_time(events), (long)event_to_remove)); } } ASSERT((events->time_from_event >= 0) == (events->queue != NULL)); } INLINE_EVENTS\ (int) event_queue_tick(event_queue *events) { signed64 time_from_event; /* we should only be here when the previous tick has been fully processed */ ASSERT(!events->processing); /* move any events that were queued by any signal handlers onto the real event queue. BTW: When inlining, having this code here, instead of in event_queue_process() causes GCC to put greater weight on keeping the pointer EVENTS in a register. This, in turn results in better code being output. */ if (events->held != NULL) { event_entry *held_events; event_entry *curr_event; { #if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK) sigset_t old_mask; sigset_t new_mask; sigfillset(&new_mask); /*-LOCK-*/ sigprocmask(SIG_SETMASK, &new_mask, &old_mask); #endif held_events = events->held; events->held = NULL; events->held_end = &events->held; #if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK) /*-UNLOCK-*/ sigprocmask(SIG_SETMASK, &old_mask, NULL); #endif } do { curr_event = held_events; held_events = curr_event->next; insert_event_entry(events, curr_event, curr_event->time_of_event); } while (held_events != NULL); } /* advance time, checking to see if we've reached time zero which would indicate the time for the next event has arrived */ time_from_event = events->time_from_event; events->time_from_event = time_from_event - 1; return time_from_event == 0; } INLINE_EVENTS\ (void) event_queue_process(event_queue *events) { signed64 event_time = event_queue_time(events); ASSERT((events->time_from_event == -1 && events->queue != NULL) || events->processing); /* something to do */ /* consume all events for this or earlier times. Be careful to allow a new event to appear under our feet */ events->processing = 1; while (events->queue != NULL && events->queue->time_of_event <= event_time) { event_entry *to_do = events->queue; event_handler *handler = to_do->handler; void *data = to_do->data; events->queue = to_do->next; TRACE(trace_events, ("event issued at %ld - tag 0x%lx - time %ld, handler 0x%lx, data 0x%lx\n", (long)event_time, (long)to_do, (long)to_do->time_of_event, (long)handler, (long)data)); zfree(to_do); /* Always re-compute the time to the next event so that HANDLER() can safely insert new events into the queue. */ update_time_from_event(events); handler(data); } events->processing = 0; ASSERT(events->time_from_event > 0); ASSERT(events->queue != NULL); /* always poll event */ } #endif /* _EVENTS_C_ */