From c906108c21474dfb4ed285bcc0ac6fe02cd400cc Mon Sep 17 00:00:00 2001 From: Stan Shebs Date: Fri, 16 Apr 1999 01:35:26 +0000 Subject: Initial creation of sourceware repository --- sim/ppc/events.c | 387 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 387 insertions(+) create mode 100644 sim/ppc/events.c (limited to 'sim/ppc/events.c') diff --git a/sim/ppc/events.c b/sim/ppc/events.c new file mode 100644 index 0000000..8384622 --- /dev/null +++ b/sim/ppc/events.c @@ -0,0 +1,387 @@ +/* This file is part of the program psim. + + Copyright (C) 1994-1998, Andrew Cagney + + 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 + +#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; + } + ASSERT(current_time == event_queue_time(events)); + ASSERT((events->time_from_event >= 0) == (events->queue != NULL)); +} + +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 - handler 0x%lx, data 0x%lx\n", + (long)event_time, + (long)to_do, + (long)handler, + (long)data)); + zfree(to_do); + handler(data); + } + events->processing = 0; + + /* re-caculate time for new events */ + update_time_from_event(events); +} + + +#endif /* _EVENTS_C_ */ -- cgit v1.1