schedule.c

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/*
 * Copyright 2008 - 2016 Chris Young <chris@unsatisfactorysoftware.co.uk>
 *
 * This file is part of NetSurf, http://www.netsurf-browser.org/
 *
 * NetSurf 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; version 2 of the License.
 *
 * NetSurf 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, see <http://www.gnu.org/licenses/>.
 */
 
#include "amiga/os3support.h"
 
#include <proto/dos.h>
#include <proto/exec.h>
#include <proto/timer.h>
#include <proto/utility.h> /* For Amiga2Date */
 
#include <stdio.h>
#include <stdbool.h>
#include <pbl.h>
 
#include "utils/errors.h"
#include "utils/log.h"
 
#include "amiga/memory.h"
#include "amiga/schedule.h"
 
struct nscallback
{
        struct TimeRequest timereq;
        struct TimeVal tv; /* time we expect the event to occur */
        void *restrict callback;
        void *restrict p;
};
 
static struct nscallback *tioreq;
struct Device *TimerBase;
#ifdef __amigaos4__
struct TimerIFace *ITimer;
#else
static struct MsgPort *schedule_msgport = NULL;
#endif
 
static PblHeap *schedule_list;
 
/**
 * Remove timer event
 *
 * \param  nscb  callback
 *
 * The timer event for the callback is aborted
 */
 
static void ami_schedule_remove_timer_event(struct nscallback *nscb)
{
        if(!nscb) return;
 
        if(CheckIO((struct IORequest *)nscb)==NULL)
                AbortIO((struct IORequest *)nscb);
 
        WaitIO((struct IORequest *)nscb);
}
 
/**
 * Add timer event
 *
 * \param  nscb  callback
 * \param  t     time in ms
 *
 * NetSurf will be signalled in t ms for this event.
 */
 
static nserror ami_schedule_add_timer_event(struct nscallback *nscb, int t)
{
        struct TimeVal tv;
        ULONG time_us = t * 1000; /* t converted to µs */
 
        tv.Seconds = time_us / 1000000;
        tv.Microseconds = time_us % 1000000;
 
        GetSysTime(&nscb->tv);
        AddTime(&nscb->tv, &tv); // now contains time when event occurs (for debug and heap sorting)
 
        nscb->timereq.Request.io_Command = TR_ADDREQUEST;
        nscb->timereq.Time.Seconds = tv.Seconds; // secs
        nscb->timereq.Time.Microseconds = tv.Microseconds; // micro
        SendIO((struct IORequest *)nscb);
 
        return NSERROR_OK;
}
 
/**
 * Locate a scheduled callback
 *
 * \param  callback  callback function
 * \param  p         user parameter, passed to callback function
 * \param  remove    remove callback from the heap
 *
 * A scheduled callback matching both callback and p is returned, or NULL if none present.
 */
 
static struct nscallback *
ami_schedule_locate(void (*callback)(void *p), void *p, bool remove)
{
        PblIterator *iterator;
        struct nscallback *nscb;
        bool found_cb = false;
 
        /* check there is something on the list */
        if (schedule_list == NULL) return NULL;
        if(pblHeapIsEmpty(schedule_list)) return NULL;
 
        iterator = pblHeapIterator(schedule_list);
 
        while ((nscb = pblIteratorNext(iterator)) != (void *)-1) {
                if ((nscb->callback == callback) && (nscb->p == p)) {
                        if (remove == true) pblIteratorRemove(iterator);
                        found_cb = true;
                        break;
                }
        };
 
        pblIteratorFree(iterator);
 
        if (found_cb == true) return nscb;
                else return NULL;
}
 
/**
 * Reschedule a callback.
 *
 * \param  nscb  callback
 * \param  t     time in ms
 *
 * The nscallback will be rescheduled for t ms.
 */
 
static nserror ami_schedule_reschedule(struct nscallback *nscb, int t)
{
        ami_schedule_remove_timer_event(nscb);
        if (ami_schedule_add_timer_event(nscb, t) != NSERROR_OK)
                return NSERROR_NOMEM;
 
        pblHeapConstruct(schedule_list);
        return NSERROR_OK;
}
 
/**
 * Unschedule a callback.
 *
 * \param  callback  callback function
 * \param  p         user parameter, passed to callback function
 * \param  abort     abort pending timer
 *
 * All scheduled callbacks matching both callback and p are removed.
 */
 
static nserror schedule_remove(void (*callback)(void *p), void *p, bool abort)
{
        struct nscallback *nscb;
 
        nscb = ami_schedule_locate(callback, p, true);
 
        if(nscb != NULL) {
                if(abort == true) ami_schedule_remove_timer_event(nscb);
#ifdef __amigaos4__
                FreeSysObject(ASOT_IOREQUEST, nscb);
#else
                FreeVec(nscb);
#endif
                pblHeapConstruct(schedule_list);
        }
 
        return NSERROR_OK;
}
 
static void schedule_remove_all(void)
{
        PblIterator *iterator;
        struct nscallback *nscb;
 
        if(pblHeapIsEmpty(schedule_list)) return;
 
        iterator = pblHeapIterator(schedule_list);
 
        while ((nscb = pblIteratorNext(iterator)) != (void *)-1) {
                ami_schedule_remove_timer_event(nscb);
                pblIteratorRemove(iterator);
#ifdef __amigaos4__
                FreeSysObject(ASOT_IOREQUEST, nscb);
#else
                FreeVec(nscb);
#endif
        };
 
        pblIteratorFree(iterator);
}
 
static int ami_schedule_compare(const void *prev, const void *next)
{
        struct nscallback *nscb1 = *(struct nscallback **)prev;
        struct nscallback *nscb2 = *(struct nscallback **)next;
 
        /**\todo a heap probably isn't the best idea now */
        return CmpTime(&nscb1->tv, &nscb2->tv);
}
 
/* Outputs all scheduled events to the log */
static void ami_schedule_dump(void)
{
        PblIterator *iterator;
        struct nscallback *nscb;
        struct ClockData clockdata;
        
        if(pblHeapIsEmpty(schedule_list)) return;
 
        struct TimeVal tv;
        GetSysTime(&tv);
        Amiga2Date(tv.Seconds, &clockdata);
        
        NSLOG(netsurf, INFO, "Current time = %d-%d-%d %d:%d:%d.%lu",
              clockdata.mday, clockdata.month, clockdata.year,
              clockdata.hour, clockdata.min, clockdata.sec, tv.Microseconds);
        NSLOG(netsurf, INFO, "Events remaining in queue:");
 
        iterator = pblHeapIterator(schedule_list);
 
        while ((nscb = pblIteratorNext(iterator)) != (void *)-1) {
                Amiga2Date(nscb->tv.Seconds, &clockdata);
                NSLOG(netsurf, INFO,
                      "nscb: %p, at %d-%d-%d %d:%d:%d.%lu, callback: %p, %p",
                      nscb, clockdata.mday, clockdata.month, clockdata.year,
                      clockdata.hour, clockdata.min, clockdata.sec,
                      nscb->tv.Microseconds, nscb->callback, nscb->p);
                if(CheckIO((struct IORequest *)nscb) == NULL) {
                        NSLOG(netsurf, INFO, "-> ACTIVE");
                } else {
                        NSLOG(netsurf, INFO, "-> COMPLETE");
                }
        };
 
        pblIteratorFree(iterator);
}
 
/**
 * Process signalled event
 *
 * This implementation only processes the callback that arrives in the message from timer.device.
 */
static bool ami_scheduler_run(struct nscallback *nscb)
{
        void (*callback)(void *p);
        void *p;
 
        callback = nscb->callback;
        p = nscb->p;
 
        schedule_remove(callback, p, false); /* this does a lookup as we don't know if we're the first item on the heap */
 
        callback(p);
        return true;
}
 
static void ami_schedule_open_timer(struct MsgPort *msgport)
{
#ifdef __amigaos4__
        tioreq = (struct nscallback *)AllocSysObjectTags(ASOT_IOREQUEST,
                                ASOIOR_Size, sizeof(struct nscallback),
                                ASOIOR_ReplyPort, msgport,
                                ASO_NoTrack, FALSE,
                                TAG_DONE);
#else
        tioreq = (struct nscallback *)CreateIORequest(msgport, sizeof(struct nscallback));
#endif
 
        OpenDevice("timer.device", UNIT_VBLANK, (struct IORequest *)tioreq, 0);
 
        TimerBase = (struct Device *)tioreq->timereq.Request.io_Device;
#ifdef __amigaos4__
        ITimer = (struct TimerIFace *)GetInterface((struct Library *)TimerBase, "main", 1, NULL);
#endif
}
 
static void ami_schedule_close_timer(void)
{
#ifdef __amigaos4__
        if(ITimer) DropInterface((struct Interface *)ITimer);
#endif
        CloseDevice((struct IORequest *) tioreq);
        FreeSysObject(ASOT_IOREQUEST, tioreq);
}
 
/* exported interface documented in amiga/schedule.h */
nserror ami_schedule_create(struct MsgPort *msgport)
{
        ami_schedule_open_timer(msgport);
#ifndef __amigaos4__
        schedule_msgport = msgport;
#endif
        schedule_list = pblHeapNew();
 
        if (schedule_list == NULL) {
                return NSERROR_NOMEM;
        }
 
        pblHeapSetCompareFunction(schedule_list, ami_schedule_compare);
 
        return NSERROR_OK;
}
 
/* exported interface documented in amiga/schedule.h */
void ami_schedule_free(void)
{
        ami_schedule_dump();
        schedule_remove_all();
        pblHeapFree(schedule_list); // this should be empty at this point
        schedule_list = NULL;
 
        ami_schedule_close_timer();
}
 
/* exported function documented in amiga/schedule.h */
nserror ami_schedule(int t, void (*callback)(void *p), void *p)
{
        struct nscallback *nscb;
 
        if(t == 0) t = 1;
 
        if(schedule_list == NULL) return NSERROR_INIT_FAILED;
        if(t < 0) return schedule_remove(callback, p, true);
 
        if ((nscb = ami_schedule_locate(callback, p, false))) {
                return ami_schedule_reschedule(nscb, t);
        }
 
#ifdef __amigaos4__
        nscb = AllocSysObjectTags(ASOT_IOREQUEST,
                                                        ASOIOR_Duplicate, tioreq,
                                                        TAG_DONE);
        if(nscb == NULL) return NSERROR_NOMEM;
#else
        if(schedule_msgport == NULL) return NSERROR_NOMEM;
        nscb = AllocVec(sizeof(struct nscallback), MEMF_PUBLIC | MEMF_CLEAR);
        if(nscb == NULL) return NSERROR_NOMEM;
        *nscb = *tioreq;
#endif
 
        if (ami_schedule_add_timer_event(nscb, t) != NSERROR_OK)
                return NSERROR_NOMEM;
 
        nscb->callback = callback;
        nscb->p = p;
 
        pblHeapInsert(schedule_list, nscb);
 
        return NSERROR_OK;
 
}
 
/* exported interface documented in amiga/schedule.h */
void ami_schedule_handle(struct MsgPort *nsmsgport)
{
        /* nsmsgport is the NetSurf message port that
         * timer.device is sending messages to. */
 
        struct nscallback *timermsg;
 
        while((timermsg = (struct nscallback *)GetMsg(nsmsgport))) {
                ami_scheduler_run(timermsg);
        };
}