rockbox/uisimulator/sdl/kernel.c
Michael Sevakis 55392f7d3c Perform the obligatory fix-the-sims dance.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@12882 a1c6a512-1295-4272-9138-f99709370657
2007-03-21 23:33:49 +00:00

369 lines
8.4 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2002 by Felix Arends
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include <stdlib.h>
#include "memory.h"
#include "uisdl.h"
#include "kernel.h"
#include "thread-sdl.h"
#include "thread.h"
#include "debug.h"
static void (*tick_funcs[MAX_NUM_TICK_TASKS])(void);
int set_irq_level (int level)
{
static int _lv = 0;
return (_lv = level);
}
#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
/* Moves waiting thread's descriptor to the current sender when a
message is dequeued */
static void queue_fetch_sender(struct queue_sender_list *send,
unsigned int i)
{
int old_level = set_irq_level(15<<4);
struct thread_entry **spp = &send->senders[i];
if(*spp)
{
send->curr_sender = *spp;
*spp = NULL;
}
set_irq_level(old_level);
}
/* Puts the specified return value in the waiting thread's return value
and wakes the thread - a sender should be confirmed to exist first */
static void queue_release_sender(struct thread_entry **sender,
intptr_t retval)
{
(*sender)->retval = retval;
*sender = NULL;
}
/* Releases any waiting threads that are queued with queue_send -
reply with NULL */
static void queue_release_all_senders(struct event_queue *q)
{
if(q->send)
{
unsigned int i;
for(i = q->read; i != q->write; i++)
{
struct thread_entry **spp =
&q->send->senders[i & QUEUE_LENGTH_MASK];
if(*spp)
{
queue_release_sender(spp, 0);
}
}
}
}
/* Enables queue_send on the specified queue - caller allocates the extra
data structure */
void queue_enable_queue_send(struct event_queue *q,
struct queue_sender_list *send)
{
q->send = send;
memset(send, 0, sizeof(*send));
}
#endif /* HAVE_EXTENDED_MESSAGING_AND_NAME */
void queue_init(struct event_queue *q, bool register_queue)
{
(void)register_queue;
q->read = 0;
q->write = 0;
q->thread = NULL;
#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
q->send = NULL; /* No message sending by default */
#endif
}
void queue_delete(struct event_queue *q)
{
(void)q;
}
void queue_wait(struct event_queue *q, struct event *ev)
{
unsigned int rd;
while(q->read == q->write)
{
switch_thread(true, NULL);
}
rd = q->read++ & QUEUE_LENGTH_MASK;
*ev = q->events[rd];
#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
if(q->send && q->send->senders[rd])
{
/* Get data for a waiting thread if one */
queue_fetch_sender(q->send, rd);
}
#endif
}
void queue_wait_w_tmo(struct event_queue *q, struct event *ev, int ticks)
{
unsigned int timeout = current_tick + ticks;
while(q->read == q->write && TIME_BEFORE( current_tick, timeout ))
{
sim_sleep(1);
}
if(q->read != q->write)
{
unsigned int rd = q->read++ & QUEUE_LENGTH_MASK;
*ev = q->events[rd];
#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
if(q->send && q->send->senders[rd])
{
/* Get data for a waiting thread if one */
queue_fetch_sender(q->send, rd);
}
#endif
}
else
{
ev->id = SYS_TIMEOUT;
}
}
void queue_post(struct event_queue *q, long id, intptr_t data)
{
int oldlevel = set_irq_level(15<<4);
unsigned int wr = q->write++ & QUEUE_LENGTH_MASK;
q->events[wr].id = id;
q->events[wr].data = data;
#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
if(q->send)
{
struct thread_entry **spp = &q->send->senders[wr];
if(*spp)
{
/* overflow protect - unblock any thread waiting at this index */
queue_release_sender(spp, 0);
}
}
#endif
set_irq_level(oldlevel);
}
#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
intptr_t queue_send(struct event_queue *q, long id, intptr_t data)
{
int oldlevel = set_irq_level(15<<4);
unsigned int wr = q->write++ & QUEUE_LENGTH_MASK;
q->events[wr].id = id;
q->events[wr].data = data;
if(q->send)
{
struct thread_entry **spp = &q->send->senders[wr];
struct thread_entry sender;
if(*spp)
{
/* overflow protect - unblock any thread waiting at this index */
queue_release_sender(spp, 0);
}
*spp = &sender;
set_irq_level(oldlevel);
while (*spp != NULL)
{
switch_thread(true, NULL);
}
return sender.retval;
}
/* Function as queue_post if sending is not enabled */
set_irq_level(oldlevel);
return 0;
}
#if 0 /* not used now but probably will be later */
/* Query if the last message dequeued was added by queue_send or not */
bool queue_in_queue_send(struct event_queue *q)
{
return q->send && q->send->curr_sender;
}
#endif
/* Replies with retval to any dequeued message sent with queue_send */
void queue_reply(struct event_queue *q, intptr_t retval)
{
if(q->send && q->send->curr_sender)
{
queue_release_sender(&q->send->curr_sender, retval);
}
}
#endif /* HAVE_EXTENDED_MESSAGING_AND_NAME */
bool queue_empty(const struct event_queue* q)
{
return ( q->read == q->write );
}
void queue_clear(struct event_queue* q)
{
/* fixme: This is potentially unsafe in case we do interrupt-like processing */
#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
/* Release all thread waiting in the queue for a reply -
dequeued sent message will be handled by owning thread */
queue_release_all_senders(q);
#endif
q->read = 0;
q->write = 0;
}
void queue_remove_from_head(struct event_queue *q, long id)
{
int oldlevel = set_irq_level(15<<4);
while(q->read != q->write)
{
unsigned int rd = q->read & QUEUE_LENGTH_MASK;
if(q->events[rd].id != id)
{
break;
}
#ifdef HAVE_EXTENDED_MESSAGING_AND_NAME
if(q->send)
{
struct thread_entry **spp = &q->send->senders[rd];
if(*spp)
{
/* Release any thread waiting on this message */
queue_release_sender(spp, 0);
}
}
#endif
q->read++;
}
set_irq_level(oldlevel);
}
void switch_thread(bool save_context, struct thread_entry **blocked_list)
{
(void)save_context;
(void)blocked_list;
yield ();
}
void sim_tick_tasks(void)
{
int i;
/* Run through the list of tick tasks */
for(i = 0;i < MAX_NUM_TICK_TASKS;i++)
{
if(tick_funcs[i])
{
tick_funcs[i]();
}
}
}
int tick_add_task(void (*f)(void))
{
int i;
/* Add a task if there is room */
for(i = 0;i < MAX_NUM_TICK_TASKS;i++)
{
if(tick_funcs[i] == NULL)
{
tick_funcs[i] = f;
return 0;
}
}
DEBUGF("Error! tick_add_task(): out of tasks");
return -1;
}
int tick_remove_task(void (*f)(void))
{
int i;
/* Remove a task if it is there */
for(i = 0;i < MAX_NUM_TICK_TASKS;i++)
{
if(tick_funcs[i] == f)
{
tick_funcs[i] = NULL;
return 0;
}
}
return -1;
}
/* Very simple mutex simulation - won't work with pre-emptive
multitasking, but is better than nothing at all */
void mutex_init(struct mutex *m)
{
m->locked = false;
}
void mutex_lock(struct mutex *m)
{
while(m->locked)
switch_thread(true, NULL);
m->locked = true;
}
void mutex_unlock(struct mutex *m)
{
m->locked = false;
}
void spinlock_lock(struct mutex *m)
{
while(m->locked)
switch_thread(true, NULL);
m->locked = true;
}
void spinlock_unlock(struct mutex *m)
{
m->locked = false;
}