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Changed queue API. Added mutex functions

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@601 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Linus Nielsen Feltzing 2002-05-16 20:57:32 +00:00
parent a39f566a7f
commit 7361340ab5
2 changed files with 35 additions and 3 deletions
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27
firmware/kernel.c
View file

@ -71,14 +71,14 @@ void queue_init(struct event_queue *q)
q->write = 0; q->write = 0;
} }
struct event *queue_wait(struct event_queue *q) void queue_wait(struct event_queue *q, struct event *ev)
{ {
while(q->read == q->write) while(q->read == q->write)
{ {
switch_thread(); switch_thread();
} }
return &q->events[(q->read++) & QUEUE_LENGTH_MASK]; *ev = q->events[(q->read++) & QUEUE_LENGTH_MASK];
} }
void queue_post(struct event_queue *q, int id, void *data) void queue_post(struct event_queue *q, int id, void *data)
@ -190,3 +190,26 @@ int tick_remove_task(void (*f)(void))
set_irq_level(oldlevel); set_irq_level(oldlevel);
return -1; return -1;
} }
/****************************************************************************
* Simple mutex functions
****************************************************************************/
void mutex_init(struct mutex *m)
{
m->count = 0;
}
void mutex_lock(struct mutex *m)
{
/* Wait until the lock is open... */
while(m->count)
yield();
/* ...and lock it */
m->count++;
}
void mutex_unlock(struct mutex *m)
{
m->count--;
}

11
firmware/kernel.h
View file

@ -41,6 +41,11 @@ struct event_queue
unsigned int write; unsigned int write;
}; };
struct mutex
{
int count;
};
/* global tick variable */ /* global tick variable */
extern long current_tick; extern long current_tick;
@ -53,7 +58,11 @@ int tick_add_task(void (*f)(void));
int tick_remove_task(void (*f)(void)); int tick_remove_task(void (*f)(void));
extern void queue_init(struct event_queue *q); extern void queue_init(struct event_queue *q);
extern struct event *queue_wait(struct event_queue *q); extern void queue_wait(struct event_queue *q, struct event *ev);
extern void queue_post(struct event_queue *q, int id, void *data); extern void queue_post(struct event_queue *q, int id, void *data);
extern void mutex_init(struct mutex *m);
extern void mutex_lock(struct mutex *m);
extern void mutex_unlock(struct mutex *m);
#endif #endif