rockbox/firmware/export/thread.h

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2002 by Ulf Ralberg
 *
 * 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.
 *
 ****************************************************************************/
#ifndef THREAD_H
#define THREAD_H

#include <stdbool.h>

/* Priority scheduling (when enabled with HAVE_PRIORITY_SCHEDULING) works
 * by giving high priority threads more CPU time than less priority threads
 * when they need it.
 * 
 * If software playback codec pcm buffer is going down to critical, codec
 * can change it own priority to REALTIME to override user interface and
 * prevent playback skipping.
 */
#define PRIORITY_REALTIME        1
#define PRIORITY_USER_INTERFACE  4 /* The main thread */
#define PRIORITY_RECORDING       4 /* Recording thread */
#define PRIORITY_PLAYBACK        4 /* or REALTIME when needed */
#define PRIORITY_BUFFERING       4 /* Codec buffering thread */
#define PRIORITY_SYSTEM          6 /* All other firmware threads */
#define PRIORITY_BACKGROUND      8 /* Normal application threads */

#if CONFIG_CODEC == SWCODEC
#define MAXTHREADS	15
#else
#define MAXTHREADS  11
#endif

#define DEFAULT_STACK_SIZE 0x400 /* Bytes */

#ifndef SIMULATOR
/* Need to keep structures inside the header file because debug_menu
 * needs them. */
# ifdef CPU_COLDFIRE
struct regs
{
    unsigned int macsr;  /* EMAC status register */
    unsigned int d[6];   /* d2-d7 */
    unsigned int a[5];   /* a2-a6 */
    void         *sp;    /* Stack pointer (a7) */
    void         *start; /* Thread start address, or NULL when started */
};
# elif CONFIG_CPU == SH7034
struct regs
{
    unsigned int r[7];   /* Registers r8 thru r14 */
    void         *sp;    /* Stack pointer (r15) */
    void         *pr;    /* Procedure register */
    void         *start; /* Thread start address, or NULL when started */
};
# elif defined(CPU_ARM)
struct regs
{
    unsigned int r[8];   /* Registers r4-r11 */
    void         *sp;    /* Stack pointer (r13) */
    unsigned int lr;     /* r14 (lr) */
    void         *start; /* Thread start address, or NULL when started */
};
# elif CONFIG_CPU == TCC730
struct regs
{
    void *sp;    /* Stack pointer (a15) */
    void *start; /* Thread start address */
    int started; /* 0 when not started */
};
# endif

#endif /* !SIMULATOR */

#define STATE_RUNNING         0
#define STATE_BLOCKED         1
#define STATE_SLEEPING        2
#define STATE_BLOCKED_W_TMO   3

#define GET_STATE_ARG(state)  (state & 0x3FFFFFFF)
#define GET_STATE(state)      ((state >> 30) & 3)
#define SET_STATE(state,arg)  ((state << 30) | (arg))

struct thread_entry {
#ifndef SIMULATOR
    struct regs context;
#endif
    const char *name;
    void *stack;
    unsigned long statearg;
    unsigned short stack_size;
#ifdef HAVE_PRIORITY_SCHEDULING
    unsigned short priority;
    long last_run;
#endif
    struct thread_entry *next, *prev;
};

struct core_entry {
    struct thread_entry threads[MAXTHREADS];
    struct thread_entry *running;
    struct thread_entry *sleeping;
};

#ifdef HAVE_PRIORITY_SCHEDULING
#define IF_PRIO(empty, type)  , type
#else
#define IF_PRIO(empty, type)
#endif

struct thread_entry*
    create_thread(void (*function)(void), void* stack, int stack_size,
                  const char *name IF_PRIO(, int priority));

struct thread_entry*
    create_thread_on_core(unsigned int core, void (*function)(void), 
                          void* stack, int stack_size,
                          const char *name
                          IF_PRIO(, int priority));

void remove_thread(struct thread_entry *thread);
void switch_thread(bool save_context, struct thread_entry **blocked_list);
void sleep_thread(int ticks);
void block_thread(struct thread_entry **thread, int timeout);
void wakeup_thread(struct thread_entry **thread);
void thread_set_priority(struct thread_entry *thread, int priority);
void init_threads(void);
int thread_stack_usage(const struct thread_entry *thread);
int thread_get_status(const struct thread_entry *thread);
#ifdef RB_PROFILE
void profile_thread(void);
#endif

#endif