rockbox/firmware/kernel/include/thread.h
Michael Sevakis 5b08f1a5b9 Remove I/O priority. It is harmful when used with the new file code.
HAVE_IO_PRIORITY was defined for native targets with dircache.

It is already effectively disabled for the most part since dircache no
longer lowers its thread's I/O priority. It existed primarily for the
aforementioned configuration.

Change-Id: Ia04935305397ba14df34647c8ea29c2acaea92aa
2014-08-30 14:01:21 -04:00

216 lines
7 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2002 by Ulf Ralberg
*
* 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#ifndef THREAD_H
#define THREAD_H
#include <inttypes.h>
#include <stddef.h>
#include <stdbool.h>
#include "config.h"
#include "gcc_extensions.h"
#include "linked_list.h"
#include "bitarray.h"
#include "corelock.h"
/* Priority scheduling (when enabled with HAVE_PRIORITY_SCHEDULING) works
* by giving high priority threads more CPU time than lower priority threads
* when they need it. Priority is differential such that the priority
* difference between a lower priority runnable thread and the highest priority
* runnable thread determines the amount of aging necessary for the lower
* priority thread to be scheduled in order to prevent starvation.
*
* If software playback codec pcm buffer is going down to critical, codec
* can gradually raise its own priority to override user interface and
* prevent playback skipping.
*/
#define PRIORITY_RESERVED_HIGH 0 /* Reserved */
#define PRIORITY_RESERVED_LOW 32 /* Reserved */
#define HIGHEST_PRIORITY 1 /* The highest possible thread priority */
#define LOWEST_PRIORITY 31 /* The lowest possible thread priority */
/* Realtime range reserved for threads that will not allow threads of lower
* priority to age and run (future expansion) */
#define PRIORITY_REALTIME_1 1
#define PRIORITY_REALTIME_2 2
#define PRIORITY_REALTIME_3 3
#define PRIORITY_REALTIME_4 4
#define PRIORITY_REALTIME 4 /* Lowest realtime range */
#define PRIORITY_BUFFERING 15 /* Codec buffering thread */
#define PRIORITY_USER_INTERFACE 16 /* For most UI thrads */
#define PRIORITY_RECORDING 16 /* Recording thread */
#define PRIORITY_PLAYBACK 16 /* Variable between this and MAX */
#define PRIORITY_PLAYBACK_MAX 5 /* Maximum allowable playback priority */
#define PRIORITY_SYSTEM 18 /* All other firmware threads */
#define PRIORITY_BACKGROUND 20 /* Normal application threads */
#define NUM_PRIORITIES 32
#define PRIORITY_IDLE 32 /* Priority representative of no tasks */
#define PRIORITY_MAIN_THREAD PRIORITY_USER_INTERFACE
#define IO_PRIORITY_IMMEDIATE 0
#define IO_PRIORITY_BACKGROUND 32
#if CONFIG_CODEC == SWCODEC
# ifdef HAVE_HARDWARE_CLICK
# define BASETHREADS 17
# else
# define BASETHREADS 16
# endif
#else
# define BASETHREADS 11
#endif /* CONFIG_CODE == * */
#ifndef TARGET_EXTRA_THREADS
#define TARGET_EXTRA_THREADS 0
#endif
#define MAXTHREADS (BASETHREADS+TARGET_EXTRA_THREADS)
BITARRAY_TYPE_DECLARE(threadbit_t, threadbit, MAXTHREADS)
BITARRAY_TYPE_DECLARE(priobit_t, priobit, NUM_PRIORITIES)
struct thread_entry;
/*
* We need more stack when we run under a host
* maybe more expensive C lib functions?
*
* simulator (possibly) doesn't simulate stack usage anyway but well ... */
#if defined(HAVE_SDL_THREADS) || defined(__PCTOOL__)
#define DEFAULT_STACK_SIZE 0x100 /* tiny, ignored anyway */
#else
#include "asm/thread.h"
#endif /* HAVE_SDL_THREADS */
extern void yield(void);
extern unsigned sleep(unsigned ticks);
#ifdef HAVE_PRIORITY_SCHEDULING
#define IF_PRIO(...) __VA_ARGS__
#define IFN_PRIO(...)
#else
#define IF_PRIO(...)
#define IFN_PRIO(...) __VA_ARGS__
#endif
#define __wait_queue lld_head
#define __wait_queue_node lld_node
/* Basic structure describing the owner of an object */
struct blocker
{
struct thread_entry * volatile thread; /* thread blocking other threads
(aka. object owner) */
#ifdef HAVE_PRIORITY_SCHEDULING
int priority; /* highest priority waiter */
#endif
};
/* If a thread has a blocker but the blocker's registered thread is NULL,
then it references this and the struct blocker pointer may be
reinterpreted as such. */
struct blocker_splay
{
struct blocker blocker; /* blocker info (first!) */
#ifdef HAVE_PRIORITY_SCHEDULING
threadbit_t mask; /* mask of nonzero tcounts */
#if NUM_CORES > 1
struct corelock cl; /* mutual exclusion */
#endif
#endif /* HAVE_PRIORITY_SCHEDULING */
};
void core_idle(void);
void core_wake(IF_COP_VOID(unsigned int core));
/* Allocate a thread in the scheduler */
#define CREATE_THREAD_FROZEN 0x00000001 /* Thread is frozen at create time */
unsigned int create_thread(void (*function)(void),
void* stack, size_t stack_size,
unsigned flags, const char *name
IF_PRIO(, int priority)
IF_COP(, unsigned int core));
/* Set and clear the CPU frequency boost flag for the calling thread */
#ifdef HAVE_SCHEDULER_BOOSTCTRL
void trigger_cpu_boost(void);
void cancel_cpu_boost(void);
#else
#define trigger_cpu_boost() do { } while(0)
#define cancel_cpu_boost() do { } while(0)
#endif
/* Make a frozen thread runnable (when started with CREATE_THREAD_FROZEN).
* Has no effect on a thread not frozen. */
void thread_thaw(unsigned int thread_id);
/* Wait for a thread to exit */
void thread_wait(unsigned int thread_id);
/* Exit the current thread */
void thread_exit(void) NORETURN_ATTR;
#ifdef HAVE_PRIORITY_SCHEDULING
int thread_set_priority(unsigned int thread_id, int priority);
int thread_get_priority(unsigned int thread_id);
#endif /* HAVE_PRIORITY_SCHEDULING */
#if NUM_CORES > 1
unsigned int switch_core(unsigned int new_core);
#endif
/* Return the id of the calling thread. */
unsigned int thread_self(void);
/* Debugging info - only! */
#if NUM_CORES > 1
struct core_debug_info
{
unsigned int idle_stack_usage;
};
int core_get_debug_info(unsigned int core, struct core_debug_info *infop);
#endif /* NUM_CORES */
#ifdef HAVE_SDL_THREADS
#define IF_SDL(x...) x
#define IFN_SDL(x...)
#else
#define IF_SDL(x...)
#define IFN_SDL(x...) x
#endif
struct thread_debug_info
{
char statusstr[4];
char name[32];
#ifndef HAVE_SDL_THREADS
unsigned int stack_usage;
#endif
#if NUM_CORES > 1
unsigned int core;
#endif
#ifdef HAVE_PRIORITY_SCHEDULING
int base_priority;
int current_priority;
#endif
};
int thread_get_debug_info(unsigned int thread_id,
struct thread_debug_info *infop);
#endif /* THREAD_H */