rockbox/firmware/kernel/thread-internal.h
Thomas Martitz 382d1861af kernel: Break out kernel primitives into separate files and move to separate dir.
No code changed, just shuffling stuff around. This should make it easier to
build only select parts kernel and use different implementations.

Change-Id: Ie1f00f93008833ce38419d760afd70062c5e22b5
2014-03-03 18:11:57 +01:00

357 lines
14 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 "config.h"
#include <inttypes.h>
#include <stddef.h>
#include <stdbool.h>
#include "gcc_extensions.h"
/*
* 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__)
struct regs
{
void *t; /* OS thread */
void *told; /* Last thread in slot (explained in thead-sdl.c) */
void *s; /* Semaphore for blocking and wakeup */
void (*start)(void); /* Start function */
};
#define DEFAULT_STACK_SIZE 0x100 /* tiny, ignored anyway */
#else
#include "asm/thread.h"
#endif /* HAVE_SDL_THREADS */
#ifdef CPU_PP
#ifdef HAVE_CORELOCK_OBJECT
/* No reliable atomic instruction available - use Peterson's algorithm */
struct corelock
{
volatile unsigned char myl[NUM_CORES];
volatile unsigned char turn;
} __attribute__((packed));
/* Too big to inline everywhere */
void corelock_init(struct corelock *cl);
void corelock_lock(struct corelock *cl);
int corelock_try_lock(struct corelock *cl);
void corelock_unlock(struct corelock *cl);
#endif /* HAVE_CORELOCK_OBJECT */
#endif /* CPU_PP */
/* NOTE: The use of the word "queue" may also refer to a linked list of
threads being maintained that are normally dealt with in FIFO order
and not necessarily kernel event_queue */
enum
{
/* States without a timeout must be first */
STATE_KILLED = 0, /* Thread is killed (default) */
STATE_RUNNING, /* Thread is currently running */
STATE_BLOCKED, /* Thread is indefinitely blocked on a queue */
/* These states involve adding the thread to the tmo list */
STATE_SLEEPING, /* Thread is sleeping with a timeout */
STATE_BLOCKED_W_TMO, /* Thread is blocked on a queue with a timeout */
/* Miscellaneous states */
STATE_FROZEN, /* Thread is suspended and will not run until
thread_thaw is called with its ID */
THREAD_NUM_STATES,
TIMEOUT_STATE_FIRST = STATE_SLEEPING,
};
#if NUM_CORES > 1
/* Pointer value for name field to indicate thread is being killed. Using
* an alternate STATE_* won't work since that would interfere with operation
* while the thread is still running. */
#define THREAD_DESTRUCT ((const char *)~(intptr_t)0)
#endif
/* Link information for lists thread is in */
struct thread_entry; /* forward */
struct thread_list
{
struct thread_entry *prev; /* Previous thread in a list */
struct thread_entry *next; /* Next thread in a list */
};
#ifndef HAVE_CORELOCK_OBJECT
/* No atomic corelock op needed or just none defined */
#define corelock_init(cl)
#define corelock_lock(cl)
#define corelock_try_lock(cl)
#define corelock_unlock(cl)
#endif /* HAVE_CORELOCK_OBJECT */
#ifdef HAVE_PRIORITY_SCHEDULING
struct blocker
{
struct thread_entry * volatile thread; /* thread blocking other threads
(aka. object owner) */
int priority; /* highest priority waiter */
struct thread_entry * (*wakeup_protocol)(struct thread_entry *thread);
};
/* Choices of wakeup protocol */
/* For transfer of object ownership by one thread to another thread by
* the owning thread itself (mutexes) */
struct thread_entry *
wakeup_priority_protocol_transfer(struct thread_entry *thread);
/* For release by owner where ownership doesn't change - other threads,
* interrupts, timeouts, etc. (mutex timeout, queues) */
struct thread_entry *
wakeup_priority_protocol_release(struct thread_entry *thread);
struct priority_distribution
{
uint8_t hist[NUM_PRIORITIES]; /* Histogram: Frequency for each priority */
uint32_t mask; /* Bitmask of hist entries that are not zero */
};
#endif /* HAVE_PRIORITY_SCHEDULING */
/* Information kept in each thread slot
* members are arranged according to size - largest first - in order
* to ensure both alignment and packing at the same time.
*/
struct thread_entry
{
struct regs context; /* Register context at switch -
_must_ be first member */
uintptr_t *stack; /* Pointer to top of stack */
const char *name; /* Thread name */
long tmo_tick; /* Tick when thread should be woken from
timeout -
states: STATE_SLEEPING/STATE_BLOCKED_W_TMO */
struct thread_list l; /* Links for blocked/waking/running -
circular linkage in both directions */
struct thread_list tmo; /* Links for timeout list -
Circular in reverse direction, NULL-terminated in
forward direction -
states: STATE_SLEEPING/STATE_BLOCKED_W_TMO */
struct thread_entry **bqp; /* Pointer to list variable in kernel
object where thread is blocked - used
for implicit unblock and explicit wake
states: STATE_BLOCKED/STATE_BLOCKED_W_TMO */
#ifdef HAVE_CORELOCK_OBJECT
struct corelock *obj_cl; /* Object corelock where thead is blocked -
states: STATE_BLOCKED/STATE_BLOCKED_W_TMO */
struct corelock waiter_cl; /* Corelock for thread_wait */
struct corelock slot_cl; /* Corelock to lock thread slot */
unsigned char core; /* The core to which thread belongs */
#endif
struct thread_entry *queue; /* List of threads waiting for thread to be
removed */
#ifdef HAVE_WAKEUP_EXT_CB
void (*wakeup_ext_cb)(struct thread_entry *thread); /* Callback that
performs special steps needed when being
forced off of an object's wait queue that
go beyond the standard wait queue removal
and priority disinheritance */
/* Only enabled when using queue_send for now */
#endif
#if defined(HAVE_SEMAPHORE_OBJECTS) || \
defined(HAVE_EXTENDED_MESSAGING_AND_NAME) || \
NUM_CORES > 1
volatile intptr_t retval; /* Return value from a blocked operation/
misc. use */
#endif
#ifdef HAVE_PRIORITY_SCHEDULING
/* Priority summary of owned objects that support inheritance */
struct blocker *blocker; /* Pointer to blocker when this thread is blocked
on an object that supports PIP -
states: STATE_BLOCKED/STATE_BLOCKED_W_TMO */
struct priority_distribution pdist; /* Priority summary of owned objects
that have blocked threads and thread's own
base priority */
int skip_count; /* Number of times skipped if higher priority
thread was running */
unsigned char base_priority; /* Base priority (set explicitly during
creation or thread_set_priority) */
unsigned char priority; /* Scheduled priority (higher of base or
all threads blocked by this one) */
#endif
uint16_t id; /* Current slot id */
unsigned short stack_size; /* Size of stack in bytes */
unsigned char state; /* Thread slot state (STATE_*) */
#ifdef HAVE_SCHEDULER_BOOSTCTRL
unsigned char cpu_boost; /* CPU frequency boost flag */
#endif
#ifdef HAVE_IO_PRIORITY
unsigned char io_priority;
#endif
};
/*** Macros for internal use ***/
/* Thread ID, 16 bits = |VVVVVVVV|SSSSSSSS| */
#define THREAD_ID_VERSION_SHIFT 8
#define THREAD_ID_VERSION_MASK 0xff00
#define THREAD_ID_SLOT_MASK 0x00ff
#define THREAD_ID_INIT(n) ((1u << THREAD_ID_VERSION_SHIFT) | (n))
#ifdef HAVE_CORELOCK_OBJECT
/* Operations to be performed just before stopping a thread and starting
a new one if specified before calling switch_thread */
enum
{
TBOP_CLEAR = 0, /* No operation to do */
TBOP_UNLOCK_CORELOCK, /* Unlock a corelock variable */
TBOP_SWITCH_CORE, /* Call the core switch preparation routine */
};
struct thread_blk_ops
{
struct corelock *cl_p; /* pointer to corelock */
unsigned char flags; /* TBOP_* flags */
};
#endif /* NUM_CORES > 1 */
/* Information kept for each core
* Members are arranged for the same reason as in thread_entry
*/
struct core_entry
{
/* "Active" lists - core is constantly active on these and are never
locked and interrupts do not access them */
struct thread_entry *running; /* threads that are running (RTR) */
struct thread_entry *timeout; /* threads that are on a timeout before
running again */
struct thread_entry *block_task; /* Task going off running list */
#ifdef HAVE_PRIORITY_SCHEDULING
struct priority_distribution rtr; /* Summary of running and ready-to-run
threads */
#endif
long next_tmo_check; /* soonest time to check tmo threads */
#ifdef HAVE_CORELOCK_OBJECT
struct thread_blk_ops blk_ops; /* operations to perform when
blocking a thread */
struct corelock rtr_cl; /* Lock for rtr list */
#endif /* NUM_CORES */
};
#ifdef HAVE_PRIORITY_SCHEDULING
#define IF_PRIO(...) __VA_ARGS__
#define IFN_PRIO(...)
#else
#define IF_PRIO(...)
#define IFN_PRIO(...) __VA_ARGS__
#endif
void core_idle(void);
void core_wake(IF_COP_VOID(unsigned int core));
/* Initialize the scheduler */
void init_threads(void) INIT_ATTR;
/* 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
/* Return thread entry from id */
struct thread_entry *thread_id_entry(unsigned int thread_id);
/* Make a frozed 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;
#if defined(DEBUG) || defined(ROCKBOX_HAS_LOGF)
#define ALLOW_REMOVE_THREAD
/* Remove a thread from the scheduler */
void remove_thread(unsigned int thread_id);
#endif
/* Switch to next runnable thread */
void switch_thread(void);
/* Blocks a thread for at least the specified number of ticks (0 = wait until
* next tick) */
void sleep_thread(int ticks);
/* Indefinitely blocks the current thread on a thread queue */
void block_thread(struct thread_entry *current);
/* Blocks the current thread on a thread queue until explicitely woken or
* the timeout is reached */
void block_thread_w_tmo(struct thread_entry *current, int timeout);
/* Return bit flags for thread wakeup */
#define THREAD_NONE 0x0 /* No thread woken up (exclusive) */
#define THREAD_OK 0x1 /* A thread was woken up */
#define THREAD_SWITCH 0x2 /* Task switch recommended (one or more of
higher priority than current were woken) */
/* A convenience function for waking an entire queue of threads. */
unsigned int thread_queue_wake(struct thread_entry **list);
/* Wakeup a thread at the head of a list */
unsigned int wakeup_thread(struct thread_entry **list);
#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 */
#ifdef HAVE_IO_PRIORITY
void thread_set_io_priority(unsigned int thread_id, int io_priority);
int thread_get_io_priority(unsigned int thread_id);
#endif /* HAVE_IO_PRIORITY */
#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);
/* Return the thread_entry for the calling thread.
* INTERNAL: Intended for use by kernel and not for programs. */
struct thread_entry* thread_self_entry(void);
/* Debugging info - only! */
int thread_stack_usage(const struct thread_entry *thread);
#if NUM_CORES > 1
int idle_stack_usage(unsigned int core);
#endif
void thread_get_name(char *buffer, int size,
struct thread_entry *thread);
#ifdef RB_PROFILE
void profile_thread(void);
#endif
#endif /* THREAD_H */